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U.S. ENVIRONMENTAL PROTECTION AGENCY

SCIENCE ADVISORY BOARD STAFF OFFICE

CLEAN AIR SCIENTIFIC ADVISORY COMMITTEE (CASAC)

PARTICULATE MATTER REVIEW PANEL PUBLIC MEETING

Marriott at Research Triangle Park

4700 Guardian Drive, Durham, North Carolina

Monday, July 26, 2010

ATTENDEES:

CASAC Members:

Dr. Jonathan M. Samet, Chair

Dr. Joseph D. Brain

Dr. H. Christopher Frey

Dr. Armistead (Ted) Russell

Dr. Helen Suh

Dr. Kathleen Weathers

Consultants:

Dr. Lowell Ashbaugh

Prof. Ed Avol

Dr. Wayne Cascio

Dr. Joseph Helble

Dr. Rogene Henderson

Dr. Philip Hopke

Dr. Morton Lippmann

Dr. William Malm

Mr. Charles Thomas (Tom) Moore, Jr.

Dr. Kent Pinkerton

Mr. Richard L. Poirot

Dr. Frank Speizer (Telephonically present)

Dr. Sverre Vedal

Science Advisory Board Staff:

Dr. Holly Stallworth

Dr. Vanessa Vu

Office of Air Quality and Planning Standards

Ms. Lydia Wegman Ms. Vicki Sandiford

Dr. Karen Martin Dr. Marc Pitchford

Ms. Beth Hassett-Sipple Mr. Tim Hanley

Dr. Scott Jenkins Ms. Joann Rice

Dr. Pradeep Rajan
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I N D E X

Page

Proceedings 3

Welcome and Opening Remarks by:

Dr. Stallworth 3

Dr. Vu 5

Dr. Samet 7

Ms. Lydia Wegman 11

Dr. Karen Martin 13

Public Comment Statements By:

Dr. Jay Turim, on behalf of American Chemistry 24

Council

Ms. Deborah Shprentz, on behalf of the American 30

Lung Association

Mr. Ben Brandes, Air Quality, National Mining 34

Association

Mr. Greg Schaefer, Arch Coal, Inc. 38

Mr. Wig Zamore, Somerville Transportation Equity 41

Partnership and Mystic View Task Force,

Somerville, Massachusetts

Dr. Julie Goodman, on behalf of American 45

Petroleum Institute

Mr. Jon Heuss, (Telephonically present), Air 49

Improvement Resources, Inc.

Dr. John Richards, Air Quality Control Techniques 54

on behalf of Particulate Matter Coalition

Dr. Deborah Drechsler, (Telephonically present), 59

California Air Resources Board

Discussion re:

Charge Question No. 1 62

Charge Question No. 2 66

Charge Question No. 3 80

Charge Question No. 4 144

Charge Question No. 5 160

Charge Question No. 6 168

Charge Question No. 7 187

Charge Question No. 8 209

Charge Question No. 9 214

Charge Question No. 10 227
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P R O C E E D I N G S

(9:00 a.m.)

OPENING REMARKS BY DR. STALLWORTH:

DR. STALLWORTH: Good morning, everyone. I'm

Holly Stallworth. I'm the Designated Federal Officer

for the Clean Air Scientific Advisory Committee

Particulate Matter Review Panel; and if you could

bear with me, I just want to remind our audience of

our requirements under the Federal Advisory Committee

Act.

CASAC is a Federal Advisory Committee; and by

EPA policy, its meetings and deliberations are held

as public meetings that meet the requirements of

FACA. CASAC is empowered by law to provide advice to

the Administrator consistent with the requirements of

FACA and with EPA policy. CASAC's deliberations are

conducted in public at meetings for which advance

public notice is given. The discussions and

substantive deliberations of the Panel, its

interactions with the public and the Agency are

conducted in sessions where I as the Designated

Federal Officer am present to ensure that the

requirements of FACA are met. These include

requirements for open meetings, for maintaining

records of deliberations, making available public
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summaries of meetings and providing opportunities for

public commenting.

Today we do have eight public commentors. We

have a list of six, and two more requests came in

after that list was photocopied.

I'll be taking the minutes of this meeting to

summarize the discussion and action items. Once

they're approved by our Chair, Dr. John Samet, they

will be posted on the CASAC Web site.

Finally, I want to say a comment on the status

of this committee's compliance with federal ethics

laws. The SAB Staff Office has reviewed information

relevant to conflict of interest, appearance of a

lack in partiality, and appropriate balance and

breadth of expertise, knowledge and experience needed

to address the charge and determined that there are

no conflicts of interest or appearance of a lack of

impartiality issues for any of the advisory members

participating in this review.

A couple of housekeeping items, we got

comments, late comments, from Dr. Hopke and Rich

Poirot, which have been passed around.

And if anyone is on the phone besides Frank

Speizer, could you identify yourself?

(No response.)
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DR. STALLWORTH: No one's on the phone. Okay.

I'm going to turn it over to Dr. Vanessa Vu,

the director of the SAB Staff Office for a brief

welcome.

OPENING REMARKS BY DR. VU:

DR. VU: Thank you. Good morning, everyone.

I'd like to welcome everybody to the public meeting

of the Clean Air Scientific Advisory Committee, or

CASAC, Review Panel on Particulate Matter.

First, I'd like to thank Dr. John Samet,

members of the Charter CASAC and members of the PM

Panel for your time and public service to EPA for the

last three years.

Probably some of you recall that the Panel was

formed in 2007. You all began with a consultation of

the Integrated Review Plan, or IRP, in November 2007.

Since then you held altogether five public

face-to-face meetings, including this one; and six

teleconference calls; and your comments and review

with regard to two drafts, the ISA, the Integrated

Science Assessment; the Risk and Exposure Assessment,

two drafts of it; first draft of the Policy

Assessment; and finally, today you are going to

provide review comments and advice to the Agency

regarding the Primary and Secondary Standards for the
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NAAQS for PM for this round of review.

Again, I want to thank each and every one of

you for your time and very helpful comments to the

Agency. I do know that the Agency represented by

Ms. Lydia Wegman and Dr. Karen Martin would also

appreciate your comments. They're all going to be

here the next two days to provide an overview and

clarify any questions regarding staff recommendations

in consideration for the NAAQS for Primary and

Secondary Standards.

As Holly mentioned, that we have public

speakers, public comments. It's part of the process.

Public input is part of the important process for the

Advisory Committee of the CASAC and is required under

the Federal Advisory Committee Act or FACA, so I

appreciate that. As always, I know that Panel

members consider public comments as a part of their

discussion deliberation.

Finally, I'd like to thank Holly. Holly has

been the DFO for this review. And I just want to

acknowledge that when we began in November 2007, that

was under the leadership of Dr. Rogene Henderson, and

now with Dr. John Samet; and Frank Butterfield was

our previous DFO for the PM Panel.

So I hope that we don't really have -- I
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presume we will have any comments from this Panel, if

we were -- after the Agency does a proposed rule

making. And if you all wish to have some comments,

we will do that; but I will consider this as probably

your last face-to-face meeting for this panel.

And again, I thank you all. With that, I'd

like to turn the floor to Dr. John Samet.

OPENING REMARKS BY DR. SAMET:

DR. SAMET: Thank you, Vanessa and Holly.

Good morning, everybody.

Hearing you recount all our meetings, I'm sort

of reminded, it sounds like the never-ending story.

I guess it will have an end. I think, in fact, for

those of you who were involved in some of the prior

PM reviews over the last decade, they did go on quite

long, as you will remember.

DR. SPEIZER: I can barely hear you, John.

DR. SAMET: Well, I can hear you. Can you

hear me now? Frank?

DR. SPEIZER: Yeah. Very -- just barely.

DR. SAMET: It's not me. It's you.

DR. VU: Wait, Frank.

DR. SAMET: I can't be any louder, or I could.

DR. STALLWORTH: Frank, if Skype doesn't work

as well, you might need to go back to using the
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phone.

DR. SAMET: Where are you, Frank?

(No response.)

DR. SAMET: Well, why don't we do a round of

committee introductions. Rogene, why don't we start

with you and go around.

DR. HENDERSON: Okay. I'm Rogene Henderson.

I'm Senior Scientist Emeritus at the Lovelace

Respiratory Research Institute in Albuquerque.

DR. VEDAL: Sverre Vedal, Professor,

Environmental Occupational Health Sciences,

University of Washington, School of Public Health.

DR. SUH: Helen Suh, Department of

Environmental Health, Harvard School of Public

Health.

DR. RUSSELL: Ted Russell, Georgia Tech,

Department of Civil and Environmental Engineering.

MR. POIROT: Richard Poirot, State of Vermont,

Department of Environmental Conservation.

DR. PINKERTON: Kent Pinkerton, Department of

Pediatrics, University of California, Davis.

DR. MOORE: Tom Moore, Air Quality Program

Manager for the Western Governors' Association.

DR. MALM: Bill Malm, Colorado State

University.
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DR. LIPPMANN: I'm Mort Lippmann, NYU

Environmental Medicine.

DR. HOPKE: Phil Hopke. I'm the director of

the Institute for Sustainable Environment at Clarkson

University.

DR. HELBLE: Joe Helble, Dean of the School of

Engineering, Dartmouth College.

DR. FREY: I'm Chris Frey, Professor of

Environmental Engineering at North Carolina State

University.

DR. CASCIO: I'm Wayne Cascio, Professor of

Cardiovascular Medicine at East Carolina University.

DR. BRAIN: Joe Brain, Harvard School of

Public Health, the Department of Environmental

Health.

PROF. AVOL: Ed Avol, Keck School of Medicine,

University of Southern California, Department of

Preventive Medicine.

DR. ASHBAUGH: I'm Lowell Ashbaugh, Project

Scientist with the IMPROVE program, University of

California, Davis.

DR. STALLWORTH: And Let me just point out

that Dr. Kathleen Weathers is en route. Her plane

was cancelled last night. She's a senior scientist

with the Cary Institute of Ecosystem Studies.
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DR. SAMET: And Frank, are you on now?

DR. SPEIZER: Yeah. I can -- are you there?

If you can hear me, I can barely hear everybody.

DR. SAMET: Okay. So we can hear you very

well and we hear each other very well. So I don't

know if there's something with the phone line that

needs to be addressed, but we'll see.

DR. SPEIZER: Well, if I'm very quiet, I can

hear you.

DR. SAMET: Okay. So just to spend a moment

on what we're doing with our agenda. Again, of

course, we're reviewing the Second Draft Policy

Assessment. We have worked in advance to prepare

comments and responses to the charge questions.

Today is directed at the Primary Standard, the NAAQS,

and tomorrow at the Secondary Standard.

I think in terms of, sort of, what we get done

and how far we can go in developing our formal

responses, I think we better just see how the day

goes. I think looking at the comments, there seem to

be a great deal of agreement among the reviewers on

where the document stands. It seems, as before, that

perhaps much of the discussion will be around aspects

of the Secondary Standard rather than the Primary, at

least looking at the comments in some of the
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remaining questions; but we do adjourn tomorrow at

11:30.

Would also note that listening to the weather

report, it doesn't look like any temperature records

are going to be broken today. It's not even going to

hit 100, it appears.

DR. STALLWORTH: What a relief.

DR. SAMET: It appears, so a little respite

for those of you from the east coast.

So with that, we'll turn things over -- I

guess, Lydia, you'll start.

OPENING REMARKS BY MS. WEGMAN:

MS. WEGMAN: Great. Good morning, everyone.

I want to thank you all again for your

participation. Hearing Vanessa's summary of all of

the meetings for the very lengthy participation in

this PM review, you've given us a great deal of

extremely useful advice. We really could not have

made the progress we've made without all the help

you've provided to us to date and we very much look

forward to hearing the discussion today.

We thank you all for the written comments

you've sent us in advance of this meeting because

they've been very helpful to us in thinking about

this meeting and preparing for it. So I just want to
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thank you all very much for your help and service to

us in the Office of Air Quality Planning and

Standards and EPA as a whole.

What I want to do is just introduce to you the

team here who will be engaging with you throughout

the next day and a half.

You all know Dr. Karen Martin. She's the

group leader who has spearheaded this effort for the

staff paper, or I should say Policy Assessment.

Beth Hasset-Sipple has been our lead person on

the primary health phase PM2.5 standard.

Scott Jenkins has been the lead on the coarse

particle standard.

Dr. Pradeep Rajan has been working with Beth

on the fine particle standards.

And for visibility, we've got our two lead

folks in the back, Vickie Sandiford and Marc

Pitchford. And they'll be coming to the table a

little later when we get to the discussion of the

Visibility Secondary Standard.

Turning now to the schedule, which is what I

want to talk about. Yeah, I just want to let you

know where we plan to go from here. We do in fact

hope there will be a conclusion to this review. That

is our fervent hope. We are having a meeting, of
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course, today on the Second Draft Policy Assessment

and there is a public comment period which will last

until August 16th, except that we have extended it to

August 30th for Chapter 4 because Chapter 4, related

to the urban focus visibility discussion, went out

later than the rest of the Policy Assessment. So we

do have a two-week extension for public comments on

Chapter 4.

We plan to issue the final Policy Assessment

in September of this year and then move forward to

have a proposed rule in February of 2011 and complete

this review with a final rule issued in October of

2011, which will be five years from the completion of

the last review of PM. So that's the schedule we

have in mind.

And now, unless anyone has any questions about

the schedule, I'm going to turn it over to Karen, who

will talk about the document and give a brief

overview of what we'll be talking about today.

OPENING REMARKS BY DR. MARTIN:

DR. MARTIN: Okay. It's my intent to do a

very brief overview of the -- primarily focusing on

the things that have been added or changed in the

second draft relative to the first draft that you

reviewed previously, as well as just a very quick
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summary of the staff conclusions for these chapters.

With regard to the structure of the document,

obviously, there's two chapters that deal with the

Primary Standards, two with Secondary Standards. The

focus of our charge questions and the focus of,

therefore, this discussion will be on Chapters 2, 3

and 4.

Chapter 5, there were limited comments from

this panel on the first draft. We addressed those

comments; therefore, we didn't identify additional

charge questions for this second draft on that

chapter, but the second draft includes changes we

made to that chapter that were reflective of the

comments we received on the first draft.

And turning to -- just looking, first of all,

at overall changes to the document as a whole, your

comments on the first draft were very pointed and

focussed us on streamlining the document, removing

redundancy, relying more on the related assessment

documents, which we have made every effort to do, we

added an Executive Summary.

We focussed in particular at the beginning of

these chapters to articulate the approach we were

using throughout the chapter. As part of our

assessment we added, sort of, a road map figure to
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highlight that up front to give the reader a better

sense of what was to come, an organization of what

was to come. And we tried therein to more strictly

follow the approach laid out up front as we went

about the discussions primarily on alternative

standard levels that the approaches spoke to most

when we got to that part of the chapter.

And finally, for all the chapters we included

the last section on key uncertainties and areas for

future research.

With regard to Chapter 2, additional analyses

and discussions that are included in this draft, we

particularly clarified our approach for translating

epi evidence into the basis for staff conclusions

primarily on levels of the standard. This chapter

now includes additional analyses that informed

conclusion on alternative forms of the standards,

looking both at the annual standard and potential

disproportionate impacts on susceptible populations,

as well as looking at a comparison of the 98th and

99th percentiles for the 24-hour standard.

With regard to levels, and in particular on

the annual standard, the approach discussion lays out

a couple different approaches to translate epi

evidence into levels of the standard. This was the
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subject of much discussion among this Panel followed

on the first draft, and we have brought that

discussion forward here.

In particular, I will note that the discussion

on looking at confidence bounds around

concentration-response functions was something that

was highlighted a lot in your comments. We presented

a discussion here upon receiving comments,

particularly comments from Dr. Vedal, on that

particular issue. We revisited what we had written,

and we took the step of conferring with investigators

on the three key studies that we called out as being

particularly relevant to that discussion to get more

information on the analyses they did and their views

about interpretation of those analyses.

So what I would like to do, rather than taking

more time now, I would like to just, when we get to

that point in talking through the charge questions,

I'd like to provide an overview of the evolution of

our thinking since we released the second draft as

informed by some of the -- and conferring with some

of the authors there.

Beyond that, then, we put together, hopefully,

a more logical discussion of looking at different

statistical metrics and talking about drawing from
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the risk assessment to help inform beyond the

evidence itself our consideration of alternative

levels.

In looking at the bottom-line conclusions that

we reached, which hopefully are clearly expressed in

the Executive Summary of the document, we conclude

that the available information, the evidence in the

risk information, clearly calls into question the

adequacy of the current primary fine particle

standards, that we've identified alternative forms

and levels that are appropriate for consideration

based on that information, appropriate to consider

eliminating spatial averaging for the annual

standard, appropriate to consider retaining the 98th

percentile for the 24-hour standard.

And with regard to levels, we have a

discussion about considering information on both

long-term and short-term exposures as part of

providing the basis for defining a generally

controlling annual standard in conjunction with the

24-hour standard that will provide supplemental

protection. And in that regard, we identified annual

standard levels in the range of 13 to 11 as

appropriate for consideration; and we looked at the

24-hour standard levels then in conjunction with the
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annual standard levels and conclude that it's

appropriate to consider retaining the level of 35

micrograms per cubic meter in conjunction with any of

the annual standards and, alternatively, to consider

revising the 24-hour standard level lower to a level

of 30 in conjunction with an annual standard level as

low as 11. And as we get to those charge questions,

I'm sure we'll have discussion about those

conclusions.

With regard to Chapter 3, thoracic coarse

particles, we have appreciably expanded the analyses

and discussions in this second draft. The first

draft was not fully complete in discussing

alternative levels, so there is much more new

material in this chapter than in the others.

In particular, expanded the discussion of

approaches to evaluating the adequacy of the current

PM10 standard, added figures characterizing PM10 air

quality in locations where we had PM10-2.5 health

studies. We expanded the discussion of the epi

evidence and the air quality information as it

relates to the adequacy of that standard.

We added discussion with regard to additional

analyses to inform consideration of the indicator and

focusing on the relationship between PM10-2.5 and PM10
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concentrations in regions across the U.S.

We've expanded discussion of relevant

considerations for the form of the standard looking

at the current form, which is a

one-expected-exceedance form averaged over three

years relative to a 98th percentile form.

And in discussion of levels, to the extent

that consideration is given to revising the standard

to look at potentially more protective standards,

we've done additional analyses that looked at the

relationship between the current and potential

alternative standards and added figures

characterizing, again, PM10 in locations of PM10-2.5 to

help inform that discussion.

With regard to the overall staff conclusions

from Chapter 3 on thoracic coarse particle standards,

we conclude that the available evidence and air

quality information could support either retaining

the current standard or revising the current PM10

standard depending on the weight placed on different

kinds of evidence and the weight placed on the

uncertainties associated with that evidence.

To the extent that revisions are considered,

we concluded that it would be appropriate to give

consideration to retaining PM10 as the indicator with
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a 24-hour averaging time and to revising the form and

level with consideration of levels between 85 and

about 65 micrograms per cubic meter in conjunction

with a revised form in conjunction with the 98th

percentile form. So that discussion starts with the

point of very rough equivalence between a

one-expected-exceedance form and the 98th percentile

form in terms of levels and then goes from there to

discuss potential alternative lower levels of the

standard.

With regard to Chapter 4, looking at

visibility-related effects and secondary standards

intended to protect against visibility impairment, we

have done a reevaluation of the choice of an

indicator drawing a lot on comments from this

committee as well as comments from the monitoring

subcommittee, the AAMMS subcommittee. In this

regard, the first draft included a discussion of two

different indicators, an indicator of light

extinction using direct remeasured light extinction,

and an indicator of aggregated PM2.5 mass. There were

a lot of discussions about the pros and cons of those

different indicators, a lot of issues raised about

both of them. We went away and thought about the

limitations and concerns with either one of them and
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tried to develop a, sort of, hybrid approach that

defined the degree of protection in terms of light

extinction and utilized speciated PM2.5 mass

information and humidity information to calculate a

light extinction. Therefore, we defined the

ineloquently termed speciated PM2.5 mass calculated

light extinction indicator, thinking that it

reflected potentially the advantages of the two

different options explored in the first chapter and

avoided some of the fundamental limitations in moving

forward with them; and we conducted new analyses to

inform consideration of alternative standards.

One point I would make here is one of the

things that happened as well is that they identified

a processing error, a data processing error in the

urban focus visibility assessment, the underlying

quantitative assessment document. That error caused

organic carbonaceous materials, estimated by the

Sandwich method, to be overestimated on some days.

It took a while to play this error out through the

calculations. The bottom line is the corrections are

quite small. They don't in any way affect the

conclusions, but it did take a while to work through

that. As a consequence, that visibility assessment

document was not released at the end of June when
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when we anticipated it would be released, but it was

released just the end of last week so that we could

fully play through this correction. And that is the

basis for extending the comment period on Chapter 4

of this Policy Assessment document. Chapter 4 was,

of course, released at the same time as the whole

Policy Assessment document; but this analysis was --

underlays and informed that chapter, so we've

provided some extension of the time for public

comment on Chapter 4. And we have included updates

in that final figure, and the Policy Assessment was

really not affected by this error correction since it

didn't play a role in the newly developed indicator

approach that we present here.

Bottom-line conclusions on Chapter 4 then, the

staff concluded that the currently available

information clearly calls into question the adequacy

of the current PM2.5 standards to protect against

visibility impairment. We've identified alternatives

that we believe are appropriate for consideration

particularly focusing on the new speciated mass

calculated light extinction indicator focusing on

daylight hours only, focusing on only hours with

relative humidity of 90 percent or below, looking at

a one-hour averaging time, all of which carries
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forward from the discussion in the first draft.

Also, looking at alternative forms, both the maximum

daily one-hour form in conjunction with 90th or 95th

percentiles, or looking at all daylight hours in a

day in conjunction with the 98th percentile form.

There's obviously a lot of different permutations one

can look at, and we focussed on those as, perhaps,

being most meaningful to compare.

And in conjunction with levels, we look in

terms of defining the degree of protection of a

standard in terms of light extinction in the range of

64 to 190 inverse megameters, which is, again, a

carryover from the range that was considered in the

first draft

So that's the overview, and if there's any

questions.

DR. SAMET: Okay. Thank you, Karen and team.

I think these figures and, sort of, the

clarity of the approach, I think, is very useful. I

mean, if you, sort of, extend it up to the top of the

page and put it in the ISA and the REA, you could

capture the whole process, which might be a useful

thing to do. Congratulations on creating an

indicator that defies acronyms.

Questions or clarification from the Panel? I
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mean, we'll have a lot -- I mean, obviously, once we

go through the details, we'll have specific items to

discuss; but, I think, in terms of the overall

approach, the overview, anything?

(No response.)

DR. SAMET: Okay. We should just go to the

public comments. Then what we'll do is move on to

the public comment period. We have eight public

commentors. We have time allocated until 10:30.

Each public commentor has been allocated five

minutes. We'll ask you to come forward to present.

What I will do is, I will give you a 30-second

warning; and I ask that when we reach the five

minutes, that you please end your presentation.

Our first presenter is Jay Turim from

Exponent, Inc. on behalf of the American Chemistry

Council, please.

PUBLIC COMMENT STATEMENTS BY:

DR. JAY TURIM:

DR. TURIM: I'm glad to be here for the third

time to speak about the PM standards. In a sense,

the most important document in the NAAQS review

process is the Policy Assessment since it's intended

to bridge the gap between the highly technical

information presented in the ISA and the Risk
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Assessment and the judgments required from the

Administrator in making her decisions.

Instead of plowing through the very detailed

scientific documents prepared by EPA in the past, the

Administrator will very likely rely heavily on the

Policy Assessment when fashioning her own judgments

as to the adequacy and whether the standard should be

changed. For that reason the Policy Assessment

should present a very balanced view of the state of

the science.

In the very little time allotted to me -- and

I learned last time the five minutes does mean five

minutes -- I'll touch on just a view of the ways the

Policy Assessment, we feel, falls short. Many other

examples are given in our written comments that we've

submitted to the CASAC committee and to EPA.

In the comments we submitted on the first

draft as well as the second, we discussed the

numerous limitations in the epidemiological studies

relied upon by EPA. Among them, limitations of the

observational studies generally, the unreliability of

the statistical methods used, inconsistencies among

the studies, and the implausibility of some of the

results.

We were very surprised to see that the first
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draft of the Policy Assessment did not discuss or

even acknowledge many of the numerous issues and

suggestions we commented on. We don't expect the EPA

to agree with every point we made, but we believe it

is incumbent on the Agency to address these issues,

not in a stand-alone document, as was done, for

example, with the comments submitted on SO2, but in

the Policy Assessment itself since that is the

document that the Administrator will rely upon in

making her decisions. I'd like to mention two issues

specifically, again, in recognition of the little

time I have to speak.

Reported risks in some studies relied heavily

upon by EPA staff are so large as to be totally

implausible biologically. One example is a study

that plays an important role in EPA's considerations,

the Miller, et al., 2007, estimated cardiovascular

events including deaths associated with fine PM

exposure. Their results imply that the risk of a

woman living in the most polluted city -- I think it

was Riverside, California, in terms of the cities

studied by Miller, et al. -- dying from heart disease

is four times higher than for a woman living in the

least polluted city, which was Honolulu, Hawaii.

This compares with the relative risk of less than two
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for a two-pack-a-day 65-69 year old woman smoker.

Does EPA really believe that the risks from fine PM

at current ambient levels are greater than smoking?

If so, then EPA should state so explicitly.

The second issue I want to speak about briefly

regards the ACS II studies. In an update of the ACS

II cohort, Krewski, et al., in 2007, showed that when

SO2 exposure was taken into account, the magnitude of

the association of mortality with fine PM was not

statistically significant. Subsequently, several

other studies, Pope, Jerrett, Krewski, all of which

were, in part, in EPA's thinking, were conducted with

the same data. In fact, the Krewski, et al., 2009

report provides the fine PM mortality coefficient

that was used in the risk assessment that was the

basis for some of the Policy Assessment results.

None of the analyses I mentioned included SO2 in

joint-pollutant analyses with fine PM despite the

very strong findings in the original Krewski

reports --

DR. SAMET: 30 seconds.

DR. TURNER: -- and despite repeated attempts

to have such analyses conducted.

To conclude, we think that at absolute minimum

the Executive Summary has to be rewritten. Clearly
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it was done in comment to, in response to, CASAC's

comments; but it does not say anything about the

uncertainties of the data, only repeats what the body

of the report included.

And finally, the second point we want to make

is the report is so --

DR. SAMET: Thank you for your comments. Your

time is up. Thank you.

DR. TURIM: Thank you. Almost got it through

this time.

DR. SAMET: Five minutes is five minutes.

Let's see, why don't you wait a moment and see

if there are questions from the Panel.

Sverre?

DR. VEDAL: Yeah, thanks for that. I had just

a question. I didn't catch what the concern was with

the Krewski reanalysis. I missed it.

DR. TURIM: The Krewski analysis did not take

into -- the 2000 analysis did a multi-pollutant

analysis --

DR. VEDAL: Right.

DR. TURIM: -- which showed that SO2

diminished the association. And there were no other

multi-pollutant analyses included in the 2009 Krewski

report, which is at the heart of some of the
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deliberations of EPA.

DR. SAMET: On a technical point, you

mentioned unreliability of statistical methods, and

there's a specific reference in your written comments

to the Cox model.

DR. TURIM: Right.

DR. SAMET: One of those widely used

statistical techniques throughout, really,

observational studies, clinical literature and so on.

Is there some particular aspect of the Cox model and

its application that you found lacking?

DR. TURIM: Yes. Well, we speak about some of

those details in our report.

The Cox model we don't think echos the actual

data in the sense that the Cox model does not reflect

the fact that the risks go down over time. And I

think we give some illustrations in the report we

submitted on that. We have the figure of that. I

don't have it in front of me, Dr. Samet.

DR. SAMET: Okay. But the Cox model can

incorporate time dependence. I'm not -- we can

perhaps look because I did not see any real details

on this --

DR. TURIM: Yeah.

DR. SAMET: -- in your comments.
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Any other questions from the panel?

(No response.)

DR. SAMET: Thank you for your comments.

DR. TURIM: Thank you.

DR. SAMET: Okay. We'll move to our next

speaker, Deborah Shprentz, consultant on behalf of

the American Lung Association.

MS. DEBORAH SHPRENTZ:

MS. SHPRENTZ: Thank you and good morning.

I'd like to focus on just a few issues

regarding the rationale underlying the

recommendations in the draft Policy Assessment.

First, with respect to the fine particle

standard, the draft states that it might be

appropriate to consider a more protective 24-hour

standard of 30 but only in conjunction with the most

protective option of an annual standard of 11. The

draft allows that it might be appropriate to consider

this tighter daily standard to protect against strong

local or seasonal sources of emissions that result in

high daily concentrations despite the annual average

standard. However, in our view it does not make

sense to consider a tighter 24-hour standard of 30

only in conjunction with the most stringent annual

standard under consideration. If daily
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concentrations are of concern with a standard of 11,

they're even more so of concern with an annual

standard of 12 or 13 because a higher annual standard

will be less effective at moderating 24-hour peaks

than a lower standard.

The justifications offered by the draft Policy

Assessment don't hold up. First, the draft states

that the annual standard should be controlling, but

the NAAQS must protect public health even if the

24-hour standard is controlling in some areas. This

whole idea of the controlling standard is not germane

to selecting standards and has no statutory basis in

the Clean Air Act.

Second, the draft Policy Assessment purports

to set a 24-hour standard based on the average

peak-to-mean ratio in most regions of the country of

2.5. The Policy Assessment states that it's

reasonable to focus on 24-hour standards that are at

least 2.5 times the annual standard. This is used to

argue that the current level of the standard of 35

meets this criterion. But again, the goal is to

identify a level that will protect public health, not

to maintain the annual standard as controlling.

The draft Policy Assessment further justifies

its failure to consider tightening the 24-hour
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standard based on regional considerations. EPA's

analysis of the air quality data shows that a

standard of 11 annual and 30 daily would primarily

impact the northwestern region of the country where

emissions from wood stoves and agricultural burning

are problems. A standard of 30 or 25 in conjunction

with an annual standard of 13 or 12 would affect

additional regions of the country. This regional

justification is not allowed under the Clean Air Act

and is bad policy because it would fail to provide

equal protection throughout the U.S.

With respect to the coarse particle standards,

we're dismayed that the Policy Assessment

contemplates a relaxation of the form of the 24-hour

standard. The current form is the

one-expected-exceedance form and the draft suggests

moving to a 98th percentile form. The goal of the

daily standard is to prevent peak daily exposures;

and as we've argued in the past, a 98th percentile

form of the standard excuses too many days of

unhealthy air quality from the compliance

determination seven days each year. The continued

reliance on one-in-six-day monitoring or

one-in-three-day monitoring is not a reason to move

to a 98th percentile standard. Indeed, it's past
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time to require daily monitoring of PM10

concentrations. Even if EPA lowers the level of the

24-hour standard to compensate for a more lenient

form, it will not address our concerns. The Agency

needs to consider the practical effect of a change in

form that does not increase the protectiveness of the

standard, that being to delay the delivery of health

benefits. States would have to reclassify

non-attainment areas, develop new implementation

plans and the deadlines for attainment would be

extended, meanwhile cleanup efforts will be stalled.

The draft Policy Assessment argues that the

PM10 indicator for coarse particles is desirable

because it would allow less coarse particle pollution

in urban areas than in rural areas and that this is a

good thing because urban coarse particles are more

toxic; but toxic coarse particles are present in

rural as well as urban areas, so this is not a valid

consideration. Mobile, off-road and stationary

combustion sources are located in rural and urban

areas.

DR. SAMET: 30 seconds.

MS. SHPRENTZ: And likewise, industrial

sources of emissions are found in less populated

areas. We believe that national standards have to
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protect all citizens, urban and rural alike.

Thank you.

DR. SAMET: Thank you.

Questions? Comments?

(No response.)

DR. SAMET: Okay. Thank you, Deborah.

Our next speaker is Ben Brandes, Director, Air

Quality, National Mining Association.

MR. BEN BRANDES:

MR. BRANDES: Thank you for your time. My

name is Ben Brandes. I'm with the National Mining

Association.

NMA is a national trade association of mining

and mineral processing companies, whose membership

encompasses producers of most of the United States

metals, coal, uranium and industrial and agriculture

minerals. NMA members operate all across the country

including the western United States where coarse PM,

fugitive dust predominates due to the air conditions.

NMA is very concerned that the decision by EPA

to reduce the level of the current PM10 standard will

throw many areas around the country into

non-attainment. This will have the effect of

limiting economic growth and impacting development

and operation of existing operations in those areas.
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We understand that EPA cannot consider economic

effects when establishing the air quality standards;

therefore, added emphasis should be placed on making

balanced decisions based on existing scientific

information.

EPA staff concluded in the second draft Policy

Assessment that consideration could be given to

either retaining or revising the current standard.

Further, staff noted that the currently available

scientific evidence could be interpreted to support

retention of the existing standard. This conclusion

is justified by the scientific limitations and

uncertainties the EPA has identified in the currently

available health studies.

Despite the scientific support for retaining

the standard, however, EPA staff suggested a

potential alternative in the document that would

effectively result in tightening the current standard

by half. The impact of PM10 regulation on sources of

PM coarse, particularly on surface mining operations

in the western United States, could be severe.

Because mines are already required to control coarse

PM through a variety of technology and management

requirements, little more can be done to comply with

the coarse PM NAAQS other than to scale back or shut
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down operations.

The impacts of a coarse PM standard to energy

and commodities markets, not to mention the

communities and ancillary businesses that depend on

mining, would be substantial, sending ripple effects

throughout the entire economy. Because of

longstanding concerns with the lack of evidence of

adverse health effects at ambient levels,

historically EPA has not regulated rural fugitive

dust in the same manner as other particulate matter,

especially PM found in urban areas.

With the health evidence increasingly pointing

to PM fine as the PM10 component of concern, CASAC and

EPA have both recognized that PM fine and PM coarse

and are two distinct pollutants. PM fine is

combustion-derived material. PM coarse is crustal,

mechanically derived material. While EPA proposed

eliminating PM10 24-hour standard in 1997 because of a

lack of adverse health effects from coarse PM and

found in 2006 that the health evidence continued to

be inconclusive and uncertain, EPA did retain the PM10

standard as a coarse PM indicator in 2006 as a

cautionary measure.

EPA also continues its finding that rural

fugitive dust is of less concern than urban PM. EPA
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noted a potential concern with urban coarse PM due to

the possibility that fine particles could contaminate

the coarse particles. No independent evidence was

adduced that coarse PM was a health concern. The

health evidence for coarse PM continues to be

comprised by the reliance on PM10 in the

epidemiological studies. As CASAC's own members have

acknowledged, when PM10 data is used as the basis for

finding adverse health effects, one cannot know

whether it is the PM fine component of PM10 or the PM

coarse component that is responsible for the observed

effects.

The final ISA adopted this past December

recognizes that the most thorough and best quality

studies find no adverse health effects from coarse

PM. In fact, there remains no evidence that rural

coarse PM of the type associated with mining

operations posed adverse risks to human health or the

environment at ambient levels.

For all of these reasons, NMA supports the

conclusions by EPA in the Policy Assessment that the

existing 24-hour standard for coarse PM should not be

revised due to the critical distinction between --

DR. SAMET: 30 seconds.

MR. BRANDES: Thank you.
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-- should not be revised due to the critical

distinction between urban and rural coarse PM and the

continued uncertainty in the health evidence.

Thank you for your continued work and

consideration.

DR. SAMET: Thank you. Questions or comments?

(No response.)

DR. SAMET: Okay. Thank you.

We'll move to our next speaker, Greg

Schaeffer, vice president of external affairs, Arch

Coal, Inc.

MR. GREG SCHAEFER:

MR. SCHAEFFER: Hi, Karen. Good morning. My

name is Greg Schaefer, and I'm with Arch Coal. We're

the second largest coal producer in the United

States, and we operate two surface coal mines in the

Powder River Basin of Wyoming, which is largely in an

arid -- hi, Tom -- largely in an arid and windy

environment, so we do see dust out there.

We've been actively engaged in the particulate

matter reviews over the years and have watched as EPA

and CASAC have struggled with developing PM standards

that are protective of human health, but at the same

time are not disproportionately more stringent in

some areas in the United States. This struggle
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continues today. This has been the case for the

western United States due to the high proportion of

coarse particulates in the PM10 fraction and the

relative absence of fine particulates.

On page 3-38 of the Policy Assessment, EPA

notes: Based on regression of 98th percentile PM10

design values and the 98th percentile PM10

concentration of 87 micrograms per cubic meter is on

average equivalent to a one-expected-exceedance

design value of 150 micrograms per cubic meter. As a

consequence, while we note that a 98th percentile

24-hour PM10 standard with a level of 87 micrograms

per cubic meter would be expected to provide public

health protection that is, on average across the

United States equivalent to the protection provided

by the current standard, in some locations such a

98th percentile standard could be more protective

than the current standard while in other locations it

could be less protective than the current standard.

And that's our concern is, once again, it

looks like this will be disproportionately more

stringent in the west. We've see on the 98th

percentile that there's significant variation from

year to year. At one of our monitors in 2008, the

98th percentile was 95 micrograms per cubic meter,
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while in 2007 was 80 micrograms per cubic meter. And

that's going to be largely a function of how close

the mining operation is to the monitor, and also it

will be the amount of moisture we have during the

year because we are in an arid environment. We

continue to urge EPA to seek a fair resolution to the

fairness issue associated with the coarse PM

standard, which includes maintaining the coarse -- or

the 24-hour standard at 150 micrograms per cubic

meter.

Attention also needs to be applied to areas

that have high density of coarse PM monitors. In

these areas one monitor may show an exceedance of the

standard while the one adjacent to it is in

compliance. It doesn't make sense to treat coarse

particles like ozone or NOx, which have very long

distance transports, while coarse particulate

transport is very short.

Thank you for your attention today.

DR. SAMET: Thank you. Not even a 30-second

warning

MR. SCHAEFFER: That's what I was shooting

for.

DR. SAMET: Okay. Thank you. Questions or

comments?
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(No response.)

DR. SAMET: Okay. Thank you. We'll move to

our next presenter, Wig Zamore from the Somerville

Transportation Equity Partnership and Mystic View

Task Force.

Actually, Frank, can you hear this?

DR. SPEIZER: Yes.

DR. SAMET: Okay.

DR. SPEIZER: Yeah, I'm hearing you now.

DR. SAMET: Okay.

DR. SPEIZER: I'm not hearing anything now.

MR. WIG ZAMORE:

MR. ZAMORE: Okay. Sorry. All right. This

is Wig Zamore. Thank you very much for giving me a

couple....

DR. SPEIZER: Okay.

MR. ZAMORE: I can sit down and just turn. I

think I can do it from here if this will work.

Thank you very much for giving me a few

minutes of time. I'm an average citizen from

Somerville, Massachusetts; and you were nice enough

to give me a few minutes 15 months ago in

Chapel Hill.

I'm going to do a PowerPoint. This is a

recent picture of conditions on I-93 in the afternoon
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in Somerville. Increases are pretty substantial in

highway travel in Massachusetts, about 25 million

vehicle miles per day per 20-year period.

Of course, it's not all highway. Here's

flying in yesterday to RDU. Here's the ports of LA

and Long Beach. And just while we're there, I'd like

to mention the California Children's Health Study,

which started out looking at regional transportation,

found some associations with ozone for four-season

outdoor athletes and with PM2.5 strong enough to cause

a remand of the PM2.5 standard, but consider their

findings of roadways to be most, most significant.

With regard to the current standard my main

point is that the numbers are very large and call for

the strictest annual PM2.5 standard possible. I think

no matter what standard you pick, the mortalities

left on the table will exceed the mortalities

associated with all other environmental health issues

in the United States.

Ischemic heart disease, of course, is a very

large issue here, and I want to talk a little bit

about that in connection with ultrafines. It seems

that ultrafines are strongly associated with ischemic

heart disease and perhaps also still neurological

function. A lot of studies showing acute effects
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both in daily mortality and then in biological

indicators, starting with the Germany series and then

more recently, with a series of studies in the U.S.

including rodent studies.

Moving to subchronic, which ties this to

longer-term cardiovascular disease, both the Delfino

senior citizens studies in California and Hertel and

Hoffman in Germany have found strong association of

UFP with high-sensitivity CRP of over a week of

averaging, up to a month of averaging, which is the

extent of their research. And here's a slide from

Hertel showing how much stronger the UFP are than

PM2.5 or PM10, effect modification for both age and

body mass in the studies.

Back to Somerville, we have a lot of citizens

who do not understand this issue because there's no

government direction, joggers, bicyclists. Panis has

found almost an order-of-magnitude increased dose for

bicyclists. Here's a young woman and her young

daughter thinking they're doing the right thing, and

this is where they are. This is what they're doing

almost every afternoon.

Same thing with our housing, we're locating

our housing extremely close to the highway. On the

right is the largest affordable housing project in
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Somerville. In the middle, the newest affordable

housing project in Somerville, Interstate 93 just off

the screen to the left.

A nice study -- I know it's too late to

include in your review -- but out of Vancouver, by an

associate, Michael Brauer, showing, similar to the

Children's Health Study in California, that when

people move in or out of highway-adjacent locations

it modifies the cardiovascular mortality response.

You can see that the effects are very, very large

here, especially for people living within 50 meters

of highways and even after modifying for

socioeconomic.

These are pretty much the summary of the

numbers I presented 15 months ago. I still believe

these to be true. I'm concerned that we're not

moving to primary mobile pollution soon enough, and I

think the particulate matter committee is the place

to do it.

Here's a young woman in Somerville hung up on

an arterial highway. You can see from her expression

she's trying to reach the EPA PM scientists in CASAC.

And the question is, what can we do about it;

and I'm going to stop there. And I guess I would ask

just for those two things. A strict PM2.5 annual
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standard and some pathway to telling you, as citizens

who exercise or live next to highways and other large

mobile sources, that they are at risk.

Thank you.

DR. SAMET: Thank you. Questions or comments?

Is that Joe Brain in one of those cars

commuting?

DR. BRAIN: Not mine. My son and grandson

live in Somerville.

DR. SAMET: Our next presenter is Julie

Goodman from Gradient on behalf of the American

Petroleum Institute.

DR. JULIE GOODMAN:

DR. GOODMAN: Thank you for the opportunity to

speak today on behalf of API.

The second external review draft of the PM

Policy Assessment has not substantially changed from

the first draft. EPA continues to rely on results

from a small number of epidemiology studies with

large inherent uncertainties to support lowering the

PM NAAQS. I've commented extensively on the

limitations of these studies, particularly as to

their relevance and informing changes to the NAAQS,

yet EPA has not been responsive to my comments.

Today I will focus on three points that EPA
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should consider before finalizing the PM Policy

Assessment. They specifically relate to the

assumption of no threshold, the evidence-based

analyses, and the bases for the alternative annual

PM2.5 standard.

EPA asserts that there is no evidence of a

threshold for PM effects and that a log-lineal model

best represents the concentration-response, or C-R

relationships. Yet, several researchers have shown

that these relationships are nonlinear. In fact,

exposure measurement errors in epi studies,

acknowledged by EPA, have been shown to result in

biases in fitted C-R curves that are large enough to

affect the interpretation in risk assessment

applications, and these biases can mask true

thresholds.

Other arguments claimed to support

no-threshold models, such as additivity to background

and heterogeneity in the population, do not actually

support this assertion. Additivity to background

only holds if it's related to a specific mode of

action that has non-universal properties, properties

that would not be expected for noncancer effects.

Similarly, heterogeneity among members of the target

population do not linearize the C-R curve, but rather
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tend to broaden it.

As to my second point, EPA continues to assert

that new epi evidence is consistent and stronger,

quote, "because of its breadth and substantiation of

the previous observed health effects." But I'd like

to quote Bradford Hill from his seminal 1965 paper

where he says, quote, "The same results from

precisely the same form of inquiry will not

invariably greatly strengthen the original evidence."

So in other words, a larger number of studies that

show the same limitations as a smaller subset does

not strengthen the argument of a causal effect. And

in fact, the studies continue to show that changes in

model specification or model assumptions as well as

the inclusion of confounders significantly changes

effect estimates.

As to my third point, to support the

recommendation of alternative PM2.5 standards, EPA

relied on data from a select few studies without

properly weighing the data and uncertainties from all

studies across all lines of epi, animal, and mode of

action evidence. In the ISA, EPA claims that

findings of cardiovascular and respiratory disease

are consistent and precise above 13 micrograms per

meter cubed, but a review of the data shown in Figure
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2-1 and 2-2 of the ISA shows this is not the case. A

higher value, where results are more consistent

across studies, should be considered to support the

standard. And in addition, the lower-bound

recommended alternative standard of 11 is based on

studies of health effects that are considered only

suggestive at this time and should not be included in

the recommendation.

So the evidence presented by EPA is not

sufficient to change the level of the standard given

the uncertainties in the epidemiology studies relied

on and the use of arbitrary statistics that are,

quote, "just below the mean" in a select number of

studies, without consideration of the larger body of

evidence.

Indeed, EPA has discussed the increased

uncertainty in risk estimates below 13 microgram per

meter cubed largely due to the lack of data at these

levels. For example, as noted in the second draft

PA, the studies that show C-R functions with

confidence bounds demonstrate greater uncertainty, in

the terms of wider confidence bounds, below the level

of the current standard. Similarly, EPA has noted

that it does not have confidence in risk estimates of

alternative standards below 13.
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So in conclusion, the uncertainty in the

underlying epi studies precludes the conclusion that

a causal relationship exists between PM and health

effects below the current standard. Furthermore,

there's evidence the C-R relationships are not

linear, that a threshold likely exists, bringing into

question the results from the risk assessment. And

lastly, the bases for the alternative standard appear

to be arbitrary and are not supported by the current

scientific evidence. So the current weight of

evidence does not call into question the adequacy of

the current PM2.5 standard.

Thank you

DR. SAMET: Thank you. Questions, comments?

(No response.)

DR. GOODMAN: Okay. Thank you.

DR. SAMET: Thank you. Our next speaker is

Jon Heuss from Air Improvement Resources, who is on,

I guess, by phone.

Jon, are you there.

MR. HEUSS: Yes, I am.

DR. SAMET: Okay. Go ahead, please.

MR. JON HEUSS:

MR. HEUSS: Thank you. My name is Jon Heuss,

with AIR.
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George Wolff and I provided written comments

on the first draft PA. In addition, Charles River

Associates, Gradient, and the American Chemical

Council, provided important comments. These

submissions raised substantive issues relevant to the

policy choices in the PA, yet the second draft either

does not acknowledge or insufficiently acknowledges

these concerns.

The most important points are: One,

assumption of equal toxicity by PM mass undergirds

the risk analysis is flawed. All the discussions of

causality in the PA must be qualified as they were in

the 2004 SCD to refer to PM, or one or more PM

component acting alone and/or in combination with

gaseous pollutants rather than just to PM mass alone.

In the last review, the administrator placed little

weight on the risk assessment since it was not clear

that controls that would reduce the fine PM would

also reduce the toxic components. That concern is

still relevant.

Two, the epi evidence is not as strong or as

consistent as portrayed in the PA. New large U.S.

multi-city studies show that the magnitude of PM

associations with acute morbidity and mortality

endpoints is smaller than thought in 2004. The
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pattern in the multi-city studies shows that when you

look just at single-city studies, there is an upward

bias due to publication bias. The multi-city studies

also provide strong evidence that stochastic

variability is much greater than heretofore thought

and shows clear spatial and temporal patterns that

are not consistent with effect of generic PM. The PA

should acknowledge these patterns and conclude that

relying on specific single-city studies in light of

the stochastic variation is unsound. All these

findings provide support for the conclusion the

current standards adequately protect the public

health.

Three, model selection uncertainty is more

important than acknowledged in the PA. HEI's

recently released APHENA study shows a pattern of

combined association that is not consistent with what

one would expect if PM10 health associations have a

real physiologic basis.

Four, if EPA claims that PM mass regardless of

composition causes health effects, then a comparison

of PM risks in other exposure situations is

warranted. The cardiovascular health signal relied

upon by EPA is not consistent or coherent with the

fine PM risks from indoor pollution in developed
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countries, massive indoor pollution in underdeveloped

countries, smoking, and occupational exposures.

Five, the arguments the PA uses to defend

making the annual fine PM standard more stringent

lack rigor. The cardiovascular signal observed in

the Eastern U.S. in the large ACS and Medicare

cohorts is not present in the Western U.S. It's also

not present in the large cohort study from the

Netherlands, Beelen, et al., 2008. These spatial

differences and inconsistencies in the chronic

mortality studies lend additional credence to the

conclusion that to the extent that there are positive

PM associations, they are caused either by

unidentified covariates, by components of PM, not PM

mass, or by historic high exposures and sources

unique to the Eastern U.S. These possibilities are

not discussed in the PA. Even if these possibilities

are dismissed, Charles River and Gradient comments

concerning the lack of knowledge of the appropriate

exposure period for attributing the effects that are

in the remaining cohorts that may cause recent

associations. These need to be fully vetted in the

PA. Thus, there is substantial evidence in

supporting retaining the current annual PM2.5 standard

that is not being considered in the draft PA.
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With regard to coarse PM, we agree with EPA

that urban and coarse -- rural coarse thoracic PM

should be treated equally. We think EPA should focus

on identifying the toxic components of ambient PM.

Tightening the generic fine or coarse PM standards

without knowing what causes the wide variations from

positive to negative in acute individual-city

associations, or the region-wide chronic PM

associations at the same PM exposure, is

scientifically unsound.

And I would add a seventh point. Since

there's a similar pattern of acute associations for

each of the criteria pollutants, the extent to which

gaseous pollutants --

DR. SAMET: 30 seconds.

MR. HEUSS: -- can cause the biological

responses attributed to PM to be rigorously

evaluated. As each criteria pollutant is being

reviewed, EPA is using selected single-city,

single-pollutant associations for that pollutant to

set the NAAQS, for example, in the recently completed

NO2 and SO2 reviews. And the recent ozone proposal

uses epi evidence as the main reason to support a low

end of the proposed range.

Now, in the PM case selected single-pollutant
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individual --

DR. SAMET: Okay. Jon, your five minutes

are -- your five minutes are done.

MR. HEUSS: -- city associations are being

used in Chapter 3 to evaluate the range --

DR. SAMET: Jon?

MR. HEUSS: -- potential 98th percentile PM10

standard. Aside from the issues of --

DR. SAMET: Thank you. Your five minutes are

done. Questions?

MR. HEUSS: -- potential double or

triple-counting of -- published single-estimate,

single-site analyses is an --

DR. SAMET: Let's see, Jon, I don't know if

you can hear me; but you're over time and we've lost

you for the last 20 or 30 seconds in any case. Thank

you.

Our next comment is from John Richards, Air

Quality Control Techniques on behalf of the Coarse

Particle Coalition.

DR. JOHN RICHARDS:

DR. RICHARDS: Good morning. I'm John

Richards. I work for Air Control Techniques, which

is a North Carolina based engineering and testing

company. I'm representing the Coarse Particulate
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Matter Coalition. That includes five organizations

shown here, and collectively they represent about

10,000 -- I mean, 100,000 employees.

I appreciate the opportunity today to present

seven points that are discussed in considerably more

detail in our written comments. I'm just going to

cover them as bullet items. If time permits, I'll

return to the first one, but I'd like to go over all

seven in the short time that I have.

Number one, we're concerned that the spatial

nonuniformity of the coarse particulate monitors is

considerably greater than indicated in the Policy

Assessment document, and for that matter,

considerably greater than reflected in the ISA; and

we'll have data to talk about that if time permits.

Number two, the supporting evidence for the

suggestive relationships, we think, is lacking and

could be improved.

Number three, in the Policy Assessment

document specifically there seems to be an

implication in section 3 that globally transported

dust from Asia and Africa is coarse material when, in

fact, it's equally distributed between the fine and

coarse modes, which does affect, I think, how they

interpret the health affects data. So I think that
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should be improved.

Number four, as other speakers have discussed

today, we are concerned about the lack of

compositional data for coarse PM across the country.

We think it's quite different and needs to be

evaluated.

Number five, we think the change in the coarse

standard to the 98th percentile three-year average is

premature given the severe lack of coarse data

specifically available. Until that data is

reviewable, I think it is premature to consider what

form that standard should be in.

Going to point number six, standard setting at

this time or changing that standard based on

insufficient data I think could aggravate already

severe unemployment, which is itself a major health

problem that deserves consideration in a

standard-setting process.

Then our seventh point is the effective

control strategies of coarse, which is going to be

the ultimate direction you go with the standard, will

be very difficult given that the dominant sources in

many parts of the country, particularly portions of

the west and the midwest, are dominated by windblown

dust from arid lands, desert areas or unvegetated
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land, controlled burns and wildfires, unpaved roads,

agricultural operations, particularly harvesting and

tilling, Asian and African dust storms, which affect

both ends of the country, sea salt and pollen. The

industrial source contribution is low in many parts

of the country, which makes attainment of the

standard very difficult. So again, I look beyond

just the standard, to the implementation and are you

going to be able to achieve what you said, and we

have concerns about that issue, as you have heard

from other speakers this morning.

Again, in the few minutes I've got left, just

quickly on spatial nonuniformity, we found very

little data in the ISA, very little, of course, in

the Policy Assessment document. We've looked back at

the AQS and looked at some coarse data. We can

reconstruct more or less from co-located PM10 and PM2.5

monitors in various urban areas. When we calculate

that data and then compare monitor to monitor in

several urban areas, we get something that's not

especially surprising.

In areas, for example, like Pittsburgh,

Los Angeles and Phoenix, when we go and calculate the

coefficient of divergence of that data, for example,

here's the Pittsburgh numbers. We see numbers like
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point 3 to point 48, two of the various four monitors

we had to work with in Pittsburgh, which, of course,

is not sufficient to cover that area. So for PM for

the coarse particulate, we have a coefficient of

divergence of point 4. When we compare that back to

PM2.5, the equivalent number is point 15, which

highlights the degree of difference in spatial

nonuniformity, and that's even before you deploy the

monitors which will uncover more spatial

nonuniformity as these monitors go out to other parts

of the counties not yet monitored. And it will also

get more marked as we get more direct monitors rather

than difference monitors that I don't think anybody

likes especially, so.

DR. SAMET: 30 seconds.

DR. RICHARDS: So again, we think the spatial

nonuniformity in the data creates a lot of

uncertainty in the epi studies, a lot more than is

discussed in the Policy Assessment document and we'd

hope that you'd consider that, and we appreciate your

attention.

DR. SAMET: Okay. Thank you. Questions or

comments?

(No response.)

DR. SAMET: Thank you, Mr. Richards --
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Dr. Richards. Thank you to all of the public

commentors for your input.

Let's see, I think this actually brings us 15

minutes ahead to break, so let me make --

DR. DRECHSLER: Excuse -- did I get missed?

DR. STALLWORTH: Is there another public

speaker on the phone?

DR. DRECHSLER: Deborah Drechsler from the Air

Resources Board.

DR. STALLWORTH. Okay. Our apologies. I

didn't have your name down.

DR. DRECHSLER: I registered to speak two

weeks ago.

DR. STALLWORTH: My apologies. If you want to

introduce yourself, then go ahead.

DR. SAMET: Okay. Please, remember five

minutes, and please introduce yourself and then go

ahead.

DR. DEBORAH DRECHSLER:

DR. DRECHSLER: This is Deborah Drechsler from

the California Air Resources Board. I thank you for

the opportunity to bring the comments of the

California Air Resources Board on the proposed ranges

for the National Ambient Air Quality Standards for

Particulate Matter as were presented in the recently
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released Policy Assessment associated with the

ongoing review of the National Ambient Air Quality

Standards for Particulate Matter. We would like to

express our support for the recommended ranges.

We have closely followed the extensive

technical work done by U.S. EPA on this review and

would like to express our support for U.S. EPA's

recently implemented framework for judging causality

in NAAQS development. This framework provides a

clearer perspective on the state of the health

science literature as a whole, and thus, the more

integrated and transparent basis for the recommended

NAAQS.

The recommended ranges for both the PM2.5 and

PM10 standards are supported by the growing body of

health science literature, which points to a clear

correlation between the adverse health effects and

exposure to PM at concentrations which meet or exceed

the current NAAQS. In addition, the Integrated

Science Assessment indicated that the evidence is now

sufficient to conclude that exposure to PM2.5 is

causally or likely causally associated with

mortality, and with cardiovascular and respiratory

effects, giving increased urgency to provide adequate

protection from PM2.5 exposure.
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U.S. EPA's adoption of more stringent

standards would avoid thousands of premature deaths

in cases of exacerbated cardiovascular disease and

asthma.

We are pleased to continue our participation

in the particulate matter of the standards review

process and appreciate the opportunity to comment on

the recommended standard.

Thank you.

DR. SAMET: Thank you. Any questions or

comments?

(No response.)

DR. SAMET: Okay. Thank you.

So we'll still, I think, stick with the plan

of break until 10:30, so 15 minutes.

Frank, we'll be back in 15 minutes.

DR. SPEIZER: Okay. I'll sign off and get

back on.

DR. SAMET: Okay. Thanks.

(Recess taken 10:14 a.m. - 10:33 a.m.)

DR. SAMET: We are back and we're going to

move along, then, with our review of the comments in

response to the charge -- charge questions.

Frank, are you back?

DR. SPEIZER: Yeah, I'm back. Can you hear
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me?

DR. SAMET: Can you hear us okay now?

DR. SPEIZER: Can you hear me?

DR. SAMET: I hear you, but do you hear me?

DR. SPEIZER: Yes, yeah.

DR. SAMET: Okay. Good. Then we'll start

with Charge Question 1. Rogene?

COMMENTS ON CHARGE QUESTION NO. 1:

DR. HENDERSON: Yes. This is the charge

question that asks what are the Panel's views on the

staff's approach to translating the available epi

data and risk and the air quality data into the basis

for reaching conclusions on the adequacy of the

current standards. My basic answer was the Panel

agrees with the approach. I mean, that's it in the

bottom line.

I was in agreement, and I think others are,

with the good overview of the approach that was

presented in Figure 2-1. I thought that was

extremely well done, very clear and included all of

the major aspects as ones you consider in judging

whether your current standards are adequate. There

are many parts of that we could discuss.

I think it's a good idea to go back to the

approach used in 1997 to consider the annual and
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24-hour standards together and using the annual

standard as a controlling standard and the short-term

standard to supplement the protection afforded by the

annual standard.

I think it's appropriate that they consider,

of course, both evidence-based and risk-based

information as well as --

UNIDENTIFIED PARTICIPANT ON SPEAKER PHONE:

Please speak up.

DR. HENDERSON: -- as well as the

uncertainties associated with it.

The second part of that question was that, has

the staff appropriately applied this approach in

reviewing the adequacy of the current standards and

the potential alternative standards.

Well, if you look at Figure 2-1 and then you

look at the outline of the section 2.3, where they're

giving these -- reviewing the adequacy of the current

standards, it's following that figure exactly; so

yes. The answer to both the questions 1.a and 1.b,

in my opinion, would be yes.

And Frank Speizer is the other reviewer.

DR. SAMET: Okay. Frank? Let's see, Frank,

are you there?

DR. SPEIZER: Yeah, yeah. Are you asking for
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me?

DR. SAMET: Yeah. It's your turn to comment.

DR. SPEIZER: Okay. All right. Well, I would

agree with what Rogene said. The only concern that I

raised was that -- this would be more semantic than

anything else; but on page 2-30, I thought this

language could be even stronger. I mean, it says,

calls into question the adequacy; yet the paragraph

that follows clearly outlines why indeed the current

standard is not adequate.

So I think it's well done. It does follow the

logic; and the logic is really, for some reason, a

lot easier to read this time around than previously.

I think the adding -- and my memory's going now. You

know, I'm getting so old. But I think the putting in

of these questions, the rhetorical questions,

throughout the chapters are very helpful even though

I probably disagreed with that the last time around.

I think it makes the logic much easier to follow, and

I have to really compliment staff on having really

streamlined the data. I think you've done very well.

I think it does meet the criteria laid out in the

questions perfectly. That's all I have to answer.

DR. SAMET: Okay. And I will -- I will add

that I do think the framework that you provided and
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the adhering to it -- I mean, it's one thing to

provide a framework, but it's another to actually

provide one and adhere to it, which you have done, I

think, which leads to a great deal of clarity; and

the flow I think is very clear and far clearer than I

think we've seen in such documents.

DR. SPEIZER: I'm only getting about one out

of every five words from you. I don't know why.

DR. STALLWORTH: Could you mute your line,

please?

DR. SAMET: Frank, were you trying to make an

additional comment?

DR. SPEIZER: No, I wasn't. I'm just trying

to hear you, and I just -- you kept cutting in and

out.

DR. SAMET: Okay. Is it just me, Frank, or

can you hear -- are you having the same difficulty

with others?

DR. SPEIZER: No, it's just with you. I can

hear you now.

UNIDENTIFIED PARTICIPANT ON SPEAKER PHONE: I

think there's a problem with the line being un-muted.

I hear you fine now, but before I was hearing just

every other word.

DR. SAMET: So if everybody on can just make
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sure that your that lines are muted, perhaps that

will take care of the issue.

Others who would like to comment on this

Charge Question 1? Sverre, are you leading up to a

comment?

DR. SEVERE: No.

DR. SAMET: Okay. Anyone else? Okay. Then

we'll move on. Charge Question 2, Phil and Helen.

Phil?

COMMENTS ON CHARGE QUESTION NO. 2:

DR. HOPKE: Okay. The issue here is, in the

previous standard there was an opportunity to average

mass values across all of the measurements in a given

area in order to get a composite value that was then

compared to the standard and the recognition that

there may be disparities in the concentrations such

that a community-wide air quality measurement may

underestimate the exposure in certain areas,

particularly those that are likely to be of concern

from environmental justice points of view. So

therefore, the idea would be that they would now

disallow spatial averaging such that the level would

be compared to the measurement made at the monitoring

site that represents the highest recorded PM2.5

concentrations. This is I think quite reasonable in
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that, obviously, you want to provide adequate

protection for all people in a given area and that if

people in some areas are exposed to higher

concentrations, they are potentially then at higher

risk and averaging down those potential

concentrations by mixing in lower concentration areas

would provide inadequate protection.

My concern or the danger here is that we'll

regress to the old approach of finding highest values

anywhere in urban locations. We used to go hunt for

hot spots and find areas that weren't on the

distributions of population exposures. They might

have been on the distributions of industrial

exposures, but not on population exposures. And so I

think it's going to be very important that in the

monitoring guidance that comes out with the standard

that we in fact mandate that there is in fact a

population that is being monitored and not a

location.

You know, it's perfectly reasonable to protect

populations. It's not appropriate to protect

locations. And so I think taking the highest

measured level of exposure as controlling value in

order to adequately protect all the population is

reasonable, but we've got to avoid reverting to the
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hot-spot mentality that was where we were in the '70s

and '80s. That's going to be finding values which

are inappropriate as a basis for setting up control

strategies and protecting public health.

DR. SAMET: Helen?

DR. SUH: I don't have much to add from what

Phil has said. I think it makes sense to eliminate

the spatial averaging. I agree with that.

UNIDENTIFIED PARTICIPANT ON SPEAKER PHONE:

Please speak up.

DR. SUH: Although not in my comments, but

hearing Phil's talk, I think it also makes sense to

think more closely about the monitor siting issue.

So that's it.

DR. SAMET: Okay. Thank you. Other comments

on this question? Phil?

DR. HOPKE: If I can stick a couple more two

cents in on the form of the standard. Having been

one of the people who pushed hard for a percentile

standard back in the mid '80s, the percentile

standard as currently implemented is still a bit

peculiar in that you're averaging the percentile

values in each of the three years in order to get it,

rather than looking at the distribution over three

years after ensuring there are enough samples in each
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quarter of the three years to have a sensible

distribution.

It really would make a lot more sense to just

look at the overall distribution over three years

rather than looking at individual one-year

distributions, at least until we get to the point of

having adequate data. I mean, it still comes back to

the lack of monitoring system that provides adequate

data since we're only monitoring every third day.

DR. LIPPMANN: At best.

DR. HOPKE: At best. You know, we really need

in this round of standard setting to get off filters

and onto continuous monitors and have the data so

that we can in fact have adequate statistical bases

for making determinations of attainment or

non-attainment of the standard and adequate data to

actually assess health outcomes, and I think it's

time we stop fooling around with filters and get on

with it.

DR. SAMET: Mort?

DR. LIPPMANN: I agree, and I think everybody

who's written comments agrees that -- get past

spatial averaging. But is it something that ought to

be said in that context in that it relates to margin

of safety? Margin of safety is an issue that keeps
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coming up and we never quite come to grips with it in

terms of satisfying ourselves or the Agency or the

public that it's being dealt with; but every place

where in fact the margin of safety is being

introduced, it should be noted. And in fact, getting

away from spatial averaging adds some margin of

safety for some population.

DR. SAMET: Other comments on this?

I want to go back to Phil's comment re:

monitor location versus population average. So it

seems to me this is an important point that we may

not have discussed enough, which is trying to

represent a population, the population's distribution

of exposure, and do the existing monitors do that for

PM in a way that is informative. I mean, we actually

have a historically located set of monitors perhaps

of uncertain representativeness.

So Phil, I think your point in general is

probably well taken and speaks to an ideal; but what

about the actual and where we are now, which I think

is what you're speaking to in part.

DR. HOPKE: Right. I mean, again, the mandate

starting with the '97 standard was to provide

population-exposure-based monitoring; and with the

number of monitors that were mandated plus the
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replicates and that sort of thing, there probably

were adequate numbers of monitors covering most

populations in most urban areas.

Now, as we have identified attainment,

non-attainment, and some of the other things,

everybody has pulled back monitors. And now if we

start to re-look at how we're going to deploy that

monitoring network with a new set of guidance, which

is not going to look at community-wide averaging, but

look at the highest value within that community, all

I'm suggesting is that we want to make sure that we

don't -- that we're still looking at population

monitoring, not hot-spot monitoring in the network,

in that community where people -- where there is not

a significant population.

DR. MARTIN: Can I just provide just some --

mic on -- some clarification of the intent. The

current standard is -- the current 24-hour and annual

PM2.5 standards are implemented in that the annual

standard is compared against concentrations measured

at monitors that represent community-wide spatial

scales. They are not hot-spot monitors. They're

community-wide spatial scales. 24-hour standard is

compared against monitors at a more localized scale,

more consistent with the purpose of the peak
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exposures. And our intent here would be to continue

that same approach, that you wouldn't use a, quote,

"hot-spot" monitor to compare against the level of

the annual standard for the sake of determining

attainment. That wouldn't be consistent with the way

in which the standard was developed and the purpose

of the standard, to capture community-wide population

exposures. So what you're saying is what the current

monitoring requirements say and what we would intend

them to continue to say.

DR. SAMET: Okay. Mort?

DR. LIPPMANN: Making it a more generic issue,

I agree with the discussion; but we're going to come

to it later with the thoracic coarse particles and at

some point down the road with ultrafine particles and

monitoring strategy becomes extremely important, and

I don't think it's explicitly addressed sufficiently

in the document in both Chapters 2 and 3.

DR. SAMET: Okay. Ted?

DR. RUSSELL: So Karen --

DR. SPEIZER: This is Frank --

DR. RUSSELL: -- help clear something up in

terms of what you just said in my mind. So you would

have one set of monitors that you would consider

hot-spot monitors that would not be used for annual
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average attainment demonstration or attainment --

yeah, attainment demonstration.

DR. MARTIN: And that's the way it's currently

done. Monitors are described in part by the spatial

scale that that monitoring location represents. So

we distinguish between community-wide, which is a

much broader spatial scale, and more localized

spatial scales. And the monitoring requirements are

such that one does not compare the more localized

spatial scale, the more hot-spot monitor to the level

of the annual standard for the sake of determining

compliance. That's the way it is now. That's the

way we would intend to continue it. I agree that

this document doesn't speak sufficiently to that

point, and we can certainly add that quali -- that

clarification into the final document.

DR. SAMET: Tom?

DR. SPEIZER: John, this is Frank.

DR. SAMET: Frank, hang on one second.

DR. SPEIZER: The discussion --

DR. SAMET: Okay.

DR. SPEIZER: -- confirms what I put in my

notes. I think what's needed here is a footnote

defining what's meant by community-wide monitors.

It's not clear in the document what that means. And
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I think the clarification of that will go a long way

to understanding that we're not talking about the hot

spots, but we're talking about something that's

representative of the community and, presumably,

either long-range or community-wide exposure. So I

think a footnote would solve that problem.

DR. SAMET: Okay. Tom?

MR. MOORE: So this actually takes me back to

1996 when Phil and others were advocating for the

percentile form, which I think is a good idea. But

the point that Phil makes about looking at the

distribution over whatever the compliance time of the

standard is, is important when you have wintertime

episodes because if they happen across the end of the

year, they get segregated into two different data

sets for the purposes of calculating the percentile,

and you really want to look for both the 24-hour and

the annual at the whole distribution over that period

because that's the period you're establishing

compliance and health protection steps for. So

rather than have this arbitrary thing where data only

exists in a certain year, it's really a three-year

compliance form. We should look at the whole

distribution during that time period. This leads to

situations where you can have very low ambient
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concentrations many days and then you get one peak

episode and it happens to fall across the end of the

year, that area meets the standards, but in fact

is -- has a very unhealthy episode. I can send you

some data that does this calculation, so.

DR. SAMET: Helen?

DR. SUH: Just a clarification question again.

So for the 24-hour standard, though, do you consider

the hot-spot monitors for the 24 hours?

DR. MARTIN: Yes. We consider them as

monitors that represent smaller, more localized

spatial scale in conjunction with comparing them to

the 24-hour standard.

DR. SUH: So then, does every community have

the hot-spot monitors? I'm guess I'm trying to

figure out about this proportion -- going back to

what John had said -- about the proportions of

hot-spot monitors that occur. Is it a requirement

for every city to have one or every large MSA or

community? Because I'm wondering if that sets up the

differential protection for the 24-hour basis.

DR. MARTIN: Requirements relate to minimum

monitoring requirements to monitor the highest

concentration at the appropriate spatial scale as

defined as part of the requirements set out in
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conjunction with the standard itself, so that we're

recognizing that there are different spatial scales

that are relevant. Minimum requirements focus on

monitoring the location where you would expect the

highest concentration to occur at the appropriate

spatial scale, if that answers your question.

DR. SUH: You know, I think it's really more a

question, not so much, I think, how you guys decide

and define it. It's really more a question of where

the monitors are placed now to determine the

component --

DR. MARTIN: What I'm describing is the

monitoring requirements that have been in place in

conjunction with the past standards -- the current

standards, and so that's the direction for the

current network; and we're not envisioning a change

in that aspect of the monitoring requirements.

DR. SUH: Okay. Thanks.

DR. SAMET: And the question of the number of

population-oriented versus local, it seems -- hot

spot, it seems to me that the balance is far more

population than hot spot or a locally source

oriented; is that correct?

MS. HASSETT-SIPPLE: I don't know the specific

answer to that question, Dr. Samet. But in the
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preliminary draft Policy Assessment, where we

provided much more detailed information on air

quality and the monitoring network, has that

information. We'll go back and bring some of that

forward in the final.

DR. MARTIN: We obviously have monitoring

experts who know the answers to those questions. I

don't have the specific answer.

DR. SAMET: It might be good just if we could

refresh our memories while we're here today. I think

that would be helpful and just try and understand

exactly what we're talking about. At least my

recollection is that in working with these data in

our NMMAPS and others said that most monitors are

coded as, quote, "population oriented" and not sort

of source oriented. So it would be useful to know

exactly what we're talking about.

DR. MARTIN: Okay.

DR. SAMET: Let's see, other comments on this

one? And let me circle back then to Phil and Helen

and see, just to summarize, sort of, your bottom-line

positions on this.

DR. HOPKE: I mean, the bottom line is that

what they're proposing, I think, is reasonable

within, as I say, a framework of just making sure
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that when they're putting the guidance together that

they're careful in making sure that overly zealous

local air quality managers are not going out to try

and find the hot spots. As I say, that that was the

approach that was taken in the early days of the

game; and, you know, those are not exposures to

populations. Those are exposures -- those may

represent exposures to the workers working in those

hot spots. So just, we need to make sure we're

careful in making measurements that, in fact, are

relevant to public health.

DR. SAMET: Good. Any other comments?

DR. SPEIZER: Can I make a counter argument

there a little bit, because it seems to me that hot

spots are, not only the workers' exposures, but

they're the gate, sort of, the margin of the gate

exposure as well; and whether or not you're at the

gate, they're getting the hot-spot exposure. There's

a difference between monitoring that for purposes of

control of exposure to a select part of the

population and a community-wide estimate of what the

exposure is for the population in general. So I

think the two kinds of measurements serve different

purposes and it's just a matter of what's being used

to measure compliance in two different settings; one,
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industrial sources versus community-wide exposure.

So I think we can't pick one over the other where the

implementation needs to go. Both are used.

DR. BRAIN: This is Joe brain. I agree with

Frank. It seems to me often poor people live near

these hot spots. I mean, that's very, very common

along roadways or in port areas where there are lots

of diesel trucks or the busses are idling. So I

mean, it's hard for me to think of hot spots in urban

centers where there aren't usually lots of people

living nearby.

DR. SAMET: So we're going to come back to

this issue. I think also the question is spatial

heterogeneity, really, when we talk about the coarse.

I think when we do that, it would be useful, maybe,

if we just had in hand a little bit more information

about exactly the distribution of monitor types and

so on.

So, I think, why don't we move to Charge

Question 3, which has six parts and a lot of, sort

of, meat to these questions. What I think we

probably ought to do is do them A, B, C, D, E, F, and

go through them one by one.

So let's see, Mort, you're in the lead on

this.
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COMMENTS ON CHARGE QUESTION NO. 3:

DR. LIPPMANN: I don't have any significant

comments until we get to F. I thought the staff did

an outstanding job of addressing each of these points

that they were asking for clarification on,

recognizing, as we always must, that they're limited

by available information, that they've examined it

carefully and made appropriate judgments. And the

only thing I would comment on is the last point, that

is the F, the conclusion that they draw. There I

have some differences of opinion.

DR. SAMET: Okay. So why don't we spend some

time on the, sort of, the technical aspects,

particularly A. I understand, Karen, this is the

point where you wanted to comment?

DR. MARTIN: Right. As I alluded to in my

opening remarks, we have done further thinking on

this particular issue that's identified in 3.a.i

about confidence bounds on concentration-response

relationships. As you recall, it was a discussion of

this committee on the first draft. We have -- we

presented what we considered to be something we

focussed on a great deal recognizing the importance

of it. We enlisted the support of our colleagues in

NCEA who developed the Integrated Science Assessment
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to help us search for studies that might provide

information on confidence intervals around

concentration-response functions. And we consider --

based on what we consider to be a thorough search, we

identified the three studies that we discuss here.

Upon reading Dr. Vedal's specific comments on

this point and his concern with how we address them,

we contacted key investigators from those three

studies to better understand what they did and their

views on what they did. And I just wanted to take a

couple minutes and talk through how our thinking has

evolved based on that kind of revisiting of this

issue.

I think there's general agreement by everyone

that these confidence intervals are intrinsically

related to the issue of data density, that

uncertainties increase in some measure with distance

from the mean of the distribution or the reference

point you're using to explore the distribution. The

question then becomes what more can they tell us

beyond what distributional statistics might tell us,

and I think that's sort of the heart of this issue

here.

In looking first at the Pope 2002 study, which

Beth has put up here, we talked specifically to Rick
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Burnett about this, who did these confidence interval

analyses. And basically, his view of them was that

the analyses were done for the purpose of exploring

whether or not they could identify major departures

from linearity in the models being looked at. They

concluded that there were not clear departures from

linearity based on the assessments presented here

and, further, that it wasn't clear to him how one

would use the point-wise confidence intervals around

the distribution to make inferences about the

underlying true concentration-response model without

doing more analyses. And one of the things he

alluded to was, perhaps, model averaging.

Bayesian-model averaging would be one approach

that would allow one to explore more fully the

question, the more fundamental question, of are

these -- whether the confidence associated with our

view of the existence of the relationship continuing

down to the lower ranges of the air quality

distribution, that while one can look at confidence

intervals around the estimates of the mean at each

point across the air quality distribution, and you

can have some confidence about or knowledge about the

uncertainty associated with the degree of risk that

you would estimate across that distribution, that's a
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different matter from having confidence about the

existence of the relationship continuing down through

the full range of air quality in the study.

We then talked with Joel Schwartz about the

second of the three studies we looked at, the

Schwartz, et al., 2008 study. And in particular, we

pulled one specific figure from that study, and

that's the figure you see here. This figure in his

view was clearly a point-wise confidence in the

effect estimates associated with each concentration

along the distribution, that it didn't speak to an

investigation of thresholds. However, he pointed out

in the same paper that they had done a

Bayesian-modeled average analysis.

This Figure 2 that you see here is a figure

that we did not include in the second draft but is a

figure that he pointed us to as being a figure that

reflects, as I said, Bayesian-model averaging across

32 models. Some of those models had options for

thresholds as low as 10 micrograms per cubic meter.

The conclusion of the analysis was that the

assessment clearly chose a linear fit below 10.

There was no evidence of a threshold, but the

observation is that the confidence intervals widen

from 10 and below. The interpretation of this in our
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view, based on the discussions we have had, more

closely represents something that informs the most

fundamental question about our confidence in the

continuation of the existence of a relationship

across the range of air quality in the studies. In

this case, however, even in light of the widening of

the confidence range toward the lower end -- and we

would note that the lower end of the range of air

quality in this study was eight. So that when you

get down to ten, you're clearly in the low part of

that distribution.

For example, one standard deviation around the

mean of this is 10.7. So if you look at the standard

deviation below the mean, it's 10.7 in this analysis.

So that again, this is telling us in part that we

have less certainty where we have less data, but it

is also reflecting confidence around the modeling

averaging across models. And from the investigators'

view and from ours, that seems to provide the kind of

evidence that more closely gets to what the

fundamental question is we're looking to address.

Let me just speak to the third study that we

identified, and that's the Miller, et al. study. And

here again, the emphasis from authors of the study

was on the purpose of the study, was to explore
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non-linearities. The analyses provided no evidence

of a threshold, no evidence that what we were seeing

was the suggestion of a threshold from these

analyses; and the encouragement we received was to

focus more on that aspect of the analysis.

It is also the case in this particular

analysis that the program that they used to run this

assessment required the specification of a reference

value. The reference value the authors selected was

a concentration of 11. Concentration of 11, based on

the information in their paper is a concentration

that is at the low end of the second quintile, i.e.,

roughly in the 21st percentile of their distribution

and that the program necessarily results in the

tightest confidence bounds around that reference

value. So in essence, this is an analysis that looks

at the relative differences of slopes and confidence

relative to a preselected reference point.

So from that perspective, we continue to

interpret this as telling us something about the

likelihood of thresholds across this range of air

quality, but especially in this case because of the

selection of a reference value it's hard to interpret

the widening of the confidence intervals using the

absolute values of the concentrations where those
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intervals widen in this curve because it is

necessarily a consequence of the selection of that

reference value.

I would note that, as I said, that this

concentration of 11 is about just above the 20th

percentile of the distribution. One standard

deviation below the mean of this air quality

distribution is 10.2.

So in revisiting this issue, we're very much

interested, obviously, in hearing your discussion of

these points; but we wanted to put on the table here

the further insights that we got from these

discussions, our further thinking. From our

perspective right now in revising this section, we

would definitely include the second figure from the

Schwartz study and highlight that as an approach that

potentially speaks most directly to the most

fundamental question. I think we would interpret the

other analyses as not being inconsistent with what we

gained by looking at the air quality metrics that

were the distributional statistics from a broader

array of studies that we can identify those kind of

statistics from.

So having said that, unless there are any

questions, I'll stop and let you all discuss the
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points.

DR. SAMET: Okay. Thank you. That was very

helpful. I think the issue of the model uncertainty

versus the distribution of the estimates at points

along the curve is an important distinction for us to

keep in mind.

Let's see, Rogene, and then we'll go back to

Sverre.

DR. HENDERSON: I have a question. In a

linear and no threshold model, how do you handle the

margin of safety part of the Clean Air Act? I mean,

it bothers me that if there's no threshold, how can

you have a margin of safety?

DR. MARTIN: Well, just because there is no

discernable threshold doesn't mean that we don't have

less confidence in understanding the nature of the

relationship as we get to lower concentrations. So

the question about where do we have decrease in

confidence is certainly a salient one to help answer

the bottom-line policy question that you're posing,

but there are different kinds of evidence that have

different kinds of uncertainties and weighing those

uncertainties against the results of these analyses

is fundamentally how we always have to deal with that

issue.
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DR. SAMET: Okay. Sverre, I think you're next

up.

DR. VEDAL: Yeah, thanks. So I guess I could

have commented even on the first current approach,

but it's probably reasonable to start the

discussion on the -- on the discussion of the level.

So I was happy to see that staff had

introduced this aspect of a way to translate epi

findings into -- to provide insight into standards

based on the earlier discussions, and so I have

several issues that that brought up.

The first one I think you addressed, which is

that there was no indication from what was presented

how thorough or comprehensive that selection of

studies was; and I understand from what I'm hearing

from you that that's what's out there. I'm not sure

that's true. I don't have the resources that you

have to do that, but I expect that's right.

DR. MARTIN: We identified studies using PM10.

DR. VEDAL: Yeah.

DR. MARTIN: We identified studies using

ozone.

DR. VEDAL: Yeah.

DR. MARTIN: In talking to other -- the

investigators in these studies, some said, well, I
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think there's more out there; but I don't know for

sure what pollutants they're looking at. So all I

can say is based on what we consider to be a thorough

exploration here, we conclude these are the three

studies that provide this information.

DR. VEDAL: And I think that's --

DR. MARTIN: If anyone has any other examples,

we absolutely welcome having them identified.

DR. VEDAL: I thought there was one from

another, Peters and others, but I'll have to try to

put my hands on it. But that's -- that's fair

enough.

The primary issue was I think where you spent

most of your energy during this presentation

addressing is really how to interpret those so-called

confidence bounds on the concentration-response

function. And I was particularly just troubled by

the statement in the Policy Assessment which was that

these analyses do not provide evidence of a

concentration below which the confidence interval

becomes noticeably wider and uncertainty in a

concentration-response relationship substantially

increases. So I took issue with that statement

because I think they do provide information about

that, and provide insight into that.
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I appreciate the arguments that are being made

here about point-wise uncertainty, whether the intent

is to address linearity as opposed to that issue of

uncertainty. Personally, I think the issue of

linearity and uncertainty are inextricably

intertwined. If you're trying to determine whether

there's a threshold there, that is -- you know, the

information that you're using to determine that is

exactly the issue of how uncertain that relationship

is.

So at the end of the day what are we left

with? We're left with very, very little information

to make use of that. And I understand why one might

want to just discard it all together just on the

basis of there not being very much information there.

I take issue with just tossing it completely because

of the arguments that it provides no insight into

this uncertainty. I think it provides a lot of

insight into the uncertainty.

The issue at the bottom of this is how we make

use of epidemiologic findings for the purposes of

standard setting. And I would argue that what we

would like is, in the epidemiologic studies, where in

the concentration distribution is the oomph of a

study? You don't find that -- you don't find that
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information by looking at the concentration

distribution; right? So you'd like to have -- where

is the oomph along that distribution in terms of

producing the findings that are being produced in

this study? All right. We don't have that.

So the next effort is then, well, what is the

link between the concentrations in the study and the

population sample; how does that link up? There is a

distribution there, and it isn't consistent or

continuous or constant along the entire distribution

of concentrations that you have.

In a time series study, it doesn't matter

because generally they're the same number of deaths

or events on any given day and that distribution of

exposures of people probably pretty much closely

corresponds to the distribution of concentrations

that are being displayed.

I think in a cohort study that's not the case.

You have monitors that monitor concentrations over

space; and what is the link, then, between those

concentrations and what the concentrations are that

the study population -- that link? And if you notice

in that bottom part of the Miller paper, there was an

attempt to do that. They show that little -- well,

they call it histogram, but it's really a density
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distribution of the population by concentration; and

there you get some insight into how those

concentrations link up with the exposures in the

population. Now, that still doesn't get at the issue

about what concentrations actually are important for

the effect estimates, but it's better than just

looking at the distribution of concentrations,

however those are monitored.

If you don't have information on the linkage

between the concentrations and the concentrations of

the population, then you're left with having to do

what you've done, which is basically take the

concentrations that are available in a study and then

do something about the distribution of those

concentrations and argue that those have relevance

with respect to the health effects that are observed,

and that may or may not be the case depending on just

the issues that I touched on. You don't know where

along that concentration distribution the oomph is,

nor where the links are with the population sample of

that study. So that's basically where I stand. At

the end of the day you're left making a lot of

recommendations about the standard on a method that

is a very indirect way of getting at what we really

want to get at. So I mean, that's basically my whole
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issue. And you know, we're now talking about

concentrations that are for consideration,

particularly the annual standard, that are lower than

what were in our, sort of, window earlier, all based

on these distributional arguments.

DR. SAMET: So Sverre, as usual, you were not

crystal clear.

(Laughter)

DR. SAMET: Just to try and capture this a

little bit more -- and I think this has to do really

with how these considerations relate to the

determinations of what levels might be appropriate.

Let's go back to your comments a minute and then I

think go to Chris.

I got a little off on this new technical term

you had introduced, oomph, which I think might refer

to the distribution of population exposure time and

also captures within that the ranges of exposure,

which events are occurring, which in part we lack.

And I think the other issue that -- I think

there are two issues, sort of, that are now

concatenated. One is what is the nature of the

exposure-response relationship at lower levels and,

then, what are the confidence bounds around some

modelled relationship. I think these are all
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considerations related to the confidence one has at

lower levels and I think this particularly relates to

the cohort study. So I don't know, have I captured

this in some -- the issues in some way?

DR. VEDAL: I don't know. I thought I was

clear.

But you know, the oomph issue is, even though

you have a population and you have this linkage

between the concentrations and the population, you

don't know where along that distribution what is the,

sort of -- I don't even know how to describe it,

where the information that actually goes into

influencing the effect estimate.

DR. SAMET: So I think that's what I said,

where the events are and where the population

exposure time is.

DR. VEDAL: Yeah. Now, attempts have been

done to do -- one way of getting at it, and it's sort

of -- it comes from sort of a time series world, is

where people have basically artificially chopped off

upper ends of the distribution and seen if the

effects still continued as they go lower and lower

and lower. That's one way of, kind of, getting at

that question. But there's nothing that we see in

anything presented that would provide that type of
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insight.

DR. SAMET: Chris?

DR. FREY: I'm not sure I have a lot to add to

what's already been said. I kind of struggled with

this section on the confidence intervals because,

just as a reader, it wasn't that clear what the

purpose was or some of the judgments made were, I

think, not expressed very clearly. So some of my

comments are more editorial, and I don't think it's

necessary to go into those in a lot of detail here.

I guess what I'm still struggling with is I

guess it seems like there's maybe a couple of main

ideas. One is the idea that the epidemiological

studies are based on observed air quality and effects

that are really only valid for that range of observed

air quality, and then there's other issues that

Sverre mentioned in interpreting that. And so that

one would be uncomfortable extrapolating the

concentration-response functions to very low average

air quality because that's not part of the

observation in the epi studies. And maybe that

point, if that's what one of the issues is, could be

made more clearly as a key motivation for what this

section's about.

And then another part seems to be what is the
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confidence interval and the concentration-response

relationship at a given value of air quality and how

does that confidence interval change with different

values of air quality. I think what I would have

expected to see in a section like this -- and I think

it's talked about later but maybe belongs in this

section -- you know, is there sort of a bottom-line

judgment as to what effects are statistically

significant at what concentration levels and at what

concentration levels, as you go lower, are the

effects no longer statistically significant but still

positive. And I also think that, just given the

statutory mandate of the NAAQS, which is to allow an

adequate margin of safety requisite to protect the

public health, that the focus shouldn't be just on,

say, the lower end of the confidence interval, but

also on the higher end; and I didn't really feel like

that was addressed at all.

So those are just some general comments. I

have, as I mentioned, more kind of editorial

comments, but maybe that's enough for now.

DR. SAMET: Mort, back to you.

DR. LIPPMANN: I want to get back to the last

item, section F, which takes all the knowledge we

have and all the uncertainties that remain and come
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up with some judgment on what's necessary. But if

there's any discussion on anything before that

perhaps people should speak.

DR. SAMET: Well, I think we need to come to a

little more useful guidance, perhaps, here. In a

way, I think one issue is what is the relationship

between the decisions made under A and what judgments

are offered around F. And I think this has to do

with the interpretation of uncertainty and how

confident one might be in proposing that 13, 12, 11,

or some other value is appropriate, or that reaching

down to the lower end begins to exceed the bounds of

what we actually know. And I think what we're saying

is we know less as we go down one way or another.

We're talking about a relatively narrow range, which

I think is also probably important to remember.

So let me ask first, does anybody else want to

comment on issue A, which is the -- the confidence

bound statistical metrics, the work that EPA has done

in going back to the studies and obtained data from

investigators.

Chris?

DR. FREY: Yeah, I guess I just want to add, I

had some discomfort with the tone of the section

because I guess the way each section's written it's
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almost like we're only going to look at this

information and then decide on levels that should be

looked at. And I sort of don't think that, you know,

part A, sub i, is a sufficient basis to choose

levels. I think it provides information that informs

that choice. For example, to look at the air quality

concentration distributions and say we're going to

look at the 10th to 25th percentile, to me that's not

a reason to choose a level by itself; but it needs to

be coupled with, well, what's the evidence of health

effects. And I think it also needs to be coupled

with some of the things mentioned, I think, even

earlier in the chapter on what are the potential

biases in concentration-response relationships,

what's not accounted for, things like the

socioeconomic status.

So maybe it's an artifact of the way the

chapter is organized, but it almost seems like it's

trying to convey that, oh, this should be sufficient

reason to choose levels; and I think it sort of is

unconvincing to me as a reader because of that.

DR. SAMET: Sverre?

DR. MARTIN: If I could offer a clarification

on that point. Our goal was quite the opposite. Our

goal, as stated up front, was to say we recognize
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there's no one right way to interpret epi to

translate it into a standard. We are going to look

at alternative approaches and collectively look at

what we think they told us. Some approaches build on

more information. Other approaches have more limited

information to inform them. But I think in the end,

our view would be all have some value and we need to

look at it all together. And by laying it out the

way we did, we tried to take one piece at a time, not

to reach a conclusion that any one piece is the right

piece to use, but rather just a more orderly process

of working through it. And if that didn't come

through clearly we can certainly revisit how we

introduce this to make that clear.

DR. SAMET: That introduction might help

because I think this is difficult and challenging

text.

Sverre?

DR. VEDAL: Yeah. No, I -- and what

Karen Martin just said, I think that is a useful

perspective and one that I don't think comes through

here. What I read from this is that, you know, the

concentration-response functions just are not useful

for this purpose and we're not going to use them.

DR. MARTIN: That was --
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DR. VEDAL: Instead, it should be something to

say we should encourage further work along these

lines and for people that present data along these

lines so that they are useful for that purpose. But

I think what you said here at the end is good, that

you are actually integrating all things to look for

consistency to support the arguments.

DR. SAMET: Does anybody else want to weigh in

on A?

DR. SPEIZER: This is Frank. I was impressed,

if you look at page 2-59, the series of three figures

that they represent -- I think they represent

different -- modestly different approaches and they

all at least tell me the same gut story, which is

that until you get down to about 12 micrograms things

are pretty tight; and it's below that level that the

confidence intervals get larger. And it seems to me

that that was a pretty consistent story and might

make for a benchmark to use as sort of what are we

looking for here. What are we looking for in terms

of being able to, sort of, pick a margin safety or

begin to think about the uncertainty slightly

differently.

I think it's a pretty simple-minded approach.

It's not statistical, I suppose, once you look at
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these figures. But it says to me that down to 12 you

can be pretty confident you've got results and then

the question becomes the Policy Assessment of

comparing both margin of safety and uncertainty below

that level.

Now, I guess with the added information that

Karen has brought in, I'm not sure it doesn't support

that even further in terms of sort of picking the way

of going at this.

DR. VEDAL: Yeah, I thought these examples

presented different approaches to qualitatively try

to do the same thing. I mean, obviously, the WHI one

was quite different because of their reliance on a

reference point, which kind of was a little weird.

It already presupposed in some sense something, which

seemed to be one shouldn't presuppose. But

basically, they were different types of methods used

to try to qualitatively get at the same issue.

DR. SAMET: So I think maybe when we get to F,

I think this will come back again in terms of -- and

I think Mort keeps reminding us of this -- it's

really the bottom line here in how the uncertainty

figures in that will be important.

So why don't we leave A, which we might

possibly talk about at greater length without saying
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anything any more useful, and move on to B, which is

potential alternative annual standard levels based on

composite monitor distributions --

DR. VEDAL: Did you forget little --

DR. SAMET: What?

Dr. Vedal: Number ii, A.ii?

DR. SAMET. Okay. A.ii. Okay. Anything

A.ii-ish?

Sverre?

DR. VEDAL: Minor things, I think, in addition

to what we've talked about before.

Now we're in the world of trying to use the

concentration distributions and then trying to say

something useful about the concentration

distributions for setting standards. There's already

been alluded to some issues. I think Phil mentioned

something about terms like, just somewhat below,

those sorts of kind of loose terms, like just

somewhat below the mean or substantially below the

mean, whatever that means. And then this -- I don't

even know quite what this was about, this issue of

trying to support use of a standard deviation versus

percentiles because it's a more robust measure across

the, you know, the various studies. I didn't

understand that at all. I kind of like the
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percentile approach because it translates nicely into

some potential sensitivity analyses you can do or

different scenarios you can explore. But so, that's

all the substance of my comments on that part.

DR. SAMET: Chris?

DR. FREY: Yeah, I agree with that comment. I

think one standard deviation is arbitrary. I would

have been happy to see 10th percentile, is equally

arbitrary, but it -- I don't know. And you know, if

it's one standard deviation, well, why not 1.65 or

1.96 standard deviate. It wasn't that clear if there

was some reasoning for that.

Let's see, I think I had one other comment.

Yeah. Well, this one is sort of like my earlier

comment. It seemed like this part was focussing on

the concentration distributions irrespective of

health effects, and I guess this is looking at the

domain of concentrations that underlies the

epidemiological estimates and it's sort of looking

at, well, we don't -- I guess the idea is that you'd

rather not extrapolate beyond that domain of air

quality concentrations. Maybe that point could be

made a little more clearly to motivate that

particular section. That's it.

DR. SAMET: Okay. Let's move -- I think let's
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spend a little bit of time separately on -- at least

B and C, D and F kind of run together. But comments

on B? We've touched on this a little bit already.

DR. VEDAL: Yeah, we have touched on it

already. I really -- I understand the argument about

margin of safety, I think. What I don't understand

is basing it on this is what's used in the epi

studies versus the form of the standard. I don't

know what should take precedent there, but it wasn't

clear to me that just because they were used as

metrics in the epi studies that had any sort of a

credibility as an argument. Also, when we start

talking about the coarse standard, this argument

doesn't rear its head at all. We're just entirely in

the world of 98th percentile.

DR. SAMET: Phil?

DR. HOPKE: Yeah. I'm not quite sure how we

have a question here because it seems to me that the

level of the standard has to be based on what our

considerations are for the health effects at a given

concentration. And if we're measuring those

concentrations in an area for which a population is

exposed then those people have to be protected. So

I'm not quite sure what the issue is here. We

certainly don't want to adjust the level of the
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standard because we're making higher measurements at

some location where there's an exposed population.

So it seems to me that -- I'm not quite sure how

these two are interlinked particularly. Other

natures of the form of the standard, like the

statistical form, then there's clearly some important

links.

Here, the main thing we're trying to decide is

what is the basis for protecting public health by

making measurements of the exposure of a population.

It seems to me that once you've found a population

that is exposed at a given level, the question is,

are they protected by the standard or not, and set

the standard based on the estimated health effects at

a given -- at given concentrations.

DR. SAMET: Okay. Any other comments on --

DR. MARTIN: If I could ask a clarifying

question on this point, the comment about once you've

identified a level at which effects are seen in a

study, then you want to protect against that level.

Of course, the level in the studies is characterized

by an air quality statistic that is arrived at by

averaging across monitors. It is not arrived at by

looking at the monitor in each of those cities at a

community-wide spatial scale that had the highest
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level. So we're sort of comparing apples and oranges

when you then apply the level of the standard at the

highest appropriately sited spatial scale monitor.

So the discussion about composite versus max monitor

is to recognize that in these studies where we've

identified effects, we commonly characterized the air

quality in the study by the mean of the distribution

based on averaging across monitors, not based on the

highest reading monitors in --

DR. HOPKE: In a lot of studies --

DR. MARTIN: There has to be

some translation --

DR. HOPKE: -- but not in all, you have things

like the Jerrett study where you relate things back

to the nearest actual monitor value; so there are

some data that are out there and, in fact, that

raises the risk estimates. So it seems to me that

this approach still provides, as Mort had indicated,

that additional margin of safety that is worth

including although it may not be quantitatively

characterizable.

DR. MARTIN: And that was the point we were

making in terms of if you were to use the composite

monitor-based concentration that is reported in the

studies and then you set a standard to protect
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against that level and apply that standard at the

highest community-wide monitor, you are building in a

margin of safety; and that was one of the points we

were trying to make in this discussion.

Another way to do it, is to look and

investigate, which we did, what were the

concentrations in the highest monitors that were

occurring at the time of the study and then think

about if you were to use those concentrations how

would you then build in a margin of safety when you

set a standard based on the highest monitor.

So either way you do it, there's sort of a

mismatch between the averaged concentrations in the

study and applying it, comparing it to the highest

monitor in an area. And you can do it either way

with either set of air quality statistics in the

studies, but they represent a different comparison

and the margin of safety considerations are then

different. And that was the purpose of that

discussion, looking at the two different types of air

quality characterizations.

DR. VEDAL: Right, and I think we understood

that.

Just to echo in further Phil's comments about

city averages and such, I mean, even the WHI study
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there, a lot of their oomph was based on, within the

city, nearest-monitor comparison. So even in studies

that are being used in this version have used not

city-wide averages. And certainly future studies are

all going to be like that, try to make use of within

city differences in concentrations rather than the

city-wide mean.

DR. SAMET: Thank you. Let me point out,

we've been joined by Kathleen Weathers. Welcome.

Let's see, other comments? Because what I'm

going to suggest is that maybe we go to, sort of, C

through F together and go over the proposals around

numbers, the confidence in those numbers and so on.

This has to do with, really, I think, much of what's

contained within C through F.

Chris?

DR. FREY: Yes. Just on B, before we go.

There's, I guess, on page 2-73, there's discussion

about ratio between the 24-hour air quality

concentrations and the annual concentrations, and

there's some nice figures. I like the figures that

follow that, but there seems to be a conclusion based

on the figures that it's reasonable to focus on a

24-hour standard level that is 25 times -- or at

least 2.5 times higher than the annual standard level
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and, therefore, it's appropriate to retain the 35

microgram standard. I thought that was a very strong

conclusion that wasn't really supported by what's

presented there.

I think what those figures show is there's

some relationship between the 24-hour and the annual

concentrations and that, maybe, on average the ratio

is 2.5; but from a health effects perspective, I

really didn't understand why 2.5 was a magic number.

And this also goes to, I guess, the notion of whether

the annual standard should be generally controlling.

And maybe -- I wasn't here for the last meeting so I

may have missed some of the discussion on that. But

just as a reader, it doesn't seem consistent to -- or

maybe it's just not realistic that that's going to be

the case everywhere, and I think that's pointed out

throughout the document, that some places the 24-hour

standard probably is going to be controlled as

opposed to the annual standard. So I'm not sure why

it's necessary to say that, but maybe that's a bigger

question than just part B.

But I think the conclusion here on page 2-73,

I think it really doesn't belong there. Maybe it

could be interpreted in some other way, but not as

strongly as how it's presented here.
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DR. SAMET: I guess this comes up in this

peak-to-mean and peakiness stuff, which is sort of

like oomph.

DR. FREY: Well, maybe just one other minor

thing, if the 2.5 is applied, there's a math error in

here, I think, or just something overlooked, that if

you multiply 11 by 2.5 it's 27, not 35. So even that

statement is not consistent.

DR. SAMET: It's plus 2.5 was my

interpretation.

DR. VEDAL: Yeah.

DR. SAMET: Was it a multiplier?

DR. VEDAL: Yeah, so just on another point

that Chris mentioned, this issue of -- it seemed to

me the argument was about the annual standard in

light of the 24-hour standard was in order to

maintain the annual standard as the controlling

standard, if we use this 24-hour standard, we better

use an annual standard of such-and-such. I don't see

that at all.

DR. SAMET: Actually, I think this really

takes us into the general discussion. Let's go back

to Mort.

DR. LIPPMANN: The issue was, you know, the

reasonableness of the recommendation. I thought they
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were reasonable in relation to the criteria

established by the Clean Air Act, those developed

which we reviewed in this process; and you know, it's

been reasonable.

I approach this, personally, from looking at

the Clean Air Act as a precautionary act and that's

why there's talk about a margin of safety and so

forth.

It seems to me that if the confidence bounds

are reasonably tight down to 12 it's unreasonable to

believe that there's a sharp turn at something -- 10

percent below that. So yeah, the lack of

observational data at the lower concentrations

accounts for the widening of the bands, but I can't

seem to find any reason to believe that it's not

extrapolate-able at least 10 or 20 percent below the

bounds where the confidence intervals are reasonably

tight. So then the choices within the options will

need to be based on the Administrator's

interpretation of the Clean Air Act requirement for

margin of safety. In other words, in the absence of

response thresholds, how much public health impact

resulting from exposure to ambient air PM2.5 is

acceptable under the Act. The least protective

option, 35-13, would provide significant additional
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public health benefits in most of the U.S. in

comparison to the current 35-15, and these benefits

would be greatest in the more humid parts of the

U.S., which I won't discuss, but that's what I read

from the various discussions. That may be because

the mass is underestimated in the other parts of the

country.

And so where was I -- oh, the most protective

option would provide significant additional public

health benefits to a larger part of the U.S.

population, and any of the intermediate options --

and any other of the intermediate options. So it

would not prevent at least some adverse effects among

the most susceptible segments of the population.

So my reading of the literature is that any of

the options selected would add public health

protection, but we're not honestly protecting the

sensitive segments of the population even with the

most restrictive standard that's under consideration.

So the decision to be made on the selection among the

alternative levels for the PM2.5 NAAQS will need to be

made judiciously with acknowledgment of its public

health consequences.

As compared to the previous round for PM, it

is no longer justifiable to rely on residual
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uncertainties as a basis for confronting the need for

significant advance in protection. We went through

this last time. We were unhappy that the

Administrator at that time used uncertainty as an

excuse for not protecting the public health in a

manner which I think the Clean Air Act intended. And

uncertainties are still there and will be there five

years hence. They get narrowed, but they'll never go

away; and in my view, the precautionary nature of the

Clean Air Act with its provision that cost should not

be considered, which has been overridden by Reagan's

cost-benefit rule, but still there in the Act, should

be considered.

I'm not advocating going below the range

that's been proposed. I think we're making

incremental progress over the last 30 years in

dealing with PM standards and giving the public more

protection against adverse effects. And since we're

now on a five-year schedule, we don't have to wait

ten more years for more information to accumulate

before we can revisit the issue. The issue will be

revisited within five years, and so I think it's

reasonable to go with the recommendations of the

staff. I would like personally to see them toward

the lower end, not necessarily at the lowest end, but
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toward the lower end as a means of gaining the most

possible public health protection that is reasonably

achievable.

DR. SAMET: Sverre?

DR. VEDAL: Yeah, just a couple of perhaps

different perspectives.

When we met the last time, or it may have been

even the time before, we were talking a little bit

about levels in context of the Risk Assessment and

otherwise; and we were unhappy and uncomfortable with

going below 12. What's changed? What's happened

since that time? Well, we've now been presented with

information that's based on the concentration

distributions. That's one thing. We've also been

presented information based on epi endpoints that

have been classified, characterized as being of a

suggestive causal nature to influence the

concentration range or focus, which I'm not happy

with. I'm basically still in favor of having

something like 12 as a lower bound.

I think the one issue that I would take issue

with, with what Mort said, has to do with that issue

of uncertainty. It's not that you bring up

uncertainty to prevent any changes or suggested

lowering of the standard, but it has to play a role.
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And to say that if we had the data, we would find

that we would have less uncertainty at a certain

concentration. That may well be true, but this is

based on current science and the current information

suggests that we don't have that information.

DR. SAMET: At what point?

DR. VEDAL: 12.

DR. SAMET: 12. So you're distinguishing in

your mind, or are you distinguishing -- I just want

to be clear -- between 13 and 12?

DR. VEDAL: I am.

DR. SAMET: You are, okay. All right.

Chris?

DR. FREY: Yeah, these are some different

points. In going from what's called the evidence

based to the risk based -- and those terms I'm a

little uncomfortable with because the evidence-based

part seemed like it was some evidence but not all

evidence and the risk based includes some evidence,

but that's a semantic thing. There was sort of an

obvious disconnect, which I understand why just given

the history of how the document evolved. But as a

reader it's confusing as to why there were various

annual and 24-hour levels in the evidence section,

and then in risk section some of those are not
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analyzed. And then furthermore, in the risk section

there's some discussion of even a level of ten that

was analyzed but not presented; and having those

kinds of disconnects, I just think would be confusing

to the Administrator.

I guess another aspect of that comment is

that -- and maybe we need to come back to whether 11

is a reasonable lower bound to come to or not. But

just to assume for the sake of argument that it is,

some of the options presented in the evidence-based

section of the 11-35 combination and the 11-30

combination are not analyzed in the risk assessment;

and it would just seem kind of easy to not give them

much weight because there's no numbers that go with

them from the risk assessment. So that's sort of a

framing issue in what gets communicated to the

Administrator. I don't know how plausible it is to

do those risk analyses before the Policy Assessment's

finalized, but I think having some consistency

throughout the document would be useful.

Another comment I have is I like the Figures

2-11 and 2-12 that present the percent risk

reduction, but I do feel like I need to point out, I

think that's irrelevant to the NAAQS. The NAAQS is

not based on risk reduction. It's based on
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protecting public health with an adequate margin of

safety, and presenting risk reductions frames it in a

different way and there are framing effects that lead

to different decision outcomes. So I think it's very

important to frame the results in an appropriate way

relative to the statutory mandate. And I think the

more appropriate risk characterization is not risk

reduction, but it is sort of the absolute risk, the

number of cases in each of those scenarios because I

don't think it's a question of, well, what's the --

we're not looking at marginal benefit and marginal

cost. If we were, then risk reduction would be

useful because we could compare that to marginal

cost, but I think that that's not relevant here.

So I'm not necessarily saying to take those

figures out, but I think something -- either they

need to be replaced or they need to be augmented with

a summary of the bottom-line results for each case.

And I think those summaries need to account, not just

for the best or central tendency estimate, but also

the confidence interval. And perhaps -- you know, I

realize that the 15 areas that were selected for

analysis doesn't represent the entire U.S., but

whether those should be summed up to give kind of a

bottom line, maybe that's something to discuss. But
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I think it's important, given that the standard is

supposed to have an adequate margin of safety to

report, not only the central tendency, but the

confidence bounds of those estimates.

The other thing that I think needs to be

brought up, but I hesitate to make this comment

because I think the document is kind of cumbersome as

it is, but it seems like the risk analysis part is

sort of the bottom-line synthesis that leads into the

final conclusions of the document. And somewhere

near the end of the document we need to come back to

what are the biases that are not quantified in the

risk assessment and does that mean that these

estimates -- do they have some margin of safety built

in, are they biased low, which from some of the

earlier text may be more likely to be the case,

either because of the model forms or it doesn't

really focus on sensitive subgroups and so on. So I

think in interpreting the risk assessment that's

really important.

I think for internal consistency the risk

analysis -- there's an analysis at 14 for the annual

and 35 for the 24-hour, and I don't really recall

elsewhere in the document motivating that particular

analysis. And you know, if staff is not recommending
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14, given that it analyzed 14, it seems like, well,

there just should be some explanation of that. And I

don't feel strongly that 14 should be part of the

recommendation, but since it was analyzed, well, why

is it not being recommended to the Administrator?

And you know, from my perspective it's also not clear

why combinations like 13 and 30 or 12 and 30 or 11

and 25 weren't looked at because those combinations

seem to be potentially motivated by earlier parts of

the document even if not explicitly stated.

And then I think, since we're trying to do C

through E or F as a group, the one other comment I

have is looking at peak-to-mean ratios to inform the

level of the 24-hour standard, I think the document

should give more priority to the health effects

evidence, not the peak-to-mean ratios. The

peak-to-mean ratios help interpret whether the

24-hour or annual standard would be controlling for a

given area. But if the recommendation is that, well,

there are health effects, short-term health effects,

then, you know, is it unreasonable that the 24-hour

standard should be controlling in some cases, which I

think may be appropriate.

That's it.

DR. SAMET: Before we go on to other committee
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members, I just wanted to ask Karen on this question

raised. It's sort of, I guess, consistency between

some of the combinations looked at and levels in the

REA and sort of this more limited set that you've

advanced. Do you want to comment there?

DR. MARTIN: I would be happy to. One thing

we have to remember is that in developing the risk

assessment, this was done over a year ago. When you

lay out the risk assessment that's going to help

inform policy considerations you have to make upfront

choices about what you're going to analyze. This is

resource intensive, time intensive. We make choices.

As we go through then and get a final Integrated

Science Assessment, we get a better handle on

understanding the underlying evidence itself. We

then look to the evidence discussion to help us

refine our thinking on alternative standards that are

most appropriately based on that evidence.

It's sometimes the case that we didn't pick

all the most germane options to run through the risk

assessment. It just is what it is. It's an artifact

of how long it takes to do the analytic assessments

versus trying to use the final information in the

science assessment to inform our review of the

evidence. So it will always be the case that there's
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not a one-for-one match.

The fact that we don't end up reaching a

conclusion to consider the full range assessed in the

risk assessment doesn't mean our considerations

aren't informed by what we did do in the risk

assessment. So I think it's an artifact of just the

relative timing and to do all the different pieces of

the assessment and it would be surprising to me if up

front we picked exactly the combinations that in the

end we felt, when you look at everything together,

are the most appropriate things to focus on. I agree

it's less satisfying, but I don't know how it could

be otherwise.

DR. SAMET: Okay. Rich?

MR. POIROT: I wanted to come to the question

of the controlling issue. I remember many years ago,

when the fine particle standards were brand new,

chatting with John Bachmann and seeing a similar

scatter plot of 24-hour versus annual and just making

the observation that, gee, it looks like 65 is the

perfect number that would guarantee that no site will

ever exceed the 24-hour but will exceed the annual,

and John said thank you. And I think it was -- and I

remember kind of agreeing with him at that time that

it seemed like good policy to actually have, when we
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were just starting out, an annual standard that was

controlling with the logic that that would tend to

seek initial controls over the kinds of sources that

affected average concentrations over broad areas.

Controlling the big sulfur emitters that were causing

the high average concentrations over very large areas

would be a great way to begin the process and would

be the most efficient way to begin the process rather

than going after the more localized sources that

would be contributing in different kinds of locations

to the higher peak concentrations.

But if we look at this scatter plot which

Chris referred to, which is very informative on

whatever -- page 2-75, Figure 2-10. And it shows

that there are a number of points that are pretty

much uniquely in the Pacific northwest or in the

northwestern region that are the ones that have these

high peak-to-mean ratios. And I got to looking at

the data a little more closely for sites in those

regions, and I know what it is for the most part.

That's winter wood smoke under inversions in mountain

valley locations. I know that's what it is because

I've got one myself in Vermont, and we get very high

peak concentrations under warning inversion

conditions in cold weather in the winter. That's
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what those extreme ratios are. And it's not just

wood smoke. It's also gasoline and diesel motor

vehicle exhaust that peaks at rush hour right when

the inversion lid is coming down. All of these

carbonaceous, bad-acting sources and other

space-heating, oil-burning emissions, so that's what

we're talking about when we see those high

peak-to-mean ratios.

Do we still want to be in this mode where

we're saying no, it's the big annual, broad sources

that we really want to focus our efforts on or should

we be looking toward standards that recognize this is

an entirely different set of sources and it's bad in

its own right and it's going to be very intractable,

by the way, to control the emissions of all of those

things under these severe meteorological conditions.

But still, if it's a different effect, I just don't

understand, as Sverre said, sort of, the logic that

one should be controlling over the other.

The other point I wanted to make on that is

that states among -- there are other uses, there are

other ways in which these standards get used aside

from just developing steps to try to attain them. In

the meantime -- and sometimes the meantime is a long

time between the proposal and actually attaining
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it -- states are out there forecasting daily air

quality values and reporting out to the public and

issuing alerts and advisories when extreme conditions

occur, so the -- and action days and asking people to

take protective action, all of which get linked back

to the standards and to the air quality indexes which

are based on the standards and are ratio'ed to the

standard.

So if we keep the 24-hour standard up high at

35 and bring down the annual one because we want the

annual one to be controlling, it's kind of sending, I

think, the wrong message. In fact, the official EPA

guidance on what we're supposed to be doing for the

air quality index and reporting hasn't even caught up

to the 35 yet. Most states have their own way of

doing it anyway. So it's another consideration, and

at a minimum we've got to get that public messaging

more reflective of the extreme short-term

concentrations.

And the last point I wanted to make about

these extreme distributions, not only do they have

high peak-to-mean ratios, 24 hours to annual, they

also have high hour-to-daily ratios. So that we're

getting a real extreme exposure regime to really bad

carbonaceous stuff, and do we really want to say that
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doesn't matter so much? I don't know.

DR. SAMET: Thank you. Other --

DR. MARTIN: I really would like to speak to

this issue. There seems to be a lot of confusion

about why would it be that we would take this

position here given the things you're talking about.

I'm going to start with one general statement.

While the Act is precautionary in nature, the Act

does say the standards are to be requisite. And as

I'm sure many of you remember, we went through many

years of litigation up to the U.S. Supreme Court to

clarify what that means. And what means is that the

standards are to be neither more nor less stringent

than appropriate to protect public health with an

adequate margin of safety.

So one question becomes do we create a suite

of standards that would result in disproportionately

stringent standards across the entire eastern part of

the U.S. for the sake of creating a standard that

would capture really high one-hour or really high

seasonal peaks in the northwest. That's what we're

talking about here.

And I would present to you one policy approach

to addressing the problem you're describing is if we

had sufficient information to set a seasonal
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standard, if we had sufficient information to set a

one-hour standard, we could set those standards that

would directly address the kind of seasonal and

one-hour exposures you're expressing concern with

without creating a suite of standards that would

result in potentially extremely more stringent

requirements across the broad scope of the U.S. And

that's the issue we're trying to grapple with and

that's something that we talked about when we

presented the results of the risk assessment.

If you recall, when we looked at alternatives

where the 24-hour standard was the controlling

standard, you don't have to get very low before you

start producing scenarios where in order to meet that

standard, you're, in essence, driving down the annual

average to quite low levels, indeed, lower than these

levels where we're seeing an expansion of confidence

ranges. So the concern is that we are -- we would be

disproportionately stringent in large areas, in large

urban areas across the country, for the sake of

chasing the tail of the short-term distribution.

The other point I would remind us of is -- I'm

going to try very carefully to say this in a way

that's accurate -- is that when we look at the

aggregated risk across a year associated with daily
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exposures, the bulk of that risk is coming from days

in which the concentrations were around the mean of

the distribution. Only very little of the aggregated

risk across a whole year is coming from days at the

tail of the distribution. So if you use a 24-hour

standard to move that whole distribution, you are

really disproportionately affecting places that have

peaky distributions because they have to move a whole

lot resulting in more much stringent controls

relative to an annual level.

And the other perspective is looking both at

long-term exposure risk and short-term exposure risk,

by far and away the bulk of the risk to populations

across the country is coming from long-term exposure

risk. It is clearly driven by moving the mean of

that distribution down. And so too, the bulk of the

aggregated daily risk across a year is associated

with moving the mean of that distribution down, not

the upper extreme values.

So the concern that making the annual standard

the generally controlling standard is trying to

address is to avoid disproportionately stringent

impacts in large -- the vast number of areas in order

to chase the tail of that short-term distribution

which contributes very little to the aggregated
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short-term risk which in and of itself is much

smaller than the long-term exposure risk. And that

fundamentally is what drove the decisions in '97 to

try to create a suite of standards that would not

ignore hot spots and make it a supplemental

protection, but would address these kind of policy

concerns; and that, again, is what we're trying to do

here. And I just --

DR. SAMET: Think we got it.

DR. MARTIN: -- I didn't mean to go off on a

tangent, but those issues are fundamentally

important --

DR. SAMET: 30 seconds.

(Laughter)

DR. MARTIN: -- from a policy perspective.

Yeah.

DR. SAMET: Okay. Thanks, Karen.

Chris?

DR. FREY: I just wanted to clarify that -- I

mean, I think I understand what you said there, but I

think -- does that presume that the implementation of

the standard would be such that it's sort of a

proportional rollback on both annual and 24-hour

concentrations in terms of control requirements or, I

think from what Rich was alluding to, was that some
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of the factors that might lead to the peaks are not

necessarily -- don't require a change in the annual,

you know, economic activity in a region, that they

might be focussed on specific source categories or

specific events, you know, kind of like we have ozone

alerts now. Well, maybe there's a PM alert in the

winter and you try to do something based on that. So

I mean, I think I understand your point, but I just

wonder in implementing it if it's really that tied

together.

DR. MARTIN: Well, of course, in implementing

it the strategies that will be put in place are those

strategies that seem most effective and efficient to

the states developing the strategies. We're not

going to set those strategies beyond doing federal

measures that are more broad in nature. So we can't

know today how much a strategy in any given area

would be driven by chasing the peak versus lowering

the annual standard. But when we did a whole lot of

simulations and simulating just meeting different

combinations of standard in conjunction with the risk

assessment, using the approaches that we all felt

were most appropriate to consider, you still saw this

real extreme effect when you have the 24-hour

standard controlling.
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DR. FREY: Yeah. I think the point I was just

trying to make is I think that analysis presumed a

certain way -- a response to the standard that might

not be --

DR. MARTIN: That analysis selected three

different ways of looking at it ranging from a very

proportional way to a very --

DR. FREY: Right.

DR. MARTIN -- peak-oriented way, and we looked

across all three different approaches.

DR. SAMET: It also seems to me, though, that

analysis is external to the considerations that we're

really addressing now. I mean, they're really on the

implementation side.

There's important stuff buried here in C to F.

Let me see if there are other comments.

Frank?

DR. SPEIZER: Yeah. I was actually impressed

with what Mort said, the idea that the reason the

confidence interval widens below 12, it clearly must

be related to the lack of data rather than

uncertainty of effects since you wouldn't expect it

to change that much.

Now, what concerns me is that by specifying

what's been specified here, 35-15 -- or 35-13 and
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30-11, because that's what the risk analysis

provided, it seems to me it puts constraints on the

Administrator that shouldn't be there and that, in

fact, somewhere along the way you indicate that this

is about the right range. I mean, I think everybody

would agree these are about the right range. But

those exact numbers are, sort of, within the range or

around the range and that there's some flexibility

about that because of the nature of the beast. As

Karen said, she hasn't been able to do all the

combinations that are possible. I think those

combinations are important for the Administrator to

have as options. She obviously has them, and I think

we have to indicate that we do not force her to use

these particular values. It might be that she will

end up with 25-12 or 25-11 or something else. And

simply because she hasn't provided those data, I

would hope she would not be constrained in not being

able to consider them; and somehow that sort of has

to be said, I think, a little more explicitly than it

has been put at this point. That's about all my

comments.

DR. SAMET: In part, these analyses relate

back to the risk and exposure assessment, amongst

others. I mean, the question of what combinations
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need to be looked at -- and this goes back to Chris's

comment about the importance of the, sort of, the

burden avoided versus the protection provided in

decision-making. We know that the burden avoided by

the nature of the models is something, and how that

figures into decision-making versus the margin of

safety to be provided tend to be quite distinct

matters.

Other comments here? So I mean, in the end, I

think it goes back to Mort's starting point, which

is, I think he said that, in essence, what is the

options. The combinations listed under F are

reasonably supported by the scientific evidence

available. And then after that, I think the

incorporation of margin of safety, which is where the

policy judgment lies, really, then reflects this

integration of uncertainty and the degree of

protection to be afforded and that's the matter of

judgment where the Administrator will have to pick.

Yeah, Mort?

DR. LIPPMANN: Chris raised the point -- which

I think probably ought to be addressed explicitly.

I've already moved into the framework of risk

reduction because the alternative of, you know,

protection of the sensitive segments with margin of
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safety is just not possible. So perhaps we have to

acknowledge that what we're talking about is degrees

of risk reduction with alternative standards and

acknowledge that.

DR. SAMET: So let me make a suggestion -- We

are roughly at past lunch -- that we take -- we

probably need to take an hour break. We break until

quarter after 1:00 and we'll just come back and

revisit this and see if there are others who would

like to make comments on what is a very important

aspect of our discussion.

So let's break until quarter after 1:00.

(Lunch recess 12:18 p.m. - 1:21 p.m.)

DR. SAMET: Okay. We're back and ready to go.

Let's see, I think what we were going to do is I

think Karen has the monitoring team here, and that

one question about the distribution of monitors

between population oriented and -- it's really source

oriented, whatever the coding is, we now have an

answer.

MR. HANLEY: So this is Tim Hanley, and I'm in

the monitoring group of OAQPS.

So there's approximately, last I looked, about

930 monitors that are cited appropriate for

comparison to the PM2.5 NAAQS. And of that 930,
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really all but about a dozen are applicable to the

annual standard as well as the daily. Everything's

applicable to daily if it's applicable to the annual.

So the states and cities are in fact continuing with

the design we had from '97, which was the emphasis on

community-wide monitoring and there's only a couple

unique cases where it's solely cited specific to the

daily standard. EPA did not require states to cite

specific only for the daily. All of the required

sites are emphasized to be community wide, to

represent community-wide air quality.

DR. SAMET: Okay. Thanks. That was my

recollection as well. Questions?

I mean, I think what this means is some of our

earlier discussion was probably perhaps a little bit

overstated in the potential to analyze these

different categories of monitors and address the

questions that we had at hand.

DR. SPEIZER: John, this is Frank.

DR. SAMET: Yeah, Tom?

MR. MOORE: So I'm not going to dispute what

Tim said because I believe that's true.

DR. SPEIZER: -- of those monitors, how

many --

MR. MOORE: It's a rather imprecise
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classification --

DR. SPEIZER: Can you hear me?

MR. MOORE: -- because it sort of depends on

season, time of day, a variety of issues. So

sometimes a community-wide monitor can be strongly

influenced by local sources, so.

DR. SAMET: Yeah, I'm sure that's true.

Rich?

MR. POIROT: So a state then could set up its

own monitor that would not be community oriented to

look at a specific purpose and have that data not

count towards the annual standard determination?

MR. HANLEY: Yeah, Rich. So there's a couple

of things there. So EPA insists in the monitoring

requirements that the sites be set up to represent

community-wide air quality. So if a state in

addition to meeting those requirements wanted to set

up a site to look at a unique source or, really,

anything that you could put under unique source,

whether that be a facility or, you know, some sort of

operation or construction, it can do so. And if the

data are -- if more than two years of data are

produced and the state no longer calls that a special

purpose monitor, then in fact that data is expected

to be compared to the daily standard, yes.
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DR. BRAIN: Do all 930 have both PM10 and PM2.5

and are there any that are doing experimental things,

looking at ultrafines?

MR. HANLEY: It's a great question. The

unfortunate answer is no, there's not a -- certainly

not 930 co-located 2.5 and 10 monitors in that sense.

A fair amount of them are co-located. There are a

few agencies that are pursuing some novel metrics

such as ultrafines.

For instance, South Coast, we just had a

meeting two weeks ago here in RTP, and they are

looking to deploy potentially -- they're certainly

going to deploy one, possibly two, of the TSI

ultrafine monitors in their agency. If we could, we

would probably do a few more.

Other things going on, there's some continuous

chemical speciation at about ten sites nationally.

It is probably not as organized as it needs to be,

meaning some agencies use, perhaps, one instrument

company, another agency might use another. We on one

hand, want to get that organized. On the other hand,

we don't want to get in the way of good work by the

cities and states. For instance, one agency might be

focusing on nitrate. I know that's happening out in

the Utah Valley. Another agency might be focussing
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on sulfate or carbons.

DR. BRAIN: So out of the 930, so you said

they're not all both 10 and 2.5?

MR. HANLEY: No.

DR. BRAIN: How many of each and then how many

are -- do you have any estimate?

MR. HANLEY: We need to get back to you on

that so we can give you a solid answer. Even within

that subset, we would break it out by, of the PM10

monitors, you might be aware there's high volume,

there's low volume, there's continuous. You can

slice and dice it a few ways, and I think we can get

back to you guys on that with a number.

DR. SAMET: Yeah, I think the answer is it's a

minority of them. We did that paper on coarse mass

PM with the Medicare data. It's a minority, I think,

have both and a declining number, of course.

MR. HANLEY: Yes, there is. That's a good

point, Dr. Samet.

So when we looked at the inventory of monitors

over the last several years, it's been steadily

declining, maybe a couple percent a year. But there

was a little bit of a drop off, let's see, in

calendar year 2008 and 2009 on PM10 monitoring. And

that might continue as the Agency -- excuse me, as
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the state agencies refocus their monitoring

priorities with various changes in NAAQS.

DR. SAMET: Okay. Ted?

DR. RUSSELL: So just to make sure it's clear,

if that monitor -- this gets back to the original

question, if that monitor has more than two years'

worth of data, it actually becomes a community

monitor?

DR. SAMET: Okay. That's --

MR. HANLEY: I mean, that's --

DR. RUSSELL: How would you actually have --

is there a way that you would have a monitor that is

showing non-attainment with two years' worth of data

that then would not be used in the attainment

process?

MR. HANLEY: Right.

DR. RUSSELL: So what's standard?

MR. HANLEY: Yeah, let me pick at the words

and make sure we're in the same place here.

So you say community wide. If an agency sites

a monitor next to a unique source and there's a

neighborhood there, we would call that population

oriented. We wouldn't necessarily call that

community-wide air quality.

DR. RUSSELL: But population oriented, okay.
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MR. HANLEY: Population oriented, yes.

DR. RUSSELL: So really, once it's got two

years' worth of data, even if it is a hot spot --

MR. HANLEY: We have a responsibility to use

the data.

DR. RUSSELL: You would have to use that data?

MR. HANLEY: Yes.

DR. SAMET: Okay. Thank you, Tim.

I think what we should do is just turn back to

3 again and make sure we're done.

Mort?

DR. LIPPMANN: While Tim is here why don't we

get some expert information on the coarse particle

monitoring because we'll be discussing that next.

DR. MARTIN: Tim is going to stay this

afternoon. So as those topics come up, coarse

particles, Tim and Joann Rice, his colleague, will be

here to address them at that point if you'd rather.

DR. SAMET: Okay. So let's just revisit 3.

DR. SPEIZER: This is Frank. Can I get a

question in?

DR. SAMET: We had a lengthy discussion on the

specific issues brought up under item A. We sort of

had a very appropriate general discussion about items

C through F, which really sort of feed into the
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bottom line on the recommendations that might come

for the 24-hour and annual max.

So let me ask, are there additional comments

or thoughts now that you've all been fortified by

lunch?

DR. ASHBAUGH: John, I want to say I don't

quite understand the argument or the discussion on

pages 2-73 to 2-74 regarding that graph and the

diagonal lines. If you could explain that a little

clearer, I'd appreciate it.

DR. SAMET: Let's see, Lowell, you mean the

figure -- oh, the figure up there. Okay.

DR. ASHBAUGH: Yeah, the figure that's up

there, Figure 2-10. And in particular, why do you

conclude it's appropriate? How do you come to the

conclusion that it's appropriate to also consider the

24-hour standard of 30 and in conjunction with the

annual standard of 11, how you got to that

conclusion.

DR. MARTIN: Okay. You're asking for

clarification of the discussion that's here relative

to that.

What we were looking to do, as we said before,

was to pick a level of the 24-hour standard that

would provide supplemental protection, while not
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becoming the controlling standard in broad areas

across the country, generally controlling, retaining

the generally controlling annual. And so we're

looking at the ratios here; and if the question is

about the arithmetic of using 2 and a half to 3 as a

ratio, that we would be trying to target for the

ratio between the 24-hour standard level and an

annual standard level. That's basically what we're

looking at, and we're looking at some general ranges

relative to that.

DR. ASHBAUGH: Well, what I see from going

from annual 12 -- what would it be, going from a

12/35 to -- which one is it -- 11/30, that puts a lot

of sites into both the annual and the 24-hour

standard having an effect. Am I looking at that

wrong?

DR. MARTIN: I didn't hear the last sentence

you said.

DR. ASHBAUGH: It looks like to me as if going

from the 12/35 to an 11/30, there are a lot of sites

that then exceed both levels, not so much the 24-hour

standard remains controlling, but a lot more of them

exceed both levels. And maybe I'm just not looking

at it right. I'm not quite sure what -- maybe I'm

just not seeing it.
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If you bring the 24-hour design line down from

35 to 30 and you bring the annual level to the left

from 12 to 11, that just adds a lot of sites into the

upper right quadrant so they're in violation of both

standards. Am I just not looking at it correctly or

why does that mean that the 24-hour standard is

controlling when it would violate both of them?

DR. MARTIN: What we're looking to avoid with

these combination of levels is a situation where the

24-hour standard would either -- would be the

controlling one for the amount of reduction to be

gotten. We don't have the 11 line on this graph, so.

DR. ASHBAUGH: Yeah, I know. I drew it on

myself.

DR. MARTIN: Okay.

DR. ASHBAUGH: Really, if you push the annual

design value to the left, that means more sites are

in violation of the annual level.

DR. MARTIN: Yes.

DR. ASHBAUGH: So that maintains the annual

level is the controlling standard. But if you're

simultaneously pulling the 24-hour design value down,

that puts more of them in violation of the 24-hour

standard as well. So how does it maintain -- how

does it keep the annual standard as the controlling
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standard?

DR. MARTIN: Well, if an area doesn't attain

either standard, then the question becomes which

standard would require greater reduction in order to

meet. So it's a question of how much above the

different standard levels you are in terms of how

much above the annual and how much above the 24 hour

and which is proportionately more above the standard

level than the other.

DR. ASHBAUGH: Okay. I don't -- I can see

where they're placed, but I'm not quite sure how that

is affected; but I'll let it go for now.

DR. SUH: Can I - maybe I can help in some

way, or maybe I'll confuse things even more.

But I guess the way I was thinking about these

lines is they could be sort of seen as quantile

regression lines looking at the upper bound of the

relationship of the scatter plot between the two

endpoints.

DR. SPEIZER: Speak into the mic.

DR. SUH: And so that 12/35 line, basically it

could be seen as, like, maybe the 25th or the 80th

quantile or the 90th quantile percentile of that

scatter plot line ignoring the light blue.

UNIDENTIFIED PARTICIPANT ON SPEAKER PHONE:
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Please speak louder.

DR. SUH: So then what would happen is if you

just go down that 12/35 line and you go down to 11,

you get to a level that's approximate but not quite

equal to 30. So just maybe out of simplicity, it was

the 11/30. That's the way I read it, but maybe it

wasn't quite right. Okay.

DR. SAMET: Okay. Other comments on this?

(No response.)

DR. SAMET: Okay. Thank you, Tim. I gather

we'll be back to you. So let's go back. I'm still

trying to just make sure that before we move on to

Charge Question 4 that there are no -- nothing left

on Charge Question 3. No other comments?

(No response.)

DR. SAMET: Okay. Then we're on to 4.

Sverre, you're the lead here.

COMMENTS ON CHARGE QUESTION NO. 4:

DR. VEDAL: There wasn't much to say about --

at least from my perspective, about point 4. I think

the main thing to note here is, to me this has the

flavor of more, sort of, pointing out future research

priorities or topics rather than necessarily the

uncertainties that influence decisions on the NAAQS.

And I guess the way I think I read in someone's
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comments, not mine, that one thing that this lacked

was some prioritization of topics or points. And I

think that may be one way of getting at that, is what

are the things that we really need to know to reduce

the uncertainties that are relevant to the NAAQS.

And the one point that sticks out in all of the

recommendations is the issue that comes up

perennially is where you make the decision on the

level. And there's only one point that kind of

addresses that, and that's to try to flesh out

information at that lower end of the

concentration-response relationship that we're

struggling with now.

All of the other points, I think, are good

ones. There are things that need to be done from a

research point of view and that will have an

influence on what the NAAQS is going to look like at

some point in the future, but the thing that keeps

coming up again and again is this issue of lack of

data at that part of the concentration-response

function that we need to focus on. And one way of

doing that is, well, we need more data, more studies,

perhaps, that straddle those types of concentrations,

more studies that provide information on bounds of

the concentration-response function.
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So I think I like the whole thing. I like all

the points that are there, but perhaps some bit of

prioritization as to what do we really need to know

for the next round.

I didn't get any comments from others, and

probably just go around, maybe, the other members of

that question.

DR. SAMET: Okay. So I think we have Chris

and Kent on the list as well.

DR. FREY: Yeah. I agree with the idea that I

didn't really see an overview of the key

uncertainties, and I think that would actually be

helpful because it -- I guess one thing that it also

is missing, but it's hard to do, is to really

enumerate what are the priorities for these various

research topics. And if the section started out with

an overview of here are the key uncertainties, maybe

in some priority order by importance, then that would

help prioritize some of the research recommendations.

A couple of comments I had just in terms of

things that are not in the recommendations relate to

setting the stage to be able to model human exposure

in a future revision, which, if you remember when we

started this process for this review, EPA was

planning to do some exposure modeling work, and then
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that kind of got dropped. And I think it would be

desirable to see that move forward for the next

revision.

There are a few exposure things that are

recommended but some that are not recommended that I

think are important. In order to do, say, a

probabilistic scenario-based exposure model activity,

there also has to be activity data to support that.

That exposure needs to take into account human diary

data as to where people spend their time. And there

is a consolidated human activity database -- it's

called CHAD -- that has, I think more than 20,000

diaries. But when you start to stratify that by

gender and age group, and if you want to look at

particular sensitive subgroups, then there are not a

lot of diaries in that database. So I think making

efforts to develop the diary database to support

exposure assessment would be helpful.

A lot of exposure to ambient PM takes place

indoors because of penetration to home,

microenvironments or work, school, bar, restaurant,

vehicle. And there is some data on the penetration

of PM2.5 mass into these microenvironments, but

there's really very little data that allows it to

differentiate by PM concentration, for example; and I
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think that would be helpful.

And likewise, I don't think there really is

much exposure work in this vein going on with regard

to ultrafine particles. So I think if the committee

thinks that exposure assessment is something that we

should see more of, that these kinds of

recommendations should be included.

That's it. Thanks.

DR. SAMET: Kent?

DR. PINKERTON: I agree with what comments

have been made so far. I think it's really important

for a document like this to actually have a section

on future research and data collection needs, and so

I think this is particularly important and I applaud

the staff for putting this into the document.

In terms of priorities, although they're not

listed, I do think that they are reflected in some of

the things that are stated, such as for the

epidemiological evidence. They continue to emphasize

the importance of the fine fraction looking at PM2.5

components, sources and the subfraction, the

ultrafines. And I think those are very good points.

I think it's important, though, that this

seems to have more of a flavor of human exposures,

epidemiological studies; and I think that it is
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important that we continue to consider the importance

in the role of toxicology in better understanding the

biological plausibility and the potential mechanisms

by which things may be occurring.

I'd also like to emphasize the emphasis that

we've placed on ultrafine particles is very critical,

but I think it's also important to even have research

that better understands what happens to ultrafine

particles over time, especially as they may

contribute to PM2.5 through their accumulation. It

does appear that they're emerging in the toxicology

literature, at least, that PM2.5 in many regards has

more of an effect than ultrafines; but again, that's

a very mixed message that we're seeing. But it

continues to become a bit more blurred; and

therefore, I think research needs are critical in

better understanding that relationship between

ultrafine particles and the fine particles.

Although it's not the mission, I believe at

this point in time in this document, I do believe

it's important to consider the co-pollutant

exposures. And again, that's one of the priorities

that is mentioned here; but also exposure-related

factors are important. And the point that I would

want to make is the emerging importance of climate in
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how that may affect PM formation. I know that

there's a very nice part of this in Chapter 3 that

really talks about climate, but I think it's

important for us to keep that in mind in terms of the

emerging research needs, especially as we look at

climate, whether it's cooling or heating up of the

climate and how that impacts on dust generation,

wildfires and even the unrelated aspects of the

length of the season for pollens.

Again, I would just emphasize that in this

research document, although it's not totally

excluded, I think there needs to be emphasis on, not

only the human component, but also the toxicology and

doing studies along those lines.

Thanks.

DR. SAMET: So you were thinking about

California when you were thinking dust storms and

fires?

DR. PINKERTON: Yes.

DR. SAMET: Just, maybe a brief comment, Mort,

then I'll get to you. Actually, I think maybe it was

Chris who said this. There's a section that starts

off in this section we briefly discussed, key

certainties. The discussion of key uncertainties

redefines brief. It's roughly nonexistent. And I
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think if you had really discussed the key

uncertainties, I think in several contexts, then the

priorities would have flowed. I think coming out of

our discussion around items -- everything under topic

3, which really had to do with the nature of the

exposure-response relationship at lower

concentrations if there's a continuation of the

current approach and the same indicators, that just

has to be sitting there as a key uncertainty; and,

you know, whether further epidemiological research

will help give any sharper answers at these low

concentrations, I think, is uncertain, particularly

if we're left with, sort of, the current family of

observational studies for the next review. I mean, I

don't think it's likely that we're going to have a

major new cohort coming at the time of the next

review. So I think that merits some thought and I

think fits in with Kent's comment about don't forget

all the other lines of research that might help us

shore up in a mechanistic basis what the

exposure-response relationship could look like. You

know, there's just a fine list of priorities here.

We've all seen this list before. So I don't think

it's been shaped by what came before, so I think

there should be that table of key uncertainties and
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then what research is needed. If there's going to be

a change in indicator, then obviously there's a lot

of work to be done and that will open up a whole host

of new uncertainties.

Mort and then Joe.

DR. LIPPMANN: I looked at the heading,

uncertainties and areas for future research and data

collection -- I'm glad they mention data collection.

But I'm looking forward, not just to the

uncertainties that we've been discussing, which

clearly need to be addressed, but what will be needed

five years down the road as, are we going to be back

here bemoaning the same state --

DR. SPEIZER: Speak up, please.

DR. LIPPMANN: -- of uncertainty that we face

and, even if that were sharpened up a little bit,

would still be a lot of things to deal with.

And so I'll beat my favored horse again, and

that is the monitoring program. Not only, as Phil

has remarked do we need to move to daily

measurements, presumably instrumental measurements to

get better statistics, but what are we measuring.

The speciation network of fine particles has been

very interesting and has put out some new thoughts

about what needs to be done, but it's still very
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limited. Again, it's useful for the annual standard,

but not for the daily standard in terms of acute

effects of components of particles.

And so I think if we're going to be in

significantly better shape in the next round -- which

is only five years away and not ten years away as in

the past -- EPA needs to move more quickly to decide

what it can do, what resources it will need to find

to do it because clearly this is not a trivial

expense. Do we need to identify those components of

fine particles which are responsible for much more

than a proportionate share of the health impacts.

Obviously, more efficient control strategies to deal

with public health protection could be mounted if we

knew which sources of pollution were most profitably

reduced in terms of the health benefits. And

clearly, EPA's been thinking about this. Beth has

been involved leading in a workshop role in what more

monitoring could be done. And just saying that it's

desirable is not sufficient. Resources need to be

developed.

It looks to me like black carbon and metals

are most likely driving the effects much more than

mass, but we can only speculate on a limited database

about that. So what about the uncertainties and data
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collection going forward. Thinking five years from

now, not just about the issues we've been discussing,

but what would we like to know and that would

significantly change the review of the next round.

Now, having mass standards for components is

not the only way. They could be handled as toxic

components and source controls could be imposed that

way. So it's not necessarily inconsistent to

continue to have mass-based standards based on size

distribution. That's reasonable, but it may not be

sufficient.

But the monitoring should be looked at to

serve several purposes as it is. Why do you have

speciation monitoring in the first place? CASAC

helped endorse that and it's generated useful data.

But clearly, the monitoring should be looked at in a

broader sense than just compliance with mass

standards.

DR. SAMET: Okay. Joe?

DR. HELBLE: Let me just echo what Mort said.

I think, in reading this document, in part because

CASAC asked you to be concise and clear in putting

this particular version together, the document's

structured in such a way, segmented in different

chapters, that makes sense in most places except, in
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my view, in looking at key areas of uncertainty and

future research.

And as I read through this in sections 2.5,

3.5, 4.5, and even wherever it appeared in chapter 5,

there were some themes that I found to be

consistently repeated throughout, this issue of

monitoring, of speciation monitoring or composition

monitoring, frequency of monitoring is applicable in

all of the different aspects that are being addressed

in terms of Primary and Secondary Standards here. So

what I was hoping to get a sense of and didn't was,

since funding's limited, what are the Agency's

overall priorities in getting ready for the next

review five years down the road.

If we looked at each of these sections, if we

looked at them in combination, right, you can lay out

a series of overall tasks and priorities. So what's

most important to answer the broadest number of

questions in getting ready for the next review. And

I don't know if that's something the Agency is

looking at CASAC to provide. I thought it would come

out in the document, and it didn't.

DR. SAMET: Okay. Others on question 4?

DR. SPEIZER: John, this is Frank.

DR. SAMET: Frank.
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DR. SPEIZER: I'd like to speak to this a

little bit. Can you hear me?

DR. SAMET: Go ahead.

DR. SPEIZER: I want to second what just was

said in the sense that what comes across is a laundry

list without -- and a good laundry list, but without

priority. And maybe it is the place for CASAC to

come to some consensus as to what are the sharpest

two phenomenon that needs to be explored, or two or

three that needs to be explored, that will help us

help the Agency five years down the road.

And not -- what I'm concerned about is that

there are two avenues. One is that would say, yeah,

let's help decide what we should do with the same

indicators five years down the road and let's see

what we can do -- that's one avenue. And that leads

to the question of uncertainties and lower levels and

so forth. But the other avenue is what should be the

new approach to what the indicator ought to be, and

that gets us into the question of, in the broad

sense, of speciation and potentially co-pollutants.

And it seems to me, those two categories, if

you -- if EPA hasn't got enough money to solve any of

these problems. But in fact, if we start to go down

the avenue of, in a broad sense, what the speciation
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is, both chemically and size-wise, and explore

co-pollutants, I think we'll move at least in the

direction that I would hope that most people want to

move in.

Now, the question is can we come to some

consensus within our committee that would be useful

as a position to take for EPA, and I don't know what

the answer to that is, whether we can first come to a

consensus or whether it's useful to do it.

DR. SAMET: So Vanessa's going to make some

comments, and I think both your comments and those

that came before highlight a few things. One is that

there is a need for prioritization. Second, that

anything said about PM necessarily really spills over

to the other pollutants and it becomes a broader

question of what scientific priorities should be

around air quality in general.

Vanessa?

DR. VU: Thanks, John.

So I know that within the Agency, OAQPS

interacted with Dr. Dan Costa, who is the national

program director for the air pollution program. He

oversees the research, both intramural and extramural

research program, the ORD, trying to address the next

five, ten years with regard to air pollution
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research, not just only on the criteria pollutant,

which includes PM and ozone and NOx, SOx, but also on

the air toxic side as well.

So besides the Advisory Board has undertaken

the 33,000-foot kind of feedback to the Agency, but I

really think it's useful that I would ask the CASAC

if you are willing to have some kind of a review that

will ask ORD and Dan Costa come in and then you can

really help the Agency look at particularly the

multi-pollutant approaches. I know that's the way --

and monitoring issues and all that kind of issues. I

know that Dan Costa has been talking to the other

parts of SAB, but I think it's useful for CASAC body

to really be on the same page where you all think

it's important.

DR. SAMET: Thank you. Mort?

DR. LIPPMANN: Yeah, I think we're getting

somewhere. CASAC has a unique statutory rule within

SAB and one of its responsibilities, which it hasn't

exercised all that much, is to advise the

Administrator on the need for an adequacy of

standards. And you know, mostly, we get together in

places like this at the request of the Agency to help

them do their job; but to a much lesser extent have

we taken on the charge within the Clean Air Act to
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think about and advise the Administrator on the needs

for clean air research.

DR. VU: Yeah, I agree with you, Mort. And I

will talk to Dan and colleagues and OAQPS on how to

organize something like some kind of advice on the

research needs to really focus on strengthening the

NAAQS review.

DR. SAMET: Okay. And I think it's -- I think

for these comments in particular, I mean, giving some

priorities and laying out the key uncertainties, I

think, giving emphasis to monitoring; but again, also

when we fold this into our comments for you, I guess

you'll be -- believe that maybe there should be this

broader review around the NAAQS, pollutants and

research in general.

Yeah, Bill?

DR. MALM: Just a quick comment since we're

talking about general monitoring strategies here.

One shouldn't forget the cutpoint, 2 and a half

versus 1 or something of that sort or 2 and a half

versus point 9. If you're going to change the

strategy and put out a monitoring system that's

different from what's currently out there now, then

one ought to -- especially if you're going to talk

about a coarse particle standard independent of a
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fine particle standard -- you ought to get the

cutpoint right, and 2 and a half isn't it.

DR. SAMET: Yeah. We've certainly we had some

of that discussion before; and again, that gets back

into the circularity of those of us who do

observational studies look at what's there and

there's this self-reenforcing. But I think we can

make that point again, and that again would be a

useful point if there were this general discussion

you could get beyond the regulatory issues and talk a

bit more about science.

Okay. Let's move on to our Charge Question 5.

Joe, that's you, and your team is down to you and

Mort.

COMMENTS ON CHARGE QUESTION NO. 5:

DR. BRAIN: Yes. So I really want to divide

my comments into three parts. I think the first

point is that the discussion we've been having for

the last two hours is very relevant to the coarse

particles. So all the reservations, the concerns

about the sampling network and how it determines the

health outcome research, it all kind of applies. In

fact, I want to finish up by really underlining the

need for, I think, a subcommittee to address future

directions. So keep in mind that we've already
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talked about many important aspects of the coarse

particle situation.

Number 2 -- Charge Question 5 has two parts,

and the responses from Bob Phalen, who sent in some

comments, and Mort and I are really pretty simple and

straightforward. We think the second draft is much

improved from the first draft and the EPA staff has

really taken advantage of the evidence that's

available, and they really have presented the basis

for reviewing the coarse particle standard.

Of course, as you know, there are inherent

difficulties. Hardly anybody ever mentions measures

directly the coarse fraction. It's usually a matter

of subtracting the PM2.5 from the PM10. And we've now

heard that co-located sampling is relatively rare;

and, of course, that also then spills over to the

health outcomes research. Again, we have to look at

PM10 studies and sort of guess and estimate how much

is attributable to the PM2.5 fraction and how much is

directly attributable to the coarse fraction. So

those are kind of familiar concerns and reservations,

but they're there part and parcel of the data we

have.

And I think the consensus was that Chapter 3

reads well and the EPA staff has done its very best
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to apply the limited amount of specific information

relating to coarse particles. They've extrapolated,

and they've extracted what they could.

B is sort of a related question, has staff

appropriately applied this approach in reviewing the

adequacy of the current standard and then analyzed

potential alternative standards. And again, I think

the consensus was, yes, given the inherent

deficiencies that we've already mentioned, EPA staff

has done its best. And again, there's a good

discussion of how the data is relevant to both the

current standards and to several possible alternative

standards. Again, some of the same things that

you've heard. There are other alternative standards

that could have been discussed; but again, there are

staff limitations. So that's a simple,

straightforward and, I think, positive answer to

Charge Questions A and B.

And the third set of comments is really just

to repeat what I've been hearing and, I think, the

consensus that's been emerging. I think what's

needed is not to beef up and work on the research

needs in this report. I mean, this report is really

about the PM standard and what the Administrator

needs to know to make a decision. I think we really
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need a separate document. We need a separate working

group composed of CASAC consultants and EPA staff to

really sit down and talk about what's needed, I

think, not only for the next five or ten years, but

when you think of -- you know, how long did it take

to really acquire PM2.5 data. So if we were really to

talk about different size cuts and say, yes, one

makes a lot more sense to create an appropriate

sampling strategy, to deploy them, to collect the

data, to get correlated health effects data, we're

really talking about, you know, data that would be in

hand in 10 or 20 years. But it's never going to

happen unless we have a very serious conversation.

So you know, I have a little list of topics

that I think such a committee and such a report would

deal with. Clearly, size cuts is one of them. What

are the devices, where should they be located. The

whole role of ultrafines, again, the EU is moving

ahead with some standards relating to ultrafines. A

lot of interest in composition and speciation; and

again, how do we distinguish crustal dust from

composition products. And even for the ultrafines, a

lot of the very familiar sources such as diesels, if

you look carefully they have ultrafines. And I think

there's a range of opinions as to whether that's a
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serious concern or not. But in any case, we need to

have data, again, both animal tox data as well as

human data.

Another topic that I think is left out of this

report, and I don't know whether it should be at

least mentioned, is nasal deposition. Again, it's

interesting that the coarse fraction is really looked

at in the context of thoracic dose. And we think of

the nose as a filter; and if the particles escape the

nose, either because we've switched to mouth

breathing during exercise or snoring, or -- you know,

we're really saying what fraction of the particles

deposit in the airways and the lungs where the action

is; but I think there's increasing interest in the

nose as a source of injury, inflammation, allergens

that may bind to coarse particles that are generated

industrially. And then even the possibility -- more

than the possibility, the demonstration that some

soluble metals can be absorbed in the nose, go

through olfactory sensory neurons, through the

olfactory bulb to the brain. And so I think this --

again, I don't think we need so much to incorporate

into this report. It's too late for that, but I

think it's an area for future research.

And then going back to the ISA, I think we
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really need to think of what are the health outcomes

that should be targeted for the future. Again, the

ones that I remember as rising to the surface are

premature birth, which is a huge and unsolved problem

in the United States, let alone neurobehavioral and

other reproductive outcomes.

So I think, I really like the way the

discussion is moving and I think we should bite the

bullet and, rather than think about beefing up and

streamlining the research directions, which I'm not

sure the Administrator will have time to look at in

context of deciding about the PM standard itself, I

think CASAC should really come out of this meeting

with a recommendation for a joint meeting that

addresses this list of topics so that 5, 10, 20 years

from now we have the data that we say we need and

want.

DR. SAMET: Okay. Mort? I think you were the

other -- yeah, you were the other commentor on this.

DR. LIPPMANN: I have nothing further to add

now. I reserve my discussion for the final part of

this.

DR. SAMET: I do think we can circle back to

this tomorrow, but in terms of the coarse and, of

course, the PM2.5, I just can't imagine a discussion
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going on five years from now if the science base is

the same where Sverre is sitting there saying, no, I

think it should be 11.5 and not 11.4, or whatever the

extent it is. I mean, at the range we moved into, I

think the discussion eventually really in terms of

protecting health will have to shift to perhaps more

sensitive and refined indicators and methods. I

think the question that's being raised is how do we

get there as we, sort of, I think, in a way, see us

coming to, sort of, the logical conclusion of one

sort of approach as the levels have been driven, have

come down more and more.

DR. LIPPMANN: On that point, John, I think

the cutpoint for fine particles is not a simple one.

What 2.5 does compared to 1 is really relate more to

deep lung deposition and not just the composition.

If you look at it purely in terms of composition and

source origin, then one makes sense except in the

humid east where things grow into the 2 micron range,

at least. That would be as dry particles less than

1.

DR. SPEIZER: Mort, can you speak more into

the microphone?

DR. LIPPMANN: Well, I've got it on. Sorry,

Frank.
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I'm saying that 2.5 is a compromise that's

based in part upon source, but it's also based in

part on where the particles go and deposit within the

respiratory tract. That is, something around 3, 3

and a half is the cutpoint for particles getting

through the conductive airways and depositing in the

deep lung, and then access to the bloodstream is an

important factor and its distribution within the

body. So it's an issue that certainly can be further

discussed and better defined, but it isn't

necessarily true as some people in the Panel think

that we should be purists and cut it at 1 micron. If

we're talking about particles and health, it's more

complex than that.

DR. BRAIN: But I think you anticipate the

outcome of the discussion. I mean, it's also not

obvious that 2.5 is the ideal cutpoint if we were

starting from scratch.

DR. LIPPMANN: No, it isn't.

DR. BRAIN: So I think, you know, you make

good points, but it needs to be discussed and argued.

DR. LIPPMANN: Not argued. Discussed. I

think there are good reasons and we have better data.

Deposition data has grown and improved since the

original decision was made that that was a reasonable
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one.

It was also chosen in part because Harvard had

a 2.1 cut sampler in six cities and we were going

with the available data, which were pretty convincing

that in the six-city study that the effects were much

more closely related to the fines at 2.1 cut than to

the larger particles up to 10 or 15. But these are

all the issues and I think I see a lot of agreement

that these issues need to be elaborated further so

that we're not stuck with the same limited

information base for the next round.

DR. SAMET: I think, just to reenforce the

complexity, Joe talked about the nose, which, of

course, is a site of high fractional deposition of

ultrafines. So again, there's complexities that are

overlooked. I think actually tomorrow we should come

back to the proposal that Vanessa raised having

discussed all the issues.

Why don't we move on to Charge Question 6,

Wayne, which is you.

COMMENTS ON CHARGE QUESTION NO. 6:

DR. CASCIO: So Charge Question 6 relates to

the adequacy of the current PM10 standard, and the

question that's asked is, what are the Panel's views

of the alternative approaches presented for
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consideration of the evidence and its uncertainties

as they relate to the adequacy of the current

standard found in section 3.2.

And Drs. Henderson, Avol and I took a look at

that; and the report is that we all agree and there

was nothing really written of any substance other

than we were in agreement with the dual approach that

was proposed by EPA to look at this.

Just to summarize very briefly, two

alternative approaches were presented. They consider

the scientific evidence and its uncertainties as they

relate to the adequacy of the current standard. Both

approaches recognize the value and the limitations of

existing data, but the first approach emphasizes the

strengths of the associations in multi-city studies

and trends in single-city studies between health

endpoints and that these health effects can occur

even when below the current standard.

This approach gives significant weight to a

significant or a limited number of studies that

generally reported PM10 to 2.5 effect estimates that

remain positive when evaluated in co-pollutant

models. And, likewise, limited controlled human

exposure PM2.5 studies showing decreases in heart rate

variability and pulmonary inflammation that is judged
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to be adequate to support a plausibility argument

between the associations reported in the epi studies.

By contrast, the other approach gives greater

weight to the lack of robustness of the statistical

associations, the limited data and attendant

uncertainties. These include the observations of

positive trends rather than statistically significant

associations between PM10 and mortality and morbidity

in some studies as well as examples of PM10 levels far

in excess of the PM standard not associated with

statistically significant health effects. The

limited number of studies examining the impact of

co-pollutants on human exposures and animal

toxicology studies providing biological plausibility,

while viewed as sufficient in the alternative

approach, is viewed as a potential limitation here.

The challenge of accurate exposure assessment in epi

studies as well as the lack of compositional data is

also viewed as a limitation.

So looking at these two, kind of, disparate

approaches, it seemed very reasonable to use them as

the backdrop for further discussion.

Thank you.

DR. SAMET: Okay. Let's see, Rogene.

DR. HENDERSON: Well, I think Wayne pretty
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much summed it up, all the thoughts that I had.

I liked the fact that they emphasized studies

where they actually had measured 10 minus 2.5 and

they give all the data; and some of the studies are

positive and not significant, some are positive and

are statistically significant.

They presented all of the evidence, I think,

and it was very well written; and then they give

these two approaches. You could either look at it as

saying, well, you know, because some of the studies

showed the significant differences in effect that we

should consider lowering the standard. Or you could

say, well, it's really kind of on the bubble if they

can barely detect these changes; and so we could

consider retaining the current standard.

And so I thought it was well done; and I

appreciated them describing the two approaches

because, in my mind, I was saying, now, is this

really going, you know -- need to be changed or not.

So I thought it was a well written section.

DR. SAMET: Ed?

PROF. AVOL: Yeah, I agree. I think Wayne and

Rogena pretty much said it all.

I just would point out one additional thing,

and that is with regard to the document, which I
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think was very well done. It tends -- by nature some

of the questions asked and the presentation is, in

fact, sort of a reactive sort of document addressing

some issues and dealing directly with them. And as

you've heard, sort of, this ground swell here, I

think we're also asking to look forward to a more

proactive document in terms of looking forward to see

what is needed.

In the case of coarse particles information,

in fact, as Kent pointed out, there are a large

number of monitors out there, not so many of which

actually monitor directly coarses, in fact, sort of a

commingling of the existing network that has some

PM2.5 samples and some co-located PM10 samplers. So

we're faced with, sort of, the challenge of how to

get useful information from both of those, sort of,

coexisting from different instrumentation, different

monitoring, etc.

So I think there are some challenges ahead,

but I do think that in terms of the adequacy of the

current standard and the description and the

discussion for here, this was well done and

appropriate, but I do think we should be looking

forward to how we use what's out there and how we

move towards where we want to be.
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DR. HENDERSON: I just wanted to add, to

emphasize what Ed just said, the composition of these

coarse particles has got to be very important; and we

all know that composition is important, but if we're

going to have a special session on looking at this, I

think -- I push for the still looking at composition

because it's not all particles are equal.

DR. SAMET: So going back, I mean, I think I

just want to rephrase what I think I heard from all

of you and what the document says. What you're

saying is that the evidence hangs in the balance, if

you will, between whether this current standard is or

is not adequate in terms of public health protection.

Is that a comment that -- and okay. Yeah, Mort?

DR. LIPPMANN. I disagree. I think it's

inadequate and we ought to say so.

DR. SPEIZER: Yeah, I think I heard you, John,

say something. You might want to repeat what you

said.

DR. SAMET: Well, I was trying to capture the

essence, Frank, of what our three commentors said and

what, I think, in a sense the document says where

this sentence -- 3-25, Given all the above, a

favorite phrase, we conclude that consideration could

be given to either retaining or revising the current
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standard -- indicating this, sort of, things are sort

of equi-handed in the two -- equi-balanced in the two

hands; and I think that's what Wayne, Rogene and Ed

said.

So what is your point of view? I mean, Mort,

I think, feels that the evidence is inadequate

towards revision, is your comment.

DR. LIPPMANN: Well, the standard, current

standard or its equivalent, if we talk about its

equivalence of 87 or 85, I think it's going to be

inadequate to protect the public health.

DR. SAMET: Okay. I thought you were

referring to the evidence. Okay. That's fine. So

you're saying that the evidence in your view

favors --

DR. LIPPMANN: The evidence is sufficient.

That we have a problem with the levels meeting the

current standard producing effects.

DR. SAMET: Okay. Frank?

DR. SPEIZER: Yeah, and I think that's where

I'm at as well. My concern is that the data that are

presented that relates to 10 minus 2.5 fall in the

suggestive category and that may move people toward

saying, well, we aren't doing anything about it. On

the other hand, there's data that's presented in some
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place -- presented that relates to PM10 says that the

current standard is not adequate to protect. And

therefore, since the PM10 is to represent -- we want

it to represent, which is the coarse fraction, I

think it says to me that we've got to lower that

standard.

DR. SAMET: Helen?

DR. SUH: I think as a point of

clarification -- I was a little bit confused. My

reading of that section was actually that there was

a --

DR. SPEIZER: You're breaking up.

DR. SUR: In the document it says there was

stronger evidence supporting for the retaining of the

standard because my reading of it is the 85 level was

presented as being comparable, given the 98th

percentile, as being comparable to the current

standard now --

DR. SPEIZER: I'm only hearing every other

word.

DR. SUH: -- based on that

one-expected-exceedance. So given that, I thought --

and then given also it said the strongest evidence

was for the 85 micrograms per cubic meter, I read

that section to read that it was really in favor of
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changing the form of the standard but keeping the

basic level of protection the same.

DR. JENKINS: Well, I think the

characterization that the evidence, the decision,

sort, of hangs in the balance, I think, is accurate.

So I think in this section what we're saying is that

depending on -- so any decision that's made on the

adequacy of the current standard is obviously going

to have to weigh the evidence against the inherent

uncertainties. So to the extent you place more

weight on one versus the other, your decision could

go one way or the other. So we don't come down

firmly in one direction or the other in this section

on adequacy.

Now, in terms of the level -- when we get

there we can talk about it, but you're right that the

upper end of that range of levels is -- the way we

characterize it is on average across the country

equivalent to the current standard. So there are

some -- if you look at the evidence, there are some

reasons why it would make sense to set -- if we were

to revise the standard, to set it at that upper end,

again, depending on how much weight that you're

placing on the evidence versus the uncertainties on

different types of studies. In terms of just looking
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at this adequacy section, we don't come down on one

side or the other.

DR. SAMET: Sverre? I thought you had your

hand up.

Mort?

DR. LIPPMANN: Well, clearly I would advocate

going to the 98th percentile for stability reasons.

But then my problem comes in with picking 85 versus

something lower because the evidence is quite clear

that this will be uneven across the country and that

some communities will have greater protection at 85,

98th percentile compared to 100, or 50, 20 maximum,

and others will have less, considerably less for

some. Now, that means that the standard is being

relaxed for some considerable fraction of the U.S.

population. And I don't think relaxing the standard,

in my view -- which apparently Frank endorses -- that

it's inadequate to protect against the effects of

coarse particles; so how can you justify relaxing the

standard, if not for the whole country, at least for

a significant part of the country?

Therefore, I come down with the need to go

below 85; and in my written comments, I said

something in the range of 65 to 75 should be the

proposal. And as an incremental risk reduction
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strategy for this round where the data are not as

clean as we would like, I would be willing to live

with 75 personally, but I don't think we should rule

out 65 as a viable option for the protection of the

public health as long as we're required to have

national standards. If we could go to local

standards that would be a different situation, but

we're not allowed to do that. So I don't see any

justification for relaxing the degree of protection

in the PM10 standard.

DR. SAMET: Scott and Karen, I have a question

a minute, and I think this might be helpful. I've

read what you wrote, but now I want to know what you

were thinking. And I think this is particularly in

regard to how you considered the fact that the

evidence was at the suggestive level. I mean, it

seems to me, there's sort of two parts, two issues

here. One is, are there adverse health effects, and

is the population -- I think this goes back to where

Mort was -- is the population experiencing

concentrations -- exposures of concentrations at

which there may be adverse health effects. So

there's really two issues that are caught up in your

determination of the adequacy. One is the strength

of evidence for adverse health effects and then,
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additionally, the exposures that the population

experiences; and they both figure in to whether

there's an adverse effect, the determination as to

whether there's an adverse effect on public health.

So how did you think this through? And I

think the precedent here is, in part, around how you

handle these levels of evidence where the strength of

evidence is, sort of, now down at the suggestive

range where there's legitimately concern for public

health but less certainty of evidence, in part,

because we just don't have very much.

DR. MARTIN: Scott can clearly speak to some

of that, but I would like to just jump in and comment

on something Dr. Lippmann said before getting into

that question.

You alluded to the notion that if the form of

the standard were to be revised to the 98th

percentile we would see more unequal protection. I

would be inclined to flip that around and say that

when you base a standard on a very extreme statistic,

like the one-expected-exceedance, the consequence of

that is to have relatively unequal degrees of

protection; and by moving to a 98th percentile you

would tend to have more equal degree of protection

across the country. And if you pick it at a level
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that is roughly equivalent, then, of course, some

would be more protective, some would be less

protective; but one of the primary motivations to

move to a 98th percentile form, regardless of what

level you set it at, is to get away from the very

extreme statistic which results in a great deal of

differing degrees of protection across areas. So I

just wanted to offer that observation.

DR. LIPPMANN: Well, I said that as I started,

that I endorse going to the 98th percentile. Then

the question is, what do you do when you make that

decision that the 98th percentile is the way to go.

You have to pick a level. And that's where

apparently I disagree somewhat with the subsequent

decision as to what is the best level where the

document suggested 85 is adequate, and there I end up

disagreeing.

DR. SAMET: We are going to come back to this

question. So why don't we leave this question for

the moment. Is that okay, Phil, or do you have --

DR. HOPKE: Right. But again, the question is

what's the right indicator, and the point is that

we're arguing over the wrong indicator.

DR. SAMET: Okay. I promise you that we have

a question labeled indicator. Okay.
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Back to the adequacy question, Scott.

DR. JENKINS: Okay. Well, I mean, you're

right that when we talk about uncertainties, we're

not only talking about the types of uncertainties

that we typically think of in terms of epidemiologic

studies, we also have the broader uncertainties with

the body of evidence associated with coarse

particles. And frankly, that weighs in, not only in

our consideration of adequacy, but in our

consideration of level, and we can talk about this

when we get to level.

So obviously we have epi studies. We have

single-city analyses that were done. We have the

Bayesian-adjusted analyses from the Zanobetti and

Schwartz study that have -- where we see positive

effect estimates, 10 minus 2.5 effect estimates in

locations that would meet the PM10 standard. So how

much weight do we put on those. Well, I mean, we

have evidence in some locations that are considerably

below the PM10 standard. So you know, if we had

really strong experimental evidence, if we had a

really strong overall database, then we might have

more confidence in some of those associations. We

might be more willing, just conceptually, you might

be more willing to push the standard lower to have
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more confidence in a conclusion that the current

standard's not adequate.

Given that we have the amount of uncertainty

that we do have, that we have suggestive evidence for

10 minus 2.5, you know, there's a logic, I think, to

be made -- a logical argument to be made that maybe

you shouldn't put as much weight on some of those,

the studies in the locations with really low

concentrations.

So I mean, we have uncertainties all around,

and one of the big ones that we're dealing with is

this overall uncertainties associated with the body

of evidence as reflected in the ISA judgment that the

evidence is sufficient to suggest a causal

relationship, but not a likely causal or causal.

DR. SAMET: I mean, I think that was helpful

and I think we shouldn't be surprised that since the

evidence is somewhere -- I'll use a fancy word --

around equipoise, that some people might view it one

way and others possibly would view it another if we

were to, sort of, explore the range of opinions

around the table.

I think in terms of the comments that will

come from this group, I guess, Wayne, I guess the

question is whether you, as you write this, need to
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reflect the fact that there is uncertainty, and I

think the document describes those sources of

uncertainty. Scott just framed them again. The

evidence, if it hangs in the balance, might be viewed

as sufficient from the point of view of public health

protection to move forward; and some might view the

evidence as, in fact, indicating inadequacy of the

current standard. So I think this will be important.

Careful writing will be -- will be needed to reflect

where the science is and the range of views about

where it is, the scientific evidence.

Do others want to weigh in on this? I think

it's an important issue.

Yeah, Helen.

DR. SUH: I don't actually know if this is

helpful, just a clarification before I start.

I was wondering if because the causality, it

was suggestive, the evidence was suggestive of a

causal association, in your mind does that make that

providing a margin of safety in and of itself because

you're including -- including evidence that is not --

there's a lot of uncertainties associated with it, so

it's a suggestively causal, and is that determination

sufficient to provide the margin of evidence in your

mind -- I mean the margin of safety in your mind?
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DR. JENKINS: Well, I think -- and Karen's hit

on this earlier. There's no real formula for how --

determining exactly how to provide that margin of

safety.

But certainly in other reviews, and in the

case of the fine particles, when we look at the

different bodies of evidence for different endpoints

and the weight of evidence, judgments that have been

made about them, we do look at suggestive evidence

and we often look at it in terms of helping us to

provide that margin of safety. But whether setting a

standard based on that evidence by itself provides

the margin of safety, I think is a different issue.

DR. SUH: This one is a little bit different

because for coarse particles, nothing passed -- I

mean, that was the highest level of --

DR. JENKINS: Right. So I think what I'm

saying is it would be part of a decision on margin of

safety; but whether it would be the whole decision, I

mean, I don't know.

DR. SAMET: Although, actually, I think I

would be careful in a sense not to contaminate the

assessment of the strength of evidence with

considerations of margin of safety.

It seems to me that, Helen, your point would
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be whether, in the face of uncertainty as to

causation, action were taken to ensure possibly that

given that there is a risk that protection is

provided. I mean, it goes back. We heard Bradford

Hill quoted this morning. His 1965 paper ends with

his famous quotation about how evidence is always

accumulating and -- something like that -- always

incomplete, and that does not mean that action should

not be taken. And if the potential risks were judged

to be sufficient, even in the face of suggestive

evidence, perhaps, one might take action. But that's

where the policy judgment comes in, I think. I mean,

the assessment of the strength of evidence should be

solely that, based on the strength of evidence

without external potential policy considerations

framing the evidence consideration to the extent that

you can do such with people.

DR. SUH: I mean, I agree with your point.

But the determination of causality was based on the

scientific evidence. So the thing is this margin of

safety is a really vague sort of undefined quantity,

and I guess my question really went to is how does

EPA view it; whereas, when I was reading the

document, I didn't view it that way at all. Then

with the subsequent discussion, it made me think,
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well, perhaps there's alternate ways to think of

margin of safety than the way I had been thinking;

and I was just wondering what the Agency had done.

DR. JENKINS: And I think that what we have

been talking about for the last 15 minutes

essentially gets at that issue that, you know, we

talk about these uncertainties that were really the

basis -- part of the basis for those

weight-of-evidence judgments in the ISA; and those

uncertainties are going to be considered in the way

that's described in the document and the way we've

been talking about in terms of they're going to weigh

on the decisions on the adequacy, on the level if we

were to revise it. So there will be -- those

uncertainties that led to that suggestive judgment

are going to be incorporated into the overall

decision including the consideration of margin of

safety.

PROF AVOL: So just to come full circle again,

I think it's clear that there's some difference of

opinion about what the bases of the arguments are.

Some believe, some don't; but I think the document

has it right. The last sentence is, therefore, we

judge it is appropriate to review the adequacy of the

standards.
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DR. SAMET: Okay. Other comments on 6?

(No response.)

DR. SAMET: Then why don't we, even though it

says after 6 we reward ourselves with break, we

won't; and let's go on to discuss question 7, the

indicator, which is Phil and Ted. Phil, this is just

that, what are the Panel's views --

DR. HOPKE: Right. Okay. 7.

DR. SAMET: Yeah.

COMMENTS ON CHARGE QUESTION NO. 7:

DR. HOPKE: So my feeling is that the PA is

still pushing for continuing to use PM10, and we

obviously have lots of epidemiological evidence for

PM10; but as we're all aware, PM10 is contaminated by

PM2.5 where risks are substantially higher. And the

point is we know how to measure PM10-2.5; and so if

we're going to set standards for coarse particles,

shouldn't we set standards for coarse particles and

not coarse particles plus fine particles? So my

feeling is that it is time for us to move on, that

you know --

DR. LIPPMANN: Felt that last time.

DR. HOPKE: Well, we felt that last time; but

the point is that Petros was right in 1996 when he

suggested that in the first place. And you know,
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continuing to stall around is not helping the

situation. Do we have enough information that we're

happy with PM10-2.5, no. Do we have about the same

amount of information as we did when we leaped off

the cliff and instituted PM2.5, I think we do. And so

the question is, let's hold hands and jump.

DR. SAMET: Ted, can you top that?

DR. RUSSELL: Maybe I'm just not ready to hold

hands and jump like Phil.

So I probably come down with we've got the

information on PM10. I think the reasoning that they

used for the PM10, to stay with PM10 at this point, is

appropriate. I mean, yes, I would love it if we had

all this PM10-2.5 data, you know, and some

compositional information. But at this point, I

would stay more comfortable with PM10 in terms of what

standard we might choose. So I think I'm just not

jumping quite so quickly as Phil.

DR. HOPKE: Well, then we have the problem of

the grossly uneven level of protection it presents

with respect to coarse particles across the United

States. And the only way we're going to have an even

level of protection is to have a standard which, in

fact, measures that which we think is causing health

effects or an overly restricted standard which forces
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excessive measures of control in areas that don't

need it.

DR. SAMET: Sverre?

DR. VEDAL: Intellectually I'm in favor of

what Phil has said. It just makes so much more sense

to be actually measuring and controlling the metric

that we're actually -- of interest here.

I don't agree with his second part. The

problem with -- there's an issue with having a pure

coarse standard and having a national standard at the

same time. A coarse standard exacerbates national

disparities more than a PM10 standard does, which we

already know has national regional disparities.

So I'm torn. You know, intellectually, I --

DR. HOPKE: Would you explain that to me? I

don't understand. I really don't.

DR. VEDAL: Well, all right. So we know PM10

is penalizing places that have more coarse particles

or higher coarse particles because they have higher

PM10 because of that. When you focus just on the

coarse fraction, those places are going to be even

worse relative to places that have a predominance of

PM2.5; right? You're going to have --

DR. HOPKE: But if coarse particles are bad,

then how is --
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DR. VEDAL: Ah, but why are they bad? That's

the issue. So you're going to be penalizing places

that have dust, coarse PM; right? And they're going

to have a lot more coarse PM than places that have

what we might argue would be more toxic coarse PM.

DR. HOPKE: And we know that in the same way

we know about the species in PM2.5 where we have 10

years of speciation data and still can't figure it

out?

DR. VEDAL: Uh, no. But I'm not willing to

take that step to penalize places in the country

where the composition of PM is largely crustal

relative to places where the composition is not

crustal. I mean, you're saying, you know --

DR. HOPKE: You'll penalize the other ones

then.

DR. VEDAL: No. You're already penalizing

places that have more crustal PM based on the PM10

standard. You're just penalizing them less than you

would if you had a coarse standard.

DR. HOPKE: You're still making the assumption

that the places that definitively have more coarse

particles --

DR. VEDAL: No, I don't think I'm being

definitive about that. I'm being --
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DR. HOPKE: -- are ones that have coarse

particles with less health effects, and I think

that's a very risky assumption.

DR. VEDAL: No. If I wanted to maintain that,

I'd do something different; but I think it's safer,

given the evidence that we have, to rely on a PM10

standard.

Now, I mean, I don't like a lot of the

arguments that are being made here to support using

PM10. I don't think, for example, in this one plot

where we've got these ratios of PM10 to PM coarse and

how it changes at the upper end of the distribution

with the conclusion that across much of the U.S., you

know, elevations in PM10 are due in large part to the

coarse fraction. I think that's an overstatement.

Even at the higher concentrations it's 55 percent of

the PM10 mass. But having said that, I'm still not

willing to do, I think, what in essence amounts to

exacerbating the current situation which -- with

respect to PM10, which is not a good one because of

the regional disparities.

DR. SAMET: Okay. Rich?

MR. POIROT: Well, I was just remembering the

last time around when the, sort of, alternative way

of trying to somewhat address the same issue was the
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concept of try and define urban coarse particles

versus non-urban coarse particles; and I was one of

the dissenting few that didn't think we should try to

make that distinction because I didn't think we could

logically do it with reasonable monitoring guidelines

and that sort of thing. So this seems to me to be a

little bit of an attempt to kind of do the same thing

by somewhat more devious means.

It's clearly stated in the document that

that's an intention of using PM10, is that in urban

areas a higher fraction of the PM10 will be fine and,

therefore, the effective coarse particle limitation

in urban areas will be lower, if I read the document

correctly, than it would be in more rural areas where

all of the -- most of the PM -- almost all of the PM10

is coarse. So given the choice of trying to call it

urban versus non-urban coarse particles, I think I

like this approach better for the present time.

DR. SAMET: Helen?

DR. SUH: Well, since Frank isn't here, and

I'd like -- several meetings ago he had suggested --

and I'm just going to bring it up now for a further

discussion -- it's possible to have three -- to

regulate PM10 and coarse, you have three indicators,

the PM2.5, the coarse, and the PM10. You brought that
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up in the last time. I think several sessions ago we

had a similar discussion about the indicator. And I

mean, I agree with Sverre and you that I think it

intellectually makes much more sense to regulate what

you're trying to regulate. So it makes much more

sense to have coarse particles being the indicator.

But given all of the other issues and all the

considerations, Frank, I remember brought up --

Frank, are you still there?

DR. SPEIZER: I'm still here. I'm trying to

remember what I said.

DR. SUH: He brought up several times ago the

idea of having three to sort of get around some of

these issues and some of these areas. And I don't

know practically how that could work out, but it is

maybe something to think about.

DR. SAMET: Frank, are you there?

DR. SPEIZER: I'm here. I'm trying to

remember what I said.

DR. SAMET: Well, maybe Helen remembered it

better than you will.

DR. SPEIZER: She's younger.

DR. SAMET: Do you want to comment on this

issue?

DR. SPEIZER: Well, you know, the concern I
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have is that we don't have -- I don't think we have

sufficient data to be able to, sort of, battle the

battle that will have to be fought for PM10-2.5 direct

health effects, that suggestive data; but we've got

an overwhelming supply of PM10 data. Now, how we

resolve that, I just -- I mean, I think it would be

nice if we could go to PM10-2.5, but I think we'd have

trouble defending it.

DR. SAMET: Just a comment, remembering 1996,

I guess along with Phil, where at that moment PM10

was, of course, telling us about PM2.5, which was the

indicator that we were going to move to to deal with

fine particles, roughly, with very limited health

data coming directly from PM2.5. Yeah?

DR. HOPKE: How is it different now?

DR. SAMET: Yes. There was very limited data,

and in some ways here the question's a little more

complex about the size cut and the biology. I mean,

here at this point, at least, there is an interest in

this particular size fraction. Then the question is

whether it's ready to be measured directly or to

continue with a surrogate that is a variably valid

surrogate across the country with these other issues

captured.

I guess the other point in this sentence of
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3-29, we further conclude that consideration of

alternative indicators (e.g. PM10-2.5) -- this is at

the top of the page -- in future reviews is desirable

and could be informed by additional research as

described below (section 3.4) -- I think you actually

mean section 3.5.

And I mean, you know, there it says things

like study PM10-2.5, but that's not going to come on a

very rapid time frame. And even thinking about five

years -- this goes back to Vanessa's point earlier

about taking a more broad and integrated look at

this -- at the issue. I'm not sure that this

so-called new research will move anything forward on

the coarse mass on the five-year time frame, and I

don't know about the ten-year.

So we'll do Mort and then come back to you

Scott. Mort?

DR. LIPPMANN: I'll take you back further in

time. Go back to the mid-1980s when we made the leap

off the cliff to go to PM10 as opposed to something

called total suspended particulate, which it never

was, and there was extremely limited data. In fact,

you had to look at monitoring data from the limited

research studies and come up with something

equivalent at that point to give protection.
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The mistake EPA made was switching from the

dichot to the single filter. If it kept using the

dichot and sharpened it up and improved it, we'd have

lots of data now, and that's really -- and it's

probably not too late to consider going back for

something like that. In fact, to the extent that

there are networks of continuous monitors going into

place, they should be a dichot version so that you

can continuously monitor automatically co-located

samples. They'd be in the same housing, and so

that's something in the broader context of advances

in gaining information that needs to be considered.

On the other hand, I think for practical

reasons I'd be willing to stick with PM10 as the

indicator in this round, this late stage of this

round for the reasons that the document supports.

But my enthusiasm is limited and it's conditioned on

getting to something better for the next round.

DR. SAMET: Scott, did you want to --

DR. JENKINS: I just wanted to remind everyone

that we did finalize an FRM for 10 minus 2.5 in the

last review and we do expect those monitors to be up

and running by the end of this year. I don't know if

Joann and Tim can comment on this.

DR. HOPKE: Yeah, except it's the wrong FRM.
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That's a case where you made up your mind and then

ignored our advice.

DR. VEDAL: And I'm not sure I would be quite

as pessimistic about in future research on the coarse

fraction as you paint it. You know, there are a

number of studies coming down the pike that are

focusing on the coarse fraction that we should have

information on well within this, sort of, five-year

time frame.

DR. SAMET: Okay. Vanessa wants to tell

you -- she thinks we're past the -- let's try and see

if we can close out the one indicator before we take

a break. We can come back and revisit.

I think we've heard a range -- I will say a

range of opinions from leap off the cliff to don't

leap off the cliff to there are pragmatic reasons to

stick with PM10, which I think is sort of the dominant

weight of the arguments in the document.

Anybody else who has not expressed a point of

view who wants to comment here?

DR. HENDERSON: I would like to ask a question

of the EPA. If you set the indicator as PM10-2.5, if

we leaped off the cliff -- I mean, could you do that?

Do you have enough information to even see if the

standard was being met?
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DR. JENKINS: Well, we do have some co-located

monitors, PM10 and PM2.5 monitors. There are issues

with the sampling protocols in terms of the

consistency between the two types of monitors. So

just for perspective, thinking back to the ISA, and I

can't remember the numbers of monitors, but the PM10

network, for example, the fine particle network, for

example, covered something like 40 to 50 percent of

the population in the cities that were evaluated.

And if you look at the co-located monitors, you use

the same sampling protocols. It was something like

less than five percent of the population. So it's a

really limited number of co-located monitors in terms

of the population coverage.

So the answer to your question is I'm not sure

off the top of my head. And Tim may want to add

something to that.

MR. HANLEY: I think the thing I want to add

is that whatever the CASAC decides in terms of

recommendations back to the Agency on setting the

standard, that's one issue and that's separate from

the logistics of the monitoring network. In the

logistics of the monitoring network, I think the

point I want to bring up is that when you think of

PM2.5, they tend to be at neighborhood scale; and when
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you think of PM10, they tend to be at middle scale.

That's why we don't have this largely one-to-one

relationship between PM10 and PM2.5 monitoring.

But there's no issue if the Agency were to

choose to implement a PM10-2.5 network as a result of

this review, there would be no issue with setting

that standard up from a technology standpoint. The

technology exists. And, you know, if Bob Vanderpool

were in the room, he'd be telling us how great

dichots and FRM's actually compare to each other, and

he has a study on that or a report that he'll be

making available. But you know, separate out the

technology from the need. The technology's there.

MR. MOORE: John, can I just --

DR. SAMET: Yeah, Tom.

MR. MOORE: Can you just define -- because you

used two terms, neighborhood and middle. Can you

just define those so everybody knows what you're

talking about?

MR. HANLEY: Sure. Thanks, Tom.

So when you think of neighborhood scale,

you're thinking of dimensions -- I think it's from

about a half a kilometer to four kilometers, is kind

of the canned language we use in the regulation. And

you're thinking of areas in a city that are
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relatively homogenous across the city.

When you're thinking of middle scale you're

thinking of areas that are on the order of, I think

it's, like, about a hundred meters to half a

kilometer and you're thinking of, sort of, peak

concentrations where there would be locations in

addition to the fine particles, the increment of true

coarse particles that are causing that location to,

in fact, have exposures of a substantially higher

concentration.

So the design of the network is, in fact,

different; and if we choose to go down this route, we

would address that in the monitoring design. But

again, that can be done. We'll never get a hundred

percent co-location. And if EPA were to do this with

the states, we would offer some flexibility to the

states on which designs because Joann just reminded

me that we have approved dichots now for 10 minus 2.5

and we have approved upper ends for 10 minus 2.5.

So there's some flexibility. And again, the

technology's there, but the design of where we site

would be a little bit different unless you as a group

spoke to that and insisted on something.

DR. JENKINS: And just to make one

clarification just to make sure everyone's on the
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same page, the availability of the technology is one

issue. The availability of existing data on which we

would base a 10 minus 2.5 standard right now is

another issue.

DR. BRAIN: Can we have our cake and eat it,

too? Why don't we affirm the PM10 standard, but also

say that as rapidly as possible EPA should deploy

dichots and begin accumulating direct data on the

coarse fraction.

DR. SAMET: Well, they did make comment -- I

guess it's two thousand -- by 2011 that the NCore

sites --

DR. JENKINS: That's right.

DR. SAMET: -- that will happen.

Ted, do you have any comments on this?

DR. RUSSELL: On what, main question?

DR. SAMET: No, this one, the indicator

question.

DR. RUSSELL: In terms of --

DR. SAMET: Mic on, put your mic on.

DR. RUSSELL: Oh, sorry.

In terms of what's viable or in terms of -- I

think as I said to Phil, is that I'm just not ready

to -- I think we have the technology to do the

measurements and all of that. That's not a problem.
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I just don't think that we have the -- I probably

fall in Sverre's and, well, definitely Richard's

camp, that I prefer this versus -- going this

approach versus trying to say that urban PM is -- PM

coarse is harmful whereas rural PM coarse is not.

So were you asking that or versus the

technologies and measurements? I wasn't sure.

DR. SAMET: I think both because they are

caught up with each other in part, so.

DR. RUSSELL: No, I mean, in terms of

monitoring, we will be able to do it. I don't think

that's a problem down the road, but I don't think we

have the database currently. It's not nearly so

strong as the PM10. So I don't think I'm answering

your question.

DR. SAMET: Well, let's go back just to wrap

up, and I think we'll take a break and maybe revisit.

Phil, I mean, if you were writing the comment,

you would say it is time for the Agency to jump off

the cliff.

DR. HOPKE: No. Again, I mean, if I'm

outvoted, I can write something that reflects the

committee. But I mean, my personal feeling is that

at this point we know enough relative to where we've

been with other kinds of standard-setting processes
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to say that we should be fixing our attention on that

pollutant for which we have decided there is a need

for control and not for something where we can't --

where we're inferring what that coarse particle is

based on a measurement which includes a variable

amount of some other pollutant which we know is more

toxic in general.

DR. SAMET: So I think it would be fair to,

with this discussion -- and I think this is at least

my view of what I've heard and part of what I've read

is that the evidence, from the technological

standpoint, making the measurements is possible. The

method is going to be implemented. And really, the

question is, if now is not the right moment for

making the switch, it is very soon that it should be

made.

DR. HOPKE: Well, it just shows you

epidemiologists are getting greedy in your old age

and you want too much data.

DR. SPEIZER: Maybe in my old age I'm becoming

more --

DR. SAMET: In whose old age?

Let's see, yeah, Rich.

MR. POIROT: To add to Joe's recommendation,

we sort of are talking like we're standing on the
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verge of this dawn of the great new age and we'll

have all this very helpful new PM coarse data in the

very near future. I think it would be very important

for us to advocate the importance of that; but in

doing that, I really think we may not actually be in

a position, once we have that new PM-coarse-mass only

data, to actually get back to the heart of the

problem of the relative toxicity of different kinds

of coarse particles. So to me, the speciation and

other kinds of information about the coarse particle

is as important as the mass.

DR. HOPKE: Well, we can get to that with the

key uncertainties. But I mean, one of the big

problems there is that you now need to also be

looking at things which we cannot look at in terms of

a large-term network like primary biologicals.

DR. SAMET: Okay. Sverre, last word before

break.

DR. VEDAL: Just a small word. The studies

that I'm alluding to that were funded by EPA, the

next wave of studies, actually has a focus on coarse

PM speciation, including biologicals. And I don't

want to be a child in the woods and appear overly

naive, but I think there's a prospect that we're

going to learn some substantial things from those
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studies.

DR. SAMET: Okay. A 15-minute break.

(Recess taken 3:01 p.m. - 3:20 p.m.)

DR. SAMET: We're back. Frank, are you with

us?

DR. SPEIZER: I'm with you.

DR. SAMET: Okay. Good.

Before break we were on indicator; and we had,

I think, a discussion that covered a wide range of --

well, there's only two points, there's only two

options, really, I guess, the jump-off-the-cliff

option or not-to-jump-off-the-cliff option for the

moment; and the issue is one of timing. So just on

this -- you know, I'm actually going to suggest that

we move on to form and that, of course -- I mean, all

these run together. So yeah.

DR. WEATHERS: May I ask a question before you

do that?

DR. SAMET: Sure.

DR. WEATHERS: I'm luckily not encumbered by

history here, so I wanted a bit of clarification.

The jump-off-the-cliff version was advocated in part

because that's what happened in the past, and I just

wondered whether there's a difference in the policy

environment now. If there's not --
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DR. HOPKE: Well --

DR. WEATHER: If there's different --

DR. HOPKE: -- we made the judgment in 1996

that even given the high degree of uncertainty

because of the limited number of studies, there was

sufficient compelling evidence that we should go head

with the PM2.5 standard.

DR. WEATHERS: Right. Yeah, I understand the

argument.

DR. HOPKE: Now, in nineteen -- in 2006, we

also agreed there should be a coarse particle

standard, although we got hung up on this urban/rural

mixup that unfortunately we weren't able to ever

dodge around and so that got us into severe troubles

because we really didn't have any information on the

relative toxicity of urban and coarse in a way that

made it possible to distinguish one from the other.

But the recommendation that went forward in the

setting of the 2006 standard was to set a coarse

particle standard. So we are in fact backsliding in

this round.

DR. WEATHERS: Right. But what I thought I

understood was that you were going down a parallel

argument line, so that we don't currently have any

more or less data than you had in the past to make a
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decision.

DR. HOPKE: I think we probably have slightly

more data than we did with the PM2.5 on PM coarse and

we're in a position that we could say we would be

better off -- again, because of the known problem of

differing amounts of PM2.5 for a given amount of PM10,

it means our current standard is unequally protective

of the onsite coarse fraction. So the argument

there, should we be measuring that which we think is

driving that set of health effects.

DR. WEATHERS: Right. But my question,

though, is has the policy environment changed. So

the requirements for jumping off the cliff from a

data standpoint seem not to have changed, at least

from some perspective; but has the policy environment

changed.

DR. HOPKE: I expect this administration would

look at these issues in a somewhat different manner

than the prior administration.

DR. SPEIZER: Well, it was the prior

administration in '96, so.

Phil, do you recall whether or not in '96 --

and I'm thinking in terms of -- what I can think of

in terms of '96, was Dockery, et al., whether we had

more than suggestive data that 2.5 is dangerous?
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DR. HOPKE: Again, we had -- no. Because

again, there was all the arguments about the way the

statistics were done because you were looking at the

differential of effects per unit, mass against mass

giving you this straight-line behavior.

So one of the arguments that George Wolff gave

me as to why I should get on to the CASAC was, you

know, you've got all these epi people doing strange

statistics to try to come up with justifying PM2.5.

So no, I don't think, you know, there was any firmer

ground back then than the quicksand we're treading

now.

DR. SAMET: But Phil, I mean, I want to remind

you as possibly one of those strange epi people that,

I mean, in both cases there's strong grounding and,

sort of, knowledge of where these particles go and

where they deposit. I mean, in both cases you can

make very rational, compelling dose, et cetera,

driven arguments, and I think equally in '96 and now,

PM2.5 then, PM10-2.5 now.

DR. HOPKE: Right.

DR. SAMET: So I mean, it just seems to me,

while everything should be grounded in epidemiology,

there are certainly many other considerations. That

was a joke, by the way about the -- I mean, just --
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DR. HOPKE: Right. So I think it's a pretty

parallel situation.

DR. SAMET: Yeah, I agree.

Okay. So we're going to move on to form and,

I guess, this is, of course, a little bit complicated

by indicator. But Phil --

DR. HOPKE: And level.

DR. SAMET: And level. So it's almost hard to

separate -- sort of, it's hard to separate 7, 8 and 9

in any way.

COMMENTS ON CHARGE QUESTION NO. 8:

DR. HOPKE: Again, let me provide some quick

history. I got into this game in 1981, when the

American Iron & Steel Institute wanted me to look at

the form of the standard, which resulted in this '84

paper that I reference in my comments, in order to

try and get the EPA to set a 98 percentile level at

the same concentration as the expected exceedance

level, which would, of course, weaken the standard.

Now, the point is that the percentile standard

is a much more robust statistical approach in terms

of at a given 90 percentile value you get much better

power, you get lower Type 1 error. So in terms of

both being protective of public health at the level

you choose to have and the probability of
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misclassifying an attainment area as non-attainment,

the percentile standard works much better. Now, the

key then is how many of those exceedances are you

going to -- or you know, exceedances of what value

are you going to have in order to have the

distribution have the kind of reduction in health

effects that you really want.

So there's an interaction here or an interplay

between the level and the form of the standard that

becomes important when you're trying to recognize a

given level of risk reduction, but that still doesn't

mean that the 98th percentile is less protective. It

is in fact more protective because it has higher

power as demonstrated in this '84 paper. So I really

would push very heavily that a 98th percentile

standard is a good one.

Now, why 98th and not 99th? Well, the biggest

problem we have is, again, back to our monitoring

program. When you only measure every third day, you

don't have a whole lot of samples. And if you don't

have a whole lot of samples, that makes the 99th

percentile harder to determine than the 98th

percentile because there's fewer samples. So again,

one of the things that may need to be revisited is if

we get a more complete monitoring system so that we
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have complete data then we're better off getting to

higher percentiles. Expected exceedance only works

better if you have more than 331 days a year that you

have monitoring data for, and we simply don't do

that.

DR. MALM: Question.

DR. SAMET: Yeah, Bill.

DR. MALM: Did you look at the -- everything

you said is precluded on assuming, like, a log-normal

size or a log-normal distribution or something of

that sort if you had a --

DR. HOPKE: No. We looked at log-normal. We

looked at exponential. We looked at Weibull. So it

holds for a variety of positively skewed heavy-tailed

distributions.

DR. MALM: But not for bimodal?

DR. HOPKE: Hmm?

DR. MALM: But not for bimodal?

DR. HOPKE: No.

DR. MALM: And you didn't consider -- did you

look at real data --

DR. HOPKE: Yeah.

DR. MALM: -- across the -- yeah, okay.

DR. HOPKE: I mean, the paper only deals with

models, but --
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DR. MALM: Yeah.

DR. HOPKE: -- with simulations. But no, we

looked at a lot of real data.

DR. MALM: Yeah.

DR. SAMET: So Phil, your comment in general

is the 98th percentile for form?

DR. HOPKE: Yeah.

DR. SAMET: Okay. Ted?

DR. RUSSELL: I generally agree.

Actually, picking up on something else Phil

said. You were talking about using the 98th

percentile of a three-year distribution versus the

average of the 98th percentile over three years, one

being preferable over the other. The point I would

make is that it should be consistent across all of

the various pollutants involved, particularly if we

look at PM coarse. In some ways what we're looking

at right now is that -- with the current

recommendation, we're sort of looking at equivalent

PM coarse of 50 micrograms per meter cubed, is what

they're -- you know, 85 minus 35. And if you change

the form between them, you wouldn't have that same

equivalency.

So I like the 98th percentile; and I'd make

the point that whatever they do, it should be
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consistent across all the pollutants, and I'd say

even ozone in terms of averaging out and such, so. I

like the way they're proposing at this point.

DR. SAMET: Okay. So this was form. I mean,

this will feed immediately into level.

Helen?

DR. SUH: I just wanted to comment a little

bit about the form if I could just before. One of

the things I think that goes to an earlier discussion

we had about monitor placement and also sampling

frequency, given the greater spatial heterogeneity of

the coarse particles and also the greater peakiness

of coarse particles, I wonder if it makes sense to

discuss the impacts of those two items on, maybe,

monitor placement or sampling frequency. For

example, peakiness, maybe it might argue to do a more

frequent monitoring schedule other than one in six

and one in three to be able to get a good

representation of what that 98th percentile might be.

And then the other thing is I liked your

Figure 3-7, which is similar to this, I think,

(indicating Figure 2-10 on display) similar idea; but

I was wondering if you could also color code it as

well to the regions. And that might get into some of

the issues people talk about, about the -- the three
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point -- basically, whether or not the -- you know,

when you say on average the 98th percentile and the

one-expected-exceedance will be equivalent at that 87

level. So it might be good to show how it might vary

by region.

DR. ASHBAUGH: I would second that

color-coding comment. I thought the same thing when

I read that diagram.

DR. SAMET: Okay. Other comments on form?

(No response.)

DR. SAMET: Okay. So why don't we go to

level.

Helen?

COMMENTS ON CHARGE QUESTION NO. 9:

DR. SUH: Okay. So we talked about this

already actually, quite a bit.

Basically, there were two alternatives

proposed, maybe three depending on how you count.

One was to keep the standard the same. In terms of

level it was the 85 micrograms per cubic meter versus

the 65. And I guess with the -- I guess the major

difference -- this is my understanding from before --

is that the 85 was meant to be somewhat equivalent to

the previous standard. And given the

one-expected-exceedance, it was sort of matched up on
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average, was the idea. Then also, the difference

with the 65 was that it included, really,

consideration of only the studies that have a

positive statistically significant impact -- I mean,

effect; whereas, the 65 was basically incorporating

other studies that had the -- a positive but not

statistically significant impact; is that correct,

pretty much the major difference between the two?

MR. HANLEY: Yeah, that's essentially correct.

87 was actually the point of rough equivalence; but

85, generally equivalent and also maintaining -- we

point out we would expect it to maintain PM

concentrations below those in locations where studies

had reported positive and significant effects.

DR. SUH: Yeah. I mean, I guess the way it

was set up it seemed that it was stated that the

major evidence was to -- generally supported the 85

standard. However, in the way it was written, and

also with the follow-up with this alternative 65

standard, it really presented the evidence in such a

way that the 85 wouldn't provide sufficient margin of

safety. That was my interpretation.

So from the reading -- and this is why I asked

about the definition of margin of safety -- it seemed

to me that the 85 would not provide the margin of
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safety given the fact that it didn't take into fact

all these issues related to exposure error, for

example. So that's why you might see a positive

impact but not statistically significant. And so

those issues would contribute, I would think, to a

margin-of-safety consideration, which would argue to

have, somewhere in that lower -- between the 65 and

85 level instead. And so from that reading of it, it

seemed that the 85 was not really going to be

sufficiently protective.

DR. RUSSELL: And another consideration I

think you have to look at here is that as you

decrease the PM2.5 -- currently you're suggesting the

85 is about equivalent to about 150; but if you

decrease the PM2.5 without also decreasing the PM10,

you're actually allowing more PM coarse. So I think

in some ways I started looking at it is that right

now if you're talking about a 35, 24-hour standard

for PM2.5 and an 85 for PM10, that's roughly a

difference of 50. So if you were to go to 30, you

would probably want to equivalently go to 80. But

actually, even if you have the annual standard as the

controlling one for PM fine or PM2.5, when you start

reducing the PM fine, if you don't have a tighter PM

coarse or a PM10, you are indeed allowing more PM
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coarse out there. So I think that's another reason

to consider a finer or a tighter PM coarse standard.

So I think that and also, there is a point

that I think, again, looking at the tables you

provided that an 85 microgram per meter cubed really

doesn't lead to as much control as the 150 does. So

you know, but I'd like to see more of that analysis.

DR. SAMET: Rich?

MR. POIROT: Most of this ground has been

covered and the comments that I wanted to make have

already been raised for the most part.

Just to add a little bit to what Helen said,

and I completely agree with everything she said, is

that, you know, there seem to be two ways -- two ways

of supporting the upper end of the proposed range.

One is this so-called equivalency test, and that's

based on another scatter plot. I don't know if we

can bring that up. It's one that scatters the

expected-exceedance form average over three years

versus the 98th percentile.

DR. HOPKE: 3-7, Figure 3-7.

MR. POIROT: And it includes a regression

line.

DR. HOPKE: Page 3-39.

MR. POIROT: Maybe we'll just wait for it.
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(Figure 3-7 displayed.)

MR. POIROT: It includes a regression line,

and then the point where that regression line --

which in my opinion, doesn't really describe the data

very well -- crosses the 150-expected-exceedance line

is about 85, actually 87; And that's then taken as

the point of equivalency. But actually, it's a range

from about 30 to 130 for the 98th percentile, that

that is equivalent to that one-expected exceedance.

So even the language that's used in the text to

describe that is something, like, on average across

the country; and I don't actually believe that that

language actually describes the intersection of the

regression line with the 150 level.

There's a table in one of the appendices,

Appendix 3A, that shows, among other things, the

fraction of counties that would be protected and the

populations that would be protected given the current

expected-exceedance form versus the alternative range

of different alternative 98th percentile forms.

If you actually asked the question at what

98th percentile level would the population protected

be most similar to the population that's currently

protected, the answer is at 75. So if you're going

for equivalency, I would say an equivalent population
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protected is more equivalent than the intersection of

the regression line. So it's just a point again that

others have made that I'll try to make a little

differently there.

The other argument that was used to help

justify the upper end was, I think, the observation

that of all the single-city positive and

statistically significant mortality results, none had

98 percentile concentrations above -- or below that

level; and that therefore, that would be another way

to support this as an upper bound to the range. And

I guess I can't fault that, really. I don't think

this is a terrible range, by the way. It seems

reasonable to me.

But on the other hand, there are so many

factors relating to coarse particle measurements.

They're not measured very precisely. When you do

measure them, the spatial representativeness is

limited, as others have pointed out. And then

indoor/outdoor relationships are further confounding,

all of which tends to push everything towards the

null hypothesis in epi work. It's not like noise.

It's actually pushing all in one direction.

Again, to sort of -- I kind of like the

argument towards the lower end, to give some
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consideration to those studies that are pretty

consistently positive associations but which don't

quite pass significance tests is consistent to me

with the margin of safety. So those were my comments

on the range.

Overall, I didn't think it was that bad a

choice. You don't have a lot of material to work

with. It's a pretty reasonable range. Maybe knock

down the upper end a little bit for reasons others

have stated.

DR. SAMET: Mort?

DR. LIPPMANN: Yeah. My logic in jumping

ahead earlier with comments on this was the Figure

3-7, that blue arrowhead that broadens as it goes;

but both Ted and Richard have given good supporting

arguments for lowering it.

It's quite clear that PM2.5 is trending down

because of the controls of sulfur and now the perhaps

new diesel engine that will come out will further

lower the soot levels in the atmosphere, which means

that there's more -- if fine particle levels are

going down, then the coarse particle levels should

come down at least proportionately.

And I'm glad Richard pointed out the 75

percent. If you look at the data, really, 75
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micrograms is really more equivalent to the 150 aside

from the argument I made before that a lot of the

country would be under-protected at the equivalent,

whether it's 85 or 75. And so that's why I was

pushing for suggesting that the range should not be

85 to 65, with 85 being preferred, but 75 at most

with 65 being a more protective level.

DR. SAMET: Okay. Other comments on this?

Tom, are you --

MR. MOORE: I'm biting my tongue. But I just

want to understand with the level where we want to be

in five years. So if we pick a level for the coarse

side, that will have one effect, I've heard people

say; and if we stay with PM10 level, a higher number,

that will have a different effect. And I'm just

wondering whether that's part of the implementation

discussion that we're not going to have or do we

have -- is this sort of a thing we should speak to in

the letter that says, here's the choices that you're

making by going with this indicator at this level

versus this other indicator at a different level

because I think the strategies to reduce coarse

material are pretty well known. They're quite

expensive to do, and so I'm wondering whether people

want to tie that to some progress the next time
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there's a NAAQS review for this indicator.

DR. SAMET: Mort?

DR. LIPPMANN: I'll take a little different

cut of where we'll be in five years. I think we'll

be like we are now with PM2.5 annual. 15 seems like a

step in the right direction, and now we understand it

wasn't far enough. So I think in that context, where

we'll be, where I would guess we'll be in five years,

we're saying, it's a good thing we lowered it to 75

because now we have evidence five years later that 75

isn't sufficiently protective.

DR. SAMET: Let's see, Helen, then Rich. Turn

your -- yeah. Thanks.

Okay. But I think your question is perhaps

relevant also in the context of this broader

discussion that we've proposed and how might this all

come together. So let me try and recap on 6, 7, 8

and 9.

It's been an interesting discussion. We had

the discussion on 6 about the question of whether the

evidence, quote, "hangs in the balance" on adequacy.

And I think a range of views across the committee,

which I think is not unreasonable given where they --

where the strength of evidence lies.

I think on this interrelated set of questions,
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7, 8 and 9, we heard that eventually there will need

to be a move to PM10-2.5 as the indicator; and the

timing of that is soon, tomorrow for some in this

room and perhaps a little bit delayed for others.

I did hear full agreement on the 98th

percentile, unless somebody wants to change their

mind, that that was the right indicator -- I'm sorry

form.

And then on terms of level, that a lower --

towards the lower range was what was needed in terms

of health protection for the values of PM10 that were

specified. So I think that captures more or less

what the discussion was.

Does anybody want to add? Again, we have time

on our hands. Rich?

DR. SPEIZER: John, this is Frank.

If we were to lean toward a 10 minus 2.5 at 65

to 75 and you add to that 10 to 12 -- 13, for PM2.5,

we are in a range which, sort of, I think most people

would be comfortable with. Now, the question is can

we see it that way? Can we set a 10 minus 2.5

somewhere between 65 and 75 and have the country not

go crazy over how that relates to what was 150 PM2.5.

And I think what I'm saying is, what is the

acceptable range of the percent of PM10 as it falls
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within 10 minus 2.5?

DR. LIPPMANN: Frank, this is Mort. We're

talking about PM10 in the range of 65-75, not PM10-2.5.

So if you want to talk about PM10-2.5 --

DR. SPEIZER: Speak up.

DR. LIPPMANN: -- then you would take the

65-75 and subtract the -- what, 30.

DR. HOPKE: 35.

DR. LIPPMANN: 35. If you wanted to go that

way, it would be a number in the 40s. I'm not

disputing where you're getting, but you picked the

wrong concentration range.

DR. SPEIZER: I'm sorry. I couldn't hear any

of that.

DR. LIPPMANN: I'm looking toward John and

speaking not into the microphone.

I'm saying we've been talking about 65-75 for

PM10 not for PM10-2.5. So you'd have to take that 65-75

and subtract 30 or 35 from it if you wanted to talk

about picking a number for PM10-2.5.

DR. SAMET: Rich?

DR. SPEIZER: Well, you'd really have to --

MR. POIROT: I'm reluctant to mention this,

just to throw out kind of an idea; but I was talking

the other day to George Allen about coarse particle
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data from the northeast. And he was commenting that

it's remarkable in the sense that it's one of the

most normally distributed of all pollutants. But

this is from the narrow perspective of looking

probably at urban areas in the northeast where we

don't have a lot of windblown dust and that sort of

thing. And yet, when we look at other aspects of the

distribution of the coarse particles, they appear to

be quite extremely episodic; and that may reflect to

a certain degree on the different kinds of emission

sources. And I would certainly expect the windblown

dust to be an extremely episodic kind of a source.

So therefore, if we were interested in

focusing more on the urban so-called kinds of coarse

particles, then possibly some consideration might be

given to a somewhat lower percentile that would be

less responsive to the episodic emissions, which are

more characteristic, I would guess, of natural

sources than just -- like I said, I don't want to

push that. I just thought I'd put the idea on the

table.

DR. LIPPMANN: I suspect that George Allen's

data are at sites not that close to major highways by

design. So you get much higher levels in the

northeast if you went near an interstate or a major
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parkway, and so that's one consideration.

The CASAC panel I wasn't on, and probably

would have disagreed with, for NOx is pushing roadside

monitoring; and that would change the picture

entirely if we thought that the proximity to roadway

is driving health effects from particles. One could

make that argument that we should be looking at

roadside levels rather than general community levels,

but that gets into another whole range of

complication which I'm not advocating.

MR. POIROT: Yeah. All I was saying, however,

was in relating to the eposodicity of the

distribution, and I suspect if we went closer to the

roads -- roads are a very chronic kind of a source,

not prone to huge episodic releases. They're there

all the time and so on and so forth. So it's just

that the distribution would tend, I would think, to

be somewhat more normalized and less skewed towards

the tails compared to dust storms.

DR. SAMET: Okay. Why don't we go on to 10.

Chris, this is you and Mort.

DR. SPEIZER: John, can I add one thing?

It seems to me I recall --

DR. SAMET: Okay.

DR. SPEIZER: I don't want to put words in
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Karen Martin's mouth, but at some point she had

suggested, I thought, that episodic exposure --

episodic events could be excluded in some way from

the consideration of the percentile level. Am I

correct thinking you talked about that before?

DR. MARTIN: Yes. We had talked about

exceptional events, which don't fall in the category

of roadside or the kinds of things you were talking

about now.

DR. SPEIZER: Is there a way to exclude those

episodics without affecting -- they didn't affect the

standard?

DR. MARTIN: I'm not quite sure what you're

asking. Episodic is not the same as exceptional if

we can predict regular episodes as opposed to truly

exceptional events that aren't predictable. They're

just different in kind.

DR. HOPKE: There have been states who have

attempted to claim that every time they get a wind

storm, it's an exceptional event.

DR. SPEIZER: Yeah. Okay.

DR. SAMET: Back to 10, I think.

COMMENTS ON CHARGE QUESTION NO. 10:

DR. FREY: Okay. This is the charge question

related to key uncertainties and areas for future
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research and data collection related to the coarse or

PM10 topic. I think what's here seems fine just with

the comment that it doesn't necessarily review the

key uncertainties as we discussed also for section

2.5, but it does touch on what seemed like reasonable

research needs.

I think in light of the discussion prior to

now it seems worth emphasizing, whether we recommend

a PM10-2.5 standard tomorrow or five years from now

presumably, just to reenforce the importance of this

information that research does get undertaken, not

just research, but also the implementation of the

coarse PM monitoring, at least the limited network

that we understand is to be implemented by 2011, and

to point out that that data is critically needed to

support a baseline for air quality that might be

helpful in setting a future standard and certainly

would be helpful presumably with future

epidemiological studies. You know, whether those

could be completed in a timely enough way to inform

the next five-year iteration, I'm not sure. So I

think emphasizing those needs would be helpful, but I

think a lot of the content is actually here. It

maybe could just be stated with a little more urgency

than perhaps it is now.
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I think something that I didn't find in here

is on the topic of continuous monitoring and what we

can do to promote that.

And then also, as I commented on section 2.5,

I think there perhaps could be a little bit more

related to data that would support exposure modeling.

Basically, the same comments I had earlier.

I think that's all I have right this moment.

DR. SAMET: Mort?

DR. LIPPMANN: Yes. I thought the -- again,

it was a good summary statement. There was just one

boner in it that needs to be addressed. That one is

animal toxicological studies of long-term exposures,

i.e., months to years to PM10-2.5 would be useful.

Indeed, they would, but they're impossible. You

can't get particles larger than 2 microns into the

lungs of a rodent, and presumably these would be

rodent studies. And the few that would get in would

not deposit very efficiently in the conductive

airways of the lung because of the different

structure of four-legged animals compared to humans

with the side branchs. And any other route of

administration would be unnatural and likely to cause

complications. I don't think you're going to have

tracheostomies in long-range exposed animals to
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bypass the filtering capacity of the nasal passages

in these obligatory nasal breathers.

So while I'm certainly sympathetic, and Kent

was right about needing more toxicology, we could

certainly use more toxicology with fine particles and

perhaps with the larger ultrafines which would get

through the nose; but it's impossible to do it in the

animals unless very creative people like Kent can

come up with a way to actually deliver the coarse

particles on a long-term basis to animals. So I'm

not saying that rules out all toxicology, but it

rules out the kind we'd most like to see.

DR. SAMET: Kent?

DR. PINKERTON: Just to follow up on Mort's

comments. It's true, it is difficult. However,

rodents do breathe the lower range of the coarse

particles. They actually can breathe up to 4 to 5

micron particles and will deposit within the

conducting airways. But if it's the particles -- the

coarse particles that are above that size that we're

really interested in, then we would miss that.

We have done studies with the coarse particles

by installation in equal mass volumes to show that

coarse particles from wildfires in California are

completely different than an equivalent mass of
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particles, ambient particles that don't come from

wildfire sources.

So there can be some things, but as Mort

points out, that's not a normal physiological

pattern; but it may give some credibility to

biological plausibility for these coarse particles

with installation studies. But inhalation studies

are really limited to that lower range of the coarse

particle fraction.

DR. SAMET: Phil?

DR. HOPKE: Yeah. One of the problems here is

going to be getting good chemical or proper

characterization of the particles because you're now

going to have a potential for significant amounts of

primary biological materials. And so simply doing

organic and elemental carbon isn't going to tell you

what you need to know, and the problem is that we

really don't have very good methods.

Mark Hernandez at University of Colorado has

spent a lot of time trying to work out methods to get

these things to work and he's got some ideas that are

sort of working; but even there, you're just getting

carbohydrates and protein. So characterization of

some of what may be important parts of the coarse

particle aerosol are still things that need to be
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worked out.

Now, one could do obviously microscopy and

morphology to get at some of this, but that becomes

difficult to do on a large-scale network basis. So

there are some issues here that need to be worked out

in terms of understanding what it is you're

collecting in your PM10 or coarse particle sample, and

they're not trivial to sort out.

DR. SAMET: Okay. Anyone else on Question 10?

Yeah, Ed.

PROF. AVOL: Just one comment with regard to

this need, just as we talked about on the fine

particle recommendations, I think there needs to be a

prioritization of the priorities. And maybe in the

context of Vanessa's presumed meeting this could

logically come about.

DR. SAMET: Okay. We've done the coarse

particle chapter. Last chance, comments, 7, 8, 9 and

10 -- or 6, 7, 8, 9 and 10?

DR. SPEIZER: John, are we going to try to

come to a resolution on whether we're going to

recommend PM10 versus PM10-2.5?

DR. SAMET: I think, Frank, I think we

probably got to a point of where the committee is. I

think that there's at least Phil, on the one hand,
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and I think probably more to the others who are

leaning but not jumping, if that's a fair

characterization, I think, of the mood of the room.

DR. SPEIZER: Well, maybe we need to quantify

it as to where people are.

DR. SAMET: Yeah. I actually think -- yeah,

we went over this a little bit actually when I sort

of asked Phil how his remarks would reflect this.

And I think it's reasonable that there is in fact a

range of views at the moment, but I think -- I'm not

sure I need to poll. But let me ask, I'll do this

briefly.

Are there any other jumpers?

DR. SPEIZER: I think I'm just coming to jump.

I'm not sure of where I was before.

DR. BRAIN: Why don't you state your proposal,

Phil?

DR. SAMET: Phil, yeah.

DR. HOPKE: I mean, at this point, you know,

because I assumed that John was going to grab me to

write a paragraph for the letter, and so my thought

was that we would say something like, although there

was extensive discussion of PM10-2.5 indicator, the

Panel felt that at this time the evidence was not

sufficiently strong to move to that, but there was
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the need for the accumulation of the monitoring data

so that further epidemio -- you know, further studies

could be made to ascertain the need to move to this

as the indicator, or something like that.

DR. BRAIN: But it really seems like there's

quite an elaborate database about health effects. Of

course, you know, there's a whole chapter on it.

DR. HOPKE: That's why I think it's time --

DR. BRAIN: I guess I would join the jumper --

DR. HOPKE: It's time to say this is where we

ought to go.

DR. BRAIN: I would join the jumper camp.

DR. HOPKE: That's good.

DR. SPEIZER: If we move to --

DR. SAMET: I think we have --

DR. SPEIZER: -- the majority are jumpers,

then I think we do have to come up with some numbers.

DR. BRAIN: Yeah, right.

DR. SAMET: Well, how many jumpers are there?

Frank, you're --

DR. SUH: I might be a jumper.

DR. SAMET: You might be a jumper. You have

to be a jumper or not a jumper. You can't might be a

jumper.

DR. SPEIZER: All right. I've become a
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jumper. I can't see the rest of the group.

DR. SAMET: Frank, I think you said you were a

jumper. We hear you mumbling in the distance.

DR. SPEIZER: Yeah. I'm going to be a jumper.

I can't see the rest of the group.

DR. HOPKE: Well, it looks like Harvard and

Clarkson, and the rest of the folks are staying well

up on the cliff.

DR. SAMET: Yeah, Mort?

DR. LIPPMANN: Being a practical sort of

engineer by origin, I'm not ready to jump now, but we

never will be if the monitoring situation remains as

it is; and so I think we're betwixt and between. We

need the data to justify switching and until we

switch we're not going to get the data. So I think a

very strong recommendation is needed that

simultaneous adjacent collections are really going to

be absolutely needed if we're going to be able to

make a rational move in the next round.

And if in fact you do have dichots ready to

go, let's start using them because that will give you

the basis for having a database that can be analyzed

and used.

DR. SAMET: How big will the data -- how many

monitors will be implemented?
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MR. HANLEY: So there's a few things going on.

Joann is here, and she can speak to the coarse

speciation work that she's leading up in St. Louis

and Arizona. That's a limited pilot at the NCore

stations. There's approximately 80 of those. About

60 are urban locations where coarse mass by approved

methods, including dichots, FRM in one approved

continuous method will be available.

Then in addition to that, of course, there are

a number of locations that have the prized existing

co-located data with, you know, sufficiently high

quality instruments that you could -- you know, folks

could use the data now. I think it's fair to say

there's not a coordinated effort amongst health

researchers and the cities and states and EPA to make

sure that every health study has the right, you know,

methods in place; but I think what I'm hearing here,

and I don't disagree with it, is that kind of push

needs to be -- needs to be made.

DR. BRAIN: Can we recommend a direct

measurement of the coarse fraction whenever possible,

something like that?

DR. LIPPMANN: I'll point out that some data

are being collected which could prove interesting and

available and in publication by the next round, and
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that's the NYCCAS study in New York City. It was 155

two-week samplers on utility poles, and that's been

supplemented in a pilot that NYU added to it with PM10

samplers in addition to the PM2.5 samplers and all the

filters are being speciated. So it's a unique

sampling strategy. It gets at heterogeneity

associated with roads and other things in a big urban

area. And I think as the publications begin to come

out that it provides a model that could be done in

other locations that would generate the kinds of data

that we're talking about, albeit in a limited number

of locations and situations. But if EPA can

encourage, support, sponsor that kind of work in

other locations that differ from New York -- you

know, New York being unique in many ways, it would be

an extremely valuable at least set of pilot

information that would help set the stage for the

future.

You're familiar with NYCCAS, I presume?

MR. HANLEY: Yes, I am.

DR. SAMET: Sverre?

DR. VEDAL: Yes. So I mean, I think arguments

in favor of better coarse monitoring network are

sound. I'm not -- I don't think I'm ever going to be

in a position to support a national coarse standard
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until we have the following bit of information that

we have some comfort with, either that the

composition of coarse PM doesn't matter or that we're

in a position to recommend a species-specific coarse

standard. A mass-based coarse standard at this point

I think is just wrong.

DR. SAMET: Helen?

DR. SUH: Well, actually, I think I was going

to speak to the same issues Sverre did is why I'm a

partial jumper is really this notion about the

windblown dust versus the urban coarse particles.

And I think that, not only should the monitoring --

increased monitoring be advocated strongly, but also

there needs to be some push for the monitoring being

done in diverse areas that include the areas

characterized by high windblown dust coarse particle

concentrations and those in the urban areas so there

can be some -- begin to have some understanding of

whether or not coarse particles mass is the issue or

whether it's some particular attribute of the coarse

particles themselves, and I think that would be

critical.

DR. SAMET: Tom?

DR. MOORE: I just wanted to point out that if

there's a warmer, drier climate on the way, that it
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might be a good idea to ask for some of that as well,

so.

DR. SAMET: Okay. So I guess the question --

I mean, Phil, you've got a sense of the balance here

between jumpers and non-jumpers. I think let's leave

this for the moment, just circle back.

I understand -- it's ten after 4:00. We're

not going to move on to visibility, the Secondary

Standard today. We'll do that tomorrow. I think

that does two things. It just gives us a chance to

revisit for the moment anything under the fine PM

standard to discuss getting our letter written and

drafted. To the extent that work can be done here, I

think that would increase our -- increase our

efficiency and will be helpful, and it's not that

working this afternoon will keep you from going

anywhere. So I think we could use the time.

So just to go back, we spent a lot of time

this morning on issues related to fine PM. I think

it's fair to say -- and I think that this came

through particularly as we addressed these charge

questions 1, on the approach taken to developing the

document, that, in fact, in terms of process, I think

this cycles through the whole PM. This being our

first, I guess, through the whole new ISA, REA,
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Policy Assessment, it seems to have flowed rather

well in the end in that the kinds of decisions that

were made in the ISA and that help guide what

outcomes should be looked at in the REA and then what

outcomes were of concern in the policy analysis, I

think created a relatively transparent approach. At

least in my mind comparing, if you go back ten years,

the criteria document to staff paper, et cetera, it's

a very, I think, much more evident and defined

process. And I think your diagrams were good. Now

you just have to go back up a little bit and put in

the rest of the story. And so I think this has

worked out, and I guess we'll have another -- some

other examples flowing through now.

So it's good. And in fact, I think you saw

that the Panel in general was offering very positive

comments about the Policy -- Policy Assessment. So

again, I think you should take that as a reflection

of a process that seems to be working and a lot of

hard work on the part of the Agency's staff. This is

actually praise, so take it; and it's deserved. I

mean, obviously, with the schedule that you're on for

all these documents, it's an awful lot in motion at

the same time for you.

I think just looking at some of the issues
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that we covered, there was a lot of discussion about

the PM, the 24-hour PM2.5 standard, the annual

standard. We talked about a relatively narrow range

for both the potential revisions of the 24-hour

standard and the annual standard. Our multi-colored

plot is gone; but in reality, they were talking about

a relatively small reduction of -- possibly of the

PM2.5 24 hours and a range that, at least in absolute

terms, are relatively small for the annual, albeit

proportionately large, going with a, from 15 to 12,

you know, percentage-wise is a larger reduction.

I think what you heard from the committee is,

of course, that as you go lower, uncertainties mount.

And that was discussed in a number of ways ranging

from model uncertainty to form of the

concentration-response relationship to the declining

amount of information and, of course, the widening of

confidence intervals in terms of our ability to

estimate the dose-response relationship, but I think

also in terms of our general confidence to what the

exposure-response relationship might be.

That said, I think what I heard from the group

was that the scientific evidence available would

support, sort of, any of the combinations within that

range that was discussed with declining confidence
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towards the lower end of the scientific evidence

available around the potential for adverse health

effects, their existence and public health benefits

from a reduction of the standards.

I think the committee was in agreement that

the evidence would support a change. The selection

of exactly what is the optimum pairing of 24-hour and

annual standards, I think largely then would reflect,

sort of, the policy judgment and how to achieve the

needed degree of public health protection, i.e.,

providing the margin of safety. So I think that's

what we said there.

You know, I think an important outcome of the

discussion around Question 4, this key uncertainties

and future research -- and this applies, spills over

to our Question 10 -- was that we ought to step back

and take a broader look and find a way with help from

Vanessa and Holly to do that. So I think that's

where we ended up on the PM2.5 standard.

Does anybody want to add anything at this

point?

(No response.)

DR. SAMET: Okay. And then I think, you know,

we just finished the discussion of Charge Questions 5

through 10, and I don't see any point in rehashing
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the discussion. I think the important key elements

of what we talked about was the -- where the evidence

stands on the adequacy of the standard and where

the -- what is the right indicator, I think both key

issues. And obviously a lot less evidence and,

consequently, a committee that I think offered a more

divided judgment reflecting where the scientific

evidence stands.

So again, I don't know if anybody wants to

revisit any of the issues here, any jumpers want to

change their mind, non-jumpers. But otherwise, I

think that's where we've ended up at 20 after 4:00.

Karen, are there things that you would like to

revisit as we sit here before we break up? It's a

rare moment when we have time on our hands.

DR. MARTIN: I'm thinking through what you

just reiterated, what you've talked about on coarse.

Of the things you have revisited and sort of

done a wrap-up of, the one thing I think I'm least

clear about is the view of the Panel on the issue of

the adequacy of the current PM10 standard. There was

a lot of discussion about the balance of the

evidence, that it hangs in the balance. A couple

people spoke to their views that they felt the

standards weren't adequate. It wasn't clear to me if
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everyone else was in the it-hangs-in-the-balance

camp.

DR. SAMET: Okay. Let's see, so we had Mort

and Frank expressing a view. Others? Sverre.

DR. VEDAL: I was convinced by Mort's argument

that we were -- by changing to 85 with that current

form that we were going to leave some segment of the

population unprotected that was protected by the

previous PM10 standard even though there would be some

that would be more protected. So I thought on that

basis, I thought the argument was reasonably good

that the PM10 standard needed revision.

DR. MARTIN: I didn't hear the end of your

sentence. I'm sorry.

DR. VEDAL: That needed revision.

DR. SAMET: Okay. Any others?

DR. FREY: John?

DR. SAMET: Yes.

DR. FREY: On the weight of the evidence,

Karen, I would also concur I think that needs

revision as well.

PROF. AVOL: I think that's a comment also

from Rogene and myself on Question 6 as well.

DR. SAMET: And I think my comment on this has

to do with what I said earlier, which is just to be
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certain as you discuss this, to carefully separate

the strength -- your response to the strength of the

evidence and then the concentration to which people

are exposed in the likelihood of effects.

And I think that's where adequacy, you know,

this question of adequacy encompasses a number of

notions. Again, I think the precedent here is how

you respond to suggestive evidence, but then in the

end how the Administrator will respond to suggestive

evidence, which to me is where -- and I think Helen

alluded to this, is margin of safety a notion related

to, as I think it's been literally construed,

building on some sort of margin on a dose-response

curve of protection or is it a broader precautionary

philosophy, which I think was what you were getting

at, and that in the absence of certainty about

causation there still might be action -- I don't

know. I think I would just be clear about the logic.

Yeah, Rich?

MR. POIROT: Couldn't the statistical

inferiority of the expected-exceedance form be a part

of the adequacy argument as well? I mean, it's not

the whole thing, but it's a good starting point, if

for no other reason that's inadequate.

DR. SAMET: Okay. Mort?
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DR. LIPPMANN: I am questioning Rich. He

convinced me it was really equivalent to 75 and not

85, and I'm surprised he's reluctant to say that it

shouldn't be lower to -- below than 85.

MR. POIROT: No. I was trying to address the

adequacy of the existing standard, 150

expected-exceedance form, and that part of the

argument for why it's inadequate has to do with its

inferior statistical properties.

DR. LIPPMANN: Right.

MR. POIROT: And then we go on from there.

DR. LIPPMAN: In effect, you're joining those

who suggest that it needs to be lower than 85, or are

you?

MR. POIROT: Well, that's another question.

DR. LIPPMANN: And you don't want to answer

that.

MR. POIROT. Yes, I will join those, but

before I do that I'd like to help us jump off the

cliff of the current standard by pointing out Phil's

argument about the statistical inferiority. That's

one of several reasons why the current standard

should be changed, and then there are others that we

come to later.

DR. SAMET: Okay. What I'm going to suggest
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then is that, remember, the person who is, sort of,

the designated lead discussionist, if you could take

on the role of compiling the comments, if you want

input from your colleagues who are here, and we have

opportunity to sit -- you have the opportunity to sit

and work together. E-mail your comments to Holly,

and she'll assemble all this; and depending on how

things go tomorrow, we hopefully will have some

chance to put the comments up on the screen and do

some review.

DR. VU: If you have the time to do it, that

will be fine. I just don't know whether you have the

time because tomorrow you still need to focus on

visibility. And the folks who lead the visibility

discussion on the Secondary Standards will not be

able to have a draft --

DR. SAMET: No, yeah. I meant --

DR. VU: So therefore, you don't have any

choice but have another public teleconference call.

DR. SAMET: No. My suggestion is if we have

time we be prepared to do that. And judging the

length of the discussions of the visibility standard

every time we've discussed it, we may not get to the

opportunity to review the comments. Let's see what

happens. Alternatively, we can start at 6:30, which
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would be fine with me.

DR. VU: No, unless you want to lengthen the

time tomorrow. I mean, right now, I look at the

agenda. You all said 11:30, but there's no reason

why you can't prolong it to 12:30 as long as -- I

mean, the issue is whether the lead writers will be

able to finish the discussion of all the Primary and

the Secondary Standards and get approval on this

phone call, I mean, at this face-to-face meeting.

That's the question.

DR. SAMET: I actually don't see us getting

approval, Vanessa, at this meeting.

DR. VU: Oh, okay. Well, in that case --

DR. SAMET: No, no.

DR. VU: -- you're going to do that --

DR. SAMET: No. I actually just see us trying

to get some of the initial work done.

DR. VU: So you're -- I'm sorry then, John. I

misunderstood. So you just want to get -- make sure

that the language gets more --

DR. SAMET: Yeah. There was just sort of --

yeah, follow through --

DR. VU: Exactly.

DR. SAMET: -- and do some discussion here.

But no, I actually by no means saw us getting the
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BRYANT COURT REPORTING SERVICES, INC.

Post Office Box 1401, Cary, NC 27512

(919) 387-5853 (919) 387-1896 (FAX)

249

letter done.

DR. STALLWORTH: So there's overnight homework

we've been discussing.

DR. SAMET: Yeah, yeah. So if you can work

and get text back in. So then if we have some time

to review it --

DR. VU: Okay. That's fine.

DR. SAMET: Because I think it's taken us,

even with our meeting, sometimes a fairly lengthy

cycle post-meeting to get our letters together. So

I'm just trying to shorten that down.

DR. STALLWORTH: So that would be due by

9:00 p.m.

DR. SAMET: Okay. So thanks, everybody. So I

think there's a dinner van at 6:00. And tomorrow we

reconvene at 8:30, so see you then.

(The meeting was adjourned at 4:27 p.m.)

---o0o---
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BRYANT COURT REPORTING SERVICES, INC.

Post Office Box 1401, Cary, NC 27512

(919) 387-5853 (919) 387-1896 (FAX)

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REPORTER: RWK

DATE: 7/26/2010

T R A N S C R I P T I O N C O R R E C T I O N S

U.S. ENVIRONMENTAL PROTECTION AGENCY

SCIENCE ADVISORY BOARD STAFF OFFICE

CLEAN AIR SCIENTIFIC ADVISORY COMMITTEE (CASAC)

PARTICULATE MATTER REVIEW PANEL PUBLIC MEETING

PAGE LINE READS SHOULD READ

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BRYANT COURT REPORTING SERVICES, INC.

Post Office Box 1401, Cary, NC 27512

(919) 387-5853 (919) 387-1896 (FAX)

251

STATE OF NORTH CAROLINA

COUNTY OF WAKE

CERTIFICATE OF REPORTER

I, ROBIN W. KING, the reporter by whom the

foregoing proceedings were taken, do hereby certify

that the proceedings were taken by me in stenotype

and thereafter reduced to typewriting under my

direction; that I am neither counsel for, related to,

nor employed by any of the parties to the

proceedings; and further, that I am not a relative or

employee of any participants thereto, nor financially

or otherwise interested in the outcome of the action.

This, the 4th day of August, 2010.

____________________________

ROBIN W. KING

Notary Public in and for

County of Wake

State of North Carolina

Notary No. 200518700077

My Commission Expires July 4, 2015

Robin W. King

Bryant Court Reporting Services

(919) 387-5853