Summary of Interagency Working Comments on Draft Language under EO12866 Interagency Review. Subject to Further Policy Review.

1. It is unclear how one translates the weak relationships observed in epidemiological studies that use ambient monitoring to determining a maximum level of NO2 one should allow near roadways. CASAC indicated a similar concern during their meeting on the pro posed NAAQS

.

2. Please crosswalk the methods used in the EPA meta

- analysis with those used by

Goodman. There is a newly published article “Meta

- analysis of nitrogen dioxide exposure and airway hyper

- responsiveness in asthmatics” by Goodman et al Critical Reviews in Toxicology 2009; 39(9): 719

- 742.

3. Are the levels being referred to here the increased airway responsiveness shown in the

meta

- analysis at 100ppb? EPA state s that the new standard is designed to limit peak exposures at concentrations that have been reported to increase airway responsiveness in asthmatics. If so, does a peak standard set at 100 ppb contain a margin of safety? As EPA points out, it is possible that similar effects occur below 100 ppb.

4. The preamble seems to imply that the marg in of safety is essentially inherent in the fact

that we are unsure whether these responses seen at 100 ppb are adverse. If this is the case, and symptoms also were not reported at 200 ppb does at what point does the margin of safety begin? At 300 ppb o r 400 ppb? Why is the lowest level at which clinical studies were conducted the correct place for the standard if similarly equivocal results were found at higher levels?

5. The studies referred to in the ISA dealt with traffic density, but the statements o n page 93 about the population at risk do not. The statement on page 93 (and associated footnote 18) add confusion. It seems unlikely that NO2 concentrations next to railways are equivalent

to those next to four

- lane highways , and four

- lane roads aren’t necessarily heavy traffic.

6. T he mandate for a new compliance network c ould be delayed until there is sufficient science to support th e approach. The draft preamble and docket present inadequate science

to inform a decision on the near

- roadway network, and the agency should consider removing this requirement, eventually addressing the issue through a separate implementation rulemaking, an approach that is consistent with previous NAAQS reviews.

EPA’s Office of Research and Development is about half way thr ough a series of near

roadway studies in Las Vegas, Raleigh and Detroit. It would be appropriate to analyze the results of these extensive research efforts in order to properly inform the monitoring network, and estimate the degree of noncompliance that w ould result from the monitoring mandate.

7. Comments received from State governments seem overwhelmingly to oppose to the new monitoring strat egy , yet the preamble seems to focus on positive comments

. In particular, the preamble text does not seem responsi ve to the concerns expressed in comments of North Carolina, New York DOT, Arkansas, Virginia, New Mexico, Mississippi, Tennessee, Kentucky, Indiana, Michigan, Missouri, Alaska, Illinois, California, Alabama, Texas, Iowa, and Wisconsin.Summary of Interagency Working Comments on Draft Language under EO12866 Interagency Review. Subject to Further Policy Review.

NACAA and the state s object to this new mandate, citing concerns about the science, safety, lack of flexibility, cost, discordance with population exposure, and the states’ inability to

control the relevant emissions. State commenters also mention that there was insufficien t notice and comment and limited CASAC review of the strategy, since EPA had previously committed to an ANPR which was never eventually published.

8. The RIA is unable to robustly estimate the degree to which exceedence of the new standard may occur near roa ds, and has made no attempt to model the near

- roadway concentrations as a function of traffic density.

5. The Agency should clarify the types of PM reduced as the result of the proposed NAAQS. In earlier conversation, sta ff thought that while the great majority of the PM 2.5 benefits came from reduced NO 2 , that there might also have been some reduction of other types of PM 2.5

EPA's view continues to be that all types of PM , perhaps through an on

- or off

- road diesel program of some sort.

2.5 are thought t o be equally harmful per unit of mass, and we also recognize that this RIA is not the place for discussion of this issue. But we do think that it would be important to note for the record other types of PM 2.5 , other than nitrates, which might be reduced a s part of the NO 2

In reading the NO2 preamble and RIA documents, and in using a "find" function, we couldn't find any mention of any other type of PM that was reduced. If this i s correct, the suggestion would be to add a sentence on pg. 4 of Ch. 4 of the RIA, after this sentence: NAAQS proposal, if this is the case. An efficient way of providing this discussion is perhaps through the use of a pie

- chart

, similar to

that used in several recent rules , which b reaks down the types of PM reduced and states that

there is uncertainty in the size of the PM benefits introduced by questions of differential toxicity.

"Our estimate of PM 2.5 co

- control benefits is therefore based on the total PM 2.5

T he added sentence would say: emissions controlled by sector and multiplied by this per

- ton value."

"The PM 2.5 emissions reduced are exclusively PM 2.5 which derive from NO 2

If, on the other hand, there were some reductions in PM emissions, for example

nitrates."

2.5 species other than those formed

from NO 2

"The PM emissions, then we would propose the following sentence instead of the one just

offered:

2.5 emissions estimated to be reduced are almost all PM 2.5 which derive from NO 2

6. Reviewers suggest inc luding a sentence to the preamble to clarify the potential for climate change impacts

. Reviewers offered a comment earlier in the process pointing to a new research article by Drew Shindell et al. Shindell works closely with Jim Hansen in the

GISS resear ch lab. That article showed that reducing NO2 actually caused a net increase in emissions, for example nitrates, but a small proportion consist of _____."Summary of Interagency Working Comments on Draft Language under EO12866 Interagency Review. Subject to Further Policy Review.

global warming, though complicated atmospheric processes. It is too early to draw hard conclusions on the size of the error bands around the findings of Shindell et al (2009)

. There is not enough time in this rulemaking to attempt to quantify the increase in global warming potential as a result of reductions in NO2 in the proposed rule

-- the amount might be meaningful, or it might be vanishingly small. However, it seems imp ortant to recognize in

this RIA that there is an issue. We couldn't find mention of "global warming" or "climate change" in any of the RIA documents, or in the actual proposed rule.

Reviewers suggest that a sentence such as this one be incorporated into t he preamble at an appropriate location:

"Climate change impacts of emissions such as NO 2 , which have not been extensively studied with regard to their impacts on net warming, are only now beginning to be investigated. Investigation of complex atmospheric chemical reactions involving NO 2 now suggests that decreases in NO 2 might actually lead to an increase in global warming, inclusive of impacts on reducing tropospheric ozone, a greenhouse gas. Quantification of such an impact has not been done. Since

wor k on this issue is only beginning, an analysis of the quantified impacts of reduction in NO2 on climate cannot yet be provided."