A Multiyear Federal Research

Plan for Particulate Matter

Within the Context of the NRC’s Committee on

Research Priorities for Airborne

Particulate Matter’s Report IV

Air Quality Research Subcommittee of the

Committee on Environment and Natural Resources

April 2007
EXECUTIVE OFFICE OF THE PRESIDENT 

NATIONAL SCIENCE AND TECHNOLOGY COUNCIL 

WASHINGTON, D.C. 20502 

April 3, 2007 

Dear Colleagues: 

I am pleased to transmit the report “A Multiyear Federal Research Plan for Particulate 

Matter Within the Context of the NRC’s Committee on Research Priorities for Airborne 

Particulate Matter’s Report IV.” This report was prepared by the Air Quality Research 

Subcommittee (AQRS) of the National Science and Technology Council’s Committee on 

Environment and Natural Resources (CENR). 

In this report, the AQRS evaluates particulate matter (PM) research being conducted or 

planned across the federal government against the findings and recommendations of the 

National Research Council (NRC) report, Research Priorities for Airborne Particulate 

Matter: IV, published in 2004. In addition, this document describes the organizational 

role of the AQRS for ensuring that the many PM related research projects conducted or 

supported by the government address the priorities, issues, and challenges identified in 

the NRC report. It profiles agency research being done under each of the ten topic areas 

identified in the NRC report, establishes research milestones for major agency-specific 

research contributions, establishes a process for periodic progress review and refinement, 

and identifies organizational roles and responsibilities in coordinating cross-agency 

research.

In describing ongoing and planned research, the report provides a description of the broad 

scope of federal research related to this important issue and identifies areas where 

additional research attention will be beneficial.

John H. Marburger, III 

Director 

Office of Science and Technology Policy 
Copies of this report are available from:

NOAA Earth System Research Laboratory, Chemical Sciences Division

Office of the Director, R/CSD

325 Broadway, Boulder Colorado 80305-3337

e-mail: aqrs@noaa.gov

Phone: 303-497-3134

Fax: 303-497-5340
A Multiyear Federal Research

Plan for Particulate Matter

Within the Context of the NRC’s Committee on

Research Priorities for Airborne

Particulate Matter’s Report IV

Air Quality Research Subcommittee of the

Committee on Environment and Natural Resources

April 2007

About the Committee on Environment and Natural Resources (CENR)

The CENR is charged with improving coordination among federal agencies involved in

environmental and natural resources research and development, establishing a strong

information-transfer link between science and policy, and developing a Federal environmental and natural resources research and development strategy that responds to national

and international issues. There are seven research subcommittees and two interagency

working groups under the CENR:

• Air Quality Research Subcommittee

• Ecological Systems Subcommittee

• Global Change Research Subcommittee

• Interagency Working Group on Dioxins

• Interagency Working Group on Earth Observations

• Natural Disaster Reduction Subcommittee

• Oceans Subcommittee

• Toxics and Risk Assessment Subcommittee

• Water Availability and Quality Subcommittee

About the Air Quality Research Subcommittee (AQRS) of the CENR

The Air Quality Research Subcommittee has articulated two major goals in its Strategic Plan:

• to enhance the effectiveness and productivity of U.S. air quality research, and

• to improve information exchange between research and policy on air quality issues,

including the scientific knowledge base for air quality standards and assessing 

compliance.

Air Quality Research Subcommittee of the CENR

Member Departments and Agencies

Department of Agriculture

Department of Commerce

Department of Defense

Department of Energy

Department of Health and Human Services

Department of Housing and Urban Development

Department of State

Department of the Interior

Department of Transportation

Environmental Protection Agency

National Aeronautics and Space Administration

National Science Foundation

Tennessee Valley Authority

Other Participating Agencies

Office of Management and Budget

Office of Science and Technology Policy

Council on Environmental Quality

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Key Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Part I: Research Recommendations by Topic Area . . . . . . . . . . . . . . . . . . 7

Outdoor Measures Versus Actual Human Exposure . . . . . . . . . . . . . . . . . 7

Exposures of Susceptible Subpopulations to Toxic Particulate

Matter Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Characterization of Emissions Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Air Quality Model Development and Testing (and Measurement) . . . . . 14

Assessment of Hazardous Particulate Matter Components . . . . . . . . . . . 17

Dosimetry: Deposition and Fate of Particles in the

Respiratory Tract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Combined Effects of Particulate Matter and Gaseous Pollutants . . . . . . 20

Susceptible Subpopulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Mechanisms of Injury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Analysis and Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Cross-cutting Research Issues and Overarching Challenges . . . . . . . . . 25

Part II: Improving Program Coordination . . . . . . . . . . . . . . . . . . . . . . . . 29

Developing a Broader Multi-agency Research Program . . . . . . . . . . . . . 29

Improved Tools for Science Tracking and Synthesis . . . . . . . . . . . . . . . 39

List of Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Agencies and Organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Federal Government Committees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Monitoring Networks and Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Methodology and Modeling-Related Systems . . . . . . . . . . . . . . . . . . . . 44

Other Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Contents

1

Airborne particulate matter (PM*) is

widely recognized as a serious environmental and public health concern at levels typical of some U.S. metropolitan areas.

EPA estimates that current regulations to reduce

air pollution can prevent tens of thousands of

premature deaths per year and prevent perhaps

hundreds of thousands of annual hospitalizations for cardiovascular and respiratory illnesses. PM obscures scenic vistas in our National

Parks and Wilderness Areas, and has an impact

on global climate change by perturbing the

Earth’s radiation balance. The science that governs the atmospheric formation, distribution,

and impacts of PM is complex. A broad-based,

multi-disciplinary research program is needed

to improve the basis for effective policy development and implementation. Such an approach

calls for high levels of cooperation, collaboration, and integration among those responsible

for and/or engaged in research on atmospheric

PM (emissions, transport, formation, growth,

deposition, etc.) and its impacts (human health

effects, visibility, radiation balance, etc.). 

In this document, we evaluate the PM research

that is being implemented across all federal

agencies against recommendations and findings

of the National Research Council’s (NRC)

Committee on Research Priorities for Airborne

Particulate Matter1. Specifically, this multiyear

plan:

• presents ongoing and planned future

research by federal agencies in the context of

the research priorities laid out in the NRC

Committee’s most recent report1, focusing

on the 10 priority research topics identified

by the Committee, 

• identifies potential gaps within the context

of these 10 research topics, 

• identifies a course of action to fill gaps, 

• presents ongoing and planned federal activities, both joint and agency-specific, within

the context of the NRC recommendations

on developing a broader multi-agency

research program and improving tools for

science tracking and synthesis, and 

• identifies a plan of action to promote further

improvements in coordination and cooperation among the federal agencies.

Federal Research and Coordination on Airborne

Particulate Matter. Federal research on particulate matter spans many different agencies and is

conducted for many different missions.

Research emphases of the federal agencies

involved in PM research, described in Table 1,

can range from human exposure and health for

informing regulation to atmospheric chemistry

for understanding climate change. As is often

the case in research, findings in one area can

benefit other areas. Indeed, the last decade has

seen an increasing recognition of the need for a

broad-based PM research program that is integrated across the agencies.

In 1997, for example, the President called for a

partnership of federal agencies to develop a

greatly expanded, coordinated, interagency PM

research program that would contribute new science associated with PM health effects, costeffective mitigation strategies, and improved air

quality monitoring. This partnership, the

Introduction

* A list of acronyms used in this report can be found on page 43. 1 NRC, Research Priorities for Airborne Particulate Matter: IV. Continuing Research Progress, National Academy

Press, Washington, D.C., 2004.
Agency/

Department*

Human

Health

Effects

Human

Exposure

Ecological

Effects

Air

Measurements

Atmospheric

Processes &

Modeling

Source

Characterization

Control

Technologies

CDC √ √

CSREES √ √ √

DOE √ √ √ √ √ √

EPA √ √ √ √ √ √ √

FHWA √ √

NASA √ √

NIEHS √ √

NIOSH √ √ √ √

NPS √ √ √

NSF √

NOAA √ √ √ √

NIST √

TVA √ √ √

USFA √ √ √

USGS √

Table 1. Federal Agencies Engaged in Particulate Matter Research.

Particulate Matter Research Coordination

Working Group or simply, the PM Working

Group, was established in 1998 under the Air

Quality Research Subcommittee (AQRS) of the

National Science and Technology Council’s

Committee on Environment and Natural

Resources (CENR). The PM Working Group

focuses on issues related to the integration of

PM research throughout the federal research

enterprise, with a specific emphasis on improving communication and collaboration between

the atmospheric sciences and human health

research communities. In 2002, the PM

Working Group published a Strategic Research

Plan for Particulate Matter2 that summarizes

current understanding, highlights and accomplishments, and identifies key information gaps

in science to support public policy on PM.

The 2002 Strategic Research Plan for

Particulate Matter is based on a conceptual paradigm for PM that integrates research across the

exposure/risk assessment/risk management continuum (see Figure 1). In this paradigm, discipline-specific research will provide key insights

to explain the source-to-receptor relationships

of exposure, the exposure-dose-response relationships of health effects and risk assessment,

and the source control – exposure reduction

relationships of risk management. Post-management decision attention to evaluating

improvements in PM exposure and corresponding improvement in human and environmental

health is an additional feature of the paradigm.

A central tenet of this strategy is that all federal

research be coordinated and fully integrated

across this paradigm, such that all aspects are

appropriately addressed to meet national statutory needs in setting and achieving air quality

standards to protect the public health and environment. Areas of PM research being coordi2

2 AQRS, Air Quality Research Subcommittee, Strategic Research Plan for Particulate Matter, 

http://www.esrl.noaa.gov/csd/AQRS/reports/srppm.html, December 2002.

* A list of acronyms used in this report can be found on page 43.
3

nated under this strategy include human health

effects, ecological effects, exposure, air measurements, atmospheric processes, and source

emissions characterization, as described in

Table 1. In addition to this multi-agency plan,

several agencies have developed agencyspecific PM research strategies to guide their

internal and external programs.

Role of the National Research Council in

Planning for Federal Research on Particulate

Matter. During this same period, Congress and

the EPA began a multi-million dollar research

effort to better understand the sources and

nature of these airborne particles, their exposures to people, and the ways that these particles cause disease.

To provide independent guidance to the EPA,

Congress asked the National Research Council

(NRC) to study the relevant issues. The result

was a series of four reports, published between

1998 and 2004, on the particulate matter

research program. The first two books offered a

conceptual framework for a national research

program, identified the 10 most critical research

needs (Table 2), and described the recommended

timing and estimated costs of such research.

The third volume began the task of assessing

initial progress made in implementing the

research program. The fourth and final volume,

Research Priorities for Airborne Particulate

Matter: IV. Continuing Research Progress1,

gauged research progress made over a 5-year

period on each of the 10 research topics and

identified needed future research, overarching

science challenges, and steps for sustained

research management. The National Research

Council concluded that particulate matter

research has led to a better understanding of the

health effects caused by tiny airborne particles.

Figure 1. Paradigm for Federal Research on Particulate Matter. Reproduced from page 2, Strategic

Research Plan for Particulate Matter, AQRS, CENR, December 2002.
Research Topic 1. Outdoor Measures Versus Actual Human Exposures

What are the quantitative relationships between concentrations of particulate matter and gaseous co

pollutants measured at stationary outdoor air monitoring sites and the contributions of these concentrations to actual personal exposures, especially for subpopulations and individuals?

Research Topic 2. Exposures of Susceptible Subpopulations to Toxic Particulate Matter

Components

What are the exposures to biologically important constituents and specific characteristics of particulate

matter that cause responses in potentially susceptible subpopulations and the general population?

Research Topic 3. Characterization of Emission Sources

What are the size distribution, chemical composition, and mass emission rates of particulate matter

emitted from the collection of primary-particle sources in the United States, and what are the emissions

of reactive gases that lead to secondary formation through atmospheric chemical reactions?

Research Topic 4. Air Quality Model Development and Testing

What are the linkages between emission sources and ambient concentrations of the biologically important components of particulate matter?

Research Topic 5. Assessment of Hazardous Particulate Matter Components

What is the role of physiochemical characteristics of particulate matter in eliciting adverse health

effects?

Research Topic 6. Dosimetry: Deposition and Fate of Particles in the Respiratory Tract

What are the deposition patterns and fate of particles in the respiratory tract of individuals belonging to

presumed susceptible subpopulations?

Research Topic 7. Combined Effects of Particulate Matter and Gaseous Pollutants

How can the effects of particulate matter be disentangled from the effects of other pollutants? How can

the effects of long-term exposure to particulate matter and other pollutants be better understood?

Research Topic 8. Susceptible Subpopulations

What subpopulations are at increased risk of adverse health outcomes from particulate matter?

Research Topic 9. Mechanisms of Injury

What are the underlying mechanisms (local pulmonary and systemic) that can explain the epidemiological findings of mortality and morbidity associated with exposure to ambient particulate matter?

Research Topic 10. Analysis and Measurement

To what extent does the choice of statistical methods in the analysis of data from epidemiological studies influence estimates of health risks from exposures to particulate matter? Can existing methods be

improved? What is the effect of measurement error and misclassification on estimates of the association

between air pollution and health?

Table 2. Airborne Particulate Matter Priority Research Topics identified by the NRC

Committee*.

* Reproduced from Box S-1, page 5, of Research Priorities for Airborne Particulate Matter: IV. Continuing Research 

Progress (Reference #1).

4
5

They further concluded, however, that the EPA,

in concert with other agencies, should continue

research to reduce further uncertainties and

inform long-term decisions.

The NRC work focused on research to improve

the scientific basis for establishing and implementing health based standards in contrast to the

broader focus of the AQRS 2002 strategic plan

outlined above. 

This Report: A Multiuear Federal Resaerch

Plan for Particulate Matter. In the following

sections, the AQRS PM Working Group evaluates PM research that is being implemented

across all agencies against the recommendations

and findings of the NRC Committee. The plan

describes the role of the AQRS in ensuring that

the many PM-related research projects across

the government address the priorities, issues,

and challenges identified by the NRC. It profiles agency research being done under each of

the ten NRC topic areas, establishes research

milestones for major agency-specific research

contributions, establishes a process of periodic

progress review and refinement, and identifies

organizational roles and responsibilities in coordinating cross-agency research. It is designed

to encourage research integration to address

multi-disciplinary research questions and

includes both intramural and extramural

research, both policy-driven projects and those

more fundamental to addressing underlying

physical, chemical, and biological relationships.

Eight years have passed since the NRC committee and the AQRS PM Working Group were

first established. Thus, a careful and comprehensive review of progress and plans related to

PM research is timely, providing a context that

member agencies can use to identify and interpret their roles in implementing the NRC findings. It is important to remember that while the

NRC study focuses primarily on research to

clarify human exposures to PM and attendant

health effects, the AQRS research portfolio goes

well beyond this scope to address a variety of

environmental research (e.g., climate and public

and ecosystem health). This being the case,

AQRS has benefited from a number of other

research assessments in addition to this NRC

study3,4,5,6,7,8. Likewise, this plan considers a

significant amount of relevant research that is

designed to address additional drivers in addition to research that is aimed directly at the

NRC recommendations. Finally, member agencies receive external guidance on research

needs and priorities from Federal Advisory

Committee Act (FACA) committees such as:

USDA’s Agricultural Air Quality Task Force,

EPA’s Clean Air Science Advisory Committee

and its Board of Scientific Counselors, and the

Department of Energy’s (DOE’s) Biological and

Environmental Research Advisory Committee.

KEY CONCLUSIONS

In Part I of this plan, the NRC findings and recommendations for each of the 10 Research

Topic Areas are described and discussed. In

3 AQRS, The Role of Monitoring Networks in the Management of the Nation’s Air Quality, 

http://www.esrl.noaa.gov/csd/AQRS/reports/monitoring.html, March 1999. 4 National Academy of Sciences, Air Quality Management in the United States, National Academies Press, 

Washington, D.C., 2004. 5 NARSTO Particulate Matter Assessment for Policy Makers: A NARSTO Assessment, P. McMurry, M. Shepherd, and 

J. Vickery, eds. Cambridge University Press, Cambridge, England. ISBN 0 52 184287 5, 2004. Available on the 

web at http://www.narsto.org/section.src?SID=6. 

6 CENR, Strategic Plan for the U.S. Climate Change Science Program, A Report by the Climate Change Science

Program and the CENR Subcommittee on Global Change Research, Washington, D.C., July 2003. 7 Intergovernmental Panel on Climate Change (IPCC), Climate Change 2001 – The Scientific Basis, Cambridge

University Press, United Kingdom, 2001.

8 National Academy of Sciences, Air Emissions from Animal Feeding Operations: Current Knowledge, Future Needs,

National Academies Press, Washington, D.C., 2003.
6

reviewing the findings and recommendations of

the NRC Committee in the context of ongoing

and planned federal research, the PM Working

Group of the AQRS has drawn a number of conclusions that are discussed more fully in the

body of the Part I. Several of these are repeated

here, including:

• The AQRS agrees with the general NRC

assessment that there has been substantial

progress answering the research questions

related to the topic of personal exposure

(see discussion of Research Topics 1 and 2,

pages 7-10). The AQRS notes, however,

that the data collected are not yet sufficient

to develop a national perspective on personal exposures, especially for susceptible individuals.

• The AQRS views assessment of hazardous

particulate matter components (see discussion of Research Topic 5, pages 17-19) as

the highest priority area of research. This

work requires a collaborative, multi-disciplinary effort by the atmospheric science

and health effects research communities.

The AQRS also acknowledges that there is a

clear interactive linkage between research to

determine the hazardous PM components,

and research to determine factors of susceptibility and biological mechanisms that elicit

health effects.

• The AQRS endorses the recommendations

of the 2005 NARSTO Emissions Inventory

Assessment9, which independently identified the same needs found by the NRC

within its own eight recommendations and

initial action plan to implement them (see

discussion of Research Topic 3, pages 10-

12). AQRS members will focus their emissions research on the objectives underlying

the recommendations and be guided by priorities developed through “...systematically

continuing to improve emission inventories

by applying sensitivity and uncertainty

analyses and by comparing them to independent sources of measured data” (Chapter

9, page 245 of Reference #3).

• The AQRS recognizes the fundamental

importance of air monitoring and finds that

new technologies and programs have been

instituted to strengthen this capability over

the past six years (see discussion of

Research Topic 4, pages 12-16). However,

important but poorly characterized components remain, notably carbonaceous PM

species, and measurements for these must

be developed and incorporated in routine

monitoring. The AQRS will update the

1999 report 4 on the nation’s collective air

monitoring, incorporating the described

changes in networks, including future plans

for methods development and network

adoption, describing their operation, and

providing a means of coordination.

• The AQRS acknowledges that the research

related to the combined effects of particulate matter and gaseous pollutants is in its

infancy and calls for more effort in this area

(see discussion of Research Topic 7, pages

20-21). Also, collaborative efforts between

atmospheric scientists, exposure scientists,

epidemiologists, and toxicologists are needed to address the difficult issue of combined

effects in human populations.

9 NARSTO, Improving Emission Inventories for Effective Air Quality Management Across North America, April 

2005.
7

I

n this section, the AQRS* addresses the

observations and recommendations made in

Chapters 3, 4, and 5 of the NRC report.1 In

Chapter 3, the NRC reviewed progress under

each of its ten Research Topics originally identified in the 1998 Research Priorities for

Airborne Particulate Matter: I. Immediate

Priorities and a Long-Range Research

Portfolio.

10 The discussion responds to the two

key questions raised by the NRC in its review:

“What has been learned?” and “What remains

to be done?” In the following pages, the AQRS

discusses the NRC’s comments and recommendations with regard to its ten Research Topics

(see Table 2, page 4) and provides descriptions

of research efforts undertaken by the member

agencies to address remaining research needs. 

Following the Research Topic discussion, an

overview is presented (see Tables 4 and 5,

pages 26 and 27) relating the work being done

by AQRS member agencies and Departments

under the ten topic areas and the crosscutting

themes identified by the NRC in Chapter 4

(“Looking Across the Research Topics”) and

the seven overarching challenges identified in

Chapter 5 (“Challenges Ahead for Particulate

Matter Research”).

NRC PORTFOLIO RESEARCH TOPIC #1:

OUTDOOR MEASURES VERSUS ACTUAL

HUMAN EXPOSURE

AQRS Approach

The AQRS agrees with the NRC assessment

that there has been substantial progress answering the research questions related to this topic.

A large number of studies have been completed, substantial data have been gathered, and

results are being published. Data from these

and supplemental studies by the EPA, National

Institute of Environmental Health Science

(NIEHS), and DOE are being used in the further development and evaluation of human

exposure models, notably EPA’s Stochastic

Human Exposure and Dose Simulation

(SHEDS) model and its comparison to other

exposure models being used in assessments of

air quality impacts. The AQRS notes that the

Part I: Research

Recommendations

by Topic Area

* A list of acronyms used in this report can be found on page 43.

10 NRC, Research Priorities for Airborne Particulate Matter: I. Immediate Priorities and a Long-Range Research

Portfolio, National Academy Press, Washington, D.C., 1998.

GUIDANCE FROM THE NRC REPORT

• Describe the quantitative relationships

between outdoor measures and actual personal exposures to PM.

• Evaluate existing exposure models.
8

data collected are not yet sufficient to develop a

national perspective on personal exposures,

especially for susceptible individuals.

Agency Current and Planned Research

EPA:

Research is currently ongoing to analyze

data from eight panel studies and to put

data into the Human Exposure Database

System (HEDS). Work is continuing on

development and evaluation of human

exposure modeling approaches, including

the SHEDS model. The Detroit Exposure

and Aerosol Research Study (DEARS) was

initiated in FY 04. This study is evaluating

relationships between central site, outdoor,

indoor, and personal measurements of air

pollutants (PM, PM components, and air

toxics) and how specific sources impact

these measurements and relationships.

DOE/National Energy Technology

Laboratory (NETL):

The Steubenville Comprehensive Air

Monitoring Program (SCAMP), co-funded by

DOE, EPA, the Ohio Air Quality Development Authority, and industry, is evaluating

exposure of individuals in Steubenville, Ohio,

to PM2.5, PM2.5 components, and gaseous copollutants using centralized monitoring, inhome monitors, and personal monitors.

Department of Health and Human Services

(DHHS)/National Institute of Environmental

Health Science (NIEHS): 

Investigator-initiated grants, and grants

through the Environmental Health Science

Centers program, use personal monitoring

to assess individual exposure that is then

correlated with disease endpoints, such as

asthma. These grants investigate differences between personal and centralized

exposures, including how indoor as well as

outdoor air exposures affect total personal

exposures, and also provide funding to

develop better personal monitors.

DHHS/National Institute for Occupational

Safety and Health (NIOSH):

NIOSH’s basic practice is to perform personal exposure measurements when feasible. NIOSH also has considerable history

in comparing area versus personal exposure

in occupational settings. For instance, a

personal direct reading monitor based on

Tapered Element Oscillating Microbalance

(TEOM) technology has been developed

for personal exposure measurement in coal

mines, and could potentially be adapted for

use in non-occupational settings. This

technology has been extensively tested in

coal mines and agrees quite well with traditional respirable sampler/gravimetric or

chemical analysis.

NRC PORTFOLIO RESEARCH TOPIC #2:

EXPOSURES OF SUSCEPTIBLE SUBPOPULATIONS TO TOXIC PM COMPONENTS

GUIDANCE FROM THE NRC REPORT

• Develop additional exposure measurement

methods for PM components.

• Design future exposure studies for hazardous components.
9

AQRS Approach

The NRC’s assessment considered that work

in this area should be “implemented only after

the work under topic 5 sufficiently advances

understanding of particle characteristics that

determine their toxicity.” We feel that

research has advanced our understanding sufficiently to begin interdisciplinary work on

this topic through integrated exposure and

health effects studies aimed at characterizing

exposures to and effects of PM components.

Integrated research efforts can facilitate and

accelerate systematic efforts to determine hazardous components. This is consistent with

the NRC-recognized need for an integrated

approach across the atmospheric science,

exposure, and health effects research spectrum

in addressing the hazardous components issue.

Exposure studies are being conducted as an

integral part of the ongoing search for the biologically relevant components of PM.

Agency Current and Planned Research

EPA:

As described above, the Office of Research

and Development (ORD) is conducting the

Detroit Exposure and Aerosol Research

Study (See Research Topic #1). As part of

this study, ORD is improving measurement

and analysis of PM components, particularly organic PM. Specifically, ORD is

improving analytical techniques to lower

detection limits for organic PM species,

thus allowing measurement and analysis of

personal exposure to these species.

DOE/NETL:

The Steubenville Comprehensive Air

Monitoring Program (SCAMP) evaluated

32 non-smoking senior adults using electrocardiogram measurements and relating

these to central monitoring station daily

concentrations of fine particles and gases.

Sulfate is being used as a marker of regional, non-traffic pollution. SCAMP is also

studying the air pollution exposures of panels of 12 to 16 children (9-13 years of age)

using personal, indoor, and outdoor fine

particle and gas measurements. Information

was also obtained on activities and time

spent in various microenvironments using

activity diaries and housing characteristic

questionnaires. (Also see Research Topic

#1 above.)

DHHS/NIEHS:

NIEHS continues to fund grants through its

Environmental Justice and CommunityBased Research Program, which evaluates

exposures among individuals with

increased health risk due to their ethnicity,

socioeconomic status, etc. Research on the

adverse effects of air pollutants on susceptible laboratory animals (e.g., aged or with

pre-existing disease) is supported through

the joint NIEHS-EPA Request for

Applications (RFA), “The Role of Air

Pollutants in Cardiovascular Disease.”

USDA/CSREES:

The Cooperative State Research, Education,

and Extension Service (CSREES) program
10

of the USDA is currently funding studies on

the exposures of animals to ambient air pollution, which may have value as surrogates

for human exposures.

AQRS Approach

The NARSTO organization, which includes

many who are also AQRS members, has developed a plan for future emissions inventory development across the United States, Canada, and

Mexico. The NARSTO effort independently

identified the same needs the NRC found and

thus its interagency plan can be used to achieve

the goals laid out by the NRC. The NARSTO

Emissions Inventory Assessment (2005)9 makes

eight recommendations to improve North

American emission inventories and puts forward

an initial action plan for the three countries to

follow in implementing these recommendations:

1. Reduce uncertainties associated with

emissions from key under-characterized

sources. Further discussion and a listing

are presented in Table 3 (corresponds to

NRC guidance calling for a master list

and plan).

2. Improve speciation estimates.

3. Improve existing and develop new emission inventory tools (corresponds to NRC

guidance on new test methods).

4. Quantify and report uncertainty (corresponds to NRC guidance on uncertainties).

5. Increase inventory compatibility and comparability.

6. Improve user accessibility.

7. Improve timeliness.

8. Assess and improve emissions projections.

AQRS members endorse these recommendations and will focus their emissions research on

these objectives, guided by priorities developed

through the further recommended action to

“systematically continue to improve emission

inventories by applying sensitivity and uncertainty analyses and by comparing them to independent sources of measured data” (2005

NARSTO Emissions Inventory Assessment,

Reference #9, page 245). AQRS members recognize that resources must be targeted to reduce

the greatest sources of uncertainty and focused

on those source categories whose control will

be most effective, from both a cost and a

health-risk reduction perspective, in achieving

air-quality management goals. Various expert

panels have proposed lists of priority emission

inventory development needs along these lines.

The preceding list (see Table 3), which has been

consolidated from these recommendations and

produced in the NARSTO assessment, is

viewed as containing the top-priority needs for

improving emission inventories.

GUIDANCE FROM THE NRC REPORT

• Develop a master list and plan for a comprehensive national emissions inventory.

• Develop and apply additional test methods

and testing for sources such as wildfires,

non-road engines, and residential wood

burning.

• Estimate the uncertainties in emissions

inventories.

NRC PORTFOLIO RESEARCH TOPIC #3:

CHARACTERIZATION OF EMISSIONS

SOURCES
11

Future periodic program reviews, as discussed

in Part II below, will focus on assessing

progress in this area by the member organizations, and future recommendations concerning

priority areas will be provided.

Agency Current and Planned Research

DOE/NETL:

The Carnegie Mellon University-Pittsburgh

air quality study is using advanced PM

characterization methods to evaluate emissions from coal plants, coke plants, steel

mills, road dust, and vehicles. Under the

Office of Fossil Energy’s University Coal

Research and Small Business Innovative

Research, DOE/NETL is also sponsoring

several projects to develop advanced methods for characterizing the emissions from

coal-fired utility boilers.

DOE/Office of Science (SC):

The DOE Office of Science anticipates

funding one or two proposals associated

with field campaigns in Mexico City that

would address emission sources contributing to aerosol loadings.

Department of Commerce (DOC)/National

Oceanic and Atmospheric Administration

(NOAA):

Ambient measurements from surface sites

and aircraft are being used to evaluate

existing emission estimates; the 2004 focus

was on the Northeast. NOAA participated

in the preparation of NARSTO’s assessment of emission inventories. They will

continue evaluations using ambient data. A

study was conducted in 2006 in east Texas,

including the Houston and Galveston areas,

which provided an opportunity to evaluate

techniques for emission characterization

using remote sensing techniques.

USDA/CSREES: 

Emissions are being characterized for several species of animal production, wild fire

and controlled burns, and fugitive dust

• Size-segregated, speciated emissions of fine

particles and their precursors, including black

and organic carbon emissions

• Toxic and hazardous air pollutants 

• Emissions from the on-road vehicle fleet

• Emissions of ammonia from agricultural and

other area sources

• Speciated, spatially, and temporally resolved

organic emissions from biogenic sources

• Emissions of volatile organic compounds

(VOCs) and organic hazardous air pollutants

(HAPs) from petrochemical and other industrial facilities

• Emissions from off-road mobile sources

including farm and construction equipment,

aircraft and airport ground equipment, commercial marine facilities, and locomotives

• Emissions from open biomass burning,

including agricultural and forest prescribed

burning, wildfires, and residential backyard

burning

• Residential wood combustion, including

woodstoves and fireplaces

• Paved and unpaved road dust

Table 3. Highest Priority Emission

Inventory Needs *

* As identified by the 2005 NARSTO Emissions Inventory

Assessment (Reference #9).
12

from agricultural production practices. Research has been solicited on all aspects of

production agriculture through USDA’s

National Research Initiative. 

DHHS/Agency for Toxic Substances and

Disease Registry (ATSDR): 

PM and other emissions from asphalt production sites are being evaluated. Seven

sites have been sampled to date. Data from

those sites are being evaluated, along with

data from NIOSH’s five sites and the EPA’s

AP42 and other site-specific data. 

EPA: 

Through its work on NARSTO’s assessment

of emissions inventories9

, EPA will identify

an approach to meet the requirement for a

systematic source testing and inventory plan.

The Office of Research and Development

(ORD) and the Office of Air and Radiation

(OAR) are actively working on new emission test methods, including those using

dilution, for identified key sources. ORD

and others have extensive research underway to upgrade source profiles. ORD is

also working with OAR to update the

Repository of Total Organic Compounds and

Particulate Matter (SPECIATE database,

which is a repository of information on total

organic compounds (TOC) and PM. Work

incorporating Geographical Information

Systems (GIS) into some emissions models

is also ongoing. In addition, ORD is working to identify source marker compounds for

use in source apportionment analyses. This

work includes improved analytical methods

for organic speciation and for detection of

trace level inorganic compounds. These

efforts will enhance source apportionment

used to develop and evaluate emission

inventories.

DOC/National Institute of Standards and

Technology (NIST):

Databases and reference materials are being

developed to provide for improved quantitative measurement of emissions. A structure is being developed for the organization

of kinetics databases for particle formation

models from the combustion of transportation fuels.

NRC PORTFOLIO RESEARCH TOPIC #4:

AIR QUALITY MODEL DEVELOPMENT AND

TESTING (AND MEASUREMENT)

AQRS Approach

The primary subject of this research topic in the

NRC portfolio is the development and testing of

GUIDANCE FROM THE NRC REPORT

• Produce integrated, well-tested aerosol

models, both source and receptor based, for

local air quality management.

• Develop and implement a plan for continuing comparisons that systematically test

emissions data, source and receptor models,

and ambient data against one another.

• Account for substantial sampling and analytical uncertainties in the measurement of

major particle species, most critically

organic material.
13

models to be used in air quality management

planning. Several AQRS members conduct

research and development of aerosol models

and this activity is profiled below (see agencyspecific activity descriptions that follow and

agency websites found in Part II and Table 6 for

full descriptions of agency models). Taken collectively, member research results in ongoing

model evaluation and improvement called for

by the NRC. In addition, periodic intensive

field programs by AQRS members under the

coordinating leadership of one or more members, e.g., the New England Air Quality Study

directed by NOAA, are specifically designed to

test the suite of available aerosol models against

one another and against all available ambient

data. AQRS members commit to this ongoing

practice as part of the next generation of model

development.

A secondary theme under this topic is the development, evaluation, and deployment of air quality

monitors. This subject was last reviewed by the

AQRS in its 1999 report on The Role of

Monitoring Networks in the Management of the

Nation’s Air Quality.

3 At the time, it profiled the

major ground-based air quality and deposition

monitoring networks in the U.S., including

IMPROVE, NAMS/SLAMS, PAMS, NADP/NTN,

NADP/MDN, CASTNet, AIRMoN, and the

GPMP programs (see list of acronyms, page 43).

The report went on to discuss the importance of

monitoring infrastructure and described the

AQRS role in encouraging sustained operation of

critical baseline programs, promoting research to

improve capabilities for emerging issues, and

coordinating network intercomparisons, sampling equipment collocations, quality assurance,

and design of new networks.

-125 -120 -115 -110 -105 -100 -95 -90 -85 -80 -75 -70

25

30

35

40

45

50

0 5 10 15 20 25

Annual Average (2001) PM2.5 (μg/m3)
14

In the seven years since the 1999 report3, substantial improvements and changes to the

nation’s collective air monitoring network have

occurred. New remote monitoring capability

has emerged, new monitoring programs have

been instituted, and a new monitoring strategy

has been prepared for the nation’s air quality

compliance network. The Interagency

Monitoring of Protected Visual Environments

(IMPROVE) network has doubled in size. A

new national fine particle network has been

added (including measurements of PM mass via

Federal Reference Method (FRM) and continuous methods and measurements of PM species

in the Speciation Trends Network (STN)), and

specialty programs have been instituted for

intensive study of fine particle formation (the

Supersites program) and screening of urban air

toxics. New methods for poorly characterized

PM components, notably carbonaceous species,

have been and continue to be the focus of intensive methods development research. Large

intensive field studies, such as Supersites and

the International Consortium for Atmospheric

Research on Transport and Transformation

(ICARTT) programs, have demonstrated the

value of new LIDAR (Light Detection and

Ranging), tethered, aircraft-based and satellite

technology for upper-air measurements crucial

for understanding the all-important transport

phenomena affecting local air quality. The EPA,

working with its state/local/tribal partners and

AQRS members, is putting a new National Air

Monitoring Strategy in place, overhauling the

national compliance and air quality management

network (National Air Monitoring Stations

(NAMS) / State and Local Air Monitoring

Stations (SLAMS), and Photochemical

Assessment Monitoring Stations (PAMS)).

Coordination of the country’s compliance networks with the nation’s infrastructure science

monitoring programs is a key feature of the EPA

strategy. The multi-agency nature of the nation’s

air quality monitoring, taken in whole, emphasizes the importance of this coordination. The

AQRS will update the 1999 report3

, incorporating the described changes in networks, including

future plans for methods development and network adoption, describing their operation, and

providing a means of coordination.

Agency Current and Planned Research

USDA/CSREES: 

Research into dispersion models, primarily

for application in cattle feed-yards, is ongoing. Effort is underway to evaluate the use of

the Federal Reference Method for estimating

PM from agricultural sources. New emphasis

is being placed on process-based models that

use a mass balance approach. New methods

that accurately estimate emissions from rural

areas using improved particle size distributions are also being developed.

DOE/NETL:

The Carnegie Mellon University-Pittsburgh

air quality study is using advanced sulfur processing methods in the Comprehensive Air

Quality Model with Extensions (CAMx) to

predict PM concentrations and composition in

the Eastern U.S. Ohio University is refining

the CMAQ (Community Multi-scale Air

Quality) model to evaluate regional/local deposition of mercury in the Ohio River valley.
15

DOE/SC:

Research is ongoing in aerosol modeling for

air quality purposes. Funding for a number

of proposals for modeling of aerosol processes relating both to air quality and climate is

anticipated. For instance, the Atmospheric

Science Program (ASP) Megacity Aerosol

Experiment – Mexico City (MAX-Mex)

study aims to “obtain a process level understanding of the concentration, composition,

size distribution, hygroscopicity, and optical

properties of ambient aerosol, and their evolution in the Mexico City plume, in the context of Mexico City urban emissions; gather

a comprehensive meteorological and chemical data set suitable for use in regional and

global-scale model validation; and determine

the direct radiative effect of aerosols in the

Mexico City plume as a function of time,

location, and processing conditions.”

DOC/NOAA:

The following activities are underway: comprehensive, intensive studies of aerosol formation and growth; use of comprehensive

datasets from regional air quality intensives

to evaluate existing PM models; laboratory

experiments on fundamental processes related to aerosol formation and growth; development of techniques to improve estimates of

aerosol deposition; quantification of fundamental kinetic and thermodynamic parameters for aerosol formation and growth; development of new techniques to quantify

aerosol properties and composition; measurement of deposition rates for different aerosol

compositions under different land use; development of new models for PM; and development of a nationwide PM forecast capability.

EPA: 

ORD is providing air quality modeling tools

(CMAQ and Chemical Mass Balance (CMB),

UNMIX source-receptor model, and Positive

Matrix Factorization, PMF) and information

(Supersites results) to support state implementation plan (SIP) development. CMAQ

is being run for periods up to a full year for

the continental U.S. and is being tested

against all available field monitoring datasets.

A comparison of CMAQ to REMSAD

(Regional Modeling System for Aerosols and

Deposition) for PM and CAMx (1c) for

ozone is being conducted. A modeling center

(Community Modeling and Analysis System,

CMAS) was created for CMAQ user support,

training, and distribution. Work continues on

improvements to CMAQ’s sub-grid processes. ORD is also working to improve receptor

modeling tools such as PMF and UNMIX.

New versions of these models have recently

been developed and will soon be released for

use by air quality managers. ORD will be

providing guidance and training in the use of

these receptor models and is now working

with several states and EPA regional offices

to apply them.

ORD is also conducting in-house ambient

measurement methods research focused primarily on Federal Reference Method (FRM)

development and testing. Beyond that, ORD

activities include efforts to improve analytical methods for organic speciation and to

address organic PM sampling artifacts. OAR

is promoting the NCore network as part of

the new National Ambient Air Monitoring

Strategy, with Level 2 sites for research and

Level 3 sites for compliance; Level 1 (postSupersites equivalent) are under consideration. In addition, ORD’s extramural Science

To Achieve Results (STAR) grants program

is supplementing methods development and

modeling research in the areas of carbonaceous PM, PM source apportionment, and

continuous PM measurement.

ORD is conducting in-house methods development focused on the FRM air sampling

method. The extramural STAR grants program is supplementing methods development, especially for carbonaceous PM.
The Council for Regulatory Environmental

Modeling (CREM) oversees the Agency’s

models knowledge base for all aerosol and

other models used in program and policy

analysis, e.g., CMAQ, REMSAD, and CMB.

Models in this inventory must meet guidelines covering peer review history, documentation and availability, best management

practices for application, and steps for continuous improvement. A record of EPA’s

actions in response to NRC modeling recommendations will be maintained in this public

database (see the website at

http://www.cfpub.epa.gov/crem/).

DOC/NIST:

A program is now underway to develop engineered PM materials reproducibly and with

traceability to a well-characterized aerosol

generation facility. Method optimization for

carbonaceous constituents in PM2.5 is being

developed as part of a NIST/EPA interagency

agreement (IAG), as well as inter-laboratory

quality assurance exercises and the development of reference materials. Method optimization focuses on measurement accuracy

for elemental carbon in ambient air that is

heavily influenced by distinctive PM

sources. New measurement techniques and

databases are being developed to address

measurement issues. A laser-based thermal

heating technique is under development to

provide thermophysical, optical, and chemical kinetics information on PM. The technique can be used to investigate potentially

spurious effects of heating a soot-bearing

surface, such as found with thermal optical

analyzers. Inter-laboratory quality assurance

exercises and development of reference

materials for organic constituents of PM2.5

are underway as part of a NIST/EPA IAG, in

addition to uncertainty assessment for elemental carbon. Inter-laboratory comparison

exercises assess measurement variability for

various organic constituents including polycyclic aromatic hydrocarbons (PAHs) and

substituted PAHs. Reference materials

include ambient PM2.5 and methods calibration solutions with assigned values for carbonaceous components that include various

toxic organic compounds and emission

source markers.

Department of the Interior (DOI)/National

Park Service (NPS):

Research is ongoing to characterize organic

aerosols, nitrate aerosols, aerosol acidity, filter artifacts and losses, and aerosol optical

properties. Organic aerosol research

includes distinguishing sources using various

organic molecular markers and carbon isotope ratios, identifying organic aerosol optical properties and hygroscopicity, as well as

investigating the variations in organic size

distributions from biomass burning as a

function of age of the smoke. New methods

for cost-effective identification of organic

molecular markers for wood smoke (levoglucosan and related sugar and anydro-sugar

compounds) are being explored.

Characterization of nitrate and other ions in

aerosol particles in the IMPROVE network

include the examination of: aerosol acidity

and its neutralization during post-sampling

handling of IMPROVE filters; the form and

size distribution of nitrate; the efficiency of

aqueous extraction of nylon filters; the losses

of ammonium from particles collected on

nylon filters; the temporal variability of fine

particle ion concentrations; and the efficiency of IMPROVE denuders for the collection

of nitric acid. Receptor and deterministic

models are used to identify contributing

source regions to aerosol concentrations.

Techniques have been developed and applied

to reconcile measured sulfate concentrations

with model results from both REMSAD and

CMAQ, to yield a more reliable estimate of

source-area contributions.

16
17

NRC PORTFOLIO RESEARCH TOPIC #5:

ASSESSMENT OF HAZARDOUS PARTICULATE MATTER COMPONENTS

AQRS Approach

The AQRS considers this its most complex and

highest priority area of research. The toxicological database has provided considerable evidence to support the hypothesis that certain

physicochemical attributes of particles can be

causally linked with regard to the observed

health effects of ambient PM. A single causal

attribute may not be found, but may contribute

to a complex mechanism driven by the nature

of a given PM and its contributing sources. The

multiple interactions that may elicit a response

in a host may make it difficult to identify any

single causal component and may also account

for the fact that mass, as the most basic metric,

shows the relationships to health outcomes that

it does.

Research in this area is moving toward sourcebased linkages with hazardous components and

their contributions to PM adverse health effects.

This new source-based approach will make use

of two techniques, source-specific studies and

source-region studies. In source-region studies,

concentrated atmospheric particles (CAPs) from

urban areas and regions across the country will

be used in coordinated epidemiological and toxicological studies of health effects, their mechanisms, and relative toxicity. Maximum use will

be made of toxicological studies with identical

protocols. Source identification will be accomplished through atmospheric sciences techniques of receptor and source-based modeling

and analysis. Source types amenable to study

in this way include: utilities producing regional

sulfates, gasoline and/or diesel fuel burning

engines, wild and agricultural fires, and metal

and other select industries. The strategy’s second approach, source-specific studies, will

make use of emissions samples collected from

representative sources in extended toxicological

studies of associated health effects. Some of

the source categories to be studied in this way

include diesel engines, coal combustion emissions, wood smoke, and road dust. Both

approaches will make use of integrated exposure studies to ensure that realistic PM composition and concentrations are used and are part

GUIDANCE FROM THE NRC REPORT

• Better integrate toxicological and epidemiological studies to ensure complementary

findings.

• Undertake a systematic, multi-disciplinary

approach to assessing the comparative

toxicity, including exposure-dose-response

relationships of particles of differing characteristics and from different sources.

• Extend toxicological investigations from

single-particle characteristics to include: 1)

addressing characteristics that have received

little attention; 2) defining exposure-dose

response relationships, at realistic exposures; 3) making direct comparisons

between PM with different characteristics

using identical protocols; and 4) evaluating

the importance and role of the characteristic

in question as it exists as a component of

realistically complex exposures.
18

of the exposure-dose-response relationships

produced as the final product of this work. 

Agency Current and Planned Research

DHHS/NIEHS:

Research to study the toxicity of particulate

matter components, using laboratorygenerated PM (including diesel exhaust particles) as well as real-world PM, is being

supported through the extramural division.

In vitro and in vivo models, as well as human

exposure models and epidemiologic studies,

are being used. For instance, research is

being supported to use statistical methods

(such as Principal Component Analysis and

Rolling Factor Analysis) to relate composition of concentrated air particulates (CAPs)

to their toxic effects. Most of this research is

supported through investigator-initiated

grants; however, research is also being supported through a joint EPA-NIEHS Request

For Applications (RFA) to specifically study

the role of PM in cardiovascular disease.

Work through program projects and

Environmental Health Science Centers is trying to integrate exposure assessment, toxicology, and epidemiology research.

DOE/NETL:

The Toxicological Evaluation of Realistic

Emissions of Source Aerosols (TERESA)

program is assessing the toxicity of coal

combustion emissions by exposing laboratory animals to actual plant emissions that

have been “aged” and converted to reaction

products. Two projects to evaluate human

health effects resulting from realistic exposures to primary and secondary PM2.5 from

coal-fired power plant emissions were initiated in FY 05. One project evaluated the

health effects of coal plant emissions and

emissions from other sources (e.g., wood

smoke, vehicle engines, road dust) by generating these emissions in a controlled laboratory setting and evaluating their relative toxicity via a series of animal exposure experiments. The second project utilized a mobile

animal exposure laboratory and particle concentrator in three different ambient environments – one dominated by vehicle emissions,

one dominated by secondary PM from coal

combustion, and one containing a mixture of

vehicle emissions, secondary PM from coal

plants, and emissions from various local

industrial and residential sources.

EPA:

Steering committees have been formed and

workshops will be held on systematic

approaches for hazardous component investigation. In-house and STAR grant programs

are supporting clinical, epidemiologic, animal, and in vitro studies for the following

purposes:

• To link components and attributes of

PM effects, in healthy and susceptible

populations, for coarse, fine, ultrafine,

CAPs, surrogates, and diesel emissions.

• To investigate thresholds and how variations in duration, concentration, and

make-up impact PM effects.

• To characterize the relationship between

the dose an individual is exposed to and

the dose delivered to the target organs,

as well as to identify a dose metric.

• To determine the plausibility and mechanisms for effect endpoints, including

cardiac, pulmonary, immunologic, and

vascular endpoints, covering short-term

and long-term effects.

• To do source apportionment and factor

analysis using multi-pollutant/multi-city

epidemiologic studies, including traffic

studies.

• To conduct controlled human, animal,

and in vitro exposure studies that link

components and/or sources to effects

and determine source potency by endpoint, including coarse, fine, and ultrafine CAPs, and diesel, coal, oil, gaso-
19

line, and wood combustion emissions.

This includes research conducted by the

EPA intramural research program,

research under the new EPA-NIEHS cardiovascular disease RFA, and Phase 2 of

the EPA PM Centers program.

DHHS/NIOSH:

Projects are underway to investigate several

multi-component aerosols including asphalt

fumes, welding fumes, diesel fumes, and

allergens.

NRC PORTFOLIO RESEARCH TOPIC #6:

DOSIMETRY: DEPOSITION AND FATE OF

PARTICLES IN THE RESPIRATORY TRACT

AQRS Approach

Given the wide range of sizes and surface characteristics of ambient particles, the AQRS agrees

that it is important to determine the sites of deposition in the airways and alveoli and the mechanisms of clearance from the lung. This has been

an active area of research for many years, and data

collected so far have increased our understanding

of how particles deposit in the lung. Further

information is needed to increase our understanding of particle clearance and how particle size and

composition impacts distribution to other parts of

the body (e.g., to cardiovascular and neurological

systems). The growing recognition of the potentially unique toxicological properties of soluble

and ultrafine particles requires that new methodologies for generating these particles and better

models for determining the deposition patterns

continue to be developed. Likewise, the availability of faster computers and more sophisticated statistical and modeling methods should facilitate

these efforts. Collaborations with researchers in

the growing fields of nanoparticle toxicity and

aerosol drug delivery, including those in the private sector, should also be encouraged. 

Agency Current and Planned Research

DHHS/NIEHS:

Investigator-initiated grants are supported

through the regular project grant program to

use computer models to evaluate the deposition of air pollutants, including PM, in respiratory tracts. Research to determine the

extent of distribution of the toxic components out of the lung and into the systemic

circulation is also supported. Research supported by the NIH’s National Health, Lung,

and Blood Institute (NHLBI) is also looking

at modeling of particle deposition and at the

dosimetry of inhaled therapeutic aerosols.

GUIDANCE FROM THE NRC REPORT

• Identify differences in the fractional and

regional deposition associated with aging.

• Relate clearance and the effects of gender,

age, and respiratory abnormalities.

• Further characterize the translocation from

the lung to other organs. 

• Produce more information on the dosimetry in animal models of human diseases.
20

EPA:

Current plans call for limited dosimetry studies of animal-to-human extrapolation and the

conduct of modeling studies that will address

fractional and regional deposition. These

studies will also address dosimetry in animal

models. Efforts are also planned to examine

the translocation from lungs to other organs. 

DOC/NIST: 

A project has been initiated to develop a

measurement approach to obtain spatially

resolved species composition of multiphase

aerosols generated from drug

delivery/inhalation devices. Included is

development of a reference aerosol generator

for calibration of inhalation devices.

NRC PORTFOLIO RESEARCH TOPIC #7:

COMBINED EFFECTS OF PARTICULATE

MATTER AND GASEOUS POLLUTANTS

AQRS Approach

The simultaneous exposure of individuals to

multiple pollutants causes two challenges for PM

research: determining the potential confounding

role of gaseous pollutants, and determining if

exposure to multiple pollutants results in a modified biological response, e.g., whether the

effects are additive or synergistic. Collaborative

efforts between atmospheric and exposure scientists, epidemiologists, and toxicologists are

needed to address the difficult issue of combined

effects in human populations. Likewise, while

laboratory studies of combined exposures are

ongoing, this area of research is still in its infancy and more efforts in this area are needed.

Agency Current and Planned Research

DOE/NETL:

A project was initiated in FY 05 to assess the

feasibility of a retrospective epidemiology

study of PM2.5 and co-pollutants in the area

of Pittsburgh, Pennsylvania, using air quality

data from 1999-2003. All exposure and

health effects projects sponsored by

DOE/NETL include the examination of the

combined effects of PM and gaseous pollutants.

DHHS/NIEHS:

Epidemiologic and clinical studies, such as

the Inner City Air Pollution study (co-funded

by EPA) and research at the Environmental

Health Science Centers, are looking at associations between air pollution and a number

of health endpoints, including cardiovascular

and respiratory disease and risk of adverse

birth outcomes. In addition, NIEHS is participating with EPA, Centers for Disease

Control and Prevention (CDC), and the

National Institute of Child Health and

GUIDANCE FROM THE NRC REPORT

• Conduct further studies to disentangle the

effects of PM from other pollutants and

determine whether PM effects vary with

concentrations of other major pollutants in

ambient air.

• Produce a better understanding of why

some mixtures and potentially those from

different sources have different effects in

different diseases.
21

Human Development (NICHD) in the

Children’s Health Study. These studies try to

factor in elements such as correlations

between pollutant levels that might result in

erroneous conclusions. 

EPA: 

In-house epidemiological studies of longterm health effects and traffic emissions in El

Paso and Detroit are being conducted, and

STAR grants for the California Children’s

Health Study and the 24-city study are being

supported. In-house and STAR grant studies

on reproductive and developmental effects

are also being conducted. In-house clinical

human studies are being done on the toxicity

of diesel emissions and CAPs and gases.

Animal studies of diesel and coal emissions,

CAPs, gases, and VOCs are also being conducted. Data from the Detroit exposure

studies are producing relationships between

ambient PM, PM attributes, and PM sources.

Models of personal exposure to PM, leading

to predicted exposure gradients, are being

developed and applied.

DOC/NIST:

A passage for aerosol particle treatment and

sampling is to be appended to the aerosol

generation facility (see NIST contribution in

Research Topic #3) to study aerosol particle

interactions with other independently introduced gaseous and solid additives.

Conditions such as temperature and humidity

will be controlled throughout the passage to

simulate atmospheric conditions of interest. 

NRC PORTFOLIO RESEARCH TOPIC #8:

SUSCEPTIBLE SUBPOPULATIONS

AQRS Approach

The AQRS PM Working Group believes that

this is a high priority area. Data show that age

and health status clearly influence susceptibility

to the adverse health effects of PM. Race and

socioeconomics have also been implicated as

susceptibility factors. Genetic background is a

likely influence, as it is in many other disease

processes, although this area has been much

less studied in relation to air pollution. Support

for controlled human exposure and epidemiologic studies will continue, with emphasis on

identifying susceptibility factors and susceptible

populations. Given the potential expense and

effort-intensive nature of these types of studies,

researchers will be encouraged to mine existing

datasets (using, for instance, meta-analysis) to

try to tease out information on this topic, and to

try to exploit existing long-term cohorts, such

as through the National Health and Nutrition

Examination Survey (NHANES) study.

Likewise, further experimental human exposure

studies on individuals having specific risk factors, and studies using animals that model

human risk factors, will be encouraged.

GUIDANCE FROM THE NRC REPORT

• Conduct more research on the different

scales of exposure, characteristics of exposure, cellular and molecular mechanisms,

range of potential adverse effects, and

potential effect modifiers.

• Investigate whether chronic PM exposures

relate to the development of disease and

organ dysfunction.

• Validate animal models and demonstrate

relevance of these models, especially for

mimicking compromised organ functions

found in susceptible individuals.
The Toxics and Risk Assessment

Subcommittee’s mission is to coordinate interagency research on problems associated with

exposures to toxic materials resulting from

releases to all environmental media. This broad

mission potentially encompasses human exposures to toxic air pollutants found in PM. The

Subcommittee collaborations to date have

focused on key toxics and risk-related issues of

endocrine disruptors, methylmercury, and human

exposure. Each of these is potentially connected

to the needs identified here for a better understanding of the different scales and characteristics of exposure and human susceptibility associated with PM and its components. The AQRS

and the Toxics and Risk Assessment

Subcommittee will work through their leadership

to insure that activities are properly coordinated

and that potential mutual benefits are explored.

Agency Current and Planned Research

DHHS/NIEHS: 

Grants are supported through the investigatorinitiated grant program, and the

Environmental Justice, Community-Based

Research, and Health Disparities Programs,

as well as the joint NIEHS-EPA cardiovascular disease RFA, to assess the burden of

exposure in populations at greater health

risk, e.g., by virtue of their race, socioeconomic status, pre-existing disease, etc.

These projects use epidemiologic methods,

community-based research, animal models,

and controlled human exposure studies to

assess susceptibility.

EPA:

Through in-house research, the STAR grant

program, and Phase 2 of the PM Centers program, studies are being conducted to assess

the relationship between CAPs; coarse, fine,

ultrafine, and diesel PM; and gaseous pollutants and adverse health outcomes. These

studies include epidemiologic panel studies

of asthmatics and diabetics and elderly individuals, as well as clinical studies of asthmatics and individuals with unspecified risk factors. Research projects through this program

also address animal models of asthma, cardiovascular disease, and diabetes in relation

to exposures to diesel exhaust and coal emissions, CAPs, pollutant gases, and VOCs.

DHHS/CDC:

The Public Health Air Surveillance

Evaluation (PHASE) project supports the

mutual efforts of the CDC, EPA, and

state/local partners to systematically and routinely link and analyze air quality characterization data and public health surveillance

data. It is designed to evaluate methods for

generating ozone and particulate matter data

that can be linked to health outcomes data, to

develop a standard method for linking the

data, to assess potential methods for analyzing the linked data, and to provide methods

that will enhance the national effort to build

an environmental public health tracking network. The CDC was given the mandate to

develop a National Environmental Public

Health Tracking Network (NEPHTN) and is

working collaboratively with the EPA, state,

and academic partners in this endeavor. An

important concept of NEPHTN is that data

will be available in the state networks for a

core set of high priority health and environ22
23

mental measures that would be similar

enough across states to be aggregated at a

regional or national level. As part of the

national effort to build the NEPHTN, CDC,

EPA, and three states (Maine, New York, and

Wisconsin) have been working since

February 2004 to develop and evaluate

strategies to link air quality data with cardiovascular and respiratory health data. The

sources of the air characterization data under

evaluation include ambient air monitors, the

EPA/NOAA Community Multi-scale Air

Quality Model, NASA Satellite Aerosol

Optical Depth data, and statistically interpolated and combined sources. The health

effects measured include hospital discharge,

emergency department, and mortality data

for cardiovascular disease, asthma, and other

respiratory effects. A final recommendation

on the most appropriate methods for generating, linking, and analyzing the air and health

data is now available.

NRC PORTFOLIO RESEARCH TOPIC #9:

MECHANISMS OF INJURY

AQRS Approach

There is a clear interactive linkage between

research to determine the hazardous PM components, and research to determine factors of susceptibility and biological mechanisms that elicit

health effects. Although the epidemiologic data

linking PM to adverse health effects continues to

strengthen, experimental research is required to

establish the cause-and-effect relationship. This

type of research is needed to identify cellular

and molecular targets, identify susceptibility

factors, and determine possible intervention

strategies. Experimental research (in vitro and

in vivo) should be informed by the human

studies, in terms of potential health endpoints

and PM types. Therefore, work will continue in

this area, with emphasis being placed on using

epidemiologic data to develop appropriate

hypotheses and on encouraging interdisciplinary

collaboration to assure that environmentally relevant PM materials and appropriate doses are

used in the protocols. 

Agency Current and Planned Research

DHHS/NIEHS: 

Research in this area is supported both in the

extramural and intramural components. This

includes in vitro, in vivo, and controlled

human exposure studies, and panel studies.

Studies examine the cellular responses to

CAPs, diesel exhaust, and artificially produced particulate material. Studies using

animal models, including dogs and wild type

and genetically manipulated rodent models,

examine the effects in the context of the

whole organism. Experimental human studies evaluate the mechanisms of pulmonary

and cardiovascular responses to PM in carefully controlled situations. 

EPA: 

Clinical and animal studies are conducted to

link the effects of components and attributes

of PM to mechanisms of action. This is

done for healthy versus susceptible subpopulations, using coarse, fine, and ultrafine PM

and components from CAPs and surrogates.

In addition, toxicology, in vitro, and molecular studies of plausibility and mechanismsof-effect endpoints, including cardiac, pulmonary, immunologic, and vascular endpoints, are conducted. Mechanisms of longGUIDANCE FROM THE NRC REPORT

• Extend physiological and cellular mechanism studies to molecular mechanisms.

• Understand the relationship between the

mechanisms responsible for acute versus

chronic effects.

• Understand the dose dependency for

mechanisms underlying exposure-response

relationships.
24

term and short-term effects are contrasted.

This work is supported by the EPA-NIEHS

cardiovascular RFA and the first phase of

PM Centers Programs. 

DHHS/NIOSH:

Several projects are ongoing to investigate

mechanisms of respiratory system response

to several types of particles including silica,

fibers, titanium dioxide, carbon nanotubes,

and other nanoparticles.

NRC PORTFOLIO RESEARCH TOPIC #10:

ANALYSIS AND MEASUREMENT

AQRS Approach

Epidemiologic studies that employ a variety of

designs, including prospective, time-series,

case-control, and case-crossover studies, need

to continue to be supported. One goal of these

studies will be to evaluate the effect of study

design and modeling approach on the results.

As mentioned above, inclusion of experts in

exposure and atmospheric sciences will enhance

this effort.

Agency Current and Planned Research

DHHS/NIEHS:

Through the investigator-initiated grant program, epidemiologic studies are supported to

assess the link between PM and disease endpoints. These studies include research to

optimize experimental design and to develop

innovative statistical methods.

DOE/NETL: 

An ongoing project, begun in FY05, is

assessing the feasibility of alternative statistical modeling approaches for conducting a

retrospective epidemiology study of PM2.5

and co-pollutants in the Pittsburgh,

Pennsylvania, area using air quality data

from 1999-2003. 

EPA: 

These considerations are inherent in ongoing

in-house and STAR grant epidemiology studGUIDANCE FROM THE NRC REPORT

• Develop a more complete understanding

of the impacts of modeling approaches in

time-series studies.

• Further investigate the issue of harvesting

or mortality displacement.
25

ies, including both the Detroit children’s

health study and the recently awarded 10-

year multi-city epidemiologic study.

DOC/NIST: 

Product performance is measured with

respect to criteria air pollutants, including

particles, based on translating their cradle-tograve releases of these pollutants into 

disability-adjusted life years that represent

health losses from air pollution. A new

measurement approach to determine soot

volume fraction has been developed for fires.

Aerosol measurements and standards are

being developed for asbestos. 

CROSS-CUTTING RESEARCH ISSUES AND

OVERARCHING CHALLENGES

The NRC report1 in Chapter 4 (“Looking

Across the Research Topics”) discusses five

cross-cutting issues that provide additional

insight into the work to be done under each of

the ten research topics and allows for alternative mechanisms to gauge overall progress in

addressing the PM issue as a whole: 

• The increasing number of health outcomes

associated with PM

• Particle toxicity of PM characteristics and

emission source types

• Increased emphasis on exposure-doseresponse relationships

• Considering PM health effects in the context

of other pollutants

• Considering the implications of setting and

implementing the PM National Ambient Air

Quality Standards (NAAQS)

Table 4 shows the relationship between these

cross-cutting topics and the 10 research priority

areas also identified by the NRC. Viewing

these research priorities in this alternative

framework highlights an important role for the

AQRS. Specifically, the multidisciplinary perspective and complementary nature of the various agency missions that constitute the AQRS

facilitate the integration of information gained

through this federal effort. 

Similarly, the NRC in Chapter 5 (“Challenges

Ahead for Particulate Matter Research”) discusses seven overarching challenges it sees that

must be faced in addressing the full complement of research under its portfolio and gauging

its progress by alternative means:

• Completing PM emissions inventories and

models necessary for NAAQS implementation

• Developing a synergistic program to assess

component and mixture toxicity

• Enhancing air quality monitoring for

research

• Investigating long-term health effects

• Improving toxicological approaches

• Transitioning to a multi-pollutant program

• Integrating across disciplines

Table 5 crosswalks these challenges with the

work being done by the AQRS associated with

each of the 10 priority research topics. Meeting

each of these challenges will take the combined

synergy of the federal air research community.

Once again the AQRS is optimally positioned to

facilitate meeting these challenges within the

context of implementing its coordinated

research strategy.
26

Cross-cutting Issue Description of Issue Research

(From Chapter 4 (Paraphrase of NRC Description) Topic(s)

of the NRC Report 1)

An increasing number Research on the health effects of air pollution, including particulate matter, #8 and #9

of adverse health out- initially emphasized the development and exacerbation of lung diseases. 

comes associated with However, in more recent years, studies have shown a strong association

PM and the related between exposure to PM and non-pulmonary diseases, most notably

susceptible cardiovascular disease, but also including adverse birth outcomes. Along

subpopulations with this came the recognition that certain individuals and populations are

more at risk for the adverse effects of PM exposure, by virtue of a preexisting disease,age, race, etc.

Particle toxicity in Current air quality rules treat all particles of a given size as equally toxic #5

relation to different and having the same dose-response relationship. It is becoming clear that

particle characteristics some particles are more toxic than others, though which types or combinaand emission-source tions are most toxic is unclear. Although acknowledged as a very difficult

types problem, a better understanding of the relative toxicities of particles and their

mixtures with different physical and chemical characteristics and from

different sources, will be important to effective reduction of PM-induced

health effects.

Increasing emphasis on Research in the past has focused mostly on the identification of hazardous #2, #5, and #9

exposure-dose-response pollutants. As more is learned about the hazardous components of PM, a

relationships shift in emphasis needs to take place toward characterizing the form of the

quantitative relationship between exposure and risk to most effectively

reduce PM-related risk.

Consideration of PM Most research results have come from experiments that use single- or two- #7

health effects within the pollutant exposures. Research is beginning to show that the health effects

broader context of the of exposures to multiple air pollutants more representative of a mixed atmosother pollutants phere can have a synergistic effect. Since many pollutants work through

similar pathophysiologic mechanisms, it is likely that simultaneous exposure

to gases would influence the body’s response to particulate matter. Further

research using multiple pollutant exposures and focusing on synergistic 

responses is needed.

Consideration of the For NAAQS implementation purposes sources that should have priority #3, #4, and #9

implications for setting need to be identified. Those will be sources emitting PM components in

and implementing the locations and during periods that most directly contribute to local PM levels

PM NAAQS above national standards. The NAAQS has four elements: an indicator, 

averaging time, numeric level, and statistical form that historically have

been set relying primarily on epidemiological data relating a PM metric to

health endpoints. In the future, a greater emphasis on understanding PM

components and their sources with an enhanced understanding of mechanism

of effects could usefully guide the setting of the NAAQS indicator and

averaging time, and lead to most effective implementation.

Table 4. Relationship Among the NRC’s Crossing-cutting Issues and Their Research Topics.
27

Overarching Challenge Description of Challenge Research

(From Chapter 5 (Paraphrase of NRC Description) Topic(s)

of the NRC Report 1)

Completing the PM The report calls for faster progress to ensure that state implementation plans #3 and #4

Emissions Inventory and are based on the best information available by promoting iterative improvePM Air Quality Models ments in emission inventories, monitoring networks, and air quality models.

necessary for NAAQS

implementation and

informing health

research

Developing a systematic Results from previous studies have given us data that are not “convergent” #5

program to assess the enough to allow strong conclusions to be drawn. The report recommends a

toxicity of different new paradigm for research on the health effects of PM components that

components of the would be more systematic and would involve better integration across

PM mixture toxicology and epidemiologic areas.

Enhancing air quality Air quality monitoring activities should begin to move away from solely #4

monitoring for research assessing NAAQS compliance to providing data that are useful for health

effects research. Redesign of these monitoring programs should get input

from health and atmospheric scientists to assure these needs will be met.

Investigating the health Estimates of disease burden associated with exposure to PM are needed and #5, #7, #8,

effects of long-term research should continue to develop on the basis of existing and new cohorts. and #9

exposure to air pollution Although long-term epidemiology studies are difficult and expensive, these

kinds of studies are needed for quantitative risk assessment and cost-benefit

analysis. Long-term animal studies are also needed, although the problems

with finding animals and designs that can model human disease are

recognized.

Improved toxicologic Toxicologic studies are needed that employ appropriate animal models and #9

approaches that use inhalation as the primary route of exposure and involve concentrations more representative of real world exposures. Endpoints other than

respiratory and cardiovascular ones should be included in the experiments.

In addition, well-characterized particle samples should be used.

From a particulate matter Most research to date has focused on one or a few pollutants, and a new #7

research program to a multipollutant experimental paradigm is needed. This shift in focus should

multipollutant research acknowledge that real-world exposures involve complex mixtures of hundreds

program of air contaminants of several physical-chemical classes.

Integrating across the In order to address these large research issues, an integrative approach #1 – #10

disciplines involving epidemiologists, toxicologists, exposure assessment experts, and

atmospheric scientists is essential, and collaboration among the specialties

needs to begin early in the experimental design process. There are several

obstacles to this type of approach, but some researchers have begun to use it.

Table 5. Relationship Among the NRC’s Overarching Challenges and Their Research Topics.

29

The NRC report1 addresses the improvement of

PM research management and the gathering and

synthesis of information. Specifically, it

addresses: (a) the need for enhancing and sustaining research management across the broader

research enterprise, and (b) the tools needed for

enhancing the tracking and synthesis of science

going forward. This part of the report discusses

how the AQRS addresses these NRC recommendations.

DEVELOPING A BROADER MULTI-AGENCY

RESEARCH PROGRAM

The NRC Subcommittee made five recommendations to enhance cross-federal management of

PM research:

1. Establish multi-agency and agency-wide

research goals and measures for determining the degree of success in meeting

national goals.

2. Prepare a multiyear plan for PM research

across agencies, transitioning to a multipollutant approach, and incorporating state

and private activities.

3. Obtain periodic independent reviews of

the multiyear plan.

4. Define the specific roles and responsibilities

of individual research funding agencies.

5. Incorporate other non-federal PM research

funding organization inputs and expand

the transparency of the federal PM

research planning process.

Each of these recommendations has been acted

upon by the AQRS with the response being provided below.

Response:

• The AQRS Strategic Research Plan for

Particulate Matter 2 (December 2002) sets

out the multi-agency and national goal,

objectives, and approach for PM

research. The goal, objectives, and

approach of the AQRS strategic plan (see

box) provide the foundation for the more

detailed plan called for by the NRC.

• Agency research plans contain agency-wide

goals and measures. Member agencies all

have multiyear research planning processes

that set goals and measures of progress in

achieving their respective science mission.

Some agency research missions are broad and

go to the general reduction of scientific

Part II:

Improving Program

Coordination

NRC RECOMMENDATION #1

Establish multi-agency and agency-wide

research goals and measures for determining

the degree of success in meeting national

goals.
30

PM Research: Goals, Objectives, and Approach from the

AQRS Strategic Research Plan for Particulate Matter

Goal:

Enhance the scientific information base for public policy that protects the public health (of primary

importance) and the environment from harmful effects due to airborne particulate matter.

Objectives:

Integrate health, exposure, ecology, atmospheric process, and source characterization research pertaining to particulate matter. Coordinate efforts among U.S. federal agencies and, as feasible, the

private sector. Address the highest priority research needs first, to inform public policy choices for

standard setting and air quality management. 

Approach:

The federal PM research strategy is based on a conceptual paradigm for PM that integrates research

across the exposure/risk assessment/risk management continuum (see Figure 1). Discipline-specific

research will provide key insights to explain the source-to-receptor relationships of exposure, the 

exposure-dose-response relationships of health effects and risk assessment, and the source controlexposure reduction relationships of risk management. Post-management decision attention to evaluating improvements in PM exposure and corresponding improvement in human and environmental

health is an additional feature of the paradigm. A central tenet of this strategy, as depicted by the overlapping and closed loops of the paradigm, is that all federal research be coordinated and fully integrated across this paradigm, such that all aspects are appropriately addressed to meet national statutory

needs in setting and achieving air quality standards to protect the public health and environment. Areas

of PM research being coordinated under this strategy include: human health effects, ecological effects,

exposure, air measurements, atmospheric processes, and source emissions characterization.

Figure 1. Paradigm for Federal Research on Particulate Matter. Reproduced from page 2, Strategic

Research Plan for Particulate Matter, AQRS, CENR, December 2002.
31

uncertainty or to advancing the state of scientific knowledge, for example to support basic

research on atmospheric aerosols, or to understand the fundamental biological mechanisms

by which environmental pollutants affect

human health. Other science missions are

problem driven and directly inform public

policy or programs, for example providing the

underlying science needed to set national standards to protect the public health from the

harmful effects of air pollution, or preparing

the scientific foundation to help remedy the

degradation of visibility in Class I areas due to

haze. In both instances the research being

done contributes to the goals and objectives of

the AQRS Strategic Research Plan for

Particulate Matter 2

, even though some

aspects are driven primarily by the PM

research agenda while some are not. Some

research may be investigator initiated and fall

under broad areas of agency interest. Other

research may be highly prescribed to meet

specific agency needs. Table 6 presents the

major parts of agency program objectives and

measures that contribute directly or indirectly

to the research needs identified by the NRC.

The activities and milestones presented in

Table 6 reflect past federal research investments, those made prior to 2006 that will produce results into 2010, and current and

planned investments under base research programs. Collectively these objectives and

measures form the central components of a

combined federal multiyear research plan for

particulate matter.

USDA/CSREES RESEARCH MILESTONES 2006 2007 2008 2009 2010

By 2007, generate comprehensive PM emission inventory for production agriculture

Research on characterizing and estimating agricultural emissions

Update inventory of agricultural emissions

By 2007, generate best practices for reducing agricultural PM emissions

Research on developing best practices to reduce agricultural emissions

Complete document of recommended best practices

By 2010, have a better understanding of the fate and transport of agricultural PM

Research on fate and transport of PM on component farm processes such as

corrals, buildings, etc.

Research on fate and transport of PM for whole farm enterprises and development of process-based models

By 2010, evaluate implementation of best practices and create PM emission reduction targets

Transfer technologies to producers to mitigate emissions

Develop emission reduction targets

Table 6. Research & Development Activity: Current and Planned Investments *

* A list of acronyms used in this report can be found on page 43.
32

Table 6, continued. Research & Development Activity: Current and Planned Investments.

DOC/NOAA PM RESEARCH MILESTONES 2006 2007 2008 2009 2010

Quantification of aerosol formation, growth, transport and deposition

Provide kinetic parameters for secondary organic aerosols (SOA) derived

from biogenic precursors (ESRL)

Quantify role of petrochemical emissions in SOA formation and growth

(ESRL)

Develop and test improved modules for SOA predictive models (ESRL)

Provide improved estimates of sulfate aerosol deposition rates (ARL)

Quantify relationship between nighttime chemistry and ambient aerosol levels (ESRL)

Quantification of aerosol optical properties

Quantify relationship between light scattering and composition for the

Northeast (PMEL)

Quantify relationship between light scattering and composition for Texas

(PMEL)

Provide improved characterization of aerosol hygroscopic growth (ESRL)

Development of instrumentation for aerosol detection and characterization

Develop fast-response instrumentation for quantification of aerosol composition (ESRL)

Develop instrumentation for remote sensing of aerosol size distribution

(ESRL)

Develop fast-response instrumentation for quantification of aerosol extinction (ESRL)

Development and deployment of PM forecast capability

Compare PM forecast models (ARL, ESRL)

Develop and evaluate smoke models for AQ forecasts (ARL, ESRL, NESDIS, NWS)

Produce prototype operational PM2.5 model (ARL, ESRL)

DOI/NPS PM RESEARCH MILESTONES 2006 2007 2008 2009 2010

By 2008, air quality in 70 percent of reporting park areas has remained stable or has improved

New methods for cost effectively identifying organic molecular markers for

wood smoke

Characterization of nitrate and other ions in aerosol particles in the

IMPROVE network

Receptor/deterministic models used to identify contributing source regions to

aerosol concentrations
33

Table 6, continued. Research & Development Activity: Current and Planned Investments.

By 2014, produce new exposure, epidemiology, toxicology, and clinical data on health risks for susceptible subpopulations from long-term PM exposures

Characterize long-term cardiopulmonary effects of PM and co-pollutants

(NHEERL, NCER)

Characterize long-term respiratory health effects of PM in children

(NHEERL, NCER)

Develop accurate surrogates of long-term exposure for PM constituents and

co-pollutants (NERL)

Assess the exposure-response relationship for PM and source-based components (NHEERL, NCER)

Characterize the combined effects of PM and co-pollutants in susceptible

subpopulations (NHEERL, NCER)

Describe mechanism of acute effects; link to PM components in susceptibles

(NHEERL, NCER)

Identify and contrast factors of susceptibility for acute, subchronic, and

chronic exposures to PM and co-pollutants (NHEERL, NCER)

* For more information see EPA’s Particulate Matter Research Program Multi-year Plan - 2003 (updated in 2006) at

http://www.epa.gov/osp/myp.htm.

EPA PM RESEARCH MILESTONES * 2006 2007 2008 2009 2010

By 2012, develop and transfer data and tools to attain PM NAAQS and refine health risks

Deliver updated air quality model, and improved emissions and ambient data

(NERL, NRMRL)

Transfer information on performance, cost-effectiveness, applicability of control technologies (NRMRL)

Update and enhance tools to model, measure, and reduce PM mass (NERL,

NRMRL, NCER)

Produce measurements and models of carbonaceous PM source to fate

(NERL, NRMRL, NCER)

Transfer data/tools to predict and measure residual non-attainment impacts

(NERL, NRMRL, NCER)

By 2009, develop and transfer new epidemiology, toxicology, and clinical data on health risks to general and

susceptible subpopulations from short-term exposures

Identify the factors of susceptibility for acute PM exposures in susceptible

subpopulations (NHEERL, NCER)

Characterize effects of PM and co-pollutants on healthy animals and humans

(NHEERL, NCER)

Identify and link effects/mechanisms of toxicity for constituents/sources

(NHEERL, NRMRL, NCER)

Determine the critical factors influencing short-term exposure (NERL,

NCER)

Characterize exposure and exposure factors for general and susceptible subpopulations (NERL)

Produce a refined and evaluated exposure model (NERL)
34

2006 2007 2008 2009 2010

By 2006, complete ambient monitoring and analysis in Ohio Valley region

Final Report, Pittsburgh Air Quality Study (Pittsburgh PM Supersite)

By 2006, complete predictive modeling and evaluation of coal plant emission charges

Analyze effects of power plant emission control strategies on PM in

Pittsburgh region using PMCAMx+

By 2009, evaluate health effects of PM from coal power plants

Assess short-term toxicity of PM from coal combustion emissions by exposing animals to actual plant emissions that have been “aged” and converted to

reaction products

Develop a strategy to better define the public health implications of PM

emissions from coal-fired power plants in the Pittsburgh region, using retrospective epidemiological study methods

Conduct laboratory animal study of selected respiratory and cardiac health

hazards from repeated inhalation exposure to PM from “simulated downwind” coal combustion emissions

Use mobile animal exposure laboratory and particle concentrator in ambient

environments to evaluate adverse cardiopulmonary effects from exposure to

coal-fired power plant and traffic-related PM

* For more information see DOE/NETL’s DOE-NETL Air Quality Research Program: Overview at

http://www.netl.doe.gov/coal/E&WR/air_q/.

** From 1998 - 2004, DOE’s Office of Fossil Energy conducted an Air Quality Research program through its National Energy

Technology Laboratory (NETL). Phase out of this program began in 2005. No new initiatives have begun since that time; however,

projects that were funded prior to 2005 are proceeding toward their scheduled completion and are reflected in Table 6 milestones.

Table 6, continued. Research & Development Activity: Current and Planned Investments.

DOT/FHWA PM RESEARCH MILESTONES * 2006 2007 2008 2009 2010

Develop and transfer data and tools to attain PM NAAQS and refine health risks

Support development of updated air quality analysis methods and improved

emissions data

Transfer information on performance, cost-effectiveness, applicability of control technologies

Determine PM emission contributions from light duty (gasoline) vehicles

Determine PM emission contributions from heavy duty (diesel) vehicles

Determine spatial distribution of PM emissions and concentration (proximity

studies)

Determine nature of PM2.5 emissions (regional versus local)

Determine cost-effective mobile source mitigation strategies

* For more information see FHWA’s Strategic Workplan for Particulate Matter Research: 2000 to 2004 at

http://www.fhwa.dot.gov/environmental/pm/index.htm.
35

Table 6, continued. Research & Development Activity: Current and Planned Investments.

DHHS/NIEHS PM RESEARCH MILESTONES 2006 2007 2008 2009 2010

By 2009, develop better understanding of role of PM in cardiovascular disease (CVD)

Evaluate results on mechanisms of PM-induced cardiovascular disease from

joint grants with EPA under “Role of Air Pollutants in Cardiovascular

Disease” RFA

Evaluate results from epidemiologic studies on air pollution and CVD

By 2008, develop better understanding of effects of PM on exacerbation of asthma symptoms

Evaluate results of epidemiologic studies from Children’s Center and 

investigator-initiated grants

Evaluate results from basic studies on the effect of diesel and other PM on

immune function in the lung

By 2008, develop better understanding of effect of PM exposure on prenatal development

Evaluate results of epidemiologic studies on risk of birth defects

Evaluate results from Fetal Basis of Adult Disease RFA that deal with prenatal PM exposure and adolescent and adult lung and cardiovascular disease 

By 2008, develop better understanding of differential effects of PM exposure on different populations

Evaluate results from Environmental Justice, Community-Based

Participatory Research, and Health Disparities programs that deal with location of residence and risk of adverse effects of PM exposure

TVA PM RESEARCH MILESTONES 2006 2007 2008 2009 2010

By 2006, further modeling and measurement studies on composition, sources, and variability of PM in the

Tennessee Valley region

Evaluate role of hourly PM composition measurements in determining variability of exposures to PM in the southeast region of the U.S.

Report on project on source apportionment of organic aerosols in TVA

region; continue cooperative study of organic aerosol source apportionment

in southeast U.S. jointly through the VISTAS RPO

Continue work on model treatment of clouds and sulfur

By 2010, model and measure effect of emissions reductions on air quality in Tennessee Valley region

Project to examine ability of models to simulate climatological variability in

PM

Trends analysis of ozone and PM data for urban and rural/background sites

in the region
Response:

• The AQRS PM Research Strategy will be

updated and will become a multiyear plan

for PM research. The PM Research

Coordination Working Group will hold a

series of reviews comparing the combined

set of agency program objectives and timelines listed in Table 6 with the research

needs identified by the NRC in Part I above.

Convening a series of reviews under its

organizing research areas and in each of the

NRC priority areas will facilitate the

exchange of project progress, thereby maximizing cross-government collaboration in

furthering our understanding of PM within

the context of federal government priorities.

These reviews will be led by designated

research area co-leads and will encourage a

more fully integrated approach to ensuring

that the government’s research provides the

science necessary for developing sound federal policies. Following these reviews, the

AQRS will update its Stategic Research

Plan for Particulate Matter 2 to address key

information and research gaps. The

resulting updated strategy document will

serve as the interagency multiyear plan for

PM research called for by the NRC. Once

drafted by the AQRS, this multiyear plan

will be forwarded to the CENR for its

review and approval.

• Member agencies participate in other

cross-organizational research planning

and coordination. In addition to the AQRS

and PM Research Coordination Working

Group, two other organizations, NARSTO

and the Health Effects Institute (HEI), facilitate cross-organizational research planning

and coordination. NARSTO (http://www.-

narsto.org) was chartered in 1995 as a public/private consortium of the major sponsors

of atmospheric sciences research in the

U.S., Canada, and Mexico. Its membership

includes state and private organizations and

many members of the AQRS. NARSTO

coordinates research on air measurements,

atmospheric processes and modeling, and

source characterization. It is guided by a

PM Research Plan, set to strategic execution

plans, periodic assessments, and regular

meetings. NARSTO provides a direct

opportunity to interact with states and the

private sector and to address multi-pollutant

issues. For example NARSTO is expanding

its role to include climate aspects of aerosol

pollution. HEI

(http://www.healtheffects.org) is an independent, nonprofit corporation chartered in

1980 to provide high-quality, impartial, and

relevant science on the health effects of pollutants from motor vehicles and from other

sources in the environment. It is supported

jointly by the EPA and industry. HEI’s priorities for research and special reviews are

guided by the five-year HEI Strategic Plan,

which is reviewed and updated annually

after consultations with HEI sponsors and

other interested parties.

• Agency research plans, programs, and

projects are increasingly multi-pollutant

in nature. The Combined Effects of PM

and Gaseous Pollutants research topic (see

NRC Research Topic #7 above) is leading

member agency research agendas to be

increasingly multi-pollutant in character.

For example, our work on PM requires us to

consider the synergistic effects of combined

sulfate, nitrate, and carbonaceous material,

and also to consider their collective impacts

on ozone and air toxic issues through the

sources and processes they have in common.

36

NRC RECOMMENDATION #2

Prepare a multiyear plan for PM research

across agencies, transitioning to a multipollutant approach, and incorporate state and

private activities.
37

Further, the science information and tools

that PM research is developing have multipollutant features. New air quality models

and source receptor models have multipollutant capabilities. Source characterization profiles are multi-pollutant. Exposure

studies report on co-pollutant results, and

health effects studies are more and more

focused on air quality and source emission

mixtures. Most agencies are routinely

taking multi-pollutant objectives into consideration during their multiyear planning

(Table 7) and preparations for individual

studies and field campaigns. The future

update of the AQRS Stategic Research Plan

for Particulate Matter 2 and expansion to a

multiyear plan will include a multi-pollutant

approach that builds on these common goals,

tools, and science outcomes.

Response:

• Agencies have their multiyear research

plans and major program plans and

related goals, measures, strategies, and

priorities reviewed by independent advisory committees. Agency-specific multiyear

research plans and major research program

plans now regularly go through external peer

review. For example, EPA’s PM Multi-Year

Plan has been reviewed in the past by the

NRC PM Research Panel and in the future

will be reviewed by a comparable panel periodically convened for this purpose. Beyond

this program-wide review, all of EPA’s program research plans are routinely externally

reviewed by its Science Advisory Board and

its Board of Scientific Counselors. Further,

EPA’s laboratory and center cross-cutting

research programs are put through external

PM RESEARCH AREA LEAD COORDINATING

AGENCIES

OTHER AGENCIES

CONTRIBUTING

Human Health Effects NIEHS and EPA CDC, NIOSH, DOE/NETL

Human Exposure EPA and NIOSH CDC, NIOSH, DOE/NETL

Ecological Effects NPS and NOAA EPA, USDA/CSREES

Air Measurements EPA and NOAA NPS, USGS, NASA, DOE/FE TVA,

NIST, USDA/CSREES, NIOSH

Atmospheric Processes and Modeling NOAA and EPA NSF, DOE/SC, TVA, USDA/CSREES

Source Characterization EPA and USDA/CREES FHWA, DOE/FE, TVA, NIOSH,

NOAA

Control Technologies EPA and DOE/NETL FHWA, NIOSH, USDA/CSREES

Table 7. Agency Co-leads for PM Research Coordination, and Contributing Research

Organizations.

NRC RECOMMENDATION #3

Obtain periodic independent reviews of the

AQRS multi-year plan and the agencyspecific plans it incorporates.
38

peer review every three years. NOAA’s

overall research plans are similarly reviewed

by an independent Science Advisory Board.

Individual NOAA laboratory research programs and projects are periodically reviewed

by an independent expert panel. The DOE

Atmospheric Science Program was recently

reviewed by an independent Federal

Advisory Committee. The review included

briefings on aerosol research supported by

both other AQRS agencies as well as agencies that contribute to the U.S. Climate

Change Science Program (CCSP). The

review was conducted in accordance with the

Federal Advisory Committee Act. Agencies

also perform an external review function for

one another. For example, EPA personnel

performed technical merit reviews that

guided the selection of three DOE/NETL

projects in FY 05 to examine the relationship

between coal power plant emissions and

human health.

• The AQRS PM multiyear plan will use a

tiered approach to external peer review.

The first tier of external review will continue

to be the ongoing reviews of individual

agency plans that form the foundation of the

AQRS multiyear plan. A second tier of

review will be provided by the AQRS parent

Committee on Environment and Natural

Resources member agencies and their science experts. This review will precede

CENR sign-off on the AQRS PM multiyear

plan before it is released to the public. A

third tier of review will take place in the

context of EPA’s role as co-lead for overall

interagency coordination. EPA’s PM MultiYear Plan,11 including its description of

interagency research, is periodically put

through external peer review by its standing

Board of Scientific Counselors and specially

convened panels such as the NRC.

Response:

• The PM Research Coordination Working

Group has identified the principal roles

and responsibilities for funding agencies.

Two different types of research are conducted by member agencies: problem-driven

research directly supporting regulatory policies and programs, and fundamental or

basic research contributing to the body of

science that generally informs public policy.

The roles and responsibilities of member

organizations tend to be characterized by

one of these two types of research. EPA,

for example, has regulatory and standardsetting missions, and its research programs

are largely problem driven. Therefore

EPA’s principal role is to see that sound science is available for its programs as needed,

producing it themselves or through cooperating with other research organizations to

fill information gaps. Other agencies such

as NIEHS, NOAA, and NSF have research

missions that contribute to the reduction of

uncertainties in areas of general societal

interest such as public health, weather,

atmospheric processes, and climate change.

Their roles are to advance the body of

knowledge in those areas, working in combination with others. 

PM research by member agencies can also be

characterized as falling into one or more of

the broad research areas of the AQRS

Strategic Research Plan for Particulate

Matter 2

: human health effects, human exposure, ecological effects, air measurement,

atmospheric processes and modeling, source

NRC RECOMMENDATION #4

Define the specific roles and responsibilities

of individual research funding agencies.

11 EPA, Particulate Matter Research Program Multi-year Plan-2003, updated 2006, www.epa.gov/osp/myp.htm.
39

characterization, and control technology. It is

by means of research in these areas that the

research needs under the topics identified by

the NRC are addressed. The primary topicspecific research contributions by member

agencies are discussed in Part I above and

their planned outcomes are profiled in Table

6. To improve the coordination of this multidisciplinary, multi-purpose research, the PM

Research Coordination Working Group has

identified lead agencies that will further

coordinate and review progress under each of

these major research areas. Lead and contributing agencies for future PM research are

designated in Table 7.

Response:

• Agency-specific research plans are multiyear and multi-pollutant in scope and

incorporate coordination with state, private, and other federal organizations. All

member agencies prepare multiyear research

plans in one form or another. Some plans

are prepared as part of the agency’s annual

budget process and some are prepared as

stand-alone planning documents. In both

cases these plans lay out the agency’s future

research direction, goals, objectives, and

measures. They also include multi-pollutant

approaches and provide for collaboration

with state, private, and other federal research

organizations. Examples of stand-alone

multiyear documents include: EPA’s

Particulate Matter Research Program Multiyear Plan - 2003, http://epa.gov/osp/-

myp.htm; DOT/FHWA’s Strategic Workplan

for Particulate Matter Research: 2000 to 2004

(being updated), http://www.fhwa.dot.gov/-

environment/pm/index.htm; DOE/NETL’s

DOE-NETL Air Quality Research Program:

Overview, http://www.netl.doe.gov/coal/-

E&WR/air_q/; and DOE/SC’s A Reconfigured Atmospheric Science Program,

http://www.asp.bnl.gov/. 

• State and private activities are additionally incorporated though large-scale,

multi-organizational research projects. In

addition to broad multi-organizational

research planning and coordination under

NARSTO and HEI, specific field campaigns

and research centers incorporate state and

private involvement. Field studies focused

on air quality characterization and processes

are typical of the partnerships formed.

Recent examples include the New England

Air Quality Study (NEAQS-2002 and 2004),

the Texas Air Quality Study (TexAQS 2000

and TexAQSII 2005-2006), and

DOE/NETL’s Steubenville, Ohio exposure

study. Similar studies are now being planned

for future years. The ongoing EPA Detroit

Exposure and Atmospheric Research Study

(DEARS) is another good example of a

research study incorporating state and private

involvement. As for health effects studies,

EPA has sponsored five PM Health and

Exposure Research Centers across the

country over the 2000-2005 five-year period

and has renewed its centers programs for

another five years beginning in 2006. The

centers have drawn investment and participation of both industry and their home states.

IMPROVED TOOLS FOR SCIENCE

TRACKING AND SYNTHESIS

The NRC Subcommittee makes two recommendations in producing the tools needed for

enhanced tracking and synthesis of science

going forward:

NRC RECOMMENDATION #5

Incorporate other non-federal PM research

funding organization inputs and expand the

transparency of the federal PM research

planning process.
40

1. Develop and maintain an inventory of PM

research and publications.

2. Improve information synthesis.

Both of these recommendations have been acted

upon by the AQRS with the response being provided below.

Response:

• The AQRS is considering several alternative approaches and will include its preferred approach in the update of its

Stategic Research Plan for Particulate

Matter2

. In recognition of the widely

ranging options and potential public expense

of such an inventory, the PM Working Group

Co-chairs appointed EPA to lead the preparation of a set of options for consideration.

EPA is to examine a set of options for a

master database to be put on the web and be

publicly accessible. Options will cover

alternative levels of scope (e.g., program and

project descriptions with updates, recent

journal articles and reports, links to other

databases, and points of contact in searchable form), resource levels, and agency

involvement in development and maintenance. One option to be explicitly discussed

is building on the Particulate Matter

Research Activities (PMRA) database instituted in 2000 to catalogue multi-agency PM

research projects, recognizing that this site

would need to be significantly redesigned to

add desirable features such as status, outcomes, and publications. The PM Working

Group will review the options presented by

EPA and endorse an approach to be used and

supported by member agencies prior to

updating its Stategic Research Plan for

Particulate Matter.

• Member agencies maintain active webbased inventories of research and publications coming out of their work. A second

source of current information on PM

research progress is available through

agency databases. In addition to access to

agency research progress available through

their planning websites (see Table 6), new

information systems are also being made

available. These include the EPA’s

Environmental Information Management

System with its Science Inventory database

and Technical Information Management

System newly coming on line (http://-

www.epa.gov/eims/systems.html). The

expansion of the CSREES Current Research

Information System (CRIS) at

http://cris.csrees.usda.gov/ is being planned

to include all extension/outreach projects

such as the indoor air quality Healthy Homes

program. CSREES also has the Research,

Education, & Economics Information

System (REEIS; http://www.reeis.usda.gov/)

that currently captures research information

across all of USDA and synthesizes reports

by year, funding, and performing agency.

Information on aerosol research funded by

the Atmospheric Sciences Program in DOE’s

Office of Science can be accessed at

http://www.asp.bnl.gov/, and lists of publications coming from that research can be

accessed at http//www.asp.bnl.gov/-

asp_pubs.html. NIH maintains the

Computer Retrieval of Information on

Scientific Projects (CRISP) database, which

contains abstracts and information on all

currently funded NIH projects

(http://crisp.cit.nih.gov). In addition the

NSF maintains descriptions of its many

sponsored atmospheric science laboratory

and field studies at http://www.nsf.gov/-

div/index.jsp?div=ATM.

NRC RECOMMENDATION #1

Develop and maintain an inventory of PM

research and publications.
41

Response:

• The AQRS will hold periodic specialty

meetings on progress. As one means of

tracking research progress and improving

information synthesis, the AQRS, beginning

in March 2006, will hold periodic specialty

meetings on progress under individual

Research Topic areas of this report (see Part

I). Meetings will review progress by

member agencies and their state and private

counterparts, and will highlight recent developments. Special progress reports will be

issued from time to time where noteworthy

advances have been made and/or where

decisions have been made leading to new

directions or priorities. In addition, members will proactively use the AQRS email list

to inform one another of any recent developments and transmit summaries and notices of

availability of major project reports. 

• Member organizations will hold specialty

conferences and workshops. Member

organizations have commonly held periodic

reviews of science progress assessing recent

advances by their organizations and affiliated programs and identifying future needs

to fill key information gaps. This practice

will be continued and extended in two ways.

There will be a greater emphasis on information synthesis, and participation will be

broadened to build interdisciplinary integration and interagency coordination. The

National Agricultural Air Quality Workshop

held in 2006 is an example of this new

approach. USDA held a workshop on June

5-8, 2006, to address all aspects of agricultural air quality, including PM emissions.

The two primary work products of the workshop will be an updated emission inventory

and a best-practices document for mitigating

agricultural emissions. These two documents will then be reviewed by the National

Academy of Sciences.

• The AQRS endorses an update of the

NARSTO PM Assessment in 2008. EPA

released its most recent update of the PM Air

Quality Criteria document 12 (AQCD) in

October 2004. This update encompasses a

review of the advances in exposure and PM

health science since the 1996 version underpinning decisions on the National Ambient

Air Quality Standard for PM. It is a complete

example of a compilation and synthesis

product of science and research results on PM

exposure and health effects. The next update

of the PM Criteria Document is scheduled for

three years from now (October 2009). While

the PM AQCD includes a review and summary of atmospheric sciences (Chapters 2 and

3), the NARSTO PM Science Assessment5

(February 2004) provides a more comprehensive review of PM atmospheric sciences as a

complement to the Criteria Document.

Specifically, the NARSTO PM Science

Assessment reviews and synthesizes the

atmospheric science used by policy makers in

the U.S., Canada, and Mexico to implement

national standards such as the PM NAAQS.

It encompasses air measurements, atmospheric processes and modeling, and source

characterization science. The next update of

the NARSTO synthesis by its own recommendation is the end of 2008. This timing

would fit well with the scheduled update of

health and exposure science. It would also fit

well with U.S. plans to institute environmental progress tracking to evaluate the success of implementation strategies required in

2008 to meet PM and ozone NAAQS.

NRC RECOMMENDATION #2

Improve information synthesis.

12 U.S. EPA, Air Quality Criteria for Particulate Matter, U.S. Environmental Protection Agency, Washington, D.C.,

EPA 600/P-99/002aF-bF, 2004.

43

Agencies and Organizations

DHHS Department of Health and Human Services

ATSDR Agency for Toxic Substances and Disease Registry

CDC Centers for Disease Control and Prevention

NIOSH National Institute for Occupational Safety and Health

NIH National Institutes of Health

NHLBI National Heart, Lung, and Blood Institute

NICHD National Institute of Child Health and Development

NIEHS National Institute of Environmental Health Science

DOC Department of Commerce

NIST National Institute of Standards and Technology

NOAA National Oceanic and Atmospheric Administration

ARL Air Resources Laboratory

ESRL Earth System Research Laboratory

NESDIS National Environmental Satellite, Data, and Information Service

NWS National Weather Service

PMEL Pacific Marine Environmental Laboratory

DOE Department of Energy

FE Fossil Energy Program

NETL National Energy Technology Laboratory

SC Office of Science

DOI Department of the Interior

NPS National Park Service

USGS United States Geological Survey

DOT Department of Transportation

FHWA Federal Highway Administration

EPA Environmental Protection Agency

NCER National Center for Environmental Research

NERL National Exposure Research Laboratory

NHEERL National Health and Environment Effects Research Laboratory

NRMRL National Risk Management Research Laboratory

OAR Office of Air and Radiation

ORD Office of Research and Development

HEI Health Effects Institute

NARSTO Originally, North American Research Strategy for Tropospheric Ozone 

List of Acronyms
44

NASA National Aeronautics and Space Administration

NRC National Research Council

NSF National Science Foundation

TVA Tennessee Valley Authority

UNEP United Nations Environment Programme

USDA United States Department of Agriculture

CSREES Cooperative State Research, Education, and Extension Service

USFS USDA Forest Service

WMO World Meteorological Organization

Federal Government Committees

AQRS Air Quality Research Subcommittee of the CENR

CENR Committee on Environment and Natural Resources

Monitoring Networks and Programs

AIRMoN Atmospheric Integrated Research Monitoring Network

CASTNet Clean Air Status and Trends Network

GPMP Gaseous Pollutant Monitoring Program

IMPROVE Interagency Monitoring of Protected Visual Environments

NADP/NTN National Atmospheric Deposition Program/National Trends Network 

NADP/MDN National Atmospheric Deposition Program/Mercury Deposition Network 

NAMS National Air Monitoring Stations

NCore National Core air monitoring program

NEPHTN National Environmental Public Health Tracking Network

PAMS Photochemical Assessment Monitoring Stations

RPO Regional Planning Organizations (TVA)

SCAMP Steubenville Comprehensive Air Monitoring Program (DOE/NETL)

SLAMS State and Local Air Monitoring Stations

STN Speciation Trends Network ambient PM monitoring program

VISTAS Visibility Improvement State and Tribal Association of the Southeast

Methodology and Modeling-related Systems

CAMx Comprehensive Air Quality Model with Extensions

CMAQ Community Multi-scale Air Quality model

CMAS Community Modeling and Analysis System model clearinghouse

CMB Chemical Mass Balance receptor model

CREM Council for Regulatory Environmental Modeling

FRM Federal Reference Method for ambient air measurements
45

LIDAR Light Detection and Ranging

PMF Positive Matrix Factorization receptor modeling approach

REMSAD Regional Modeling System for Aerosols and Deposition

SHEDS Stochastic Human Exposure and Dose Simulation

TEOM Tapered Element Oscillating Microbalance

TERESA Toxicological Evaluation of Realistic Emissions of Source Aerosols

UNMIX Source Receptor Model

Other Acronyms

AQCD Air Quality Criteria Document

CAPs Concentrated air particulates

CCSP United States Climate Change Science Program

CMU Carnegie Mellon University

CRIS Current Research Information System (CSREES)

CRISP Computer Retrieval of Information on Scientific Projects (NIH Database)

CVD Cardiovascular Disease

DEARS Detroit Exposure and Aerosol Research Study

FACA Federal Advisory Committee Act

GIS Geographical Information Systems

HAPs Hazardous Air Pollutants

HEDS Human Exposure Database System

IAG Interagency Agreement

ICARTT International Consortium for Atmospheric Research on Transport and

Transformation

IPCC Intergovernmental Panel on Climate Change

MAX-Mex Megacity Aerosol Experiment - Mexico City

NAAQS National Ambient Air Quality Standards

NHANES National Health and Nutrition Examination Survey 

PAHs Polycyclic Aromatic Hydrocarbons

PHASE Public Health Air Surveillance Evaluation

PM Particulate matter

PM2.5 Particulate matter with an average atmospheric diameter of less than

2.5 micrometers

PM10 Particulate matter with an average atmospheric diameter of less than 

10 micrometers

PMRA Particulate Matter Research Activities

RFA Request for Applications

SIP State Implementation Plan

SOA Secondary Organic Aerosol

SPECIATE Repository of Total Organic Compounds and Particulate Matter

STAR Science To Achieve Results Grants Program (EPA)

TOC Total Organic Compounds

VOCs Volatile Organic Compounds

Copies of this report are available from:

NOAA Earth System Research Laboratory, Chemical Sciences Division

Office of the Director, R/CSD

325 Broadway, Boulder Colorado 80305-3337

e-mail: aqrs@noaa.gov

Phone: 303-497-3134

Fax: 303-497-5340