Special Issue of Aerosol Science and Technology for Particulate Matter: Atmospheric Sciences, Exposure, and the Fourth Colloquium on PM and Human Health

In response to epidemiological studies published over twenty years ago, at least three research communities have been intensively studying airborne particulate matter (PM). These efforts have been coordinated by approaching the source–atmospheric accumulation/receptor–exposure–dose–health effects paradigm (adopted from NRC 2001) from different perspectives or along different parts of the paradigm. The atmospheric sciences communities consider the emissions of particles and precursors from sources, their transport and transformation in air to receptor locations, and finally removal from the atmosphere. The exposure communities' interest is to examine the pathways by which pollution or particulate matter, in this case, approaches and enters the body, typically by trying to relate PM concentrations at central location(s) to exposure and perhaps dose. Both the atmospheric sciences and exposure communities approach the paradigm from left to right. In contrast, the health effects communities have studied health outcomes, including hospital admissions, school absences, disease rates and deaths in human populations, and potential mechanisms of biological actions in laboratory settings. In general, the health effects communities approach the paradigm from right to left, attempting to correlate an observed adverse health effect with dose or exposure measures. For the most part, research results are reported in scientific publications and conferences for each community. Over the years there has been little effort to integrate information from these diverse groups in a substantive way. While a major attempt took place in 1998 at the Chapel Hill workshop (Albritton and Greenbaum 1998), little has occurred since.

In April 2003, the American Association for Aerosol Research held its first specialty conference entitled “Particulate Matter: Atmospheric Sciences, Exposure, and the Fourth Colloquium on PM and Human Health,” which was intended to bridge this gap. The conference was cochaired by Drs. Cliff Davidson (CMU, Pittsburgh, PA), Robert Phalen (UC Irvine, Irvine, CA), and Paul Solomon (U.S. EPA, Las Vegas, NV). Over 550 scientists, air quality managers, and policy makers from the public and private sectors participated in the meeting representing science and policy investments from 20 countries. The program consisted of a series of workshops with three concurrent sessions the first day, a series of plenary sessions that included over 70 invited speakers, and poster sessions where 388 posters were presented during the course of the meeting.

The overall goal of the conference was to bring together health and exposure scientists with atmospheric scientists, air quality managers, and policy makers to allow for enhanced communications and exchange of information among these groups. Specific objectives of the conference were to:

1.	facilitate the dissemination of findings from among the major particulate matter (PM) health, exposure, and atmospheric science research programs worldwide to the scientific, regulatory, and regulated communities in a timely manner, and to enable rigorous debate of the findings;
2.	showcase national assessments (e.g., the NARSTO North American PM Assessment and Integrated Critical Review, Canadian Assessment, and others) and to evaluate progress on national PM strategies (e.g., the NRC Committee on Research Priorities for Airborne Particulate Matter); and
3.	add significantly to the peer-reviewed literature by publishing research results presented at the conference in a variety of special issues of selected journals.

Six peer-reviewed special journal issues resulted from this conference, helping to meet the last of the three specific objectives described above. The first two specific objectives were successfully achieved during the meeting. Four special journal issues are appearing in atmospheric sciences–related journals and include: Aerosol Science and Technology, the journal of the American Association for Aerosol Research; the Journal of Geophysical Research—Atmospheres; Atmospheric Environment; and the Journal of the Air & Waste Management Association. We estimate that nearly 60 papers will be published in these journals, and all four journals will be published during the last half of 2004. Two dedicated issues of Inhalation Toxicology allowed for the publication of health-related papers, one focusing on the impacts of ambient environmental particulate air pollution on the respiratory tract (Volume 16, Special Supplement) and the other on the nonpulmonary effects of such particles (Volume 16, issues 6 and 7, June 2004). Thirty papers resulting from presentations at this meeting are being published in these issues of Inhalation Toxicology. Papers published in these journals have been subject to the normal peer-review process of their respective journals.

Articles in this special issue of Aerosol Science and Technology report on new aerosol measurement methods as well as characteristics of urban aerosols. In the first category, Heim et al. describe the counting efficiency and quality of measurements made with the new Grimm ESC 5.4-300 electric mobility spectrometer. This article is followed by a report by Kenny et al., who present the results of tests of a new PM2.5 size-selective inlet, based on cyclone technology, which maintains cut-point integrity for extended periods. Gupta et al. then describe the effects of aerosol chemistry, solubility, hygroscopicity, and particle origin on the Harvard Ultrafine Concentrated Ambient Particle System (HUCAPS) used in inhalation toxicology studies. Finally, Yi et al. discuss a prototype electrostatic precipitator for use with the R&P TEOM to reduce errors from aerosol volatilization.

The second category on urban aerosols includes an article by Ynoue and Andrade on characteristics of particles in Sao Paulo, including-size resolved mass, black carbon, inorganic ions, and elemental composition as well as continuous carbon data from an R&P 5400 semicontinuous ambient carbon particle monitor. Rice then discusses work comparing aerosol carbon data from the R&P 5400 with results from the Magee Scientific Aethalometer and from the thermal optical transmittance (TOT) method. Fan et al. describe characteristics of urban carbonaceous aerosols in Toronto, followed by McDonald et al. reporting on aerosol characteristics near highways in Cincinnati. Tang et al. discuss the regional homogeneity in concentrations of aerosols of different chemical compositions, considering multiple stations sampling simultaneously and backward airmass trajectories. Finally, Long and Sarnat examine indoor–outdoor relationships for elemental components of the ambient aerosol.

The American Association for Aerosol Research was the primary professional society sponsoring the AAAR PM Meeting. The conference was cosponsored by the Air and Waste Management Association. The primary financial sponsor was the U.S. Environmental Protection Agency. Other sponsors include the National Science Foundation, American Chemistry Council, American Petroleum Institute, EPRI, Ford Motor Company, Health Effects Institute, International Society for Aerosols in Medicine, Mid-Atlantic Region Air Management Association, NARSTO, National Institute of Environmental Health Science, New York State Energy Research and Development Authority, South Coast Air Quality Management District, Southern Company, U.S. Department of Energy (Office of Fossil Energy, National Energy Technology Laboratory), and the University of California Irvine Center for Occupational and Environmental Health. The sizable financial sponsorship allowed for a reduced general registration fee, numerous travel grants, and further reduced registration fees for students attending the conference, as well as enhancing the overall character of the meeting.

Many people contributed to the success of the AAAR PM Meeting and AAAR's first specialty conference, and their efforts are greatly appreciated. These include members of the Organizing Committee and Science Advisory Committee, who provided guidance throughout the development of the meeting and acted as session chairs during the meeting. Actively working on publications from the conference are the members of the Publications Committee, whose work began after the conference and continues with diligence. Special thanks are given to Richard Flagan, journal editor, and Marcy Fowler, editorial assistant, for this special issue of Aerosol Science and Technology. Finally, thanks are given to the authors who presented high-quality technical papers across a multi disciplinary topic and to all who attended the conference. Without you, the Particulate Matter: Atmospheric Sciences, Exposure, and the Fourth Colloquium on PM and Human Health conference would not have been a huge success.

Acknowledgments

This special issue represents a subset of the papers presented at the first specialty conference of the American Association for Aerosol Research, 31 March to 4 April 2003, Pittsburgh, PA. Other papers are being published as described within this preface.

The United States Environmental Protection Agency through its Office of Research and Development collaborated in the preparation of this preface. It has been subjected to Agency review and approved for publication. We also thank Drs. Cliff Davidson and Robert Phalen for their review and comments on this preface.

Additional information

Notes on contributors

Paul A. Solomon

* Guest Editors

Notes

* Drs. Paul Solomon and Robert Phalen are cochairs of the publications committee overseeing the Atmospheric Sciences special issues and Health and Exposure related special issues, respectively.