Preface to special section on Particulate Matter: Atmospheric Sciences, Exposure, and the Fourth Colloquium on Particulate Matter and Human Health

[1] In response to epidemiological studies published over 20 years ago, at least three research communities have been intensively studying airborne particulate matter (PM). These efforts have been coordinated by approaching the sourceatmospheric accumulation/receptor-exposure-dose-health effects paradigm (adopted from National Research Council (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 a 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 respectively. 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. [2] 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 co-chaired by Cliff Davidson (Carnegie Mellon University, Pittsburgh, Pennsylvania), Robert Phalen (University of California, Irvine, California), and Paul Solomon (U.S. Environmental Protection Agency, Las Vegas, Nevada). 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. [3] 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: [4] 1. Facilitate the dissemination of findings from among the major 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. [5] 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). JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 109, D16S01, doi:10.1029/2004JD005040, 2004