In proposing a new ambient air quality standard for fine particulate air pollution in 1997, the U.S. Environmental Protection Agency responded to a body of epidemiologic literature reporting increased deaths, hospital admissions, and exacerbation of respiratory diseases associated with increased particulate air pollution concentrations. At the same time, it was recognized that there was little supporting evidence from toxicologic or controlled human exposure studies. The epidemiologic findings were questioned as only statistical associations without a plausible biological mechanism or an identified causal agent in the complex mix of pollutants characterized as fine particles. In response to these perceived weaknesses in the scientific evidence, a series of research initiatives have been undertaken in exposure assessment, controlled animal and human exposures, and assessments of free-living populations. Key papers have been subjected to comprehensive review and replication. It is now between four and seven years since the seminal papers suggesting adverse health effects of fine particles were published. Have these results held up over time? Have other investigators confirmed these studies in other populations? Do we have insights into the biologic mechanisms? Have the specific toxic characteristics of particles been identified?
Learning Objectives: § Identify the elements of scientific evidence required for standard setting § Identify weaknesses in the available scientific data
Keywords: Air Quality, Public Health Policy
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.