Airborne Particles and Health: What do we know and not know in 2009

Speaker:Jonathan M. Samet, MD, MS,
Professor and Flora L. Thornton Chair, Department of Preventive Medicine;
Keck School of Medicine, Director, Institute for Global Health,
University of Southern CaliforniaAbstract: Particles of varied size, composition, and structure are ubiquitous in indoor and outdoor air. The sources of the particles are myriad and include both natural phenomena and man's activities. In regard to outdoor air, particle concentrations and sources are regulated in the United States by complex legislation that addresses sources and concentrations. The principal evidence-based regulation under the Clean Air Act requires the promulgation of a National Ambient Air Quality Standard (NAAQS) that sets a concentration for particulate matter (PM) in outdoor air that protects public health with a margin of safety. This presentation reviews the scientific evidence on PM and risk to health, moving from the historical evidence that high levels of PM led to disastrous numbers of excess deaths to the current context in the US and other developed countries, where PM levels are now far lower. Worldwide, PM remains a public health threat in developing countries, where people experience extremely high levels in urban areas, particularly the increasing numbers of mega-cities, and indoors from unvented or poorly vented smoke from biomass fuel combustion.Research is now focused on quantifying risks at lower levels, characterizing mechanisms of toxicity, identifying characteristics of particles that determine risk, and targeting the most critical sources from the public health perspective. The research evidence is broad, coming from the fields of engineering, atmospheric sciences, toxicology, and exposure assessment and epidemiology. An expanded evidence base is needed for protecting public health as cities continue to grow, motor vehicle usage increases, and energy production from coal combustion increases.

Location: Kaprielian Hall (KAP) - 209

Audiences: Everyone Is Invited

Contact: Evangeline Reyes