Health Effects and Exposures to Particulate Matter and Associated Air Pollutants Air pollution in the United States is regulated under the authority of the Clean Air Act to protect public health and welfare. Significant uncertainties remain, however, about the biological mechanisms that could cause increased mortality or morbidity from PM exposures and about the nature of human exposures. While several hypotheses regarding possible mechanisms underlying recently reported PM effects have been proposed, little research has been conducted to evaluate these hypotheses and to explore issues of dose-response and exposure scenarios. In addition the lack of research as to whether, and to what extent, the effects attributed to PM exposures are modified by other commonly occurring pollutants such as SO 2 and ozone, leads to uncertainties in interpretation of epidemiological studies. In addition, there are important scientific uncertainties regarding PM exposures.
Research is needed on coarse, fine, and ultrafine particles.
Research to reduce uncertainties in exposure assessment for PM and associated copollutants. New or improved instruments or techniques may be required for these studies also. Duration of awards may be up to three years.