PARTICULATE AIR POLLUTION AND MORTALITY IN THE UNITED STATES: HAVE THE RISKS CHANGED FROM 1987 TO 2000?
Abstract
The evaluation of the public health impact of air quality regulations, referred to as accountability research, is increasingly viewed as a necessary component of responsible governmental policy interventions. In this paper we present an example of accountability assessment based on evaluating change in the short-term effect of airborne particles over a period of increasingly stringent regulation that might have changed the chemical composition and toxicity of the airborne particles. We use updated data and methods of the National Mortality Morbidity Air Pollution Study (NMMAPS) to estimate national average relative rates of the effects of PM10 (particulate matter less than 10 µm in aerodynamic diameter) on all-cause, cardiovascular and respiratory mortality, and other cause mortality for the period 1987-2000. We also estimate national average relative rates of the effects of PM2.5 (2.5 µm) on all-cause mortality for the period 1999-2000. We find strong evidence that lag 1 exposures to PM10 and PM2.5 continue to be associated with increased mortality. We also find a weak indication that the lag 1 effects of on mortality declined over the period 1987-2000 and that this decline mostly occurred in the eastern U.S. The methodology presented in this paper can be used to track the health effects of air pollution routinely at a regional and national scale.