PM2.5 from Motor Vehicles and Coal Combustion is Linked to Increased Mortality
Investigators from Harvard Medical School used data on the elemental composition of size-fractionated particles to identify the sources of fine particles in six eastern U.S. cities that have been the subject of a long-term air pollution study.
For example, lead was used as a tracer for motor vehicle exhaust, selenium for coal combustion, and silicon for soil and crustal matter.
Each of these fractions was examined in association with daily mortality rates in each city.
The study reported that a 10 µg/m3 increase in PM2.5 from mobile sources accounted for a 3.4% increase in daily mortality, while the equivalent increase in fine particles from coal combustion sources accounted for a 1.1% increase.
Fine particles from crustal sources were not associated with mortality.
The study conclude: “the results indicate that combustion particles in the fine fraction from mobile and coal combustion sources, but not fine crustal particles, are associated with increased mortality.”
The cities studied were: Watertown, MA, Kingston-Harriman, TN, St. Louis, MO, Steubenville, OH, Portage, WI, and Topeka, KS.
Laden, F. Neas, L.M., Dockery, D.W., and Schwartz, J. Association of Fine Particulate Matter from Different Sources with Daily Mortality in Six U.S. Cities. Environmental Health Perspectives 108:941-947, October 2000. Environmental Health Perspectives [ehpnet1.niehs.nih.gov/docs/allpubs.html] published the abstract online.
