Risks of Coarse Particulate Air Pollution

Francesca Dominici, Ph.D. and Jonathan Samet, MD;
Departments of Biostatistics and Epidemiology
Johns Hopkins Bloomberg School of Public Health
NIEHS Grant R01ES012054 and P30ES003819

A nationwide study of coarse particulate air pollution, defined as 2.5-10 microns in diameter, found some evidence of an association with hospital admissions for cardiovascular disease and no evidence of an association for respiratory disease. Researchers at Johns Hopkins University, supported by NIEHS, conducted the study, the largest on record, for both public health and regulatory purposes.

The study examined associations between daily changes in hospital admission rates for cardiovascular and respiratory outcomes and daily changes in coarse and fine particulate matter concentrations in ambient air in 108 urban counties across the U.S. The study included over 12 million people enrolled in Medicare from 1999-2005.

The EPA regulates the level of fine particulate matter pollution, defined as particles less than 2.5 microns in diameter, but does not currently regulate coarse particulates. Fine particles are generally the result of combustion from automobiles and coal burning power plants. Coarse particles are produced by processes such as mechanical grinding, windblown dust, and agricultural practices.

Previous research by this research team on fine particulate matter pollution demonstrated a strong link to hospitalization for cardiovascular and respiratory illnesses. According to the researchers, the coarse particle association found in the current study warrants the attention of EPA regulators when the Agency readdresses its standard for particles in the air.

Citation: Peng RD, Chang HH, Bell ML, McDermott A, Zeger SL, Samet JM, Dominici F. Coarse particulate matter air pollution and hospital admissions for cardiovascular and respiratory diseases among Medicare patients. JAMA. 2008 May 14;299(18):2172-9.