Title: Sulfate concentrations as an indicator of ambient particulate matter air pollution for health risk evaluations.
Authors: Lippmann, M; Thurston, G D
Published In J Expo Anal Environ Epidemiol, (1996 Apr-Jun)
Abstract: Retrospective population studies that have compared regression coefficients for mortality and morbidity for sulfate (SO4(2-), fine particles (PM2.5; aerodynamic diameter < 2.5 microns), thoracic particles (PM10; aerodynamic diameter < 10 microns), and total suspended particulates (TSP; undefined and variable upper cut-size) generally have found SO4(2-) concentrations to be correlated with effects as well as or better than PM2.5. In addition, both SO4(2-) and PM2.5 have yielded somewhat stronger associations with adverse health effects than PM10, and much stronger associations than TSP. Sulfate has advantages over PM2.5 for retrospective epidemiology, at least in the United States, because considerably more data on sulfate have been collected in recent decades, and there is a broader epidemiological database in the literature for comparison to other studies. While SO4(2-), per se, is an unlikely causal factor for mortality or morbidity, it often is correlated closely with variations in the strong acid component of ambient particulate matter (H+) and PM2.5 concentrations (especially in summer), which are more likely causal factors. A detailed analysis of the SO4(2-) epidemiological database is presented in this paper. In addition, drawing on our substantial archives of SO4(2-) and H+ data, we show that SO4(2-) and H+ correlate, both spatially and over time, in the eastern United States. We demonstrate the utility of SO4(2-) as a useful surrogate for ambient PM2.5 and H+ in epidemiological studies and as an index of PM exposure in ambient air quality guidelines and standards.
PubMed ID: 8792293
MeSH Terms: Aerosols/analysis; Air Pollutants, Environmental/analysis*; Environmental Exposure/statistics & numerical data*; Environmental Illness/epidemiology*; Environmental Illness/etiology; Environmental Monitoring/methods*; Europe; Health Status Indicators*; Humans; Hydrogen-Ion Concentration; Mortality; North America; Particle Size; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.; Respiratory Tract Diseases/chemically induced; Respiratory Tract Diseases/epidemiology; Retrospective Studies; Smoke/analysis; Sulfates/analysis*; Urban Health/statistics & numerical data