The burden of air pollution: Impacts among racial minorities

Various epidemiologic investigations have shown that ambient air pollution levels are associated with acute increases in hospital admissions and morta lity in the United States and abroad. The objectives of this investigation were a) to determine if racial minorities are more adversely affected by am bient air pollution than their white counterparts and b) to assess the cont ribution of socioeconomic status to any observed racial differences in poll ution effect. Time-series regression methods were conducted to investigate these hypotheses for daily respiratory hospital admissions in New York City , New York. Pollutants considered included mean daily levels of particulate matter with a mass median aerodynamic diameter less than 10 mum (PM10), oz one (O-3), strong aerosol acidity (H+), and sulfates (SO42). The relative r isk for respiratory hospital admission was calculated for each pollutant fo r a maximum minus mean increment in mean daily pollutant concentration. The greatest difference between the white and nonwhite subgroups was observed for O-3, where the white relative risk (RR) was 1.032 [95% confidence inter val (Cl): 0.977-1.089] and the nonwhite RR was 1.122 (95% Cl: 1.074-1.172). Although not statistically different from each other, the various pollutan ts' RR estimates for the Hispanic nonwhite category in New York City were g enerally larger in magnitude than those for the non-Hispanic white group. W hen these analyses incorporated differences in the underlying respiratory h ospitalization rates across races (that for nonwhites, was roughly twice th at for whites), the disparities in attributable risks from pollution (in te rms of excess admissions per day per million persons) were even larger for nonwhites versus whites. However, when insurance status was used as an indi cator of socioeconomic/health coverage status, higher RRs were indicated fo r the poor/working poor (i.e., those on Medicaid and the uninsured) than fo r those who were economically better off (i.e., the privately insured), eve n among non-Hispanic whites. Thus, although potential racial differences in pollution exposures could not be explored as a factor, within-race analyse s suggested that most of the apparent differences in air pollutant effects found across races were explained by socioeconomic and/or health care dispa rities.