In this study, the authors evaluated the relative risk of residential exposure to air pollution from an aluminum plant. The authors used government-compiled data to compare hospital admissions in 1997 for selected respiratory diseases for 2 communities in Brazil. One community, Ouro Preto, was located near an aluminum plant, and the other, Diamantina, was located far from any source of industrial air pollution. The relative risk of hospital admissions for selected respiratory diseases was 4.11 (95% confidence interval = 2.96, 5.70). The risk was highest among individuals between 30 and 39 yr of age (relative risk = 11.70; 95% confidence interval = 1.52, 89.96). Admissions per thousand residents were highest for individuals under 10 yr of age and for individuals older than 70 yr of age. The authors assessed exposure with environmental measurements. Dust deposition was collected in the residences of participants (n = 36 in each location), and the dust was analyzed for aluminum, manganese, magnesium, and calcium content. There were significantly different (p < .05) levels of aluminum in the 2 communities; the highest quantities were found near the aluminum plant. Measurements from independent studies indicated that both 24-hr maximum values and annual mean concentrations of suspended particulate matter exceeded the average of international standards in Ouro Preto (i.e., aluminum plant area). These results suggested that exposure to greater air pollution in the aluminum plant area (i.e., Ouro Preto, Brazil) versus the control area resulted in statistically significant health effects in those individuals who resided in Ouro Preto.