Waste incinerators are an increasingly common means of solid waste disposal. However, little is documented about the physical health of community members who live close to incinerators. During a 3-yr epidemiological study, spirometric lung function was tested once annually among residents from 3 communities surrounding a hazardous waste, biomedical, or municipal incinerator and among residents in 3 comparison communities. A total of 1,016 nonsmoking individuals, aged 8-80 yr, participated during at least 1 of the 3 yr of the study; 358 individuals participated all 3 yr. Daily air-quality sampling was done for 1 mo/yr in all 6 communities. The average monthly concentrations of particulate matter with diameters of 2.5 microns and less (PM2.5 [range = 14.6-31.5 micrograms/m3]) in all communities were similar during the 3 yr of study. The mean daily PM2.5 concentrations were significantly less than the U.S. Environmental Protection Agency's allowable 24-hr standard of 65 micrograms/m3. Individual incinerators contributed less than 2.5% of the areas' total PM2.5 levels. There was no difference in percent predicted forced vital capacity, forced expiratory volume in 1 sec, or forced expiratory flow rate over the middle 50% of the forced vital capacity among members of the incinerator communities, compared with nonincinerator communities, and there were no significant differences in lung function within the 3 sets of communities. There was no evidence from this study that an association existed between residence in these 3 waste incinerator areas, which met state and federal emissions regulations, and average spirometric pulmonary function of nonsmoking community members.