Long-term ambient concentrations of total suspended particulates, ozone, and sulfur dioxide and respiratory symptoms in a nonsmoking population.

Seventh-day Adventist nonsmokers, who, subsequent to 1966, had resided within 8 km (5 miles) of their 1977 residence (N = 3,914), completed the National Heart and Lung Institute (NHLI) respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations of total suspended particulates (TSP), ozone, and sulfur dioxide (SO2) in excess of several cutoff levels were estimated by month and by interpolating ambient concentrations from state air-monitoring stations to their residential and workplace zip codes for the month. Statistically significant relationships between ambient concentrations of TSP and ozone, but not SO2, were found with several respiratory disease outcomes. Multivariate analyses adjusted for past and passive smoking and occupational exposures. Results are discussed within the context of standards setting for TSP and ozone.