CHRONIC RESPIRATORY SYMPTOMS ASSOCIATED WITH ESTIMATED LONG-TERM AMBIENT CONCENTRATIONS OF FINE PARTICULATES LESS-THAN 2.5 MICRONS IN AERODYNAMIC DIAMETER (PM2.5) AND OTHER AIR-POLLUTANTS

Seventh-Day Adventists (SDAs), nonsmokers who had resided since 1966 i n the vicinity of nine airports throughout California (n = 1,868), com pleted a standardized respiratory symptoms questionnaire in 1977 and a gain in 1987. For each participant, cumulative ambient concentrations of fine particulates less than 2.5 microns (mu m) in aerodynamic diame ter (PM2.5) were estimated from airport visibility data. Long-term amb ient concentrations of estimated PM2.5 in excess of 20 micrograms per cubic meter (mu g/m(3)) were found to be associated with development o f definite symptoms of chronic bronchitis between 1977 and 1987. Estim ated mean concentrations of PM2.5 were associated with increasing seve rity of respiratory symptoms related to general airway obstructive dis ease, chronic bronchitis, and asthma. It was felt that the observed re lationships, with the exception of the relationship between increasing severity of chronic bronchitis symptoms and PM2.5, could be due to su rrogate relationships with other ambient pollutants.