AIR-POLLUTION AND RESPIRATORY MORBIDITY AMONG ADULTS IN SOUTHERN CALIFORNIA

This paper reports the results of an investigation of the acute effect s of air pollution in 321 nonsmoking adults residing in Southern Calif ornia. Previous epidemiologic investigations of effects of acute expos ure to ozone have focused on groups who may not be representative of t he general public, such as asthmatics or student nurses. For this stud y, participants recorded the daily incidence of several respiratory sy mptoms over a 6-month period between 1978 and 1979. The authors examin ed the impact of ambient concentrations of ozone, particulate sulfates , and other air pollutants on the incidence of respiratory morbidity, measured as either upper or lower respiratory tract symptoms. Using a logistic regression model, the authors found a significant association between the incidence of lower respiratory tract symptoms and 1-hour daily maximum ozone levels (odds ratio (OR) = 1.22, 95% confidence int erval (Cl) 1.11-1.34, for a 10 parts per hundred million (pphm) change ), 7-hour average ozone levels (OR = 1.32, 95% Cl 1.14-1.52), and ambi ent sulfates (OR = 1.30, 95% Cl 1.09-1.54, for a 10-mug/m3 change), bu t no association was found with coefficient of haze, a more general me asure of particulates. The existence of a gas stove in the home was al so associated with lower respiratory tract symptoms (OR = 1.23, 95% Cl 1.03-1.47). The effects of ozone were greater in the subpopulation wi thout a residential air conditioner. In addition, ozone appears to hav e had a greater effect among individuals with a preexisting respirator y infection.