THE RISK OF ASTHMA ATTRIBUTABLE TO OCCUPATIONAL EXPOSURES - A POPULATION-BASED STUDY IN SPAIN

The prevalence of occupational asthma has usually been estimated from registers of cases rather than population surveys. We examined the cau ses and derived estimates of the risk of asthma attributable to occupa tional exposures in a randomly selected population of five areas of Sp ain. The study is part of the EC Respiratory Health Survey and compris es 2,646 subjects age 20 to 44 yr. Bronchial reactivity was determined in 1,797 subjects and atopy in 2,164. Twenty-one occupational sets we re defined using information on current occupation, or in subjects rep orting change of occupation due to respiratory problems, their occupat ion at that time. The highest risk of asthma was observed for laborato ry technicians, spray painters, bakers, plastics and rubber workers, w elders, and cleaners. The risk of asthma attributed to occupational ex posures after adjusting for age, sex, residence, and smoking status wa s 5.0% when asthma was defined as ''bronchial reactivity and a report of wheezing or whistling in the chest during the last 12 mo,'' and 6.7 % when asthma was defined as ''bronchial reactivity and a report of as thma-related symptoms or medication.'' Estimates of the attributable r isk for adult onset asthma were higher. Occupational exposures constit ute a substantial cause of asthma in the young adult Spanish populatio n.