SUMMERTIME HAZE AIR-POLLUTION AND CHILDREN WITH ASTHMA

In order to investigate associations between summertime haze air pollu tion and asthma at an individual level, 52, 58, and 56 children (ages 7 to 13) attending a summer ''asthma camp'' were followed duping the l ast week of June in 1991, 1992, and 1993, respectively, Most of the su bjects had moderate to severe asthma. Dairy records were kept of the e nvironmental conditions, as well as of subject medication use, lung fu nction, and medical symptoms. Air pollution was found to be significan tly and consistently correlated with acute asthma exacerbations, chest symptoms, and sung function decrements. The pollutant most consistent ly associated with adverse health consequences was ozone (O-3), althou gh associations with sulfates and hydrogen ion suggest a possible role by fine particles as well. Effects were found tee be roughly monotoni c as a function of O-3 concentration. Regression of morning (8:00 A.M. ) to afternoon (5:00 P.M.) peak flow change on O-3 indicated pulmonary function reductions similar to those previously reported for more act ive children without asthma. Moreover, analyses also indicated an incr eased risk of an asthma exacerbation and of experiencing chest symptom s of approximately 40% on the highest pollution day, relative to the m ean. Based on these relative risk estimates, a rise in the 1-h daily m aximal O-3 from 84 ppb to 160 ppb was associated in this group with an increase from 20 to 28 (+/- 2) in the expected number of unscheduled medications administered/day, and from 29 to 41 (+/- 3) in the expecte d total number of chest symptoms/day. Thus, air pollution can be a maj or contributor to the respiratory problems experienced by children wit h asthma during the summer months.