ASSOCIATION OF AMBIENT AIR-QUALITY WITH CHILDRENS LUNG-FUNCTION IN URBAN AND RURAL IRAN

During the summer of 1994, a cross-sectional epidemiological study, in which the pulmonary Function of children in Tehran was compared with pulmonary function in children in a rural town in iran, was conducted. Four hundred children aged 5-11 y were studied. Daytime ambient nitro gen dioxide, sulfur dioxide, and particulate matter were measured with portable devices, which were placed in the children's neighborhoods o n the days of study. Levels of these ambient substances were markedly higher in urban Tehran than in rural areas. Children's parents were qu estioned about home environmental exposures (including heating source and environmental tobacco smoke) and the children's respiratory sympto ms. Pulmonary function was assessed, both by spirometry and peak expir atory flow meter, Forced expiatory volume in 1 s and forced vital capa city-as a percentage of predicted for age, sex and height-were signifi cantly tower in urban children than in rural children, Both measuremen ts evidenced significant reverse correlations with levels of sulfur di oxide, nitrogen dioxide, and particulate matter, Differences in spirom etric lung Function were not explained by nutritional status, as asses sed by height and weight for age, or by home environmental exposures. Reported airway symptoms (i.e., cough, phlegm, and wheeze) were higher among rural children, whereas reported physician diagnosis of bronchi tis and asthma were higher among urban children. The association betwe en higher pollutant concentrations and reduced pulmonary function in t his urban-rural comparison suggests that there is an effect of urban a ir pollution on short-term lung function and/or lung growth and develo pment during the preadolescent years.