Association between air pollution and lung function growth in southern California children

Average growth of lung function over a 4-yr period, in three cohorts of sou thern California children who were in the fourth, seventh, or tenth grade i n 1993, was modeled as a function of average exposure to ambient air pollut ants. In the fourth-grade cohort, significant deficits in growth of lung fu nction (FEV1, FVC, maximal midexpiratory flow [MMEF], and FEF75) were assoc iated with exposure to particles with aerodynamic diameter less than 10 mu m (PM10), PM2.5, PM10-PM2.5, NO2, and inorganic acid vapor (p < 0.05). No s ignificant associations were observed with ozone. The estimated growth rate for children in the most polluted of the communities as compared with the least polluted was predicted to result in a cumulative reduction of 3.4% in FEV1 and 5.0% in MMEF over the 4-yr study period. The estimated deficits w ere generally larger for children spending more time outdoors. In the seven th- and tenth-grade cohorts, the estimated pollutant effects were also nega tive for most lung function measures, but sample sizes were lower in these groups and none achieved statistical significance. The results suggest that significant negative effects on lung function growth in children occur at current ambient concentrations of particles, NO2 and inorganic acid vapor.