The effects of ambient NO2 on lung function in primary schoolchildren

The effect of ambient NO2 on lung function was investigated in a sample of 423 schoolchildren. At each of four locations NO2 was monitored continuously. Over a 6-month period from January to June 1990 two surveys were performed and spirometry recorded each time for each child. Linear regression was used to estimate the effect of NO2 for different time intervals preceding lung function testing. A decrease of NO2 between surveys was significantly associated with a higher forced vital capacity (FVC) at the second survey. For each microgram/m3 NO2 decrease the model predicted an increase in FVC of 1.5 ml [for the 2-hr mean (P < 0.05)] and 3.1 ml [for the 12-hr mean (P < 0.01)]. We conclude that even at NO2 levels below current air-quality standards children demonstrate significant changes in lung function.