Effects of air pollution episodes on pulmonary function and respiratory symptoms.

In January 1985, a decline of primary school children's pulmonary function was observed during an air pollution episode. Ambient 24 hour average levels of SO2, TSP and RSP were in the range of 200-250 micrograms/m3. The response persisted for at least two weeks. In January 1987, again a decline of school children's pulmonary function was observed associated with an air pollution episode. Levels of TSP were about as elevated as in the 1985 episode. Two weeks after the episode, lung function levels were even lower than during the episode. In June 1987 a long term study was started to investigate potential effects of winter and summer air pollution episodes on pulmonary function and occurrence of acute respiratory symptoms of primary school children. An important issue for this study is the characterization of short term variation of lung function in absence of air pollution. Exposure is characterized by ambient levels of several gases (SO2, NO2, O3, HNO3), PM10, TSP and components of particulate matter (SO4(2-), NO3-, H-, NH4+). Sampling is being conducted on a daily basis to obtain a continuous exposure estimate. In the winter of 1987/1988, no air pollution episodes were observed. The study will continue through the winters of 1988/1989, and 1989/1990.