Incidence of diseases of the lower respiratory tract in family practice and low level air pollution.

A simple contact registration in family practices in an urban area in the Netherlands was shown to be a suitable instrument for measuring and analysing the incidence of diseases of the lower respiratory tract. This incidence showed a topographical and a temporal variation. The topographical component was related to the sulphur dioxide (SO2) air pollution in the different districts. The temporal component consisted partly of seasonal variations and partly of short-term variations. A moderate effect of the SO2 air pollution on the temporal variation was observed, but it was weak, possibly owing to the relatively low levels of SO2 in Amsterdam. The present study shows that contact registration in family practices may yield useful data for epidemiological analysis.