Respiratory illness in British schoolchildren and atmospheric smoke and sulphur dioxide 1973-7. I: cross-sectional findings.

The relation between respiratory illness and atmospheric smoke and sulphur dioxide (SO2) was investigated from 1973 to 1977 in children aged 6 to 11 from a random sample of 28 areas in England and Scotland. Cross-sectional results are presented for 1975, and results from other years briefly summarised. In 1975 there were 19 areas with data on pollution and in these areas the sample included 5787 children of white ethnic origin of whom 4116 (71%) had complete information of respiratory illness and other variables considered in the analysis. After allowing for the effects of age, social class, population density, type of fuel used for cooking in the home, and season of examination, the prevalence of respiratory illness in both sexes was in the home, and season of examination, the prevalence of respiratory illness in both sexes was positively associated with the levels of smoke over the range of annual means 8 to 51 microgram/m3 )P less than or equal to 0.05). No relation was found between illness and annual means of SO2 ranging from 12 to 114 microgram/m3. Similar results were found in other years, and in 1977, when information of tobacco smoking at home was collected, the association between illness and atmospheric smoke appeared to be independent of smoking within the home. The levels of smoke were much lower than those at which effects on health hve previously been reported so the association is unlikely to be causative. We postulate that higher levels of atmospheric pollution at an earlier period in some areas may have predisposed children living there to respiratory illness during their primary school years. Alternatively, some other characteristics of the polluted areas may explain the findings.