Traffic is a major source of atmospheric carbon monoxide and oxides of nitrogen and exhaust emission rates are regulated. Measurements were made of the levels to which eight people were exposed during their normal activities. Extensive results were obtained for carbon monoxide but the nitrogen oxide data were restricted by instrument limitations. The main sources of carbon monoxide were traffic, cooking and tobacco smoke which, with the exception of cooking, also produced oxides of nitrogen. Although the highest pollutant concentrations were observed near to these identifiable sources, much of the subjects' intake was during prolonged exposure to lower concentrations in their homes. Traffic related activities contributed about 25 per cent of the carbon monoxide exposure of non-smokers. The physiological effects of the measured carbon monoxide concentrations would be insignificant. This work did not consider occupational exposures to the pollutants.
Abstract