Mr. Alan W. WilliamsTo ask the Secretary of State for the Environment what assessment his Department has made of which are the main sources of exposure to benzene vapour in the environment; and if he will quantify the contribution made by each of those sources.
§ Mr. AtkinsThe main sources of exposure to benzene vapour in the environment arise from the benzene content of ambient air and, in smokers, from cigarette smoke. Of the former, the greater proportion arises from the use, production and distribution of petrol. The recent report of the expert panel on air quality standards estimated that 78 per cent. of benzene emissions in the United Kingdom in 1991 arose from petrol engine exhausts. Cigarette smoke contains benzene and this may be the main source of exposure for a heavy smoker.