§ Mr. ButlerTo ask the Secretary of State for Transport what information he has on the volume of carcinogenic substances emitted on a yearly basis by the average motor car; and if he will take steps to monitor the future pattern of such emissions.
§ Mr. ChopeEstimates of the emissions of benzene and polycyclic aromatic hydrocarbons (PAHs)—the substances in question—vary greatly. Recent work by the university of East Anglia for the Department of Transport suggests that about 11,000 tonnes of benzene and 40 tonnes of PAHs are emitted each year from road transport. The estimates are too general to allow the figures to be calculated for the average motor car, as a substantial portion of the emissions comes from trucks and buses.
The amount of benzene and PAHs emitted by new petrol-engined cars will be greatly reduced when catalysts become standard fitment at the end of 1992. The EC directive that will provide for this will also require the control of evaporative emissions from cars, restricting another way that benzene escapes to the atmosphere.
Diesel engines fitted to trucks and buses are the primary source of PAHs from road traffic, and the tight new standards for these engines agreed in the Community last month address this area.
Part of the Department of Transport's research effort is directed at producing better estimates of these emissions. The Department of Environment is also stepping up its monitoring of the atmospheric concentrations of hydrocarbons, including benzene.