§ Mr. Alton
To ask the Secretary of State for the Environment (1) what information his Department has about atmospheric carbon monoxide and lead levels in cities during peak traffic flow; and if his Department has commissioned studies as to how these levels are anticipated to change in the next decade;
(2) what information his Department has about atmospheric carbon monoxide and lead levels in city centres during rush hour traffic; and if he will make a statement.
§ Mr. Trippier
Urban concentrations of both pollutants are monitored on behalf of my Department by Warren Spring laboratory.
Between November 1989 and March 1990, and depending upon the prevailing weather conditions, weekly average levels of carbon monoxide in central London varied between 0.9 and 8.1 parts per million at 0800 hours, and between 1.1 and 5.6 parts per million at 1800 hours.
Direct monitoring data for lead are not collected for the short time intervals required by the question. However, estimates from other data suggest that peak lead concentrations in central London would be of the order of 4 microgrammes per cubic metre (µgm-3), with an annual average of 0.6 µgm. For comparison these figures are well below the EC lead in air limit value of 2.0 µgm.
My Department has a substantial programme of research into the modelling and assessment of air pollution which takes into account the effects of pollution abatement measures on ambient concentrations. The increased sales of unleaded petrol and the strict exhaust emission standards set by the EC vehicles directive are expected to reduce urban concentrations of these pollutants markedly well before the year 2000.