§ Mr. SedgemoreTo ask the Secretary of State for the Environment on how many days for the latest year for which figures are available, air at each site where air pollution levels are monitored failed to meet the World Health Organisation safety level for(a) carbon monoxide, (b) nitrogen oxides and (c) ozone.
§ Mr. TrippierWorld Health Organisation air pollution guidelines are meant to provide background information and offer guidance, and are not intended to set limit values or standards.
Data are not available on daily exceedances of WHO guidelines for carbon monoxide and ozone since these guidelines are expressed in terms of exceedances of concentration levels averaged over shorter periods of time —one hour and eight hours. Data for these pollutants is therefore presented under these criteria.
The following data were obtained from the pollution monitoring network operated on behalf of the Department by Warren Spring laboratory, and covers the period January to July 1989.
Carbon monoxide (CO)
CO is monitored at two central London sites. One of these sites recorded 25 exceedances of the one-hour limit (25ppm) and two exceedances of the eight-hour limit (10ppm).Nitrogen dioxide (NO2)
NO2 is monitored at six urban and rural sites. Four of these sites recorded a total of 17 exceedances of the 24-hour limit (80ppb).Ozone (O3)
O3 is monitored at 11 urban and rural sites. Exceedances were recorded at all sites; a total of 669 for the one-hour limit of 76–100ppb and 3092 for the eight-hour limit of 50–60 ppb.