§ Mr. Simon HughesTo ask the Secretary of State for the Environment if he will state for each air pollutant monitored by his Department at what levels the Department classifies the pollution as good, average and below average; if he will list the guidelines or standards advised by the World Health Organisation in each case; and if he will make a statement.
§ Mr. MacleanFor the purposes of the air quality bulletins issued by the Department to the media for public consumption, the quality of air, based on measured concentrations of ozone, nitrogen dioxide and sulphur dioxide, is divided into four categories: very good, good, poor and very poor. The bandings are as follows:
Department of Environment guidelines (parts per billion/1 hour) Very good Good Poor Very poor OZONE < 50 50–89 90–179 > = 180 NO2 < 50 50–99 100–299 > = 300 SO2 < 60 60–124 125–399 > = 400
World Health Organisation guidelines (parts per billion) 1 hour 8 hour 24 hour OZONE 76–100 50–60 33 NO2 210 — 80 SO2 122 — 35