§ Mr. David Priceasked the Secretary of State for the Environment what steps he is taking to monitor the levels of sulphur dioxide, in the atmosphere; and what level he regards as the maximum 116W acceptable to the health of the community.
§ Mr. Peter WalkerWarren Spring Laboratory receive results from 1,200 sites, monitored by nearly 500 local authorities and other bodies throughout the country and publish them in the National Survey of Smoke and Sulphur Dioxide. Average ground-level concentrations during 1970–71 were 10.8 per cent. lower than in 1968–69 and 26.7 per cent. lower than in 1960–61. These downward trends are expected to continue. One cannot be specific about a maximum consistent with public health, but medical advice is that some adverse effects might be detectable after exposure for 24 hours to an atmosphere containing over 500 microgrammes per cubic metre. The highest annual average for any locality during 1970–71 was 132 microgrammes per cubic metre in Greater London, with a maximum winter average of 340 at some inner London sites.