§ Mr. Dalyell
To ask the Secretary of State for the Environment what work is being carried out in the national material exposure programme on building decay.
§ Mr. Baldry
The national materials exposure programme was initiated in 1987 as a joint exercise involving the Building Research Establishment of the Department of the Environment, the Central Electricity Generating Board—now Power Gen-National Power— the Warren Spring Laboratory of the Department of Trade and Industry, and British Coal. The aim of the programme is to assess the effects of air pollution on a range of building materials, including metals and stone.
Results so far indicate that dry deposition of sulphur dioxide on metals and stone is the main cause of attack by pollution. The wet deposition of pollutants on to materials 583W is of lesser consequence. The dissolution of calcareous stone by rainwater can be a significant factor, however, even in areas of low pollution.
Some of the sites used on the national materials exposure programme are also part of an international programme by the United Nations Economic Commission for Europe.