§ Mr. Dalyell
To ask the Secretary of State for National Heritage what is the extent of the decreases in concentrations of sulphur dioxide according to the information available to his Department, in relation to the rate of decay of historic buildings.612W
§ Mr. Brooke
The report of research on atmospheric pollution and stone decay for the joint working party between the Cathedrals Fabric Commission for England and the joint environmental programme of National Power plc and Power Gen plc, published last year, found that the annual average concentrations of sulphur dioxide had decreased very markedly over the last 30 years. However, there is likely to be decay in historic stone as a result of past depositions. The Building Research Establishment is maintaining a programme of research on the effects of sulphur dioxide and other pollutants on the decay of stone and other materials as part of the national materials exposure programme of the Department of the Environment and the international materials exposure programme of the United Nations Economic Commission for Europe.