HC Deb 27 November 1992 vol 214 c889W
Mr. Llwyd

To ask the Secretary of State for the Environment what research has been undertaken by his Department upon the effect of diesel emissions on the soiling of building exteriors within the United Kingdom.

Mr. Maclean

My Department has commissioned research at Queen's university, Belfast and Middlesex university on the sources and mechanisms of soiling of building exteriors. Diesel smoke is recognised as a major contributory factor.