§ Mr. John Hallasked the Minister of Transport if his attention has been called to the volume of cancer-producing benzypyrene discharged into the air by diesel-engined vehicles; and what action he proposes to take to check this increasing danger to health.
§ Mr. MarplesI have studied with interest the work of the Medical Research Council on air pollution in bus garages and the Blackwall Tunnel. While it is reassuring that even in such92W conditions the concentrations of 3:4 benzypyrene from both petrol and diesel engines are so low, I hope that the measures we are taking to reduce the amount of black smoke caused by imperfect combustion will also reduce still further the emission of all polycyclic hydrocarbons.