§ Mr. Derek Page
asked the Secretary of State for Education and Science (1) whether, in view of the current investigations into a possible link between benzene and chromosome abnormalities, he will ask the Medical Research Council to extend investigations to cover toluene and similar aromatic compounds;
(2) whether work on a possible link between benzene and chromosome abnormalities gives any indication whether this is due to benzene itself or to trace impurities;
(3) whether current work on a possible link between benzene and chromosome abnormalities gives any indication whether this might be due to vapour or liquid exposure.
§ Mr. Crosland
The recent study by a unit of the Medical Research Council which showed that chromosomal abnormalities may be associated with exposure 27W to high atmospheric concentrations of benzene is part of a wide programme of fundamental research on factors associated with chromosomal changes. Changes similar to those found in association with benzene have been observed following exposure to ionizing radiation; and there is further evidence that such changes also occur in old people and may be associated with the normal process of ageing.
The significance of these chromosomal changes in terms of human disease or disability has not been determined. An important aim of the present research programme is to throw light on this problem but very much more data will have to be collected and analysed before there can be any prospect of drawing firm conclusions.
The question of extending investigations to cases of exposure to toluene and similar aromatic compounds has been considered, but in the light of what is known about the metabolism of these substances in the body it is not thought that this would further the carefully-planned research programme already in hand.
There is every reason to believe that the observed chromosomal abnormalities have been associated with exposure to benzene itself, but the possibility that they might be attributable to trace impurities cannot absolutely be ruled out.
The present work on exposure to benzene has been almost entirely in relation to its inhalation in the form of vapour.