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Dept of Health

Answer

Mr. Baker: To ask the Secretary of State for Health what advice his Department gives to water companies regarding the chlorination of drinking water. [132347] Yvette Cooper: [holding answer 24 July 2000]: Chemical disinfection of drinking-water is an important part of the treatment of water to protect human health. There are, however, concerns that traces of the chemical by-products of disinfection processes may be harmful. Standing expert advisory committees, whose members are appointed by the Chief Medical Officer, have advised the Drinking Water Inspectorate (DWI) at the Department of the Environment, Transport and the Regions on the evidence linking the consumption of chlorinated tap-water with cancers and with adverse reproductive outcomes. The Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment concluded that: Overall, the further epidemiological studies fail to provide persuasive evidence of a consistent relationship between chlorinated drinking-water and cancer. It remains possible that there may be an association between chlorinated drinking water and cancer which is obscured by problems such as the difficulty of obtaining an adequate estimate of exposure to chlorination by-products, misclassification of source of drinking water (including the use of bottled water), failure to take adequate account of confounding factors (such as smoking status), and errors arising from non-participation of subjects. We therefore consider that efforts to minimise exposure to chlorination by-products remain appropriate, providing that they do not compromise the efficiency of disinfection of drinking-water. The statement was published in March 2000 in the 1998 Annual Report of the Committees on Toxicity, Mutagenicity and Carcinogenicity of Chemicals in Food, Consumer Products and the Environment. The Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment concluded that: We consider that there is insufficient evidence to conclude that the presence of chlorination by-products in tap-water increases the risk of adverse reproductive outcomes. We recommend, however, that the claimed associations between patterns of drinking-water intake and the incidence of adverse reproductive outcomes be investigated further, since any causal association would be of significant public health concern. We therefore consider that efforts to minimise exposure to chlorination by-products by individuals and water authorities remain appropriate, providing that they do not compromise the efficiency of disinfection of drinking water. The statement was published in March 2000 in the 1999 Annual Report of the Committees on Toxicity, Mutagenicity and Carcinogenicity of Chemicals in Food, Consumer Products and the Environment. Copies of the Annual reports have been placed in the Library, and may be found on the internet at http://www.doh.gov.uk/coc.htm The advice was passed on to water and sewerage companies, and water companies, in England and Wales, by DWI in Information Letter 12/99 on 14 July 1999. The letter included additional advice from DWI to the companies. The letter may be found on the internet at http://www.dwi.detr.gov.uk/regs/infolett/1999/ info1299.htm

Secondary information

Type

Written question

Reference

354 c632-3W; 132347

Session

1999-00

Subjects

Drinking water Water companies Water treatment Chlorine

Link

View this Written question on www.publications.parliament.uk