§ Mr. Wigley
To ask the Secretary of State for the Environment in how many cases during the past 12 months toxins have been found in drinking water in England and if he will analyse these to specify(a) any recognised or suspected carcinogens, (b) any recognised or suspected co-carcinogens and (c) any recognised or suspected mutagers.
§ Mr. Heathcoat-Amory
Traces of many chemicals have been detected on occasion in water supplies, but their presence could not always be quantified because of their low concentrations. Medical advice has been that at these low concentrations, if any risk to health existed, it was likely to be extremely small. A sufficiently large and lengthy exposure to some of those chemicals has been shown to be toxic, carcinogenic or mutagenic in appropriate test systems, but there is no evidence that water consumers have been subject to such exposure during the past 12 months.