§ Mr. Skeetasked the Secretary of State for the Environment, pursuant to his answer of 7 March, Official Report, c. 311–12, concerning nitrate levels in drinking water, if the figure of 50 mg. per litre is intended as a maximum continuous safe level; and what assessment he has made of such levels for children under the age of (a) 10 years and (b) one year, respectively.
§ Mr. Kenneth ClarkeI have been asked to reply.
The level of 50 mg. nitrate in 1 litre of water is an acceptable level for continuous exposure. It is known that an excessive intake of nitrate can cause methaemog-lobinaemia in young babies. However, there was no evidence of this clinical condition occurring following the drought in 1976–77 when nitrate levels in public water supplies were well above 50 mg. in some areas.