§ Mrs. Dunwoody
asked the Minister of Agriculture, Fisheries and Food whether his Department has taken measurements of the radioactivity of coastal sediments in the area surrounding Windscale power station; and how these levels compare to national norms.
§ Mr. MacGregor
My Department carries out detailed investigations into the levels of radioactivity in coastal sediments in the area surrounding the plant and into the resulting dose to man. The results are published annually in aquatic environment monitoring reports on radioactivity in surface and coastal waters of the British Isles, published by my Fisheries Radiobiological Laboratory, copies of which are placed in the Library of the House.
The most recently published report shows that the gamma radiation dose rate over intertidal areas from readings taken at 1 metre above the surface near the plant ranged from 0.23 to 0.95 micrograys per hour compared with background levels over sediments in comparable situations elsewhere in the United Kingdom ranging from 0.03 to 0.1 micrograys per hour. The dose to the most exposed group of the public from this source is equivalent to 11 per cent. of the limit for members of the public recommended by the International Commission for Radiobiological Protection.