§ Mr. Frank Cookasked the Minister of Agriculture, Fisheries and Food what was (i) the maximum level of radioactivity in the United Kingdom measured in milk in the period 30 April to the latest available date and the date and site of this measurement, (ii) the derived emergency 372W reference level for radioactivity in milk used in the United Kingdom and (iii) the emergency reference level of radioactivity in milk recommended by the International Atomic Energy Agency; and if he will make a statement advising on contingency action in the event of radioactivity above safe levels in milk supplies.
§ Mr. Jopling[pursuant to his reply, 9 May 1986, column 267]: (i) The highest levels found in milk in England and Wales were for iodine-131, which reached a maximum of 371 bq/litre on 4 May in one of the areas affected by the high rainfall on the night of Friday 2 May in the north of England. This was one isolated example. In the last few days, while iodine-131 has started to decay quite substantially, the level of caesium has risen to a maximum of 446 bq/litre; (ii) the derived emergency reference level for iodine-131 in milk is 2,000 bq/litre and 3,600 bq/litre for caesium-137; (iii) we are advised by the NRPB that it is not aware of an emergency reference level published by the International Atomic Energy Agency. NRPB action levels used by this Department have been derived from standards published by the International Committee on Radiological Protection. Powers under part I of the Food and Environment Protection Act 1984 would enable us to take immediately any appropriate action to control the sale of milk or other foodstuffs in the event of radioactivity being found above safe levels.
§ Mr. Frank Cookasked the Minister of Agriculture, Fisheries and Food if he will compare the normal levels of radioactivity in milk with those measured on Wednesday 30 April, Thursday 1 May, Friday 2 May, Saturday 3 May, Sunday 4 May, Monday 5 May and Tuesday 6 May, respectively; if he will also compare these with the derived emergency reference level for radionuclides in milk; and if he will make a statement.
§ Mr. Jopling[pursuant to his reply, 9 May 1986, column 267]: As soon as we heard of the accident at Chernobyl on Monday 28 April, daily sampling of milk was instituted but no effects were detected until Friday 2 May when traces of the predominant radionuclides iodine-131 and caesium-137 were detected for the first time. These are not normally present in milk in the United Kingdom. This triggered intensification of monitoring to give comprehensive national coverage of milk from creameries and individual farms. The majority of results for iodine-131 across the country have remained at around 10 to 50 bq/1 and for caesium the majority have been less than 50. However, following heavy rain on Friday evening while the airstream carrying radioactivity from the Chernobyl power station was still over certain parts of the United Kingdom, the levels of milk taken from cows on open pasture on Saturday 3 May reached 350 bq/1 for iodine-131 and 200 bq/1 for caesium-137. The most radiologically significant nuclide was initially iodine-131, for which emergency reference level is 2,000 bq/1, but as this element declines quickly, caesium-137 is now being relatively significant.
Because of the uneven incidence throughout the country, it is not possible to give a single figure for the levels of radioactivity in milk on a daily basis from Wednesday 30 May until Tuesday 6 May but the highest level reached on any reading, which was from cows on open pasture, was on 4 May when it reached 371 bq/1 for iodine-131.