Risk view challenged

Press, Volume CXII, Issue 32941, 13 June 1972, Page 22

Risk view challenged

(N.Z. Press Association) WELLINGTON, June 11. Reported comments by the assistant director of the National Radiation Laboratory (Mr H. J. Yeabsley) could be misleading, said Mr B. Mitcalfe, chairman of the Peace Research Media Project, today.

Mr Mitcalfe added, however, that the laboratory’s role in moderating possible alarmist statements was understood. Mr Yeabsley’s comments on nuclear fall-out, in so far as it referred to the French nuclear tests at Mururoa Atoll, was accurate, but it had concentrated on the aspects of fall-out that were likely to be harmless and had omitted reference to effects that might be harmful, said Mr Mitcalfe. “His statement that no hazards to health were likely from the French tests centres on the argument that the strontium-90 level of' soil in the Northern Hemisphere had increased after a large number of United States and Russian atmospheric tests,

but not to a level considered dangerous, and to a level about four or five times higher than that in New Zealand,” he said.

Mr Yeabsley ignored that fission products did not fall in an even distribution, but were concentrated firstly in the hemisphere of origin, secondly in areas of high rainfall, and thirdly were stored in the form of iodine 131 in milk and in the thyroid glands,” added Mr Mitcalfe.

During the 1970 series of French tests, radio-active iodine in New Zealand milk had increased by as much as 300 per cent for brief periods. The northern Cook Islands, which were less than 600 miles from the testing zone and for which New Zealand was responsible in foreign affairs, relied entirely on rainwater for their water supply. National Radiation Laboratory tests of water contamination were too infrequent to be a safeguard, and the islanders were too remote to be rescued should there be a concentrated fall-out because of a sudden shift in weather, he said.

While the acceptance of permissible levels of radiation on which Mr Yeabsley had apparently based his statement seemed to be accepted by the Christchurch radiation laboratories, this was undergoing re-evaluation elsewhere because of inadequate knowledge of the genetic effects of fall-out. "Acceptance of permissible levels means the acceptance of a certain level of risk over whole populations,” said Mr Mitcalfe.