Scientist’s Comparisons In Radioactivity

Press, Volume XCVIII, Issue 28950, 18 July 1959, Page 11

Scientist’s Comparisons In Radioactivity

If a person ate about a pound of brazil nuts in a year he would absorb as much radioactivity as from all the wheat he would eat. a former secretary of the Department of Scientific and Industrial Research (Sir Ernest Marsden) told members of the mathematics and physics section of the Canterbury branch of the Royal Society of New Zealand at a meeting in. Christchurch. Sir Ernest Marsden said that brazil nuts, which were very high in phosphate, were tremendously active in experiments he had carried out, although generally speaking most foodstuffs, although erratic, and very little activity. “But I would like to dispel any idea that by adding fertilisers you add activity significantly to the soil; you would get .more from’ test fallouts,” he said. Brazil nut ash had been measured by him to contain 84 micro-micro-curies per gram of alpha particles, compared with 0.7 for skim milk powder ash, he said. Average New Zealand soil gave a count of 7.5 and wheat 2. On his way put from England in a ship he had broached cargo out of curiosity and measured Antwerp basic slag at 5, but Eng-* lish basic slag at 3. he told bis audience. Cow And Calf Sir Ernest Marsden said that cow bone ash was 5.5 but little activity was absorbed by a foetus for a new born calf was measured at 0.6, Similarly, a ewe had a count of 4.4, but a newborn lamb only 0.45. Human bones were measured at 0,4. “It is very interesting that human bones, and pig, horse and dog bones only get about a tenth of the activity per gram of ash as cows and sheep,” he said. A Suffolk sheep killed in 1921 measured out at only 10 per cent, of the activity of “normal” ones and it was possible that the reason for the small amount of radioactivity found was indicative of food at the time being less active than now. More might soon be found out about this in much the same way as Captain Scott’s food stored for years in Antarctica had been used for norms against which to compare fall-out test data. Sir Ernest Marsden said.

Among other, things he had found was that an anti-nausea preparation for pregnant women was “almost pure thorium.” “I am sure they did not know about it,” he said. Wheat and Breakfast Food

A shredded wheat sample had a count of 5.6 compared with 1.9 for a breakfast food. There were fit-looking footballers on the shredded wheat packet. “No wonder, with a count like that,” Sir Ernest Marsden said Sir Ernest Marsden said he had recorded a count of 800 micro-

micro-curies of alpha particles on Niue Island compared with average soil values ef 8 or 9. “Yet people have been living there for a long time. Those people are very interesting to us to see whether there is is any effect of living in such an environment. Fortunately, or unfortunately, more than half the island is coral with no radioactivity,” he said. Sir Ernest Marsden said he had arranged to obtain foodstuffs, bananas and bones from Niue to see whether the radiation absorption was very much different from that in New Zealand. “It gives some idea of how much can be taken In these tests,” he said.