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Reindeer herds graze on lichens and mosses.

A substantial portion of the Laplanders’ diet is reindeer meat.

Here personal data and eating habits are recorded for each person to be counted.

A Laplander in a whole body counter.

The University of Helsinki (Finland) study revealed a close correlation between the consumption of reindeer meal and the Lapps’ body burdens of cesium-137. However, these levels did not exceed acceptable limits.

Figure 12 Using a whole body counter to determine radioactivity in milk.

The idea that this nuclide had entered the body with food later was tested by placing various foods in the whole body counter. All foods tested were found to contain some cesium-137, but beef and dairy products had highest levels. The radiation spectra of persons of the same age but different diet habits were compared, and correlation was found between their cesium-137 content and the amount of dairy products they ate.

In October 1960, Kurt Liden at the University of Lund in Sweden encountered evidence of the source of cesium-137 in humans. While he was using the whole body counter at the University’s Radiation Physics Department, Liden found several Norwegians whose bodies contained quantities of cesium-137 several times higher than previously recorded. He substantiated these data by counting 15 additional Norwegians from Oslo and 6 from Bergen. The Oslo residents averaged 21 nanocuries (abbreviated nc) of cesium-137 and the Bergen group 60 nc. Swedes averaged only 8 nc. (A nanocurie is one billionth of a curie, the standard unit of radioactivity.)

Curiosity regarding these high values in the Norwegians led him to investigate goat cheese, which Norwegians consume in larger quantities than Swedes. Goat cheese at that time showed a high cesium-137 content of 41 nc per kilogram. In northern Norway, near Bergen, another main food is reindeer meat, which was found to contain 28 nc of cesium-137 per kilogram, compared to 0.1 nc per kilogram in beef. These factors indicated that goat cheese and reindeer meat were responsible for the high cesium-137 count in the Norwegians.

Investigation of the soil in northern Norway revealed that it averaged 20 nc of cesium-137 per square meter. Only thin covers of lichens grow in this region, and reindeer must graze over large areas to obtain sufficient food. It was obvious that cesium-137 from fallout was collecting on lichens and then was being concentrated in the bodies of the reindeer before they were killed for meat.

Similar studies have been conducted by scientists of the Pacific Northwest Laboratory at Richland, Washington, who since 1959 have been measuring radioactivity of plants and animals in Alaska. When they found high levels of cesium-137 in lichens and caribou, they became interested in the body burdens of fallout isotopes in the Eskimos.

A portable crystal type of whole body counter was used to measure the cesium-137 content of Eskimos at five villages. The Eskimos cooperated willingly; in some communities nearly everyone accepted the invitation to be counted. This table presents the results:

(For comparison, the average body burden of cesium-137 of residents of Richland, Washington, during this period was between 5 and 7 nanocuries.)

These data show that the Eskimos who lived inland at Anaktuvuk and ate heavily of caribou meat carried cesium-137 burdens up to 20 times greater than Eskimos who lived in the four villages along the coast and had more variety in their food. (See pages 18 and 19 for photo story of a similar project in Finland.)

PROTECTION OF LABORATORY PERSONNEL

For chemists or others working with arsenic, cyanide, or other chemical poisons, safety depends on recognizing the materials and keeping them where they belong. When accidents do happen and poisons are swallowed or breathed in, successful treatment requires that someone find out exactly what and how much of the poisonous material was involved.

In the event of accidents in nuclear laboratories or reactors, it would be equally essential to identify accurately and quickly the quantity and kind of unstable nuclides the victim has absorbed. A reactor accident conceivably could add a unique hazard since neutron radiation might change the normally stable, nonradioactive atoms in the bodies of nearby workers into radioactive ones. Even gold or silver fillings in their teeth might become radioactive.