Radiocesium sources

The accident at the Chernobyl, Ukraine, nuclear reactor on April 26, 1986, contaminated much of the northern hemisphere, especially Europe, by releasing large amounts of radiocesium-137 and other radionuclides into the environment. In the immediate vicinity of Chernobyl at least 30 people died, more than 115,000 others were evacuated, and the consumption of locally produced milk and other foods was banned because of radiocontamination. The most sensitive local ecosystems were the soil fauna and pine forest communities. Elsewhere, fallout from Chernobyl measurably contaminated freshwater, marine, and terrestrial ecosystems, including flesh and milk of domestic livestock. Reindeer (Rangifer tarandus) calves in Norway showed an increasing frequency of chromosomal aberrations that seemed to correlate with cesium-137 tissue concentrations tissue concentrations, in turn, were related to cesium-137 in lichens, an efficient absorber of airborne particles containing radiocesium and the main food source of reindeer during winter. A pattern similar to that of reindeer was documented in moose (Alces) in Scandinavia. 

Hove, K., O. Pederson, T.H. Garmo, H.S. Hansen, and H. Staaland. 1990a. Fungi amajor source of radiocesium contamination of grazing ruminants in Norway. Health Phys. 59 189-192. 

There are various sources of radiocesium in the environment. The input from atmospheric weapons testing in the mid-twentieth century leads to the most widespread and homogeneous contamination of soil and water. The accumulated contribution of Cs in Europe from this source is estimated to be about 1000 Bq m 2. The fairly uniform deposition of Cs from fallout followuig the nuclear weapons testing has led to the widespread use of this isotope as a tracer of erosion (Ritchie and McHenry, 1990 Agudo, 1998). The accident that occurred at the Chernobyl nuclear plant in April 1986 led to more localized contamination. The events that led to this accident and the consequences have been widely... 

Between 1988 and 1992, Cs levels declined in sediments from 52 lakes in southern Finland by 27% and in fish tissues by 26-39%. Radiocesium-137 concentrations in whole freshwater fishes from Norwegian lakes contaminated by Chernobyl fallout were quite variable. Major sources of Cs variations included the fish weight and growth rate, and these were related to fish age and diet. Change over time in dissolved phase Cs concentrations of lake water is significantly related to water residence time and mean lake depth these variables have been incorporated into models to predict estimates of Cs decline in freshwater systems. Radiocesium-137 activity in muscle of brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) from six lakes in Cumbria, England, between June 1986 and October 1988 were highest between December 1986 and March 1987, with maximum values of about 1200 Bq/kg FW in trout and 350 in char. Maximum Cs values were related to the initial concentration of Cs in both water... 

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