Radiocesium tissue

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. 

Haffelder, 1995). Indeed, this heterogeneity is still apparent at 10 years after the Chernobyl accident, as demonstrated by the radiocesium contamination of muscle tissues in game animals living in low- and highly contaminated areas of Bavaria (Table 1-5.1) (Hecht, 2004). 

Most cesium compounds are water-soluble, and this enables plants to absorb almost all radiocesium from the soil (Zhu and Smolders, 2000). The cesium isotopes are transported and stored in plants much in the way that potassium ions are stored, and this results in total radiocesium contamination of the plant tissues that in turn are eaten by animals (Zhu and Shaw,... 

In animals, cesium is absorbed almost totally in the intestine, and then distributed through the whole body via the blood circulation. Based on their analogy to potassium, radiocesium isotopes mainly accumulate in muscle tissues (Whickers and Finder, 2002). By contrast, connective tissues contain much less radiocesium, and fatty tissues are virtually radiocesium-free. 

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... 

Radiocesium isotopes from the Chernobyl accident transferred easily to grazing farm animals. Both Cs and Cs were rapidly distributed throughout the soft tissues of animals after dietary ingestion and were most highly concentrated in muscle. Radiocesium activity in milk and flesh of Norwegian sheep and goats, for example, increased three- to fivefold 2 years after the accident and coincided with an abundant growth and availability... 

---