[The mechanism of milk contamination in the territory of Gomel Oblast].

Abstract

The authors provide the results of studying 137Cs and 90Sr pollution of soil, plants and milk in the Gomel region in 1986-1989. Describe the dynamics of the ratios soil-grass and milk-soil during that period. The content of 137Cs in milk ranged from n.10(-10) to n.10(-7) Ci/l in polluted regions and from n.10(-10)-n.10(-9) Ci/l in the so-called pure regions. In all the regions examined, the concentration of 90Sr in milk was far lower than that of 137Cs. After the accident the levels of 137Cs in milk rose 18-350-fold and those of 90Sr 3-16-fold on the average in the regions. One can observe a progressive decrease of the ratios of accumulation in the grass-soil and milk-soil systems and a decline of the concentration of 137Cs and 90Sr in milk. However, the percentage of samples with an increase of the temporarily permissible in 1988 levels of cesium radionuclides was fairly high in 1989 in certain regions: in the Vetkovsk region, it was 35.3%, in the Chechersky region, it was 28.0%. During 1987-1989, the concentration of 90Sr in milk did not exceed 1 x 10(-9) Ci/l in the areas examined. The broad range of the indicators of milk pollution with 137Cs and 90Sr is specified by varying density of the area pollution, differences in the physicochemical status of radionuclides in accident fall-outs, and geochemical characteristics of the soil sheet.