Impact of environmental radiation on the health and reproductive status of fish from Chernobyl

Aquatic organisms at Chernobyl have now been chronically exposed to environmental radiation for three decades. The biological effects of acute exposure to radiation are relatively well documented, but much less is known about the long - term effects of chronic exposure of organisms in their natural environment. Highly exposed fish in freshwater systems at Chernobyl showed morphological changes in their reproductive system in the years after the accident. However, the relatively limited scope of past studies did not allow robust conclusions to be drawn. Moreover, the level of the radiation dose at which significant effects on wildlife occur is still under debate. In the most comprehensive evaluation of the effects of chronic radiation on wild fish populations to date, the present study measures specific activities of 137Cs, 90Sr and transuranium elements (238Pu, 239,240Pu and 241Am), index conditions, distribution and size of oocytes, as well as environmental and biological confounding factors in two fish species perch (Perca fluviatilis) and roach (Rutilus rutilus) from seven lakes. In addition, relative species abundance was examined. The results showed that both fish species are, perhaps surprisingly, in good general physiological and reproductive health. Perch, however, appeared to be more sensitive to radiation than roach: in the most contaminated lakes, a delay of the maturation of the gonads and the presence of several undeveloped phenotypes were evident only for perch and not for roach

Impact of environmental radiation on the health and reproductive status of fish from Chernobyl

© 2018 American Chemical Society. Aquatic organisms at Chernobyl have now been chronically exposed to environmental radiation for three decades. The biological effects of acute exposure to radiation are relatively well documented, but much less is known about the long-term effects of chronic exposure of organisms in their natural environment. Highly exposed fish in freshwater systems at Chernobyl showed morphological changes in their reproductive system in the years after the accident. However, the relatively limited scope of past studies did not allow robust conclusions to be drawn. Moreover, the level of the radiation dose at which significant effects on wildlife occur is still under debate. In the most comprehensive evaluation of the effects of chronic radiation on wild fish populations to date, the present study measures specific activities of 137Cs, 90Sr, and transuranium elements (238Pu, 239,240Pu, and 241Am), index conditions, distribution and size of oocytes, as well as environmental and biological confounding factors in two fish species perch (Perca fluviatilis) and roach (Rutilus rutilus) from seven lakes. In addition, relative species abundance was examined. The results showed that both fish species are, perhaps surprisingly, in good general physiological and reproductive health. Perch, however, appeared to be more sensitive to radiation than roach: in the most contaminated lakes, a delay of the maturation of the gonads and the presence of several undeveloped phenotypes were evident only for perch and not for roach

Change of radionuclide bioavailability in conditions of swamping territories within the Chernobyl accident Exclusion Zone

Presented studies were carried out during 1997–2007 within Krasnensky flood-lands on the left bank of the Pripyat River, which is the most contaminated region of the Chernobyl accident exclusion zone and where the complex of hydraulic engineering structures as flood protection dams was constructed, which preventing washing away of radioactive substances from soils and changing a hydrological mode of floodplain flows during a high water. In its turn it was by the reason of strengthening of over-moistening and swamping processes within embankment territories. As a result – on a background of the common tendencies of increase of the mobile forms of 90Sr in soils of catchment territories and bottom sediments of the exclusion zone, there is an increase of humic acids concentrations in waterlogged soils of Krasnensky flood-lands. It is also raises the content of the water-soluble forms of 90Sr forming with acids the soluble complexes. Thus the increase of concentrations of the mobile radionuclide forms and their inclusion into biotic circulation of aquatic ecosystems is observed. Such dynamics of 90Sr and 137Cs contents is significantly reflected on dose rate for hydrobionts due to incorporated radionuclides