The effect of chronic low-dose environmental radiation on organ mass of bank voles in the Chernobyl exclusion zone

Abstract

Purpose: Animals are exposed to environmental ionizing radiation (IR) externally through proximity to contaminated soil and internally through ingestion and inhalation of radionuclides. Internal organs can respond to radioactive contamination through physiological stress. Chronic stress can compromise the size of physiologically active organs, but studies on wild mammal populations are scarce. The effects of environmental IR contamination on organ masses were studied by using a wild rodent inhabiting the Chernobyl exclusion zone (CEZ). Material and methods: The masses of brain, heart, kidney, spleen, liver and lung were assessed from bank voles (Myodes glareolus) captured from areas across radioactive contamination gradient within the CEZ. Relative organ masses were used to correct for the body mass of an individual. Results: Results showed a significant negative correlation between IR level in the environment and relative brain and kidney mass. A significant positive correlation between IR and relative heart mass was also found. Principal component analysis (PCA) also suggested positive relationship between IR and relative spleen mass; however, this relationship was not significant when spleen was analyzed separately. There was no apparent relationship between IR and relative liver or lung mass. Conclusions: Results suggest that in the wild populations even low but chronic doses of IR can lead to changes in relative organ mass. The novelty of these result is showing that exposure to low doses can affect the organ masses in similar fashion as previously shown on high, acute, radiation doses. These data support the hypothesis that wildlife might be more sensitive to IR than animals used in laboratory studies. However, more research is needed to rule out the other indirect effects such as radiosensitivity of the food sources or possible combined stress effects from e.g. infections.

Selection parameters in lines of Drosophila melanogaster Meig., obtained from populations living in territories with different levels of radiation pollution: approbation of the Crow’s method

“…Багато уваги приділяється вивченню фізіологічних (Einor et al, 2016), генетичних (Alexander, Bergendahl, 1964;Golub, Chernyk, 2008;Skorobagatko et al, 2020), у тому числі епігенетичних (Vaiserman, 2011;Guerrero-Bosagna et al, 2014) наслідків опромінення. Більшість досліджень було проведено в лабораторних умовах, але, як відзначають різні автори, їх результати не можна перенести на популяційні процеси (Козерецкая и др., 2008;Kivisaari et al, 2020). Дослідження дії радіації на біологічні об'єкти у природних популяціях мають певні особливості, серед яких можна відзначити наступне:…”

“…(3) За думкою експертів (Garnier-Laplace et al, 2013;Mothersill et al, 2019;Kivisaari et al, 2020), дика природа може бути більш чутливою до іонізуючого опромінювання, ніж тварини, які використовуються в лабораторних дослідженнях, що пояснюється наявністю інших чисельних стресорів у природному середовищі.…”

The Biology of Chernobyl

“…Coincidentally, the coat color of bank voles is less red and lighter in color in more radioactive areas (Boraty ński et al 2014). A short selection of other important phenotypic effects includes reduced germination and seedling growth in wild carrots (Boraty ński et al 2016), shortened calling song in cuckoos (Møller et al 2016a), reduced growth rates in trees (Mousseau et al 2013), increased frequency of tumors and developmental abnormalities , increased prevalence of cataracts in the eyes of birds ) and rodents (Lehmann et al 2016), and decreased brain size in birds (Møller et al 2011) and voles (Kivisaari et al 2020).…”

Population transcriptogenomics highlights impaired metabolism and small population sizes in tree frogs living in the Chernobyl Exclusion Zone

“…A good example is the bank voles ( Myodes glareolus ) living in the Chernobyl Exclusion Zone (CEZ), for which a large number of studies showed that they are still experiencing individual functional modifications along the radioactive gradient more than 30 years after the nuclear power plant accident (e.g. colouration [ 32 ], cataracts [ 33 ], organ mass [ 34 ], DNA damage response [ 35 ]). These modifications were associated with decreased populations size [ 36 ] and thus question the impact on the vulnerability of populations in contaminated places.…”