Effect of 90Sr and 137Cs concentration on Hematological Parameters of Bats in the Chernobyl Exclusion Zone (Ukraine)

We examined the effects of the level of internal 90Sr and 137Cs concentrations on hematological parameters of bats captured in the Chernobyl Exclusion Zone (Ukraine). In total, 68 animals of six bat species were live-monitored with measurement of the whole-body activity concentrations of the two radionuclides (90Sr and 137Cs) and blood sampling for further analysis. We found statistically significant positive correlations between the blood neutrophil count and whole-body 90Sr activity concentration in individuals of Eptesicus serotinus; and between the neutrophil/lymphocyte ratio and 90Sr concentration, and between the red blood cell (RBC) count and 137Cs concentration in Vespertilio murinus. We did not observe any correlation between concentrations of 90Sr and 137Cs and hematological parameters in individuals of Pipistrellus nathusii. Moreover, none of these three species showed significant sexual (male versus female) or age (adult versus sexually immature) differences in 90Sr and 137Cs concentrations. Our results contribute to better knowledge and understanding of the eco-immunology of free-ranging bats in one of the most radioactively contaminated areas in the world — the Chernobyl Exclusion Zone. To our knowledge, this is the first study investigating the relationship between radionuclide contamination and hematological parameters of bats.