Population sizes of bank voles are lower in the areas where radiation level in the environment is increased. In her dissertation at the University of Jyväskylä Kati Kivisaari studied the effects of ionizing radiation on bank vole growth and reproduction. In males, the quality of the sperm was weakened and females produced smaller litters in the contaminated areas. In addition, brain mass was decreasing and spleen mass increasing with increasing radiation level in the environment. Results are indicating more stress related response towards radiation instead of e.g. mutations.
Click here for original story, Ionizing radiation in the Chernobyl region lowers the population sizes of bank voles
Source: Phys.org