Assessment of DNA damage and stress in wildlife chronically exposed to low-dose, low-dose-rate radiation from the Fukushima Daiichi Nuclear Power Plant accident

DOI:https://doi.org/10.1016/j.envint.2021.106675

Commentary

The health effects associated with chronic low-dose, low-dose-rate (LD-LDR) exposure to environmental radiation are uncertain, and all dose-effect studies conducted outside of controlled laboratory conditions are challenged by the inherent complexity of ecosystems and the difficulty of quantifying doses to free-ranging organisms in natural environments.

As a result, the effects of chronic LD-LDR radiation exposure on wildlife health are poorly understood and much debate continues.

In this study, samples from wild boar and rat snakes were collected between 2016 and 2018 across a gradient of radiation exposure at Fukushima, Japan.

Biomarkers of in vivo DNA damage and stress were assessed as a function of multiple measurements of radiation dose.

These biological parameters allowed us to correlate robust calculations of radiation dose rates at capture and plausible upper lifetime doses, both of which incorporated internal and external doses.

As a result, no significant relationship was observed between dicentric chromosome frequency, telomere length and dose rate at capture or lifetime dose.

Radiation exposure was significantly associated only with cortisol, and low concentrations were associated with high dose rates, but the relationship is more likely due to other factors.

These results suggest that wild boars and snakes chronically exposed to LD-LDR radiation sufficient to prohibit human habitation did not experience significant adverse health effects as assessed by biomarkers of DNA damage and stress.