Researchers from Colorado State University, the University of Georgia and the Fukushima Environmental Radioactivity Institute have found out how radiation exposure affected the genome of animals. According to the main author of the project, Dr. Kelly Cunningham, judging by the results, local residents can return to previously contaminated areas without risk to health. Details of the study are published in the journal Environmental International.

To find out how the radiation affected the structure of the DNA of the local fauna, scientists took samples of wild boars and snakes and analyzed their bioparameters. They measured the activity of dicentric chromosomes produced by irradiation, the length of telomeres, which can be used to determine age, and the level of cortisol, a stress hormone. They then compared the data with the radiation dose rate received ten years after the accident. According to University of Georgia professor and study co-author James Beasley, studying wild animals has implications for humans as well.

The accident at the Fukushima-1 nuclear power plant occurred in March 2011. The damage caused by the Great East Japan Earthquake resulted in a massive release of radioactive material. The country’s authorities had to evacuate more than 150 thousand local residents.

The study showed that chronic exposure to low-level radiation did not affect the animals’ DNA. Scientists attribute this to the fact that by the time the study began in 2016, the concentration of cesium-134, the main radioactive element released during the accident, had decreased by more than 90%. Researchers attributed this to a short half-life of two to thirty years.

The study also confirmed low levels of cortisol in animals. According to Colorado State University professor Susan Bailey, if boars were stressed, their telomeres would shrink. In addition, she explains the well-being of animals by the absence of people.

“This is similar to what we see at Chernobyl. The fauna is thriving mainly because there are no people around who give them stress, ”she said.