Animals living in the area near the damaged Fukushima Daiichi Nuclear Power Plant in Japan are reportedly not suffering any adverse health effects despite being exposed to high levels of radiation.
The plant suffered a meltdown in 2011 after it was hit by a tsunami that damaged several of its reactor cores, leaving the surrounding area largely inaccessible to humans without suffering health consequences.
In the decade since the incident, multiple generations of local animals have been exposed to the radiation. But a team at Colorado State University have studied wild boar and rat snakes across a range of radiation exposures and did not find any significant adverse health effects.
First author Dr Kelly Cunningham said their findings could suggest that people do not need to be as fearful of moving back into the remediated areas as they thought.
The wildlife study particularly relevant to humans because human physiology is relatively similar to wild boar, said co-author James Beasley. While mice have traditionally been used as a radiation biology model from which human effects are extrapolated, pigs – which are descendants of wild boar – are physiologically more like humans than mice and thus a more appropriate biomedical model species, he said.
Furthermore, environmental radiation decreased precipitously after the accident. By the time the research began in 2016 to 2018, Caesium-134, one of the major radionuclides released from the accident, had decreased by as much as 90 per cent because of its short half-life.
Key genetic markers, known as telomeres, tend to shorten if exposed to high levels of radiation; the researchers found this was not happening in the either the boar or snake DNA. The researchers thought that, given wild boar rooting behaviour and snakes living in contaminated soil, they would have received large doses of radiation. They also found lower levels of the hormone cortisol, a primary indicator of stress, in wild boar living within the Exclusion Zone.
“It’s similar to what they’re seeing in Chernobyl,” said professor Susan Bailey, senior author on the paper. “The animals are flourishing mostly because there aren’t people around, and they don’t experience the related stress that brings.”
In 2016, Fukushima’s clean-up operation hit a snag when specialised robots created to retrieve radioactive material from Fukushima were unable to complete their task after their circuitry was destroyed by radiation.
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