Fukushima’s nuclear disaster has caused genetic damage, a decline in the population and other changes to non-human organisms from plants to butterflies to birds in the area, US and Japanese scientists say.
In a series of articles published in the latest of US science magazine Journal of Heredity, researches revealed the widespread impact of the March 2011 Fukushima nuclear disaster on biological organisms in the region.
“A growing body of empirical results from studies of birds, monkeys, butterflies, and other insects suggests that some species have been significantly impacted by the radioactive releases related to the Fukushima disaster,” stated Dr. Timothy Mousseau, of the University of South Carolina, lead author of one of the studies.
Scientists of all the studies agreed that chronic low-dose exposure to ionizing radiation leads to genetic damage and increased mutation rates in reproductive and non-reproductive cells.
In one study, Mousseau compared effects on non-human organisms of the Fukushima catastrophe with the 1986 nuclear disaster in Chernobyl, Ukraine.
Barn swallows with abnormal white spots on their plumage were found near the Chernobyl plant after the disaster while similarly plumaged swallows in Fukushima were also reported in the wake of the 2011 crisis, the researcher said.
“Barn swallows with aberrant white feathers were first detected in Fukushima in 2012 and were observed in increasing frequencies in 2013 and 2014. Although such partial albinos are believed to have reduced probabilities of survival, there are sufficient data to suggest that this character can be inherited and may at least in part result from a mutation(s) in the germline, based on parent–offspring resemblance,” the study said.
Mousseau said that researchers were monitoring these species for
signs of population decline due to abnormalities in mitochondrial
DNA, since the same problem was reported in Chernobyl.
Genetic mutations have been previously found in three generations of pale grass blue butterflies living near the crippled Fukushima plant. Researchers found size reduction, slowed growth, high mortality and morphological abnormality both at the Fukushima site and among laboratory-bred butterflies with parents collected from the contaminated site.
“Non-contaminated larvae fed leaves from contaminated host plants collected near the reactor showed high rates of abnormality and mortality,” explained Dr. Joji Otaki of the University of the Ryukyus in Okinawa, Japan.
Researchers also suggested that there may be possible evolution of radiation resistance in Fukushima butterflies as well.
Another study showed the impact of radiation on rice. Healthy seedlings were exposed to low-level gamma radiation at a contaminated site in Fukushima Prefecture. After three days, such effects as activation of genes involved in self-defense, ranging from DNA replication and repair to stress responses to cell death were observed.
Mousseau called for continuing studies at Chernobyl which could predict likely effects in the future at the Fukushima site. Following the Chernobyl nuclear power plant meltdown scientists were able to obtain biological samples for research after extensive delays which resulted in limited information on the impacts. At Fukushima scientists began collecting information only a few months after the catastrophe, which enabled them to reveal the serious effects on non-human organisms.
"Detailed analyses of genetic impacts to natural populations could provide the information needed to predict recovery times for wild communities at Fukushima as well as any sites of future nuclear accidents," Mousseau said. "There is an urgent need for greater investment in basic scientific research of the wild animals and plants of Fukushima."
The findings raise fears over the long-term effects of radiation on people who faced exposure in the days and weeks following the disaster.