For decades popular culture has portrayed babies born to the survivors of nuclear accidents as mutants with additional heads or at high risk of cancers. But now a study of children whose parents were exposed to radiation from the Chernobyl disaster in 1986 suggests they carry no more DNA mutations than children born to any other parents.
The study, published in Science, is one of the first to systematically evaluate alterations in human mutation rates in response to a manmade disaster, such as accidental radiation exposure.
As well as providing fresh insights into how radiation affects the human body, the findings should help reassure other people who may have been exposed to radiation, such as those living near the Fukushima Daiichi plant in Japan in 2011, that it is safe to return home or have children.
“There’s a lot of reticence among people to go back, and one of the major concerns is the transgenerational effects,” said Dr Stephen Chanock, of the National Cancer Institute in Rockville, Maryland, who supervised the research. “There’s this science-fiction societal view of three-headed babies, which is really accentuated in the Fukushima setting right now.”
Although ionising radiation can damage DNA in the cells of people exposed to it, potentially their risk of cancer, it was less clear whether egg and sperm cells were similarly affected. In theory, mutations in these cells could be transmitted down the generations, potentially triggering developmental disorders or cancers in the descendents of radiation-exposed individuals.
To investigate this possibility, Chanock and his colleagues analysed the genomes of 130 children born to parents who were either involved in the cleanup of the Chernobyl site after the accident, or were evacuated from nearby towns and settlements, as well the parents’ genomes. All of the children were conceived after the accident.
Even though their parents had been exposed to high levels of radiation, there was no increase in the number of new mutations – those not detected in either parent but that could have arisen because of damage to their eggs or sperm – in these children.
“These mutations may be in the parents’ blood, but we’re not seeing this horrific science-fiction-like mutation of sperm and eggs,” said Chanock. “I think this should be reassuring data that there’s a lack of evidence for substantial or significant transgenerational effects.”
Dr Alex Cagan, a postdoctoral fellow at the Wellcome Sanger Institute in Hinxton, England, said: “While these findings do not diminish the innumerable personal tragedies associated with the Chernobyl nuclear accident they do provide a glimmer of hope that the potentially damaging effects to DNA do not appear to have been passed down to the children of those involved.”