Chernobyl Survivors Do Not Pass Excess Mutations on to Their Children After All

Considered one of the most disastrous nuclear accidents of its kind, the Chernobyl nuclear power plant explosion killed 31 people and released massive amounts of radioactive contamination into the air and environment at the time. An estimated 8 million people were exposed to high doses of radiation throughout Eurasia, including 200,000 people who were part of the cleanup efforts, reports Ed Cara for Gizmodo. Now, 35 years later, new research has shown the aftermath may not have strong generational effects on survivors and their children after all.

When researchers looked at the genomes of Chernobyl survivors' children, they found the kids had not developed genetic mutations from their parents, reports John Timmer for Ars Technica. The study was published on April 22 in the journal Science.

The Chernobyl nuclear power plant disaster occurred on April 26, 1986, after two explosions following routine maintenance set Chernobyl's No. 4 Reactor ablaze. The ruptured reactor unleashed large swaths of radiation across the neighboring landscape and left survivors living in fear about how the radiation would affect them. Many wondered if the exposure had mutated their sperm or eggs, possibly endangering the genetic health of their future children, reports Richard Stone for Science.

While it is understood that exposure to ionizing radiation causes DNA damage and increased risk of cancers, it was not understood how germline mutations, or mutations to sperm and egg cells, may occur from radiation exposure, reports Linda Geddes for the Guardian. However, after Dimitry Bazyka, an immunologist and director-general of the National Research Centre for Radiation Medicine in Ukraine, and his team looked at the genetics of 200 Chernobyl survivors and their children, they found no mutations among the survivors' children, suggesting the mutations related to exposure do not get passed down in the germline, reports Science.

The idea to look at germline mutations began after Stephen Chanock, the director of the U.S. National Cancer Institute's Division of Cancer Epidemiology and Genetics, collaborated with Bazyka to find mutations in radiation-exposed parents and their children, Science reports. Together, they tracked down cleanup crew members and people who lived nearby when the accident occurred, Science reports.

After sequencing the genomes from 130 children born between 1987 and 2002 and the genomes of 105 parents, they found that the number of germline mutations was no greater in the children of highly exposed parents than those of children born to parents who were not exposed, Science reports.

"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 to the Guardian. "I think this should be reassuring data that there's a lack of evidence for substantial or significant transgenerational effects."

The study also suggests that those exposed in other nuclear accidents, such as the 2011 Fukushima nuclear accident in Japan, may also not see any transgenerational effects from radiation exposure in their children, reports Gizmodo.

"We view these results as very reassuring for people who were living in Fukushima at the time of the accident in 2011," said Chanock in a statement. "The radiation doses in Japan are known to have been lower than those recorded at Chernobyl."

The researchers plan to track down more children of cleanup workers as well as grandchildren to see if any mutations occur as time goes on, Science reports.

Elizabeth Gamillo | | READ MORE

Elizabeth Gamillo is a daily correspondent for Smithsonian and a science journalist based in Milwaukee, Wisconsin. She has written for Science magazine as their 2018 AAAS Diverse Voices in Science Journalism Intern.