Genetic Mutation In Chernobyl Kids Scientists Report First Evidence Genetic Damage Can Be Passed On To Future Generations
On the eve of the 10th anniversary of history’s worst nuclear power plant disaster, scientists report that a group of children 120 miles away who were born eight years after a reactor exploded near Chernobyl, Ukraine, have twice as many mutations in their DNA as do other children.
Although researchers long have known that radiation can damage DNA permanently, this study by scientists in Russia and England offers the first evidence that people can pass such mutations to their children.
The findings lend support to a scenario advanced by nuclear apocalyptics and sci-fi writers alike: Genetic alterations wrought by escaped radiation can become part of the human legacy, woven into the fabric of a generation that did not even exist when the disaster took place.
The researchers say they do not know whether the mutations will affect the health of the children, who otherwise appeared normal. Using DNA fingerprinting, the investigators analyzed stretches of DNA that have no known biological function but are nonetheless vulnerable to mutations, thus serving as a chemical sentinel of change within a person’s genome, or genetic makeup.
“We cannot predict the impact of this increase in mutations on the health of future generations,” said the study’s lead author, Yuri Dubrova, a human geneticist at the Vavilov Institute of General Genetics in Moscow. He is currently a visiting professor at the University of Leicester in England, where he collaborated on the study with biologist Alec Jeffreys, a founder of DNA fingerprinting techniques.
Still, the scientists can’t rule out harmful health effects of mutations, either. “The implication is if there’s an effect seen in this part of the genome, then there are also likely to be effects seen in parts of the genome that have a more direct bearing on human health,” said David Hillis, a radiation biologist at the University of Texas. He said the mutations documented were so pronounced as to be “surprising” and “unexpected.”
Indeed, some researchers viewed the study as groundbreaking for detecting human genetic alterations in the absence of outright disease or injury. “My concern is that radiation protection standards do not take into account this kind of impact,” said Penn State geographer Judith Johnsrud, who has studied radiation exposures at Chernobyl.
For the most part, she said, safety thresholds for radiation exposure are based on the risk of an individual developing cancer at any given dosage. But this study, she said, suggests that “subtle but significant” effects occur in the children of adults exposed to relatively low doses over a long period.
The new study appears in today’s issue of the journal Nature, which is also publishing an analysis of voles living near the shut-down Chernobyl reactor. Surprisingly, the vole population appears to be thriving, even though the animals are so radioactive that they exceed the scale of a Geiger counter.
“The bottom line is there are no monsters” as a result of the radiation, said the vole study’s lead author, biologist Robert Baker of Texas Tech University.
The explosion and subsequent burning of Reactor 4 of the Chernobyl Nuclear Power Plant on April 26, 1986, released a host of radioactive chemicals into the environment, resulting in the evacuation of 135,000 people within 18 miles of the plant.
More than 30 people were killed by the explosion and acute radiation sickness, and researchers have documented a rise in thyroid cancer and congenital malformations among people living near the reactor. But the effects of low-level radiation over a long period of time are less well understood.