The Children of Chernobyl Are Not, In Fact, Mutants

Comic books aren’t real life, and thankfully neither are decades of ever-growing lore about what radiation does. Some good news from the awful tragedy that was Chernobyl.

ARS Technica:

The study did genome sequencing for both those exposed and their children, which allowed the researchers to detect how many new mutations had been inherited from those exposed. A number of new mutations appear with each generation, so the team was looking at a higher rate than found in controls born after the event.

And the researchers found nothing. Their search was sensitive enough that they were able to detect the effect of parental age on the number of new mutations (old parents pass on more mutations to their offspring), but it saw no effect from the dose of radiation their parents had received. Parental smoking and drinking had no impact on their offspring’s DNA as well.

One of the radioactive elements spread widely by Chernobyl was a radioactive isotope of iodine, which causes elevated thyroid cancers. As expected, a number of people exposed to the Chernobyl debris have since developed this cancer, and the researchers obtained both cancerous and healthy tissue from them. Again, they sequenced the genomes and looked at the mutations that occurred in these cancers.

As cancerous cells often tend to pick up additional DNA damage for a variety of reasons, all of the samples had mutations. So the researchers focused on identifying the types of mutations that increased with increasing exposure. The class that was most notably increased by radiation exposure was small deletions, typically caused by repair of a double-stranded break in the DNA. Double-stranded breaks that led to larger rearrangements, such as exchange of DNA between chromosomes, were also boosted by exposure.

In some cases, these mutations seemed to be directly connected to the genetic damage that drove the cancer itself. In other cases, the connection was difficult to determine.

Overall, the big news is that, even though the radiation exposure appears to have been sufficient to cause extensive DNA damage and cancer, it doesn’t appear that this damage is being passed on to future generations at an appreciable rate. So, while Chernobyl has left a horrifying legacy, there are limits to how far the legacy is likely to spread.