A new scientific study, the first of its kind, shows that dogs living around the Chernobyl reactor where a major nuclear explosion occurred in the mid-eighties of the last century have become genetically different from their counterparts living elsewhere.

The finding, recently published in the journal Science Advances, is important for scientists to better understand the relationship between radiation and health.

The Chernobyl nuclear power plant suffered a nuclear explosion in 1986 that released a large amount of radiation (Shutterstock)

Stray dogs at the disaster site

In 1986, one of the reactors of the Chernobyl nuclear power plant in Ukraine exploded, releasing a large amount of radioactive contamination into the atmosphere that spread throughout Europe and North America.

Residents were forced to leave the area in a hurry in the early hours after the explosion, and the Ukrainian government later issued instructions to kill pets abandoned by residents.

But some pet dogs survived the operation and lived within the exclusion zone surrounding the reactor with a diameter of 30 kilometers. Over time, members of the intervention teams working on the project to isolate the nuclear power plant after the disaster fed and cared for these animals, which were then left to fend for themselves.

It is currently estimated that more than 800 of the "descendants" of these dogs live in and around the reactor.

Today, nearly four decades later, radioactive elements released following the disaster continue to permeate soil and water, and are carried by animals living in the exclusion zone, including Chernobyl dogs.

But how has radiation affected the genes of these organisms over time?

Scientists believe that answering this question, by studying its DNA, could help them better understand the effects it has on organ function and health.

The group of dogs living around the nuclear power plant forms a genetically separated family (Shutterstock)

Genetic variation discovered

According to a report published on the Daily Geek Show website, between 2017 and 2019, researchers from the US National Genome Research Institute took blood samples from more than 300 free-rogue dogs living near the Chernobyl station to sequence their genome.

This sample is divided into 3 groups, the first living inside or near the Chernobyl facility and consisting of 132 dogs, the second about 15 kilometers from the station and consisting of 154 dogs, and the third 45 kilometers from the site of the explosion and containing 16 dogs.

By studying subtle changes in DNA, the team was able to measure the genetic similarity of these groups. Comparing their genetic makeup to those of dogs of the same species living in distant areas, the team revealed that the group of dogs living around the nuclear power plant forms a genetically separate, closed family.

Although the researchers found that the mutation detected in this group was not genetically transmitted between successive generations, the study does not conclusively confirm that radiation in the disaster zone was the cause of these changes, especially since isolation and mating between members of the same close family can cause changes such as those observed by the team in the group's DNA.

The effects of radiation in many organisms around Chernobyl have been revealed by numerous studies (Shutterstock)

Development of radiation protection in humans

Although the results of the study were not conclusive about the relationship of radiation to mutations found in dogs as the first mammals studied around Chernobyl, previous research has found traces of radiation in many different organisms in the region, from insects to birds.

For example, a paper published in 1997 showed that swallows, which were exposed to radiation around Chernobyl, had more mutations and made them more whitish. Other studies have shown a decrease in biodiversity in contaminated areas, according to a report published by CNET.

Scientists have also discovered a type of fungus that contains high levels of melanin, a pigment capable of absorbing radiation and converting it into energy. The production of high levels of melanin could act as a kind of sunscreen or protective "shield" for astronauts exposed to cosmic radiation, according to the same source.

According to the authors, future studies, which will build on the results of this new study, will contribute to revealing how radioactive environments affect the genetic makeup of animals, and thus identify genetic variants that increase cancer resistance or help develop radiation protection in humans or other organisms.