What Chornobyl dogs can tell us about survival in contaminated environments

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Scientists from North Carolina State University, Columbia University, the University of South Carolina, and the National Institutes of Health recently conducted a study on two groups of dogs living within the Chornobyl Exclusion Zone.

The study was the first investigation into the genetic structure of stray dogs living near the Chornobyl nuclear power plant.

The results showed that the two groups of dogs, one at the site of the former Chornobyl reactors and another 16.5 km away in Chornobyl City, had significant genetic differences between them, indicating that these are two distinct populations that rarely interbreed.

The 1986 Chornobyl nuclear power plant disaster displaced more than 300,000 people living nearby and led to the establishment of an Exclusion Zone, a “no man’s land” of an approximately 30 km radius surrounding the damaged reactor complex.

The disaster caused massive steam explosions that released enormous amounts of ionizing radiation into the air, water, and soil, leading to ecological and environmental damage.

Chemicals, toxic metals, pesticides, and organic compounds left behind by years-long cleanup efforts and from abandoned and decaying structures, including the nearby abandoned city of Pripyat and the Duga-1 military base, also contribute to the disaster.

The researchers aimed to understand how dogs, and possibly humans, might adapt to intense environmental pressures such as exposure to radiation, heavy metals, or toxic chemicals.

They investigated the genetic impact of the Chornobyl disaster on the dogs living in the area.

The researchers found that the genetic structure of the two populations of dogs was genetically distinct and identified 391 outlier regions in the genomes of the dogs that differed between dogs living at the two locations.

The researchers are not sure if the genetic differences are due to genetic drift or the unique environmental stressors at each location.

However, they found that some of these markers are pointing to genes associated with the genetic repair, specifically with genetic repair after exposures similar to those experienced by the dogs in Chornobyl. Further research is needed to determine if any genetic alterations are in response to the multigenerational and complex exposures.

The dog is a sentinel species, and understanding the genetic changes in dogs living in such a hostile environment may help researchers understand how they survived and what that might mean for any population, animal or human, that experiences similar exposures.

The research may also help scientists understand how environmental hazards can impact humans and how best to mitigate health risks.

Although 37 years have passed since the accident, the danger posed by radiation exposure is still very much real, and there are real human health concerns raised for the thousands of people who continue to work within the Exclusion Zone on continuing cleanup efforts as well as at two newly constructed nuclear fuel reprocessing plants.

Understanding the genetic and health impacts of chronic exposures in dogs will strengthen our broader understanding of how these types of environmental hazards can impact humans and how best to mitigate health risks.

The research was published in Canine Medicine and Genetics.