In 1986, the Chernobyl nuclear reactor in the Soviet Union, now in Ukraine, explodedwhich emits large amounts of radioactive material into the environment. Nearly four decades later, stray dogs roaming near the Chernobyl Nuclear Power Plant are genetically different from the nearby city of Chernobyl—but it’s probably not because of the radiation.

Researchers from North Carolina State (NC State) University and Columbia University Mailman School of Public Health concluded that the genetic differences between dogs in Chernobyl City and those near the Chernobyl Nuclear Power Plant (NPP) were probably not driven of radiation-induced mutations. . Their research, detailed in a December 27 study published in the journal PLOS Oneprovides insight into how harmful environmental contamination affects nearby populations over time.

“We are working with two dog populations that, while separated by only 16 kilometers, or about 10 miles, are genetically distinct,” said Matthew Breen of NC State, who participated in the study, at a university statement. “We’re trying to figure out if low-level exposure over the years to environmental toxins like radiation, lead, etc., can explain some of the differences.” on previous genetic analysisBreen and his colleagues have identified nearly 400 regions along the genome that represent differences between the two dog populations, some of which contain genes involved in repairing DNA damage.

In a recent study, the team confirmed that the city’s dogs are genetically similar to dogs in neighboring regions such as Russia and Poland, establishing them as a representative control population with which they can be compared. the NPP group. They then look for abnormalities and mutations in NPP dogs that may have accumulated over time. Germline DNA mutations, for example, are inherited changes within the DNA of reproductive cells. The researchers began their analysis at the chromosomal level, and then gradually zoomed in on smaller and smaller genetic segments.

“Think of it like using the zoom function on your phone’s camera to get more details — we start with a wide view of a subject and then zoom in,” Breen explains. “We know that, for example, exposure to high doses of radiation can introduce instability from the chromosomal level down. While this dog population is 30 or more generations removed from one that was present at the time of the 1986 disaster, the mutations would still be detectable if they gave a survival advantage to the original dogs. But we found no such evidence of this dogs.

In other words, the researchers did not find genetic mutations that could be caused by exposure to radiation. The evolutionary pressures caused by the nuclear reactor disaster, however, may still cause genetic differences between city dogs and NPP dogs.

“In human terms, it’s like studying a population centuries removed from the one that was at the time of the disaster,” said Megan Dillon of NC State, who led the study. “It’s possible that dogs that survive long enough to breed already have genetic traits that increase their ability to survive. So there may have been severe selection pressure to begin with, and then the dogs at the power plant remained isolated from the town’s population. Investigating that question is an important next step that we are currently working on. “

The adverse effects of the Chernobyl nuclear accident, in fact, are not only limited to radiation, said Kleiman of Columbia University, who was also involved in the study. Toxins including heavy metals, lead powder, pesticides, and asbestos (a carcinogenic mineral) are released into the environment during the cleaning process. The broader impact of a nuclear disaster on nearby dog ​​populations provides important clues about how future contamination crises may influence human health.

“The importance of continuing to study the environmental health aspects of major disasters like this cannot be overemphasized,” Kleiman said, “as certainly, given our increasingly technological and industrialized societies , there will always be other disasters in the future. , and we need to understand the potential health risks and how best to protect people.”

It is also comforting to know that the puppies roaming near the Chernobyl Nuclear Power Plant are not related to the wild dogs from Chernobyl Diaries.