If today we are talking about Ukraine, for the armed conflict that is taking place there, yesterday the country was that of the greatest nuclear disaster of all time in human and environmental terms. Remember April 26, 1986, reactor number 4 exploded in seconds! An accident caused by a combination of human error and reactor design flaws. During a safety test, the operators made a series of errors that resulted in a sudden increase in power, causing a steam explosion and the ensuing fire. The explosion released from large amounts of radioactive particles in the air, which spread across much of Europe. Recently, American researchers looked into the impact of the explosion on stray dogs, and it’s quite amazing. Discovery.
Chernobyl, a global impact
Nearly 40 years later, this disaster still has repercussions on the abandoned lands of their inhabitants, which will, a priori, never be reinhabited again. More than 300,000 people were evacuated and a 30 km exclusion zone was established around the plant. This explosion resulted in the immediate death of two plant workers, and 28 other people died of acute radiation illness in the weeks that followed. It is estimated that up to 4,000 additional cases of cancer could be directly attributed to the accident, and the long-term health effects are still being studied. The area remains heavily contaminated and will remain so for thousands of years. Stray dogs stayed put and bred. Timothy Mousseau (University of South Carolina, Columbia, USA), Elaine Ostrander (NIH, Bethesda, USA) and their team studied 302 stray dogs to try to find out the impact of exposure to nuclear radiation.
How did they conduct this study?
The researchers characterized the genetic structure of 302 dogs representing three free-ranging canine populations living in the plant itself, as well as those located 15 to 45 km from the disaster site. THE genomes of Chernobyl dogs would be genetically distinct from dogs further from the nuclear power plant, as they explain in the study published on Sciences Advances. This study was launched in 2017, due to a significant increase in wild dogs, estimated at around 800 individuals within the perimeter of the nuclear power plant. From 2017 to 2019, 302 blood samples were taken, including 132 taken directly from the plant site.
What does this study reveal?
According to the first results of this study, the dogs living in the factory, fed by the workers, were more inbred and of the German Shepherd type. A few kilometers further, in the city of Chernobyl evacuated after the explosion, where 50,000 people lived in 1986, the dogs looked more like “modern” individuals, with a mix of larger breeds. They identified 15 families out of the 302 individuals, the largest covering the nuclear plant directly. In Slavutych, the city built in a few months to accommodate those expelled from Chernobyl, which is 45 km away, the dogs identified did not have “kinship ties” with those closer to the plant.
This study presents the first characterization of a domesticated species at Chernobyl, establishing its importance for genetic studies of the effects of long-term exposure to low-dose ionizing radiation. Furthermore, they also demonstrated that the dogs living closest to the epicenter still carried traces of the irradiation, such as cesium-137 deposits. This rate is more than 200 times higher than those living a few tens of kilometers away. This study is the first of a gigantic genetic project. However, researchers are still unable to understand how these dogs manage to survive with such a high level of cesium-137 in their blood.. This will obviously be the subject of a future study. More information: science.org / nature.com