It was the April 26, 1986 when the reactor number four of Chernobyl blew up. It was a catastrophe, the most serious nuclear accident of history. However, after thirty years, the territory no longer appears as a post-apocalyptic desert, but as an unexpected oasi. This is said by the UN through its agency Unep (United Nations environment program) which celebrates the “third nature reserve largest in continental Europe ”as an iconic“ example of resilience of nature”. There are bears, wolves, lynxes, bison, deer, black grouse, while the trees have grown to form a dense forest and luxuriant. All this was possible because one was created around the nuclear power plant, precisely for safety reasons alienation zone, the Chernobyl exclusion zone (CEZ): 2,800 square kilometers north of Ukraine. More than 100 thousand people they were forced to abandon their homes, leaving two large cities empty and more than one hundred villages and farms.
“The reason for a return of nature is explained by three decades of isolation and prohibition of any human activity ”, explains a Ilfattoquotidiano.it the ethologist Luca Caviglia. But two other factors also played a part: “The area has been repopulated because it is nearby Belarus, also affected by the Chernobyl disaster, was established Polesskiy Radiological Reserve, this has favored a passage of animals between the two nations and work is being done to create a protected area cross-border“. And then there were real interventions by man: “In the exclusion zone, specimens of European bison and in the period between 1998 and 2004 also some wild horses of Przewalski, the closest relative to our domestic horse “. Unep is supporting this renaissance by working together with environment minister of Ukraine, through a six-year project – launched in 2015 – which aims to make Chernobyl a national biosphere reserve. The project is funded by Global environment facility and is called “Conserving, enhancing and managing carbon stocks and biodiversity in the Chernobyl exclusion zone”. As for the radiation hazard, UNEP reiterates that most of the radioactivity released by the reactor is now lapsed: only a small percentage of the initial contamination, while after a year the contamination had dropped to less than 1%.
For the ex-nuclear engineer Alex Sorokinhowever, we must not get caught up in a superficial reading of this data. “It is very true what Unep says, today the radiation in the area around Chernobyl is much lower than that after the explosion, but this does not mean that the radiation has become harmless”, Explains Sorokin al Fatto.it. “The effects of radiation on living organisms accumulate over time “, therefore” prolonged exposure to the radiation present in the area today causes a probability of get cancer unacceptable for human beings “. Obviously the animals invade the territory without humans, “unaware of the risks they run ”, but are likely to“ live less because of tumors caused by radiation “. The duration of exposure is in fact an element often overlooked when it comes to radiation risks. “The negative effects caused by the brief moment of an x-ray are considered acceptable because they are counterbalanced by the diagnostic benefit. But if we expose our body to that same intensity of radiation over a prolonged period of months or years, then this causes rather effects. serious”.
To a non-industry reader, reading that just one year after the accident, radiation dropped by 99% would suggest that after thirty years it should be gone, but that’s not the case. “In the first months after the accident, the high intensity radioactivity was mainly generated by rapidly decaying radionuclides, such as iodine-131 or cesium-134, which have a half-life of a few days “, the engineer always explains,” but subsequently the slow-decaying radionuclides remain active, which last thousands of years“. Therefore, “over the years the radioactivity decreases, but the reduction times become longer and longer, and the radiation never drops to zero”. The narration of a victorious nature over everything, including radiation, does not even convince the ethologist Caviglia: “It is a thesis supported since the 90s by study projects conducted and financed by the IAEA (International Atomic Energy Agency, ed) “, However,” in 2020 Timothy Mousseau, professor at the University of South Carolina, e Anders Møller, ornithologist and evolutionary biologist of the Pierre and Marie Curie University of Paris, on the basis of innovative investigation techniques developed a Fukushima, confirmed in Chernobyl the correlation between high levels of radiation and a reduction in the abundance of wildlife”.
In particular, “between mammals, birds, insects i more significant drops higher than 60%, concern species with a restricted range “. The radioactive cloud spread under the action of patchy winds and the effects on wildlife distribution were experimentally demonstrated: “In a further work, Mousseau and Møller set up inside the alienation zone two hundred artificial nests for great tit and black nurse it has been verified that the birds chose the nests corresponding to the areas with less radioactivity ”, concludes Caviglia. “We must rejoice in the undeniable return of one biodiversity, but without letting go of easy enthusiasm, forgetting that radioactive contamination continues to influence ecosystems and the long-term effects are still to be investigated and understood ”.