Technologies

33 years ago, the disaster at the nuclear power plant forced people to leave Chernobyl. Now this is a unique “refuge” for wildlife .

An ecosystem with large mammals and 200 bird species is developing in the exclusion zone, research confirms.

Until the 19th century, the Pripyat River passed through wetlands and dense forests, until the large-scale industrialization of the USSR in the 20th century conquered these territories. Until April 26, 1986, when the explosion at the Chernobyl nuclear power plant forced more than 300 thousand people to leave their homeland because of the threat of radiation. So there was a zone of alienation – an area of ​​2,600 square kilometers, free from people.

The answer to the question of what happened there after this is still the subject of controversy in the scientific community. For years, experts have talked about the death of many plants and animals, as well as the pernicious mutation of the rest. But modern research indicates that the exclusion zone is not as damaging to the ecosystem as was thought. On the contrary – this is a place where wildlife is free from human influence.

The scale of the influence on nature

The scientific community still does not fully know the true level of the impact of the Chernobyl disaster on the health of millions of people, including the liquidators and residents of the polluted zones. A number of studies have shown that these categories of people are more often prone to various diseases – for example, cataracts (visual disturbance, up to complete loss) and reduced immunity.

Iodine-131 isotope was contained in the radiation clouds formed due to the catastrophe, a product of the fission of uranium, plutonium and thorium. When irradiated, it significantly increases the likelihood of thyroid cancer. Moreover, emergency responders more often encountered leukemia and other severe cancers.

In 2017, researchers associated the Chernobyl accident with a surge in diagnosing in the elderly New Yorkers an extremely rare type of eye and optic nerve cancer – vitreoretinal lymphoma . As it turned out, ten patients once lived near Chernobyl or the affected area.


Red Forest – one of the most polluted places in the exclusion zone Photo Getty

The accident had no less impact on the local ecosystem. 30 minutes after the explosion of the fourth power unit of the nuclear power plant, many trees in the area of ​​202 square kilometers died and turned reddish-brown. For this, the territory was called the Red Forest and for a long time was considered the most polluted part of Chernobyl.

During decontamination, the forest was bulldozed and buried by planting seedlings. They grew to the size of a real forest, and, although so far the gamma-background of individual islands of soil is higher than the allowable, the May survey in 2019 foundrelatively safe zones.

Early studies in Chernobyl recorded a decline in the population of birds, invertebrates and mammals. “If in the spring you visit the most contaminated areas, such as those in the Red Forest, you can hardly hear the birds singing,” says environmentalist Anders Møller from the University of Paris-Sud XI. “I assure you, if we go to the exclusion zone, I will be able to assess the level of radiation on the ground by the activity of birds in the area,” the expert continues.

According to Möller, birds in the exclusion zone are more likely to exhibit signs of radiation damage, including albinism (lack of melanin pigment, affects coloring) and sperm anomalies (they are also recorded in rodents). The frequency of mutations of the barn swallow in Chernobyl is 2-10 times higher than anywhere else in Ukraine, similar results apply to other animals and plants.

Proven and more – the total population of invertebrates in and around the zone is less than in other places. Especially negative radiation affects insects, spiders and butterflies. However, with large mammals everything is different – their population is stable. A study of the 1990s did not record changes in numbers due to radiation.

Twenty years later, a team of international scientists went to the Zone and counted the animals from a helicopter. They found no significant differences in the population of moose, deer, wild boar and a sevenfold increase in the number of wolves compared to similar uncontaminated natural reserves. And this concerned the mammals that grew up from the first decade after the accident.

Why did it happen? Exactly unknown. Perhaps animals breed faster than radiation kills them. Even if 10% of the mammal population is affected, this is not enough to provoke a reduction.

Perhaps animals die before they are killed by mutation or cancer. Most individuals do not live longer than a few months, and those that grow up die in a few years. In this case, the cancer simply does not have enough time for development. However, due to lack of research, it is not known which mutations large mammals in the exclusion zone have encountered. They may be forced to live with cataracts or severe forms of cancer, which almost makes it impossible for them to get food.

Ecosystem without borders

Since the time of counting animals from a helicopter, the research methodology has changed. Now scientists lure individuals to the “smell station” – these are places with baits with fatty acids that animals like to sniff. When the camera appears, it photographs the animal, giving researchers the opportunity to find out the total number of the species in Chernobyl.

In the 1990s, around 200-300 Przhevalsky horses were released into the zone, which is actually considered a reserve, where they lived safely until poachers were active. According to the data for 2011 (there is no more up-to-date information), due to the actions of the intruders, no more than 30-40 rare individuals remained in the area. A 2012 survey showed that Chernobyl was again populated by brown bears, whose numbers correspond to regional conditions.


Przewalski’s Horses in the Exclusion Zone Photo by Michael Coetter, Flickr

In March 2019, 30 international experts from European countries, including Ukraine, reported on the results of fresh research on the exclusion zone ecosystem. They came to the conclusion that animals and plants are actively developing in the abandoned areas, while the effect of radiation on their lives is insignificant. Moreover, the populations of the mammalian species studied grow and develop.

According to modern estimates, European bison, wolves, lynxes, raccoon dogs, wild boars, foxes and more than 200 species of birds live in the exclusion zone, their numbers are at the level of places where people do not hunt them.


Animals in the Exclusion Zone Proyecto TREE Collage

As amphibians have shown in Chernobyl, their population is growing even in the most polluted areas, and they are adapting to new conditions. Some frogs have a darker color than their relatives living outside the radioactive zone. Scientists noted that the life expectancy of some species of insects in the zone has decreased, but in general it does not affect the local ecosystem.

What follows from recent research on the exclusion zone ecosystem:

  • Wildlife can be much more resistant to radiation than previously thought;
  • Manifestations of signs of adaptation in some creatures may indicate the ability to cope with radiation and live in the exclusion zone without harm; 
  • The absence of people in the exclusion zone can lead to the development of many species of animals, mostly large mammals.

In other words, now the exclusion zone is a territory with a unique ecosystem that develops without a person. The question is what role radiation plays in this. Some people think that some of the radioactive isotopes went into the earth, others believe that local animals can transfer these particles to new territories. But even determining the level of radiation is a problem without a solution.

Researchers at the University of Bristol tried to use drones to capture data. And at the University of Georgia, we tested GPS-collars with integrated dosimeters for individuals of the Zone to find out the level of doses collected by animals. But so far these are only experiments without exact confidence in success.

Scientists insist on continuing to collect data in Chernobyl, considering that the exclusion zone is one of the few such places on Earth. Another example is the area in Fukushima, Japan, from where residents were evacuated due to a radiation accident in 2011. These territories serve as an ideal model for another world. The world that people have left.


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