Nuclear contamination left Chernobyl for the first time in 30 years, and scientists followed closely

After the Chernobyl accident, the human exclusion zone became animal territory, and there were 7 times as many wolves as in other unspoiled areas. Science and Technology Daily chart

For 30 years, the Chernobyl accident left a huge toxic area. But scientists recently reported that they observed some signs of "unusual" in the area — the latest finding being that a young wolf had walked out of the Chernobyl quarantine zone.

This uninhabited area covers an area of about 4,300 square kilometers and is still considered highly polluted and uninhabitable today. But without human interference, some wild animals appear to have thrived and are beginning to push the boundaries of quarantine. The report was published in the recent journal Wildlife Research Europe.

May carry mutated genes

Chernobyl was once the safest and most reliable nuclear power plant ever seen. But in 1986, after a loud bang, fireworks burst into flames, completely destroying this myth.

According to official Ukrainian statistics, as of 2006, about 2.4 million Ukrainians (including 428,000 children) were affected by the radiation from the accident and had physical and mental health problems. Human health problems are mainly affected by the radioactive material iodine-131. Strontium-90 and cesium-137 cause more persistent pollution of the soil, plants, insects and mushrooms absorb cesium-137 from the soil, and contaminated food may appear on the human table. So some scientists worry that nuclear radiation will have centuries of local effects.

In February 2015, researchers installed GPS global locators on 13 wolves and began monitoring their every move. With GPS localization, scientists can learn more about how nuclear decay affects these wild animals.

Not long ago, scientists accidentally found a GPS locator on a 3-year-old male gray wolf far away from the radiation zone — it traveled to about 369 kilometers. This is the first time scientists have tracked a wolf out of the radioactive Chernobyl zone, reaching such a distance.

The researchers believe that the discovery may indicate further expansion of wildlife populations in the future, but at the same time, the mutated genes they carry may also spread.

This is not an "ecological black hole"

After the nuclear accident, the Chernobyl disaster area became a "ghost domain". The Soviet government allegedly evacuated more than 90,000 residents, and large areas of modernized settlements were classified as blockade areas.

But for 30 years, the human exclusion zone has become animal territory – the UK Centre for Ecology and Hydrology has previously launched the TREE programme to assess the risk of nuclear radiation. The researchers installed 40 automated cameras in the disaster area to track wildlife, filming a brown bear pacing in the snow outside the fence, possibly foraging, and the cameras also included more local animals — lynxes, wild boars, gray wolves, deer, horses and otters that ignored radiation.

Michael Beierner, a scientist at the University of Missouri-Columbia, was one of the scientists who monitored and analyzed the wolves wearing GPS locators. He said there were seven times as many wolves in the Chernobyl region as in other unspoiled areas.

This is likely due to the large-scale withdrawal of humans, and the pressure and interference on the local ecology has also been sharply reduced, providing an opportunity for animals to return to their habitats. Some of the larger mammals appeared here almost immediately, and they multiplyed in no-man's land, growing rapidly.

Byrna believes that the Chernobyl exclusion zone is far from being an "ecological black hole", and the migration behavior is likely to occur in other wild animals.

But the study also found that 12 other wolves wearing GPS remained in their "hometowns." In general, wolves, as social animals, rarely "run away from home", let alone walk hundreds of kilometers away. It is not excluded that the wolf pack is too dense, and a certain wild wolf is forced to spread outward. At the moment, scientists don't know what happened to the fleeing wolves.

There are many issues at issue

Despite cameras, locators and uninterrupted investigations, scientists don't really know the overall impact of the Chernobyl disaster on local wildlife populations, and studies have found evidence of increased mutation rates in some animals, but the overall picture remains obscure.

That's why scientists monitor this group of gray wolves, which have flourished in staggering numbers and are quite representative.

Now, a bold and determined wolf has far exceeded the quarantine area. The amount of radiation carried by the escapee had little effect on humans in the areas where it appeared, but through it, scientists could further reveal how genetic mutations entered a wider animal population— in other words, how far genes from radiation-mutated wild animals could travel.

However, the extent to which this "mutation" is now occurring is another controversial issue in the scientific community.

A 2016 study concluded that the impact of the accident on the surrounding ecological environment will not subside, or even be permanent. A team of researchers from the University of South Carolina and Columbia University has released a report showing that radiation leaked from the Chernobyl nuclear accident has caused anomalies in the biological ecosystems of the surrounding area.

But Byrner confirmed that the wolves his team tracked all had four legs, two eyes and a tail, and didn't glow green around them — but unfortunately, they didn't have any "hard data" on the genetic differences between these wolves and other unradated wolves so far.

Can nature's capabilities sweep away the haze of accidents? When will the uninhabited area really recover? These questions may take years to answer.

(Originally titled "For the first time in 30 years of nuclear contamination, a wolf leaves the quarantine area, scientists closely follow it – Chernobyl, is there any possibility of natural recovery?") 》)

Source: Science and Technology Daily Intern Editor: Sun Mengke