Officials do not know the cause of the elevated radiation levels, but they believe it may have originated from Eastern Europe.
Among other things, Ruthenium-106 is used for chemotherapy to treat eye tumors. It is also occasionally used in so-called radioisotope thermoelectric generators (RTGs), which provide power to satellites. It's one of the more stable, least dangerous, ruthenium isotopes.
When humans are gone
Thirty years after the nuclear disaster at Chernobyl in the USSR, large areas around the power plant, in the territories of today's Ukraine and Belarus, are still deserted for fear of the long-term consequences of a nuclear leak. Instead of houses and buildings, packs of wolves, deer, birds and other animals are reappearing.
'People can never live there'
Different kinds of animals have been spotted on the site, like this fox in the picture taken by the Minsk-based Belarusian Reuters photographer Vasily Fedosenko, who shot this series. Reuters has quoted Ukrainian Ecology Minister Hanna Vronska as saying that "people can never live there - it's impossible - not even for the next 24,000 years."
Evacuated and resettled
The accident took place on April 26, 1986, when a failed experiment at the nuclear plant in Pripyat led to an explosion in reactor No. 4, which was built a mere three years prior to the disaster. An immense amount of radioactive material was released into the atmosphere, extending throughout Europe. More than 350,000 people were evacuated from affected areas and resettled between 1986 and 2000.
Researchers remain divided over the repercussions of the disaster on flora and fauna in the region, especially in light of the contradiction between the negative effects of radiation and the positive effects of human absence. Nevertheless, it seems like nature cannot be stopped, as demonstrated by this herd of bison near the village of Dronki, Belarus.
A 2014 report on "60 Minutes," the flagship news program of the US TV channel CBS, has exposed the almost untouched ruins of Pripyat, an abandoned town that was home to roughly 50,000 people on what today is the border between Ukraine and Belarus. Here, ruined farm buildings near the Belarusian village of Pogonnoe are seen in what was declared the 30-kilometer (18-mile) exclusion zone.
Many people fear the long-term health effects of such a radioactive environment. In March, Belarusian Nobel Prize winner Svetlana Alexievich told DW that "all of my friends who have passed away in the last 10 years died of cancer - and not a single day goes by that I don't hear from one acquaintance or another that someone else has gotten sick or passed away."
No one is immune
A wolf looks into the camera in the abandoned village of Orevichi, Belarus. Evidence show that although various species of plants, flowers and animals continue to populate the area around the former nuclear reactor, many of them have a higher-than-average mortality rate and suffer from tumors and other complications. The impact of the radiation seems to vary by species.
'Hazardous for centuries'
"It was very obvious that deformed patterns were much more prevalent in areas of high contamination," the biologist Timothy Mousseau told DW after spending years collecting mutant bugs, birds and mice from around Chernobyl and Fukushima, in Japan. "Many areas will remain hazardous for centuries - even thousands of years," he added. Here, elk are seen near Dronki.
Effects on Belarus
An eagle sits on the roof of a school in the abandoned village of Tulgovichi, about 370 kilometers (230 miles) southeast of Minsk. The Soviet region that is now independent Belarus received about 70 percent of the radioactive fallout from the accident. Over 20 percent of the agricultural lands that fall into the country's contemporary borders were contaminated.
Thirty years on, accurate figures on cancers caused by the Chernobyl disaster and the indirect toll are still inconclusive. The number of deaths directly attributed to the explosion stands at 31, but there is still no comprehensive picture - or even a consensus on a method to account for the health impacts.
From one generation to the next
Examining animals like this woodpecker spotted near the village of Babchin has led scientists to believe that the effects of the radiation are both passed through the food chain, but also from one generation to the next. Animals tested around Chernobyl have been found to have increased rates of tumors, cataracts and neurological defects such as smaller brain sizes.
Some scientists believe that several species found around Chernobyl today did not exist there prior to the disaster. However, these claims have not been confirmed, and most scientists are cautious about such statements.