The Chernobyl accident on April 26, 1986, threatened to cover the entire European continent in highly radioactive dust smoke. Two Chernobyl Power Plant workers died immediately when the plant’s Reactor Four suffered a steam explosion and another 28 people died in the following weeks from radiation poisoning. The World Nuclear Disaster estimates around five percent of the reactor’s nuclear core was released into the atmosphere, travelling from northern Ukraine as far as Sweden within days. But the legacy of Chernobyl and other incidents like the 2011 Fukushima Daichi nuclear disaster in Japan could rear their ugly head again in the future.

Researchers from the University of Plymouth’s School of Geography, Earth and Environmental Sciences have warned the combined nuclear fallout from Chernobyl, Fukushima and Cold War nuclear tests is collecting in the world’s glaciers. Significant amounts of highly radioactive particles are trapped in the world’s iciest regions, waiting to be released. And if the dire effects of global warming contribute to the accelerated melting of glaciers, decades-worth of nuclear fallout could be released into the atmosphere. Plymouth’s scientists have found evidence of man-made radioactive fallout in 17 glaciers across the Arctic, Iceland, Antarctica, Canada and the Caucasus mountains. READ MORE: How many people died in Chernobyl?

Chernobyl: Fallout from the nuclear disaster has settled in now melting glaciers

Chernobyl: The exploded Reactor Four released radioactive substances into the air for 10 days

Caroline Clason, a lecturer in Physical Geography at Plymouth said: “They are some of the highest levels you see in the environment outside nuclear exclusion zones.” The dire news was published in April this year at the 2019 General Assembly of the European Geosciences Union (EGU) in Vienna, Austria. But with the release of HBO’s and Sky Atlantic’s historical drama in May this year, public interest in the dangers of radioactivity is on the rise again. Dr Clason said: “Radioactive particles are very light so when they are taken up into the atmosphere they can be transported a very long way. READ MORE: What are the symptoms of radiation sickness?

“When it falls as rain, like after Chernobyl, it washes away and it's sort of a one-off event.

You can see a clear spike where Chernobyl was Caroline Clason, University of Plymouth

“But as snow, it stays in the ice for decades and as it melts in response to the climate it's then washed downstream." When Chernobyl’s Reactor Four exploded in 1986, the burning reactor core continuously released clouds of radioactive smoke for 10 days. The Ukraine, Belarus and Russia were hit the worst by the radioactive fallout but increase background radiation levels were reported in Scandinavia and West Europe. READ MORE: How to visit Chernobyl power plant site after tragedy

The exact death toll of the Chernobyl disaster is up for debate but the Union of Concerned Scientists estimates between 4,000 and 27,000 people died as a result of increased radioactive exposure. A 19-mile-wide (30km) Chernobyl Exclusion Zone now surrounds the power plant and the nearby city of Pripyat, where more than 100,000 people were evacuated from never to return. Nuclear fallout concerns were then raised once again in 2011 following the deadly Tōhoku earthquake and tsunami in Japan’s Fukushima prefecture. The tsunami struck the Fukushima Daiichi Nuclear Power Plant in Ōkuma, triggering the second biggest nuclear disaster in history. To date, Chernobyl and Fukushima are the only nuclear meltdowns ranked Level 7 by the International Nuclear Event Scale.

Another source of nuclear fallout collecting in the world’s glaciers are the frequent nuclear weapon tests conducted on either side of the Iron Curtain during the Cold War. Dr Clason said: “We're talking about weapons testing from the 1950s and 1960s onwards, going right back in the development of the bomb. “If we take a sediment core you can see a clear spike where Chernobyl was, but you can also see quite a defined spike in around 1963 when there was a period of quite heavy weapons testing.” According to the expert, the results are evidence the humanity’s “nuclear legacy hasn't disappeared yet.”

Chernobyl: A 19-mile radioactive exclusion zone surrounds the power plant

Fukushima disaster: Another major incident occurred in Japan in 2011

How big was the 1986 Chernobyl nuclear disaster? In the immediate aftermath of Chernobyl’s reactor erupting, the World Nuclear Association claims the “largest uncontrolled radioactive release into the environment ever” occurred. The nuclear disaster continued to release radioactive material from the burning open reactor into the air for 10 days. The eruptions released deadly radiation in the form of iodine-131 and caesium-137 isotopes. The World Nuclear Association said: “Initial radiation exposure in contaminated areas was due to short-lived iodine-131; later caesium-137 was the main hazard. “About five million people lived in areas of Belarus, Russia and Ukraine contaminated and about 400,000 lived in more contaminated areas of strict control by authorities.”