Melting Arctic permafrost releases radioactive waste and viruses dormant for thousands of years

Permafrost covers an estimated 23 million square kilometers of the Northern Hemisphere, according to the National Snow and Ice Data Center (NSIDC).

But rising global temperatures have caused permafrost to recede at unprecedented rates.

Scientists have warned that thawing permafrost could awaken viruses and bacteria that have been dormant under the Arctic ice sheet hundreds or perhaps thousands of years ago, releasing chemicals and radioactive waste that threaten human health and wildlife.

Up to 65% of permafrost could thaw by 2100 (Getty Images)

Permafrost and its dangers of receding

Permafrost is defined as any type of land, whether it is soil, sediment, or rocks, that remains frozen for at least two consecutive years, and its thickness may range from one meter to more than a thousand meters.

Reports have indicated that Arctic temperatures are rising 2-3 times faster than the global average.

The higher the air temperature, the higher the underground temperature, and the consequent melting of the ice.

A recent study, published in the journal Nature Climate Change on September 30, warns of the dangers of thawing permafrost to ecosystems and human health.

The researchers noted that most of the permafrost in the Arctic remained frozen from the Pleistocene epoch, from 2.6 million years ago to 11,700 years ago.

Melting may start gradually from the upper, newer layers to release its stored components and then extend to the lower, older layers, or it may be sudden.

In this case, it will quickly release microorganisms and chemical compounds that have been trapped in the lower layers for thousands of years.

Ice kept human and animal carcasses from decomposing and retained gases (Getty Images)

greenhouse gas storage

When plants and animals die, the microbes that break down their bodies release carbon dioxide and methane into the air, but this process stops when they are buried in ice, which serves to preserve the organisms' bodies and trap gases that would have been released in the event of decomposition.

When the ice melts, microbes continue to break down organic matter and release greenhouse gases again.

Given the staggering numbers of human and animal carcasses such as mammoths that have been buried in permafrost over thousands of years, thawing permafrost would release millions of tons of carbon dioxide and methane annually.

Awakening dormant viruses and germs

Other than greenhouse gases, permafrost harbors a range of viruses and microorganisms that have the ability to withstand extreme environments for extended periods of time.

These microorganisms have evolved a variety of methods to help them survive in ice for thousands of years with minimal amounts of nutrients and water, such as hibernation, membrane fluidization, or DNA repair.

The 2016 outbreak of anthrax in Siberia may reveal just how dangerous these frozen spores are.

The spores of Bacillus anthracis have helped it survive in the ice for decades or centuries.

Scientists attributed the outbreak of the disease to the presence of carcasses of animals that were infected with the disease decades ago in the permafrost, and rising temperatures and melting ice have led to the spread of bacteria again in the Arctic.

Similarly, a new virus appeared in Alaska in 2015, belonging to the Orthopox family of viruses that cause smallpox.

Smallpox called it Alaskapox.

Scientists have not yet identified its sources or the risks of infection.

Decades of mining in the Arctic have left wastes rich in heavy metals (Getty Images)

In 2015, scientists found 4 types of giant viruses, from a sample of 30,000-year-old permafrost in Siberia.

Although these viruses infect one of the amoeba species, the researchers stated that the preservation of these huge viruses in their ability to transmit infection in permafrost layers may raise the alarm about rising global temperatures.

Although the potential for pandemics of these permafrost viruses is as yet uncertain, the survival of viruses in these frozen environments may depend on their ability to infect a host adapted to cold environments.

However, it is possible to recover these viruses from the bodies of victims and recreate them in the laboratory.

Scientists have managed to recover RNA from the Spanish flu virus from the lung of a woman buried in a mass grave 6 feet deep in ice more than 75 years ago.

Scientists were able to synthesize the genome sequence of the virus.

The researchers pointed out that the carbon - which will be released into the atmosphere as permafrost melts - may enhance the reproduction of microorganisms that have been suspended due to lack of nutrients and extreme cold.

Permafrost harbors a range of viruses and microorganisms that have the ability to withstand extreme environments (Reuters)

nuclear waste

Permafrost also traps radioactive material dating back to the beginning of nuclear testing in the 1950s.

During the period from 1955 to 1990, the Soviet Union conducted 130 nuclear tests near the archipelago of Novaya Zemlaya in the Arctic Ocean, during which about 265 megatons of nuclear energy were released.

The Russian authorities sank more than 100 decommissioned nuclear submarines in the Kara and Barents seas.

The pollutants resulting from these radionuclides still remain in the soil layers in the region.

High levels of radioactive plutonium and cesium have been found on the sea floor, ice sheets, plants, and soil beneath glaciers.

Similarly, the American Camp Century Research Center for nuclear-powered research in Greenland produced huge quantities of nuclear waste and diesel fuel, and when the center was decommissioned in 1967, this waste remained under the accumulated ice.

It is estimated that levels of radioactive material in the Arctic will remain dangerously high until the year 2500.

The researchers reported that Arctic soil also contains concentrations of natural minerals left over from decades of mining, including arsenic, nickel and mercury.

Arctic soil traps radioactive material belonging to multi-source nuclear waste (PIXABI)

The Arctic permafrost also contains high levels of dangerous chemicals that were banned at the beginning of the third millennium, such as the insecticide Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCP). .

These chemicals and other persistent organic pollutants traveled through the air to the Arctic, becoming concentrated over time in the permafrost.

If these substances are released into the air again, they may negatively affect the ecosystem and the health of humans and animals.

The researchers pointed out that permafrost stores between 600 and 1656 gigagrams of mercury.

Melting Arctic ice could spread mercury into ecosystems through water and air, and possibly reach food supplies.

It has been proven that exposure to heavy metals, such as lead, mercury and cadmium, causes organ damage, cancer and may lead to death.

The study concluded that melting ice caused by climate change will continue to affect the Arctic Ocean, the atmosphere and land systems.

It may seem obvious that the main way to reduce the risk of exposure to chemical pollutants and pathogens buried in Arctic ice is to take immediate steps to slow the rate of melting of permafrost.