Science

Huge Amounts Of Mercury Trapped Under The Permafrost

Scientists have discovered huge amounts of mercury in the northern hemisphere’s permafrost regions. There is a almost twice as much there as the rest of the planet’s mercury combined. Researchers from the U.S. Geological Survey conducted a study of the Alaskan permafrost, and according to their estimates, there is 793 million kilograms of mercury, which is tucked deep under the northern hemisphere’s permafrost, dating as far back as the last Ice Age.

Huge Amounts Of Mercury
Hi-Res Images of Chemical Elements [CC BY 3.0], via Wikimedia Commons
The permafrost has already started melting in the Arctic. The melting revealed giant, although dormant viruses, which are tens of thousands of years old. Also, deforestation has resulted in permafrost to start melting in Siberia, which resulted in the ground collapsing into a huge crater. That being said, if the permafrost continues to melt, it will also unleash huge amounts of mercury, which could impact ecosystems all around the world.

“There would be no environmental problem if everything remained frozen, but we know the Earth is getting warmer,” lead author Paul Schuster, a hydrologist at the U.S. Geological Survey said in a statement. “Although measurement of the rate of permafrost thaw was not part of this study, the thawing permafrost provides a potential for mercury to be released – that’s just physics.”

The natural mercury gets into the permafrost from the atmosphere. In a part of something called the mercury cycle, atmospheric mercury vapor binds with organic material in the soil, which then gets buried by sediment. As time passes, it gets frozen and turns into permafrost.

According to the calculations done by the team, there are 793 gigagrams, or more than 15 million gallons, of frozen mercury located in the northern hemisphere’s permafrost. According to the researchers, that’s about 10 times the amount of all human-caused mercury emissions in the last 30 years.

If the non-permafrost soils in the permafrost regions are included, there are 1,656 gigagrams of mercury tucked away there also. If it somehow entered the water, it could result in massive implications, as inorganic mercury can get transformed by microbes into methylmercury, which is a potent neurotoxin.

There have been cases of methylmercury poisoning in humans after they ate fish which lived in methylmercury-contaminated water. It can result in central nervous system damage, and even birth defects.

“There’s a significant social and human health aspect to this study,” said Steve Sebestyen, a research hydrologist at the USDA Forest Service in Grand Rapids, Minnesota. “The consequences of this mercury being released into the environment are potentially huge because mercury has health effects on organisms and can travel up the food chain, adversely affecting native and other communities.”

If the mercury would enter the atmosphere, it would be capable of traveling around the globe. The next step in Schuster’s research is to show a model of how climate change would result in permafrost melting and releasing huge amounts of mercury. Also, they would analyze how it would travel around the world.

Researchers published their findings in the journal Geophysical Research Letters.