Scientists found massive natural reserves of mercury in Arctic permafrost, a toxic heavy metal that can build up in fish and other animals and cause health problems in humans.
According to a study published in the journal, Geophysical Research Letters, the mercury deposits found in the icy north may be 10 times greater than all the mercury released by humans in the atmosphere from pollution sources over the last three decades. Earth’s rising temperatures may one day thaw the permafrost releasing significant quantities of the poisonous metal into the environment.
According to study co-author, Kevin Schaefer of the National Snow and Ice Data Center, the recent discovery is the biggest pool of mercury on the planet. Paul Schuster, the study’s lead author, and US Geological Survey hydrologist calls the discovery a “game- changer” for mercury.
“It’s a natural source, but some of it will be released through what we’re doing with climate change.” Schuster noted.
Mercury is a naturally occurring element which is released by forest fires, volcanic eruptions, and the weathering of rock. However, an estimated two-thirds of the mercury found in the air can be traced to coal-burning, burning of medical waste or some types of mining. Mercury eventually finds its way back to Earth, slipping into water or on land. Once there, the metal is picked up by fish and animals, accumulating in higher amounts the farther up it climbs the food web.
Mercury is a potent neurotoxin in some forms, capable of affecting children’s brain development including cognition, language, memory and motor and visual skills. Adults are susceptible to the metal as well, as excessive amounts can impede vision, speech and muscle movements, and even compromise reproductive and immune systems.
The scientists took cores from permafrost across Alaska, measured their mercury levels and calculated how much of the toxin is present in permafrost across the world, specifically in Canada, Russia, and other northern countries.
How much mercury would be released depends on the volume of greenhouse-gas emissions and warming of the planet.
“The magnitude of this risk is as yet unknown,” the researchers said.
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