Produced by: Tarun Mishra Designed by: Manoj Kumar
As Arctic temperatures rise, permafrost along the Yukon River in Alaska is eroding, releasing mercury that has been trapped in the frozen soil for thousands of years. The sediment carried by the river contains this toxic metal, which poses significant environmental and health risks.
Researchers from USC Dornsife have developed a more accurate method for estimating the amount of mercury released from permafrost. By analysing sediments from riverbanks and sandbars, they have provided a clearer picture of the mercury levels present in the environment.
The release of mercury from thawing permafrost threatens the health of approximately 5 million people living in the Arctic region. With more than 3 million residing in areas where permafrost could vanish by 2050, the risk is growing.
Due to atmospheric circulation, mercury pollution tends to accumulate in the Arctic. Plants absorb the mercury, which eventually becomes part of the permafrost. As climate change accelerates thawing, mercury concentrations in the soil increase, raising concerns about its release into the environment.
The research team, including collaborators from Caltech, MIT, and other institutions, conducted detailed analyses of sediments in Alaska’s Yukon River Basin. They found that mercury levels in sediments were consistent with the highest estimates from previous studies, confirming the reliability of sediment sampling for measuring mercury content.
Using remote sensing data, researchers monitored the changing course of the Yukon River, which affects how much mercury-laden sediment is eroded from riverbanks. Understanding these dynamics is crucial for predicting the movement and impact of mercury in the environment.
While the immediate threat of mercury exposure through drinking water is low, the long-term effects on health, particularly in Arctic communities reliant on fish and game, could be severe. Mercury accumulates in the food chain, increasing the risk of contamination over time.
Researchers emphasize the need to understand both the erosion and reburial processes of mercury-laden sediments. They hope their new tools will provide a more precise assessment of the “mercury bomb,” potentially helping to mitigate the threat as Arctic temperatures continue to rise.