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The Arctic’s ‘Giant Mercury Bomb’: A Looming Threat to the Food Chain
Context:
Scientists have discovered that the melting Arctic permafrost releases harmful mercury into the water, which could impact the food chain and the environment.
More on News:
- The study reported by ABC and conducted by the University of Southern California (USC) highlights the potential environmental threat.
- Researchers have investigated sediment transport in Alaska’s Yukon River, which flows from Alaska to the Bering Sea.
- USC Dornsife College of Letters, Arts and Sciences professor has referred to this situation as a potential “giant mercury bomb” in the Arctic.
Mercury Accumulation in the Arctic
- Mercury accumulates in the Arctic due to natural atmospheric circulation, which transports pollutants to higher latitudes.
- In the Arctic, mercury is absorbed by plants, which eventually dies and contributes to soil accumulation. This mercury has become sequestered in permafrost over thousands of years.
- A 2022 study by Finnish and Norwegian researchers found that the Arctic has warmed nearly four times faster than the global average since 1979.
- This temperature increase exacerbates the release of mercury from permafrost, which could pose a significant environmental and health threat.
- Approximately 5 million people live in the Arctic and more than 3 million people in areas where permafrost is expected to disappear completely by 2050.
Key Highlights:
- Previous methods were limited by soil sampling depth, typically only covering the top three metres of permafrost. The new research analysed mercury in deeper soil layers from riverbanks and sandbars.
- The study found that finer-grained sediments contained more mercury than coarser grains, indicating that different soil types may present varying risks.
- According to Norway’s Meteorological Institute, the Svalbard archipelago recently recorded its highest August temperature ever, reaching 20.3 ℃.
- The phenomenon is particularly concerning because it can travel long distances through the atmosphere and water systems. This means that even regions far from the Arctic could be affected by increased mercury levels.
Environmental and Health Impacts:
- Mercury is a potent neurotoxin that can accumulate in the tissues of living organisms and cause severe health issues.
- In humans, exposure to high levels of mercury can damage the nervous system, impair cognitive functions, and affect motor skills.
- As mercury enters the water systems, it is absorbed by microorganisms and then moves up the food chain, affecting fish, birds, and mammals.
- Mercury accumulation can disrupt reproductive systems and lead to population declines for wildlife. Indigenous communities in the Arctic, which rely heavily on local wildlife for their diet, are particularly at risk.
Future Implications:
- These new factors will provide a more accurate estimate of the total mercury that could be released as permafrost melts over the coming decades.
- The research underscores the urgent need to monitor and predict the movement of mercury in Arctic environments to mitigate potential risks.
- As climate change continues to affect permafrost and mercury release, understanding these dynamics is essential for protecting both the environment and the health of Arctic communities.
Permafrost refers to rock or soil that stays at or below 32°F for at least two years. It typically lies beneath an “active layer” of ground that freezes and thaws annually with seasonal temperature changes.
