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Straits Times
14-06-2025
- Science
- Straits Times
Study shows mercury levels in arctic wildlife could rise for centuries
Previous research has shown that mercury can persist in oceans for more than 300 years. PHOTO: AFP Levels of mercury in Arctic wildlife could continue to rise significantly even as countries curb their emissions, a new study suggests. Researchers analysed more than 700 samples of fish, mammals and peat collected across Greenland over the past 40 years and found evidence that the mercury in them was distributed by ocean currents. The finding, published this week in the journal Nature Communications, helps explain why levels of mercury contamination have continued increasing in the Arctic even as global emissions have begun to plateau. 'We got a lot of surprises when we analysed the data,' said Dr Jens Sondergaard, a senior ecological science researcher at Aarhus University in Denmark and lead author of the study. 'It's a really striking trend.' Exposure to high concentrations of mercury, a potent neurotoxin, can lead to neurological and other health-related effects and the study confirms that mercury emitted today could continue posing a large threat to humans and wildlife in the region for centuries. By analysing mercury isotopes, a unique kind of chemical signature that can be matched like a fingerprint, the researchers traced the spread of mercury contamination to the patterns of ocean currents around Greenland. Previous research has shown that mercury can persist in oceans for more than 300 years. The results indicate that large, century-old stores of mercury in the ocean could actually be the dominant means by which the element proliferates through marine ecosystems in the Arctic, Dr Sondergaard said. This poses a problem for people who live in the region, particularly Inuit communities that hunt large marine mammals with high concentrations of mercury, like seals. 'It's a quite unique situation. This population that ought to be, you know, in a clean environment, has some of the highest concentrations,' said Professor Rune Dietz, a professor at Aarhus University and a co-author of the study. Mercury is primarily spread through the environment by human activities such as burning coal or mining heavy minerals, like gold. According to a 2023 estimate by researchers at the Harvard School of Engineering and Applied Sciences, atmospheric mercury concentrations have risen nearly sevenfold since the 1500s. Mercury emissions in North America and Europe began falling in the 1970s, following the enactment of a series of environmental regulations like the Clean Air Act. Other countries with high levels of pollution, like China and India, began curbing their emissions a little more than a decade ago, after signing a global agreement known as the Minamata Convention. Earlier this week, the Environmental Protection Agency began moving to loosen limits on mercury emissions, along with those on other pollutants, from power plants. There is no known safe level of methylmercury, the toxic form of mercury that can form in aquatic environments. In high bodily concentrations it can cause neurological problems, kidney damage and affect fetuses in the womb. Despite hosting almost no mercury-producing industries, the Arctic has become a hot spot of contamination, in part because of the natural pattern of the Earth's atmosphere and oceans, which tend to circulate pollutants toward higher latitudes. Large predators that eat significant amounts of contaminated prey end up ingesting the most mercury. Studies have shown that such marine mammals, like ring seals and pilot whales, can carry concentrations of mercury up to 50 times greater than some smaller fish, like herring. The new paper found that concentrations of mercury found in polar bear tissues have doubled in the last 40 years. Professor Niladri Basu, a professor of environmental health sciences at McGill University in Canada who was not affiliated with the study, said that Indigenous groups with hunting practices are most at risk for exposure to mercury. 'The species that drive exposure in communities are not species that are harvested for global transport and trade,' he said. Prof Basu added that mercury advisories have led to some Inuit communities cutting back on traditional food sources, representing a significant cultural loss. Emissions aren't the only mercury contamination threat in the Arctic. In 2024, a study found that the region's frozen soils, known as permafrost, have been accumulating mercury for centuries, reaching levels estimated to be higher than the atmosphere, oceans and life-forms combined. As climate change continues to warm the planet, scientists worry that these stores of mercury could be released. In November, international delegates will meet for the Minamata Convention's sixth major meeting. 2025 also presents the first deadline for the more than 120 countries who signed on to the treaty, to begin phasing out mercury use in certain types of production. Even in light of the global action on mercury, Prof Basu said, it could take centuries for the Arctic to recover. 'On one hand, we want to take action, and we have to recognise that mistakes are made and that we can't continue as business as usual,' he said. 'But on the other hand, we have to recognise that it's going to take a long, long time to undo all the damage.' NYTIMES Join ST's Telegram channel and get the latest breaking news delivered to you.
New York Times
13-06-2025
- Science
- New York Times
Study Shows Mercury Levels in Arctic Wildlife Could Rise for Centuries
Levels of mercury in Arctic wildlife could continue to rise significantly even as countries curb their emissions, a new study suggests. Researchers analyzed more than 700 samples of fish, mammals and peat collected across Greenland over the past 40 years and found evidence that the mercury in them was distributed by ocean currents. The finding, published this week in the journal Nature Communications, helps explain why levels of mercury contamination have continued increasing in the Arctic even as global emissions have begun to plateau. 'We got a lot of surprises when we analyzed the data,' said Jens Sondergaard, a senior ecological science researcher at Aarhus University in Denmark and lead author of the study. 'It's a really striking trend.' Exposure to high concentrations of mercury, a potent neurotoxin, can lead to neurological and other health-related effects and the study confirms that mercury emitted today could continue posing a large threat to humans and wildlife in the region for centuries. eBy analyzing mercury isotopes, a unique kind of chemical signature that can be matched like a fingerprint, the researchers traced the spread of mercury contamination to the patterns of ocean currents around Greenland. Previous research has shown that mercury can persist in oceans for more than 300 years. Want all of The Times? Subscribe.
Yahoo
12-06-2025
- Science
- Yahoo
Mercury from centuries-old pollution still circulating in oceans, study finds
Toxins released by long-extinguished fossil fuel fires and gold smelters are showing up in the bodies of Arctic wildlife, according to new research pointing to mercury released by pollution hundreds of years ago still circulating in ocean currents. A paper published Thursday in Nature Communications sought to untangle a paradox: why levels of the potent neurotoxin mercury in Arctic whales and polar bears are increasing — despite steps the world has taken to curb mercury pollution. Those levels are now 20 to 30 times higher in Arctic wildlife than they were before the industrial era began, even as global mercury pollution has fallen since the 1970s. 'We've monitored mercury in Arctic animals for over 40 years. Despite declining global emissions since the 1970s, we see no corresponding decrease in Arctic concentrations — on the contrary,' coauthor Rune Dietz of Aarhus University, said in a statement. The researchers' conclusion: mercury released by pollution hundreds of years ago is still circulating in ocean currents, which convey it up to the Arctic. The findings come amid reports that the Trump administration is seeking to overturn rules limiting the release of mercury from U.S. power plants — a step that reverses a long campaign to slow its accumulation in the atmosphere. If these U.S. changes take place, the findings suggest, they will continue to contaminate the environment well into the 2300s. Mercury — particularly forms that have been processed by bacteria — wreaks havoc on the brain and body, disrupting the ability of humans and animals to move, sense and think. While a global effort has been successful in cutting levels of mercury in the atmosphere, Thursday's findings point to a mystery: Levels of the toxin in the muscle and tissue of top predators like seals and polar bears are still going up. In addition to being released into the environment from burning fossil fuels, mercury is also used to purify gold extracted in small-scale or wildcat mining — a practice that is still common in the world's forests, but has significantly decreased from its 19th Century peak. In gold rushes like those in 1850s California or the modern Amazon, miners used mercury to bind together gold together from a slurry of dirt and ore, and then burn it off to leave pure gold — sending the mercury into the atmosphere. From there, mercury rains down onto the land and flows into lakes and rivers, where bacteria break it down — as well as into the oceans, where that breakdown can take as much as 300 years. The same quality that lets mercury pull together gold flakes gives it an insidious role in the environment because animals cannot easily purge it from their bodies. That means mercury levels concentrate in the bodies of top predators — whether bears or humans. The long duration of mercury in oceans gives it time to make its own epic journey from 19th Century smelters to the modern Arctic, the scientists found. 'Transport of mercury from major sources like China to Greenland via ocean currents can take up to 150 years,' Dietz said. 'This helps explain the lack of decline in Arctic mercury levels.' Though China is working to phase out mercury mining and pollution from coal, the findings suggest a long lag time. Even if mercury pollution continues to decrease, the scientists projected, its levels will continue to go up in the Arctic. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
12-06-2025
- Science
- Yahoo
Study: Centuries-old mercury pollution threatens Arctic wildlife
June 12 (UPI) -- Mercury concentrations in Arctic wildlife are on the rise despite reductions in mercury release, according to a new study published Thursday. Researchers from Aarhus University and the University of Copenhagen found that ocean currents may be transporting centuries-old mercury pollution to the Arctic, the study published in the journal Nature Communications said. "We've monitored mercury in Arctic animals for over 40 years. Despite declining global emissions since the 1970s, we see no corresponding decrease in Arctic concentrations -- on the contrary," said Professor Rune Dietz from Aarhus University said in a statement. Mercury from coal combustion and gold mining can remain in the air for about a year but when it enters the ocean, it can stay for 300 years. Researchers have looked at more than 700 environmental samples from animals across Greenland over the past 40 years which has led them to identify regional differences that go alongside current patterns. "These isotope signatures act like fingerprints, revealing the sources and transport pathways of mercury," Senior Researcher Jens Sondergaard from Aarhus University explained. Mercury disrupts the normal function of nervous systems in polar bears and toothed whales. The concentrations are higher by 20-30 times before industrialization. It creates serious health risks to native marine mammals. "Transport of mercury from major sources like China to Greenland via ocean currents can take up to 150 years," said Rune Dietz. "This helps explain the lack of decline in Arctic mercury levels." The "GreenPath" project team is continuing its work on the study of mercury pollution across the Arctic.
UPI
12-06-2025
- Science
- UPI
Study: Centuries-old mercury pollution threatens Arctic wildlife
A new study published shows that despite reductions in mercury release, mercury concentrations in Arctic wildlife continue to rise. Photo by Bill Greenblatt/UPI | License Photo June 12 (UPI) -- Mercury concentrations in Arctic wildlife are on the rise despite reductions in mercury release, according to a new study published Thursday. Researchers from Aarhus University and the University of Copenhagen found that ocean currents may be transporting centuries-old mercury pollution to the Arctic, the study published in the journal Nature Communications said. "We've monitored mercury in Arctic animals for over 40 years. Despite declining global emissions since the 1970s, we see no corresponding decrease in Arctic concentrations -- on the contrary," said Professor Rune Dietz from Aarhus University said in a statement. Mercury from coal combustion and gold mining can remain in the air for about a year but when it enters the ocean, it can stay for 300 years. Researchers have looked at more than 700 environmental samples from animals across Greenland over the past 40 years which has led them to identify regional differences that go alongside current patterns. "These isotope signatures act like fingerprints, revealing the sources and transport pathways of mercury," Senior Researcher Jens Sondergaard from Aarhus University explained. Mercury disrupts the normal function of nervous systems in polar bears and toothed whales. The concentrations are higher by 20-30 times before industrialization. It creates serious health risks to native marine mammals. "Transport of mercury from major sources like China to Greenland via ocean currents can take up to 150 years," said Rune Dietz. "This helps explain the lack of decline in Arctic mercury levels." The "GreenPath" project team is continuing its work on the study of mercury pollution across the Arctic.
