Eroding Alaskan Permafrost Unleashes Hazardous Quantities of Mercury
Rewritten Article:
Steeping concerns abound as melting Alaska permafrost exposes high levels of mercury, potentially jeopardizing Alaska Native communities, according to a new study from the University of Southern California. This research, published in the journal Environmental Research Letters, examined sediment from thawed permafrost along the Yukon River.
Previously, scientists understood that the Arctic's permafrost was releasing some mercury, but the exact amount remained uncertain. The latest study found that the minimum mercury release is double the previous estimate, ranging from approximately 86 kilograms per square kilometer to 131, and the researchers' method of confirming this by analyzing soil samples lends credibility to their findings.
Mercury, though a naturally occurring element, often becomes a human-induced pollutant. Consumption of this silvery metal can severely impact the neurological system, particularly affecting pregnant women and children, prompting many governments to establish health limits on certain fish intake during pregnancy.
Previous estimates suggested that thawing permafrost released between 40 to 150 kilograms of mercury per square kilometer. However, this new study reveals a more alarming situation, hinting at the potential dangers to the environment and Indigenous populations.
Josh West, a professor of Earth sciences and environmental studies at USC and one of the study's co-authors, describes the emerging mercury exposure as a looming concern.
"Permafrost soil contains more mercury than all other soil on the planet combined, plus all the oceans, plus the atmosphere," West said. "So there's an enormous amount of mercury trapped in these icy soils, where climate change is happening faster than the rest of the world. It's like a ticking time bomb."
The study focused on sediments in sandbars and riverbanks near the Yukon River villages of Beaver and Huslia. Researchers not only collaborated with USC and university partners but also with the Yukon River Inter-Tribal Watershed Council, an Indigenous non-profit dedicated to safeguarding the Yukon River Watershed.
West underlines that while there's still much to learn, researchers are investigating whether the mercury released transforms into methylmercury - a toxic variant that can cause brain damage if consumed. They're also looking into whether melting permafrost is causing mercury to contaminate the fish that local residents, including Native peoples, rely on for sustenance. Though the answer remains unclear, the need for more data is evident.
The Arctic is warming at a rate four times faster than the rest of the planet, resulting in forced relocation for some communities due to thawing permafrost.
Darcy Peter, a Koyukon and Gwich'in Athabascan from Beaver, Alaska, who works on climate adaptation at the Woodwell Climate Research Center, shares her concerns. Diminishing salmon runs are already a pressing issue in the Yukon, exacerbated by warmer waters from climate change. Peter notes that salmon populations have dwindled dramatically in recent years, posing additional worries about mercury contamination.
Mercury poisoning among Indigenous communities is a global problem. In Canada, First Nations peoples have suffered from mercury contamination in their fish, which has been linked to high rates of youth suicide in the Grassy Narrows First Nation. In the Amazon, the Yanomami tribe has endured high levels of mercury due to illegal gold mining. The severity of the issue has prompted international advocacy for increased Indigenous representation at the United Nations' annual convention on mercury.
Alaska is not immune to these issues. A 2022 study concluded that Arctic Indigenous peoples are among the most exposed individuals when it comes to foodborne mercury, emphasizing the importance of collaborating with Indigenous communities on research.
Mercury pollution not only poses health risks or discourages Indigenous fishing practices; it also threatens traditional cultural practices that native communities have maintained for millennia, imperiling their cultural identity rather than merely their health and existence.
"Back in Beaver, we don't have grocery stores. We build our own cabins. We haul our own water. We hunt our own food," Peter said. "We definitely feel it on a physical, emotional, and financial scale - the decline of salmon and the presence of mercury in the Yukon River."
Correction: This story originally misrepresented how mercury forms.
This article was previously published in Grist, a nonprofit, independent media organization focusing on telling stories about climate solutions and a sustainable future. Discover more at Grist.org.
- The research by the University of Southern California revealed that the minimum mercury release due to melting Alaska permafrost is double the previous estimate, ranging from approximately 86 to 131 kilograms per square kilometer.
- Permafrost soil contains more mercury than all other soil on Earth combined, plus all the oceans and the atmosphere, according to USC professor Josh West, one of the study's co-authors.
- Alaska Native communities are especially vulnerable to the potential dangers of climate-change-induced mercury release, as mercury contamination can impact their fishing practices and traditional cultural identities.
- The Indigenous non-profit Yukon River Inter-Tribal Watershed Council collaborated with researchers on the study, focusing on sediments in sandbars and riverbanks near the Yukon River villages of Beaver and Huslia.
