Mercury in a Warming Arctic: Science, Public Health Hazards and the Path Forward

As the Arctic warms at four times the global rate, Alaska is experiencing rapid permafrost thaw that is reshaping landscapes, ecosystems, and community health. For millennia, mercury has accumulated and remained locked within frozen soils—absorbed by Arctic vegetation from global atmospheric circulation and deposited as plants died and decomposed. As climate change accelerates thaw, this mercury is being released into rivers, wetlands, and surrounding environments, creating new and uncertain pathways for exposure.

Mercury is a potent neurotoxic metal that poses serious risks to the brain, heart, and immune system. Once released, it can enter rivers, accumulate in fish, marine mammals, and people. This presents a growing concern for the approximately five million people living in the circumpolar North—especially Indigenous communities whose diets, culture, and food security rely on traditional harvesting. How much mercury will ultimately be released, and the full extent of its impacts, remain critical open questions.

Recent research from the Yukon River Basin reveals that fine-grained sediments contain significantly higher mercury levels than coarse sediments, highlighting how sediment composition influences long-term storage. The study confirms that riverbank mercury concentrations align with high-end estimates from earlier Arctic assessments, underscoring that permafrost holds vast quantities of mercury. It also documents shifting river channels and variations in flow speed, suggesting that although most mercury remains stored for now, warmer conditions could mobilize mercury-rich sediments into aquatic systems.

This webinar will explore the emerging science of mercury release from thawing permafrost, the influence of climate-driven landscape change, and the consequences for human health, ecosystems, and environmental justice in Alaska and across the Arctic. We will examine current sources of mercury, including mining and coal combustion. Speakers will discuss monitoring efforts, community-led responses, and strategies to reduce exposure and risk. The session will also highlight the urgent need for strong policies that safeguard public health and protect Arctic communities in a rapidly changing climate, including the Minamata Convention on Mercury.