Mercury (Hg) levels in the Arctic have significantly increased since pre-industrial times, primarily driven by anthropogenic sources such as gold mining and fossil fuel combustion.

Hg is transported to the Arctic through various pathways, including atmospheric transport, rivers, and ocean currents, where it biomagnifies in food webs, posing health risks to top predators like polar bears and humans.

Recent studies indicate that Hg deposited in Greenland is predominantly in the form of gaseous elemental Hg (Hg(0)), accounting for up to 97% of recent atmospheric deposition.

Research suggests that ocean currents may play a more significant role than atmospheric transport in the uptake of Hg in Arctic marine environments, particularly highlighting the influence of the West Greenland Current.

Significant regional differences in Hg stable isotopes were identified between Central West and Northeast Greenland, with higher 202Hg signatures in Central West Greenland, likely due to varying ocean currents affecting Hg sources.

The study employs Hg stable isotopes to explore the sources, pathways, environmental processes, and trophic transfer of Hg in aquatic species across Greenland over the past 40 years, focusing on species such as Arctic char, ringed seals, and polar bears.

Marine species exhibit increasing 202Hg levels with trophic level, indicating that internal metabolism and isotopic fractionation significantly influence Hg accumulation within the food web.

Variations in 202Hg signatures across different species and locations reflect long-term differences in Hg source inputs, with evidence showing significant increases in Hg concentrations over the last four decades.

Despite a general decrease in atmospheric Hg deposition across the Arctic, biological matrices are showing increasing Hg trends, highlighting the need for further research into Hg sources and pathways in the region.

These findings underscore the complex interactions between atmospheric deposition, oceanic processes, and biological uptake of Hg in Arctic ecosystems, emphasizing the necessity for integrated monitoring of Hg sources and their effects on wildlife and human health.