Scientists at Peking University in China report that melting Antarctic ice is continuously releasing toxic mercury into the ocean. The study, led by environmental scientist Chengzhen Zhou, was published in the Proceedings of the National Academy of Sciences. Researchers identified the concern while analysing sediment samples from the Antarctic Peninsula, an area they describe as among the fastest-melting parts of Antarctica due to environmental pollution.

Mercury is listed among the World Health Organization's 10 chemicals of major public-health concern and is toxic even at low levels. Scientists say fossil-fuel burning for industry and mining have sharply increased environmental mercury. Antarctic ice has long acted as a mercury sink, absorbing pollution from the environment, but greenhouse gases from the same industries are accelerating ice melt and releasing stored mercury. Mercury accumulation in the peninsula increased by 160 percent after the Industrial Revolution, the researchers said.

The study said melting ice increased mercury release onto land by 550 percent and atmosphere-to-ocean mercury exchange by 350 percent. Mercury discharge from the peninsula into open waters through currents rose by 400 percent. Researchers also observed rising mercury levels in Southern Ocean animals, often exceeding previous records.