Current Affairs Brain Booster for UPSC & State PCS Examination

Topic: Mercury found in Rivers Linked to Greenland Ice Sheet

Why in News?

• According to the latest research report, high concentrations of mercury, a naturally occuring toxic metal, were found in the water bodies fed by the Greenland Ice Sheet.

Key Highlights of the Report

• The mercury content in the rivers and fjords of southwestern Greenland was similar to that found in the polluted inland rives of China.
• The researchers collected water samples from three rivers and two fjords connected to the ice-sheet and found almost ten times the volume of mercury than normal rivers.
• Typical dissolved mercury content in rivers are about 1 – 10 ng L-1 (the equivalent of a salt grain-sized amount of mercury in an Olympic swimming pool of water).
• In the glacier meltwater rivers sampled in Greenland, scientists found dissolved mercury levels in excess of 150 ng L-1, far higher than an average river.
• Particulate mercury carried by glacial flour (the sediment that makes glacial rivers look milky) was found in very high concentrations of more than 2000 ng L-1.

Reasons

• According to the scientists, the toxins did not end up in the meltwaters from industries or other anthropogenic activities, as is the case with most contaminants.
• Mercury-rich bedrock is weathered during the slow movement of glaciers down the slope of hills and the ground particles are carried into the streams as the glacier melts.

Concerns

• According to the researchers, mercury coming from climatically sensitive environments like glaciers could be a source that is much more difficult to manage.
• Water pollution caused similarly can be heightened as the Earth continues to heat up and ice-sheets and glaciers melt faster than ever before. The findings, thus, open a new chapter in understanding the impacts of global warming.
• The findings strengthen a growing body of research that dismisses the conception that glaciers have little or no influence on the Earth’s geochemical and biological processes.
• The large volumes of the metal can find its way into the coastal food webs through bioaccumulation and impact the Arctic ecosystem. Greenland is a major seafood exporter.