A study conducted by scientists from Florida State University, the German Research Center for Geosciences and the University of Bristol and published on Science, reveals how Greenland's ice and rivers contain high levels of mercury.
To make a comparison, the mercury present in the ice and melt waters in Greenland is like that in the water mirrors of industrial China. The research team found concentrations above 150 nanograms per liter. Particulate mercury transported by glacial meal was found in concentrations above 2,000 ng L-1.
Researchers say such mercury concentrations raise concerns about the serious repercussions that could occur throughout the food chain, especially since Greenland is a major exporter of cold-water shrimp, halibut and cod.
James Hawker, a lecturer at South Florida State College, said: "This discovery leads us to a number of new questions about how mercury could enter the food chain. The source of mercury should be the Earth itself. This aspect could be important for the way scientists and policymakers think about mercury pollution management.
Efforts to manage this toxic element have been conducted on the basis of the idea that the increasing concentrations resulted from direct anthropogenic activities, such as industry . Mercury from clinically sensitive environments such as glaciers could be a much more difficult source to manage."
Glaciers melting accelerated over the past 20 years
Melting of ices has accelerated over the past 20 years, and it has contributed to nearly a fifth of sea level rise. Their mapping in HD, published in Nature by an international team led by the University of Toulouse, will allow to improve models on climate change with which to predict future scenarios.
The glaciers present in Alaska and the Andes are the ones that have recorded the greatest losses in the last twenty years, while the Alpine glaciers hold the world record for the reduction of the average thickness, equal to about one meter per year.
Experts said the melting of glaciers involves the loss of important water reservoirs capable of helping agriculture and industry by buffering the scarcity of rainfall in dry periods. Furthermore, the melt water ends up in the seas, which are rising by 3.5 millimeters per year: a problem not only for cities like Venice, but also for the 11% of the world population who live in coastal areas that risk be submerged.