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Mercury Mystery in the Arctic

August 9th, 2011 | | 0 Comments |

More mercury is deposited in the Arctic than anywhere else on the planet. NTNU researchers think one explanation for this may lie in the meteorological conditions in the Arctic spring and summer.

The concentration of mercury in humans and animals that live in polar regions is on the increase. Polar bears and humans that eat marine mammals are the most affected. 

But why is there more mercury in the Arctic than elsewhere? 

Scientists have been puzzling over this question since the beginning of the 1990s. Their first breakthrough came when it was discovered that under certain meteorological conditions, mercury from the air is deposited on the snow and ice in polar areas. The phenomenon occurs when the sun rises over the horizon in the spring, after a long polar night.

Now new research from NTNU PhD candidate Anne Steen Orderdalen and Professor Torunn Berg at the Department of Chemistry and the Norwegian Institute for Air Research (NILU) shows that this process also occurs in the summer as well as in the spring. In a series of publications, the researchers have documented the types of mercury found over the Arctic and are tracking its fate and transport. Essentially, far more mercury is deposited in the Arctic than initially thought, which may be due to the extended time period during which it can be transformed and deposited. 

Scientists still don’t know exactly why and how the process occurs. But sunlight appears to be an important factor. Read More