Mercury mystery in the Arctic

(31.01.2011) 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.




A dangerous transformation   


  Accumulates in the food chain   
When mercury enters the food chain, it is taken up by microorganisms, and then by ever larger organisms. Marine mammals, polar bears and humans are the top of the food chain in the Arctic, and thus are subject to the most contamination, because the farther up the food chain you go, the higher the concentration of mercury becomes.

  Mercury is stored in the body and there is much evidence that the contaminant damages the nervous system. Mercury can also have a serious effect animal health, but also threatens people who largely live off marine mammals. Some studies of children in the Faeroe Islands have shown learning disabilities which are suspected to be linked to high mercury concentrations in the food that they eat.

  Long-term air measurements   
The discovery may help to explain the high levels of mercury found in marine mammals and polar bears, because the mechanism would enable significant amounts of mercury to be carried into the ocean during snowmelt. In addition, climate change can play a role.   

The findings are based on air measurements at Svalbard, where a series of field studies have been undertaken at the air station in Ny-Ålesund on Svalbard. The measurement station records the concentration of mercury and other substances continuously throughout the year. Only Canadians have a longer record of mercury measurements than those that are available from the station in Ny-Ålesund.

Understanding the Arctic

Polar bear in Svalbard. Photo credit: Jenny Bytingvik
NTNU researchers have a series of projects designed to investigate the mysteries of the Arctic, from polar bear health to the fate and transport of mercury. For information about polar bear research, contact Bjørn Munro Jenssen, and for information about mercury research, contact Torunn Berg.