Mercury emissions and its effect on the Arctic
By Frits Steenhuisen|
Mercury levels found in the Arctic food chain are alarmingly high and considered a health hazard for wildlife and humans. Some human populations in the Arctic that rely on marine mammal species as part of their traditional diets receive dietary exposures to mercury that exceed WHO tolerable weekly intakes. In some areas a significant proportion of pregnant women have blood mercury levels exceeding guidelines established to protect infant health.
Atmospheric transport brings mercury from lower latitudes into the Arctic, where specific atmospheric conditions in spring lead to an increased deposition of mercury to ice and snow, which when it melts may lead to a pulse of mercury becoming available for uptake in the food chain. Almost none of this mercury is originating from local sources .
Identified sources for atmospheric mercury are from industrial processes, waste incineration and, in particular from the use of coal for energy production and heating. A less known, but also significant source is small-scale and artisanal gold mining. In many parts of the world large quantities of mercury are used to separate gold from sediment and rock. Most of the mercury used in this process is not recovered and is thus released directly into river water and into the atmosphere.
To quantify global mercury emissions to air, a spatial model has been developed to geospatially distribute emissions from a variety of sources to a 0.5 degree resolution global grid. These emission data in combination with transport models can be used link sources of mercury in the lower latitudes with sites of high mercury levels in the Arctic. This makes it possible to study the effect of reducing mercury emissions for a healthier Arctic.
|Willem Barentsz Poolinstituut|
Bundeling van kennis, onderzoek en onderwijs over de Noord- en de Zuidpool
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