Environmental Engineering Reference
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Figure 8.5
Mercury concentrations in the hair of polar bears in relation to various effects and guideline levels
AMAP has prepared two assessments dealing with mercury (1998 and 2011). The AMAP
2011 Mercury Assessment isverycomprehensiveandwascompletedjustintimetoprovide
a welcome stimulus for completion of negotiations for the Minamata Convention. The as-
sessment found evidence that in some parts of the High Arctic, atmospheric mercury levels
have shown a recent decline, presumably in response to reduced emissions in Europe. If so,
this trend could soon be reversed by increasing emissions from East Asia. In other areas,
eithernodeclineornostatistically validtrendscanbeseen.Partofthedifficultyhereisthat
short-term variability from natural processes can be greater than variation between years.
More than 50% of the mercury delivered to the Arctic arrives through atmospheric depos-
ition, mainly during the polar spring, which is also when atmospheric mercury depletion
events (AMDEs) occur. This phenomenon was first reported in 1997 by Bill Schroeder and
his colleagues at an AMAP meeting in Tromso and published in Nature the following year.
TheyfoundthatjustafterthepolarsunriseoccursinthespringatAlertonEllesmereIsland,
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