Environmental Engineering Reference
In-Depth Information
he is always one of the first to spot new issues and alternative ways of looking at things.
His mind is never trapped by accepted dogma. Robie organised an assessment team that
produced an AMAP report on climate and contaminants that was published in 2002-2003.
Another version was published by Robie and colleagues in 2003 in the journal
Human and
Ecological Risk Assessment
. Essentially, the prediction is that as the sub-Arctic and Arc-
tic warm, some of the POPs sequestered in the oceans, soils, sediments and lakes will be
reemitted back into the atmosphere. In the case of the oceans, this process will be further
enhanced by the removal of summer seasonal ice which otherwise presents a barrier to sea-
atmosphere gas exchange and heat transfer.
Eight years later, another AMAP assessment team organised by Roland Kallenborn
published a comprehensive report that further clarified the predictions and reviewed the
emerging evidence showing that POPs are indeed being remobilized in response to climate
warming and, in particular, to warming in the Arctic. The most complete long-term Arctic
air-monitoring data sets available (back to the early 1990s) are from Alert on Ellesmere
Island and from Zeppelin on Svalbard. They enable trends in concentration to be detected
for the legacy POPs that were the first targets of the CLRTAP protocol and the Stockholm
Convention. For a few POPs (HCB and some PCBs), increasing levels have been observed
inthefirstdecadeofthepresentcentury.However,mostoftheotherlegacysubstancesnow
show a general slow decrease in concentrations, presumably reflecting the decreasing use
and increasing control of these substances. In 2011, Jianmin Ma and colleagues published
resultsofastudyindicatingthatatmosphericlevelsofthePOPpesticidesalpha-HCH,DDT
and chlordane are showing an increasing trend that corresponds well with increasing mean
Arctic sea level temperature and with declining Arctic sea ice cover. Although the stat-
istical methods used were subsequently challenged, the difficult question of clarifying the
impact and significance of rising temperatures on the polar distribution of POPs is now at-
tracting much attention. The 2013 papers by Henry Wöhrnschimmel and by Todd Gouin
with their respective colleagues (listed in the
bibliography
)
will help illustrate just why it
is such a challenging topic. The elements to be considered include the inventory of “old”
POPs presently sequestered according to their volatility characteristics in soils, water and
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