The
Global Fate of Persistent
Contaminants
The presence
of persistent,
anthropogenic compounds in remote areas such as the Arctic has resulted
in considerable interest in their global transport and accumulation
behaviour.
Our work aims at an improved conceptual understanding and
quantification
of the processes involved in the global dispersion of these chemicals.
In 1993, we put forward the hypothesis of global fractionation and cold
condensation for semi-volatile organic compounds, which states that
certain
characteristics make chemicals prone to preferential deposition and
accumulation
in cold areas. Chemicals become fractionated latitudinally based on
their
temperature-controlled atmosphere-surface partitioning characteristics.
We are presently developing and testing a passive air sampling
technique
to probe this hypothesis by mapping the large scale dispersion
behaviour
of persistent contaminants across Canada. We are further developing and
using zonally averaged global computer models to simulate the long term
fate of persistent organic chemicals, such as organochlorine pesticides
and the polychlorinated biphenyls. |
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