INDUSTRIAL plants in the US have been fingered as the main polluters of
Nunavut, thousands of kilometres away in the Canadian Arctic. A report on
cross-border pollution released this week identifies an incinerator in Iowa as
the single biggest source of dioxin pollution in this remote Arctic area.
The report, released by the North American Commission for Environmental
Cooperation, an intergovernmental organisation set up by Canada, the US and
Mexico, is the first attempt to pin down the precise sources of the dioxin.
Researchers say that the three countries can now use the findings to clamp down
on polluters.
The remote, sparsely populated Nunavut territory has virtually no sources of
dioxin, which is a by-product of many industrial processes. But some Inuits
native to the area have twice as much dioxin in their blood as people in
southern Canada. Their diet of marine and game animals is high in fat, where
dioxin tends to concentrate.
Advertisement
According to the report, 35 per cent of the total dioxin deposited on Nunavut
in one year came from just 10 sources, all but one of them in the US. These
sources included municipal waste incinerators, cement kilns, copper smelting and
iron sintering plants. Sources in the US caused between 70 and 82 per cent of
the dioxin pollution, Canada accounted for 11 to 25 per cent and Mexico for 5 to
11 per cent.
鈥淭here is no way to protect Nunavut from airborne dioxin. You have to bring
about the reduction at the source,鈥� says report co-author Barry Commoner of the
Center for the Biology of Natural Systems at the City University of New York.
鈥淏ut with 44,000 sources, where do you start?鈥�
To find out where the dioxin comes from, Commoner and his colleagues used a
computer model called HYSPLIT, originally developed by the US National Oceanic
and Atmospheric Administration (NOAA) to track accidental radiation releases. To
trace the path of a pollutant, researchers tell HYSPLIT where and when it was
released. The program then tracks its path through known North American weather
patterns.
Commoner used HYSPLIT to follow how dioxin emissions from 44,000 separate
sources could have been carried to eight different areas in Nunavut between July
1996 and June 1997.
Commoner admits the predictions aren鈥檛 perfect. The dioxin emissions had to
be estimated using data from government environmental organisations. But Paul
Miller, head of the commission, says that governments should now be able to
approach the worst polluters and ask them to measure, and control, how much
dioxin they are releasing.
