1994 Arctic Ocean Section
Air-Water Gas Exchange of Hexachlorocyclohexanes in the Arctic
Liisa Jantunen and Terry Bidleman
Our objectives for the AOS-94 cruise were to measure the transfer of chlo-
rine-containing pesticides between the atmosphere and the Arctic Ocean. The
focus was on pesticides that have largely been banned in Canada and the United
States but are still used in other countries. These chemicals are emitted into
the atmosphere through current usage and volatilization of old residues from
soils. Air currents carry them to remote areas worldwide, including the Arctic.
One pesticide of special interest was hexachlorocyclohexane (HCH).
HCH is applied as a technical mixture that contains several isomers, largely
α-HCH (6070%), β-HCH (512%) and γ-HCH (1015%) (Iwata et al.
1993). The active ingredient, γ-HCH, is also produced in pure form and sold
as the pesticide Lindane. Both insecticides were produced during World War
II and are still in large-scale use today. Canada banned technical HCH in
1971, followed by the United States in 1978. Lindane is still registered for restrict-
ed applications in these countries and is the main HCH product used in Europe
(Barrie et al. 1993, Hinckley et al. 1991). Technical HCH was heavily used in
Asian countries throughout the 1980s. Reports from India range from 20,000 to
47,000 tons/year (Iwata et al. 1993, Hinckley et al. 1991). It is estimated that the
cumulative worldwide use since the introduction of HCH products is over 500,000
tons (Voldner and Li 1995). Because of their widespread usage and ease of trans-
port, HCHs are the most abundant pesticides in the Arctic air and surface
waters.
Air was sampled by drawing approximately 700 m3 per day through a filter
followed by a polyurethane foam cartridge. HCHs were extracted from water
by passing 420 L through a filter followed by a C8-bonded silica cartridge.
Analysis was done in the home laboratory, using capillary gas chromatography
with electron capture detection and negative ion mass spectrometry.
The accompanying figures show the results of air and water sampling for
α-HCH; they also contain data collected in the Bering and Chukchi Seas in 1993
aboard the Russian R/V Okeah to complete the overall picture. The figures show
the spatial distribution of α-HCH, from the Bering Sea to the Greenland Sea over
the North Pole. Concentrations of α-HCH in water of the Bering and Chukchi
Seas averaged 2.00 0.48 ng/L (Jantunen and Bidleman 1995), increased in
Liisa Jantunen and Terry Bidleman are with the Atmospheric Environment Service, Downsview, Ontario,
Canada.
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