The historical residue trend of chlorinated hydrocarbons in the Agassiz Ice Cap, Ellesmere I., Canada

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:230832

Gregor, D J ^[1]; Peters, A J ^[2]; Backus, S ^[3]; Fisher, D ^[4]; Zheng, J ^[5]

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1. Univ. of Waterloo, Ontario (Canada)
2. Environment Canada, Burlington, Ontario (Canada)
3. Backus Consulting, Stoney Creek, Ontario (Canada)
4. Natural Resources Canada, Ottawa, Ontario (Canada)
5. National Research Council, Ottawa, Ontario (Canada)

Current detailed measurements of contaminant deposition can not provide a historical perspective except through long term monitoring programs. In the Arctic, ice caps provide an alternative to lake sediments in that the annual snow layers reflect the atmospheric deposition. As a result of the remoteness of the Agassiz Ice Cap (80{degree}49`50``N, 72{degree}56`30``W) and the limited summer melt, annual layers undergo little chemical change, especially after the first summer season, and therefore provide a well defined historical record. PCBs were first measured above detection limit in the core in the late 1950`s. Mean concentration of {Sigma}PCB over the thirty year period is 3.5 ({+-}1.3) ng. L{sup {minus}1}. {Sigma}PCB is dominated by the lower chlorinated congeners with only infrequent detections of congeners with eight or more chlorines. Deposition peaked at 930 ng.m{sup {minus}2}.a{sup {minus}1} in 1967/68 and decreased to 90 ng.m{sup {minus}2}.a{sup {minus}1} in 1980/81. Since 1980/81, deposition has again increased to a local maximum of 850 ng.m{sup {minus}2}.a{sup {minus}1} in 1989/90. PAHs are detectable throughout the sampling period. Only 7 individual PAHs were above the quantification limits including naphthalene (accounting for an overall mean of 88% of the {Sigma}PAH) acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene. No PAHs with five or more aromatic rings were observed to be present above the detection limits. The flux of PAHs to the Ice Cap remained relatively constant from 1790 to 1940 at approximately 3 {micro}g.m{sup {minus}2}.a{sup {minus}1}. The period 1940 to 1980 is dominated by a large increase in deposition peaking at 70 {micro}g.m{sup {minus}2}.a{sup {minus}1} in the early 1970`s. The final period, 1980 to 1993 shows a steady increase by a factor of about 2 from a minimum of 10--20 {micro}g.m{sup {minus}2}.a{sup {minus}1}.

• OSTI ID: 230832
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ACENAPHTHENE
AIR POLLUTION
ARCTIC REGIONS
CANADA
CHEMICAL COMPOSITION
CHRYSENE
CONDENSED AROMATICS
ECOLOGICAL CONCENTRATION
FLUORENE
HISTORICAL ASPECTS
ICE CAPS
NAPHTHALENE
PHENANTHRENE
POLYCHLORINATED BIPHENYLS
POLYCYCLIC AROMATIC HYDROCARBONS
PYRENE