氯丹
北极的
生物累积
环境科学
环境化学
生物放大
海熊
食物链
生物群
海洋生态系统
Mercury(编程语言)
污染物
持久性有机污染物
污染
生态系统
生态学
杀虫剂
化学
生物
程序设计语言
计算机科学
作者
Derek C.G. Muir,R. Wagemann,B. T. Hargrave,Deborah J Thomas,David B. Peakall,Ross J. Norstrom
标识
DOI:10.1016/0048-9697(92)90246-o
摘要
The current state of knowledge of levels, spatial and temporal trends of contaminants in the Arctic marine ecosystem varies greatly among pollutants and among environmental compartments. Levels of polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and some heavy metals such as mercury and lead, in Arctic marine mammals and fish are relatively well documented because of the need for comparisons with biota in more polluted environments and interest in the contamination of native diets. Levels of heavy metals, alkanes, polyaromatic hydrocarbons (PAH) and OCs in the Arctic Ocean are comparable to uncontaminated ocean waters in the mid-latitudes. But concentrations of α- and γ-hexachlorocyclohexane (HCHs) are higher in northern waters far removed from local sources, possibly because lower water temperature reduces transfer to the atmosphere. Bioaccumulation of OCs and heavy metals in Arctic marine food chains begins with epontic ice algae or phytoplankton in surface waters. Polychlorinated camphenes (PCC), PCBs, DDT- and chlordane-related compounds are the major OCs in marine fish, mammals and seabirds. Mean concentrations of most PCBs and OC pesticides in ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic are quite similar indicating a uniform geographic distribution of contamination, although α-HCH showed a distinct latitudinal gradient in bears due to higher levels in zones influenced by continental runoff. Ringed seals from Spitzbergen have higher levels of PCBs, total DDT and polychlorinated dioxins/furans (PCDD/PCDFs). In contrast to other OCs, PCDD/PCDFs in Canadian Arctic ringed seals and polar bears were higher in the east/central Arctic than at more southerly locations. Remarkably high cadmium levels are found in kidney and liver of narwhal (Monodons monoceros) from western Baffin Bay (mean of 63.5 μg g−1) and western Greenland waters (median of 39.5 μg g−1). Mercury concentrations in muscle of ringed seal and cetaceans frequently exceed 0.5 μg g−1 especially in older animals. Cadmium concentrations in polar bear liver increased from west to east, while mercury levels were higher in ringed seals from the western Canadian Arctic, which suggests that natural sources of these metals predominate. Studies of temporal trends in OCs in ringed seals and seabirds in the Canadian Arctic indicate PCB and DDT levels declined significantly from the early 1970s to the 1980s. There is a lack of temporal trend data for other OC pesticides as well as for heavy metals and hydrocarbons. There is also a need for studies of the effects of elevated levels of contaminants such as mercury, and of low levels of exposure to PCBs, on top predators in the marine food chain and at the ecosystem level.
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