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The catchment area of the Arctic Ocean is extensive, with the watersheds of Arctic rivers penetrating far south (see map below). The quality of Arctic freshwater systems was close to pristine until the development of industrial activities and natural resource extraction in the region started to have a major impact on the environment after World War II.
The most affected areas include those on the Kola Peninsula and around Norilsk adjacent to metal smelters. Between 1991 and 1994, copper concentrations reached more than 2 500 times and nickel concentrations up to 130 times locally-set permissible limits. In some areas of Arctic Canada, Finland, the Russian Federation and Alaska, the levels of lead in rivers exceed water quality guidelines set out for more temperate latitudes. Metals are not the only problem. A mixture of metals, sewage, petroleum hydrocarbons, acidifying substances and other chemicals combine to attack ecosystems.
Lake sediments in both northern Canada and Fennoscandia contain increasing levels of mercury. The relative contributions from anthropogenic and naturally-occurring sources are unclear.
Several rivers and estuaries in northern Russia suffer from oil contamination. Hydrocarbon concentrations often reach several mg/litre in the lower part of the Ob River, for example, and most samples taken from rivers in northwestern Siberia have levels of hydrocarbons that exceed permissible limits. Oil and gas production poses a serious threat to wetlands where wastes are disposed of directly into wetland depressions which act as sinks for contaminated fluids. When these sinks spill their banks, they contaminate local rivers and lakes (AMAP 1997).
There are high levels of HCH in several Russian rivers, most notably the Ob, apparently due to the use of the pesticide lindane. DDT is present in Arctic rivers, ranging from 0.03 ng/litre in rivers flowing into Hudson Bay to 5 ng/litre in the Ob River. Russian rivers also have high levels of PCBs. The levels of POPs in some Russian rivers draining into the Arctic may be higher than those found in urban North America and Western Europe.
The rivers of the Kola Peninsula in the Russian Federation have suffered a significant decrease in alkalinity and some streams undergo rapid acidification during the spring snow melt. The general situation with respect to acidification is improving over northern Fennoscandia as a result of decreases in European emissions. The situation on the Kola Peninsula shows some sign of improvement but this reflects economic factors rather than emission controls.
Radioactive isotopes have been released into Russian rivers which flow into the Arctic. These releases have come from reprocessing plants and a nuclear weapons production facility, all south of the Russian Arctic. Levels in Russian rivers have dropped since the 1960s and it is believed that levels peaked in the late 1940s and 1950s (AMAP 1997). Today, the biggest threat is probably from ponds at, for example, the Mayak plant which are artificially dammed in order to contain radioactive waste. If these dams were to fail, then significant radioactive contamination could flow into the Arctic.
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