What are environmental contaminants?

Environmental contaminants is a term used to describe various chemicals with the following qualities:

• They are poisonous on a short- or long-term basis
  Contaminants often have acute poisonous effects and/or they can incur a more long-term and chronic effect, e.g. through being cancerous.

• They degrade slowly and are often stored in fatty tissue
  Environmental contaminants can be degraded to harmless compounds in nature, but this usually takes a very long time. Contaminants that occur dissolved in water degrade particularly slowly. They may therefore be transported far and will remain in natural chemical cycles long after the release of the chemical into the environment has ceased.
  

• They have a tendency to accumulate in living organisms
  Many of the contaminants are fat soluble, which makes them hard to degrade and excrete for organisms. Because of this, animals which prey on other animals will accumulate their prey's contaminants in such a manner that they become more contaminated than their prey. This process of contaminant concentration is called biomagnification.
  

The concentration of contaminants therefore tends to increase as one moves up in the food chain. Food chains with a marine connection tend to be marked by this effect to a larger degree, perhaps because such chains usually are longer and therefore experience stronger biomagnification.

Organisms that contain contaminants also use a very long time to excrete them.

Different kinds of environmental pollutants

Contaminants in the Arctic can usually be placed in one of two main groups:

Heavy metals
Several metallic elements are defined as heavy metals, and they can form an array of different chemical compounds. In the Arctic environment the elements most studied are mercury, lead and cadmium. These are metals that occur naturally in nature but which are also released in large quantities by human activities.

Persistant organic pollutants (POP)
POP is a label used for many different chemical contaminants, among others organochloride insecticides, industrial chemicals and certain byproducts of combustion processes. In many respects, the Arctic regions may serve as indicator regions for both known and new POPs because finding these human-made chemicals in the Arctic in itself indicates low degradation rates and effective transportation mechanisms.

Contaminants in the Arctic

The scale and distribution of contaminants in the Arctic has been studied for years, not least by the Norwegian-led Arctic Monitoring and Assessment Programme (AMAP), which is one of the five working groups under the Arctic Council.

The Arctic is generally considered to be a very clean area, with little or no production, use or storage of contaminants. The environment in the Arctic is still one of the cleanest on the planet. The general level of contaminants in organisms in the Barents Sea is for example lower than that found in the Baltic Sea and the North Sea.

But the Arctic is in no way untouched, and traces of contaminants have been found everywhere in the Arctic environment and ecosystem: in the air, in soil and sediments, in snow and ice, in salt and fresh water, in birds, other animals and humans. In some areas the high concentrations of certain kinds of contaminants in some species, ecosystems and human populations have caused concern amongst researchers.

Concrete effects of POPs high up in the food chain have been documented in most of the Arctic. For instance, POPs have probably led to the weakening of the immune systems of polar bears, glaucous gulls, Arctic charr and harp seals.

PCB levels in polar bears in Svalbard are 2-6 times higher than in polar bears from Alaska and Canada. Furthermore, Svalbard's polar bears have higher levels of certain kinds of brominated flame retardants.

Air measurements from the Zeppelin Station at Ny-Ålesund in Svalbard show PCB levels higher than levels found at corresponding measuring stations in Canada. This indicates that the European Arctic receives more PCB than the North American Arctic.

A range of novel POPs has also been found airborne in Svalbard, such as certain types of brominated flame retardants.

The introduction of global restrictions and the phasing out of a range of contaminants, such as PCB, DDT and HCH, have been internationally agreed upon. There are very few data series that can unequivocally show the effects these actions have had in the Arctic. However, a tendency for lower air levels of the contaminants has become apparent. For other POPs the changes are slight, and for others an increase has been observed.

Research at the Norwegian Polar Institute

The Ecotoxicology Programme, led by Dr G. W. Gabrielsen, gathers knowledge that will improve our understanding of the sources and biological effects of contaminants in the European Arctic.

The emphasis is on POPs. A central task is the establishment and development of a POP monitoring programme in the Norwegian Arctic.