The Arctic is a wild, remote sparsely populated region, with little industry. Nevertheless pollution is a threat to the indigenous population and wildlife. Industrial and agricultural chemicals are transported in the air and ocean currents from Europe, Asia and further away, and settle in the Arctic Ocean basin, which acts like a reservoir or 'sink' for pollutants from around the world. The cold temperatures and ice bound environment trap the toxins and make them slow to degrade. They stay in the ground, air and water for longer. In the summer when the ice melts, the toxins get washed into the sea and rivers.
Diagram: "Pathways of contaminants to the Arctic"
Top of the POPS
The main contaminants are heavy metals, such as mercury and lead, and persistent organic pollutants (POPS), such as DTT, PCBs and dioxins, which evaporate into the air but are slow to degrade. These toxic materials bioaccumulate in the food chain from micro-organisms which are eaten by fish and then on to larger wildlife. Polar bear, seals, and whales, feed on the smaller contaminated prey, storing more and more toxins in their fatty tissue and organs.
This can increase their risk of high levels of exposure which may directly effect Arctic wildlife and the indigenous population who hunt these species, for food, as part of a traditional diet, considered healthy and nutritious. People living in the northern and eastern region of Greenland eat polar bear, one of the most contaminated species. Research has found that the Inuit of Canada and Greenland have higher levels of contaminants in blood and breast milk than people from the southern regions of these countries. How these toxins will effect the long term health of indigenous peoples is uncertain. Although it is known that these contaminants can harm hormone function, reproduction and development and weaken the immune system. More research is needed.
The graphic above, produced by the Arctic Monitoring Assessment Programme, shows Persistant Organic Pollutants concentration in the blood plasma of mothers, pregnant women and women of child-bearing age during different time periods.
Two short films produced by AMAP:
A summary of the most recent report on Mercury in Health by AMAP in 2011 can be found at AMAP Assessment 2011: Mercury in the Arctic.
For indigenous people the traditional diet, supplied from natural resources is an important part of their culture. Alternative sources of food have been imported but they are expensive and often unhealthy, and lead to problems such as diabetes, heart disease and obesity.
The Arctic is generally considered to be pristine, as there are few local sources of pollution. However, during the past 10-15 years there has been increasing evidence (mainly from the Arctic Monitoring and Assessment Programme) that the Arctic environment is threatened by pollution and climate change.
Why is it called the Arctic paradox?
People living in the Arctic are the most contaminated, despite the fact that they live far away from the sources of these pollutants. Inuit in Canada and Greenland face a significant health risk as a result of their dependence on traditional food - meat and blubber from seals and whales - that contains high concentrations of pesticides and industrial pollutants.
Because of long-range transport by air, water currents and river outflow, the Arctic is a sink for industrial and agricultural pollutants from the "south." When these accumulate in Arctic marine food webs, they affect humans and wildlife. In some human populations living in the Arctic, levels of persistent organic pollutants (POPs) and mercury are the highest anywhere on Earth and exceed health and safety guidelines. In children living in northern Canada, POPs have been documented to affect the immune system, as shown by higher than normal rates of infectious diseases.
People there eat a marine diet, considered to be among the world's healthiest (based on the content of iron, proteins, vitamins and omega-3 fatty acids) - but the levels of pollutants are so high that it threatens their wellbeing. Unfortunately, switching to Western food increases the risk of other diseases not normally found in these populations, such as cancer, heart disease and diabetes. This poses a dilemma for public-health officials: they encourage the Inuit and others to eat traditional foods, but advise them to reduce their consumption of such foods.
Source: Nature 436, 177-178 (14 July 2005) | doi:10.1038/436177a
It is important to note that although the indigenous population may face significant, elevated concentrations, the levels for a number of contaminants are decreasing in Arctic wildlife and several Arctic human populations.