World industry poisons Arctic purity

A climatic trick dumps chemicals from afar on people and animals in the far north, writes Geoffrey Lean
Their language may have 30 different words for "snow", but it does not have one for "contamination". So it is hard to explain to the Inuit people of the remote and pristine Broughton Island, in the Canadian Arctic, that - thanks to a strange and newly discovered trick of the world's natural systems - they are more polluted by some of the world's most toxic chemicals than any other people on earth.

And yet research shows that the bodies of the 450 people of the small island, thousands of miles away from the sources of the pollution, have the highest levels of polychlorine biphenyls (PCBs) ever found, except in victims of industrial accidents. The chemicals are increasingly suspected of causing cancer, suppressing fertility and damaging the immune system.

Neighbouring peoples, on the vast Baffin Island next door, shun them as "PCB people" and try to dissuade their children from marrying them. But the neighbours are highly contaminated too: Inuit from Greenland, on one side of Baffin and Broughton Islands, to Arctic Quebec on the other, have seven times as much of the chemicals in their bodies as people living in temperate and industrialised parts of Canada.

PCBs were long ago banned in most industrial countries after being used in a host of applications from paints to pesticides, plastics to electrical equipment - but they are still concentrating in the Arctic. Curiously, they are doing so as the direct result of of their continued use in developing countries in the tropics.

It is a similar story for a host of similarly dangerous chemicals. Measurements quoted by the authoritative technical magazine, Environmental Data Services, show that Greenlanders have more than 70 times as much of the pesticide hexaclorobenzene (HCB) in their bodies than temperate Canadians. Another pesticide, HCH, is over 100 times more concentrated in the waters of the Arctic Beaufort Sea than in the Java Sea, near where it is mainly used.

Polar bears, seals, fish and birds of prey are also heavily polluted, and Arctic eco-systems are under threat. Dr Frank Wania of the Norwegian Institute of Air Research at Tromso, 200 miles north of the Arctic Circle, says: "The circumpolar nations should be very concerned."

Dr Wania - who first stumbled across the growing crisis at the beginning of the decade when studying for his doctorate - and other scientists increasingly believe that the cause is "global distillation", which picks up pollutants from where they are released and dumps them, many thousands of miles away, on some of the most fragile ecosystems and vulnerable peoples in the world. The alarming planetary phenomenon is turning the roof of the earth into its ultimate chemical dump.

In this process, the world seems to act as a giant distillery. Volatile chemicals - such as PCBs, HCB, dioxins and other pesticides such as toxaphene and DDT - boil off into the air when they are used in the tropics. The chemicals are then carried by the winds until they hit cooler climates, where they condense and fall to earth.

As in the fractionated distillation equipment used in school science classes, different groups of chemicals condense at different temperatures. DDT, for example, is less volatile than many others and, seems to be deposited mainly in temperate regions. So is toxaphene: high levels of the pesticide are found in North Sea fish, even though it has been rarely used in Europe.

HCB, HCH and some forms of PCBs - which are much more volatile - seem to carry on all the way up to the Arctic: concentrations in seals, for example, increase the further north you go. An estimated 99.9 per cent of the HCH used on rice paddies in South India boils off into the atmosphere to condense out elsewhere. And research shows that concentrations of HCBs are negligible in the tropics, where they are mainly used, except in the and high African mountains, where the temperature drops enough for the condensation to occur.

Dr Wania says that the chemicals can take between a few weeks and decades to find their way north. At one extreme, a favourable wind can carry them straight up from the tropics in just a fortnight. At the other, they may move northwards in a series of small jumps that he calls "the grasshopper effect", repeatedly condensing out and then evaporating again for the next jump, as temperatures change with the season. "Even pesticides sprayed in the 1950s may still be on their way," he says.

However long the journey, the Arctic is the end of the line. Less is known about what is happening in the Antarctic, because far fewer measurements have been done, but Dr Wania thinks there is less global distillation there. The chemicals are mostly used in the northern hemisphere, he says, and winds and the pollution they carry tend not to cross the Equator. There also seems to be less movement of air towards the Pole in the southern hemisphere.

The chemicals concentrate in the Arctic because it is a relatively small area, attracting pollution from the whole hemisphere. Other special factors also increase the danger - the cold slows down the natural decomposition of the chemicals, and Arctic wildlife relies on thick layers of blubber and fat, in which the pollution builds up. The Inuit are at the top of the food chain, eating a lot of local fish and wildlife. So, although they have contributed virtually nothing to the pollution, and do not benefit at all from the use of the chemicals thousands of miles to the south, they are becoming its principal victims.

Dr Wania believes that the use of these chemicals will have to be banned worldwide, because of what is happening in the Arctic. The United Nations Environment Programme is beginning work on a draft international treaty which could achieve this, but the pollution of many years is already in the planet's atmosphere, working its way towards the Poles.