Agreement needed to eliminate toxic chemicals

David Suzuki / CNEWS Science 10dec00

One of the most remarkable traits of the human species is our adaptability. We quickly learn how to cope with change and find innovative ways to deal with complex problems.

But that adaptability also has a downside -- it makes us short-sighted and quick to forget. Try to imagine, for example, a world without the convenience of ATMs, cell phones or the Internet. Yet these things did not exist just 20 years ago. And when our actions degrade the environment or our health, we often arrogantly assume that we are clever enough to find some technical way to solve the problem instead of simply changing our behaviour.

So when scientists tell us that they are finding large quantities of human-made toxic chemicals in some of the world's most pristine environments, it doesn't really shock us anymore. Most of the people alive today were born since 1950 and cannot remember a time when human activities were not pervasive across the planet. We have become accustomed to our domination of the Earth, without accepting the responsibility that this power entails. You could say that as a species, we have entered our adolescent years -- a frightening thought.

But there are some signs that we are maturing. The recent International Climate Summit in the Hague, although a colossal failure in some respects, was at least an attempt to accept responsibility and find a global solution to the problem of global warming. Meanwhile, this week delegates from the world's nations are meeting in Johannesburg, South Africa, to negotiate a treaty on persistent organic pollutants (POPs).

POPs are synthetic chemical compounds that include the well-known pesticides DDT, aldrin and toxaphene, as well as some industrial chemicals like PCBs and industrial by-products like dioxin. The problem with these chemicals is that they are all very toxic, they are "persistent" in that they do not degrade easily into less harmful components, they are easily transported by water and air currents, and they accumulate in body fat. As a result, they are everywhere. In fact, all human beings now carry some amount of POPs in their bodies, even though these chemicals did not exist 75 years ago.

POPs are often described as being like "grasshoppers" because they evaporate in warm areas, are carried by the wind and then settle in cool areas. This hopping around the globe often leads to concentrations of POPs in colder regions like the Canadian Arctic. Although thousands of kilometres from the American border, the territory of Nunavut receives up to 82 per cent of its dioxin from the United States. Once in the Arctic, POPs accumulate in the body fat of fish, seals, polar bears and people. These toxins are then passed on to the next generation through breast milk. The milk of Inuit women of the Eastern Arctic contains 1,210 parts per billion (ppb) of DDT and its derivative, DDE, while milk from women living in southern Canada only contains about 170 ppb (which is alarming in its own right).

Researchers are concerned that such high concentrations of POPs in Canada's Arctic peoples will lead to immune dysfunction, cancer and developmental delays. Recent studies on nursing human infants, for example, have found that even "background" levels of PCBs can increase the incidence of disease.

That's why a global treaty aimed at eliminating these chemicals is so important. POPs are not limited by national boundaries and can only be effectively dealt with on a global level. But elimination will not happen overnight. The pesticide DDT, for example, is still needed to combat mosquito-spread malaria, which kills millions of people every year. But there are other ways to fight malaria that, if properly funded, could eventually eliminate the need for DDT. As Sheila Watt-Cloutier, President of the Inuit Circumpolar Conference, has said: "I cannot believe that a mother in the Arctic should worry about contaminants in the life-giving milk she feeds her infant. Nor can I believe that a mother in the South has to use these very chemicals to protect their babies. Surely we must commit ourselves to finding and using alternatives."

http://www.canoe.ca/CNEWSScience0012/06_suzuki-can.html