Old pesticides pose new problems for developing world. (Trade/Commerce).

For decades, stockpiles of obsolete, expired, and banned pesticides have posed significant health risks to people in developing countries. Now some observers are cautiously optimistic that the problem is beginning to be addressed.

The United Nations Food and Agriculture Organization (FAO) estimates that 500,000 tons of obsolete pesticides no longer usable for their intended purpose are scattered throughout developing countries. Africa is the best inventoried continent, and the problem there is severe, but pesticides also threaten health in Latin America, Asia, and the former Soviet republics.

Stockpiled products originate primarily in western Europe, but also come from the United States, China, India, and other countries. They may originally have been sold or donated, either directly or through aid organizations. Among the pesticides of concern listed in Baseline Study on the Problem of Obsolete Pesticide Stocks, a 2001 report by the FAO, are persistent organic pollutants (POPs) such as aldrin, chlordane, DDT, dieldrin, and endrin. These can cause nausea, convulsions, liver damage, and death. DDT is also classified as reasonably anticipated to be a human carcinogen by the U.S. Department of Health and Human Services.

End users in recipient countries may be unable to read usage instructions and precautions (where they exist), and may use containers for carrying drinking water or food. Governments are often aware of the health threats posed by the pesticides, but may be constrained by a lack of funding and knowledge of proper disposal procedures. Thus, many stockpiles are buried, burned in open containers, or simply left outdoors to migrate into soil and water from leaking containers. Some products decay into even more toxic compounds. For example, malathion can decay into malaoxon, which is 10 times more toxic than the original pesticide.

Tanzania's case is typical. According to Tanzanian registrar of pesticides Jonathan Akhabuhaya, a 1998 inventory funded by the Netherlands turned up 905 tons of obsolete pesticides, of which 200 tons were POPs, More than half the containers had no labels. Three-quarters will need to be repackaged for safe transport, although the money is not there to repackage these wastes, much less transport them.

Several international agreements have fostered efforts to deal with obsolete pesticides. The 1989 Basel Convention addressed transboundary movement of hazardous wastes. The 1998 Rotterdam Convention established the principle of prior informed consent, under which countries have the right to full disclosure of hazardous ingredients in pesticide donations or purchases. And in May 2001 the Stockholm Convention declared the international community's intent to ban certain POPs globally.

A comprehensive effort to clean up obsolete stockpiles called the Africa Stockpiles Project is being organized by the World Wildlife Fund and Pesticide Action Network UK in the hope of clearing the entire continent within a decade. The World Bank and the industry association CropLife International have endorsed the project. But CropLife International says that, while its members are committed to safe use and proper storage of their products, they will take responsibility only for the stocks they still own. Annik Dollacker, a member of CropLife International's Obsolete Stocks Project Team, says, "We need to know we are cleaning our products"--and not anybody else's.

Activists criticize this policy. When Andreas Bernsdorff recently led a Greenpeace team to clean up a stockpile in Nepal, he found that various brands were significantly cross-contaminated--the warehouse floor was covered with a thick layer of different pesticides that had leaked from their containers. Such mixtures make it impractical, Bernsdorff says, for a company to "go and get three barrels of their stuff" and leave the rest as is.

Still, many stakeholders are encouraged by the worldwide shift in awareness. Monica Moore, program director of Pesticide Action Network North America, says that even within the last 12 months awareness is growing, and there is "increasing recognition of the gravity of the situation and a willingness to do something about it."