(March 2001) Early last December, negotiators from 122 countries met in Johannesburg, South Africa, to devise ways to rid the world of persistent organic pollutants (POPs), some of the most toxic chemicals on the planet. In contrast to the fractious climate change talks that fell apart in The Hague last November, this meeting appears to have achieved its purpose. Negotiating Committee Chairman John Buccini called the treaty that emerged from the session “a declaration of war on POPs.”

The treaty restricts the production, import, export, disposal, and use of 12 particularly dangerous POPs. The 12 chemicals include pesticides (including DDT), industrial chemicals (including polychlorinated biphenyls, better known as PCBs), and two byproducts of combustion and industrial processes (dioxins and furans). While none of the pesticides or industrial chemicals covered by the treaty is now produced in the United States, their use remains legal in many less developed countries (see table).

Number of Countries Banning Selected POPs as of 1996

Chemical Africa* (53) North and Central America* (24) South America* (12) Asia* (46) Europe* (39) Oceania* (10)
DDT 1 3 4 10 9 3
Hexachlorobenzene 1 1 1 2 6 2
Aldrin 1 4 2 9 10
Dieldrin 2 5 3 10 10 3

*Source: UN Environment Programme (UNEP), “UNEP Survey on Sources of POPs,” 1996.

Need for Global Cooperation

While POPs are not used in every country, they can show up anywhere. Through what is known as the “grasshopper effect,” these toxic compounds can travel great distances through a repeated cycle of evaporation and precipitation. These substances may also be stored for decades in fatty tissue, allowing them to be spread by migratory animals that ingest them. As a result, “no region is exempt from POPs,” according to Clifton Curtis, director of the World Wildlife Fund’s Global Toxic Chemicals Initiative. “Everybody has some amount of these chemicals in their bloodstream.”

High levels of exposure to POPs have been linked to a wide range of health problems, including allergies, immune system disruption, nerve damage, reproductive disorders, birth defects, and cancer. Fetuses and infants are particularly susceptible since the POPs that have accumulated over decades in their mothers” bodies may be passed to them during pregnancy and nursing. Prenatal exposure has been linked to reduced fetal and postnatal growth, neurological deficits, delayed development of motor functions, and impaired short-term memory.

The tendency of these chemicals to build up in fatty tissue means that they become increasingly concentrated at higher levels in the food chain, making fish, mammals, and predatory birds especially vulnerable to their toxic effects. Human communities that consume high levels of meat are thus particularly at risk. Inuit women in the Arctic, for example, typically have high PCB levels in their breast milk since fatty meat from large animals makes up a heavy portion of the Inuit diet.

In the United States, POPs levels in the Great Lakes region have aroused particular concern. With heavy industry and agriculture well-represented in the area, POPs and other pollutants were routinely disposed of in the lakes until the 1970s. Despite decades of clean-up efforts, POPs concentrations in some local fish populations remain elevated, posing a continuing threat to people who rely heavily on fish in their diet. In the Great Lakes region, this group includes subsistence fishermen, poor urban families, American Indians, and immigrants from Southeast Asia.

In Europe, a scientific panel recently advised the European Union that fish from the North and Baltic seas, as well as fish farms, are frequently contaminated by dioxins and similar toxins. European fish meal and fish oils have dioxin levels up to eight times higher than those of similar products from less industrial regions, such as the waters off Peru and Chile. The U.S. Environmental Protection Agency ranks dioxin in the top 10 percent of chemicals known to be hazardous to human health — dioxin exposure is a key risk factor in cancer and a range of reproductive health problems.

Treaty Provisions

Most of the POPs in question are banned by the treaty, though there are a few exemptions and qualifications. DDT, for example, is used in many less developed countries to control malarial mosquitoes, and it may still be used for this purpose until an affordable substitute is found. According to the World Health Organization, malaria kills more than 1 million people each year worldwide and is directly responsible for one in five childhood deaths in Africa. South Africa and Sri Lanka have banned DDT in recent years only to see malaria rates soar.

The treaty also requires industrialized countries to provide new and additional financial resources to less developed countries to help enforce the ban and develop alternatives to POPs. The Global Environmental Facility, an international financial entity that funds environmental initiatives in coordination with the UN and the World Bank, is expected to be the primary channel for this aid and has proposed annual assistance of $150 million for this purpose.

The treaty is scheduled to be signed in May. It will then have to be ratified by at least 50 governments. While the treaty has broad support, U.S. government officials expect ratification to take four to five years.

Bingham Kennedy, Jr. is associate editor of Population Today.

For More Information

For fact sheets and U.S. policy positions on POPs, visit the U.S. State Department’s resource page on POPs negotiations, www.state.gov/www/global/oes/fs-001129_pops_overview.html