By Janet Raloff
On Oct. 23, a new international treaty–the Protocol on Persistent Organic Pollutants (POPs)–went into effect, although the United States hasn’t signed on. Brokered under the aegis of the United Nations, the POPs treaty calls for reduction or elimination of toxic chemicals that are long-lived and have the propensity to travel long distances.
When first drafted in 2000, this treaty looked to curb what many scientists referred to as the dirty dozen: dioxins, furans, polychlorinated biphenyls (PCBs), and the pesticides aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene (SN: 12/16/00, p. 389). Since then, signatory nations have added four more POPs to the list: the pesticides lindane (also known as gamma-hexachlorocylcohexane) and chlordecone (also known as kepone); hexabromobiphenyl, a polybrominated flame retardant; and polycyclic aromatic hydrocarbons (PAHs), which are combustion byproducts.
Most of the POPs are slated for immediate elimination by nations that have ratified the treaty. In the United States, most of the POPs are already banned or severely controlled. A few compounds, such as DDT and PCBs, will remain in limited use in some countries for the time being. Because no one deliberately produces dioxins or PAHs, the treaty commits nations to restricting release of these chemicals as much as possible.
To date, Canada, Iceland, and 15 European nations, including France and Germany, have ratified the new treaty.
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