28.12 THE STOCKHOLM CONVENTION ON POP

The Stockholm Convention on Persistent Organic Pollutants was adopted at a Conference of Plenipotentiaries on 22 May 2001 in Stockholm, Sweden and entered into force on 17 May 2004,

POPs

Persistent Organic Pollutants (POPs) are organic chemical substances, that is, they are carbon-based. They possess a particular combination of physical and chemical properties such that, once released into the environment, they:

♤ remain intact for exceptionally long periods of time (many years);

♤ become widely distributed throughout the environment as a result of natural processes involving soil, water and, most notably, air;

♤ accumulate in the fatty tissue of living organisms including humans, and are found at higher concentrations at higher levels in the food chain; and

♤ are toxic to both humans and wildlife.

In addition, POPs concentrate in living organisms through another process called bioaccumulation. Though not soluble in water, POPs are readily absorbed in fatty tissue, where concentrations can become magnified by up to 70,000 times the background levels.

The 12 initial POPs

Initially, twelve POPs have been recognized as causing adverse effects on humans and the ecosystem and these can be placed in 3 categories:

1. Pesticides: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, toxaphene;

2. Industrial chemicals: hexachlorobenzene, polychlorinated biphenyls (PCBs); and

3. By-products: hexachlorobenzene; polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), and PCBs.

The new POPs under the Stockholm Convention Nine new POPs

At its fourth meeting held in 2009, the CoP adopted amendments to Annexes A, B and C to the Stockholm Convention to list nine new persistent organic pollutants.

1. Pesticides: chlordecone, alpha hexachloro- cyclohexane, beta hexachlorocyclohexane, lindane, pentachlorobenzene;

2. Industrial chemicals: hexabromobiphenyl, hexabromodiphenyl ether and heptabro -modiphenyl ether, pentachlorobenzene, perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride, tetrabromodiphenyl ether and pentabromodiphenyl ether; and

3. By-products: alpha hexachlorocyclohexane, beta hexachlorocyclohexane and pentachlorobenzene.

Endosulfan

At its fifth meeting held in 2011, the CoP adopted an amendment to Annex A to the Stockholm Convention to list technical endosulfan and its related isomers with a specific exemption.