Potential adverse effects on the environment and human health of exposure to POPs are of considerable concern among governments, nongovernmental organizations, and the scientific community. The persistence of such substances in the environment and their capacity to cover long distances from the point of release require that concerted international measures are adopted to efficiently control exposure. To this end, two international legally binding instruments have been negotiated and finalized: the global Stockholm Convention on POPs, opened for signatures in May 2001 and entered into force on 17 May 2004, and the Protocol to the Regional UNECE Convention on Long-Range Transboundary Air Pollution on POPs, opened for signatures in June 1998 and entered into force on 23 October 2003.
The Stockholm Convention on POPs provides an international framework, based on the precautionary principle, which seeks to guarantee the elimination or the reduction of production and use of POPs. Initially, the convention covers the 'dirty dozen' substances, but
Bluefin tuna Mackerel
Anchovy Gulper shark Red mullet
60 11 10
Mackerel Anchovy Red mullet
Red mullet Longnose spurdog Gulper shark
Gray mullet Fourspot megrim Longnose spurdog ln (PCB pg g-1 ww)
Figure 1 Indicative concentrations of total PCBs in muscular tissue or in the organism of Mediterranean ichthyofauna specimens. The concentrations increase as the trophic position, the organism size, and the species-specific lipid contents increase. In larger animals, the restoring of balance can take time. They may ingest more pollutants through the food web than they will ever release to the environment, and their POP body burden may be in an imbalanced state with those in the water. PCB total levels have been reported on a whole weight basis, thus encompassing the variability due to the species-specific content of lipids.
any signatory state ofthe convention may submit proposal to include new substances in the list covered by the Convention. The chemicals to be eliminated under the Stockholm Convention are those reported in Table 1, that is, the pesticides aldrin, chlordane, dieldrin, endrin, heptachlor, HCB, mirex, and toxaphene, as well as the industrial chemicals PCBs. The use of DDT as disease vector control is allowed until safe, effective, and affordable alternatives become available. The Parties to the Convention are required to take the necessary measures to reduce the unintentional release or production of PCDDs, PCDFs, and HCB with the ultimate goal of their complete elimination.
The protocol to the Convention on Long-Range Transboundary Air Pollution on POPs is one of the eight specific protocols which extend the Convention on Long-Range Transboundary Air Pollution. The protocol to the Convention on POPs aims at controlling, reducing, or eliminating discharges, emissions, and losses of persistent pollutants. It focuses on a list of 16 substances, comprising 11 pesticides, two industrial chemicals, and three by-products/contaminants. In particular, the protocol bans the production and the use of eight substances (aldrin, chlordane, chlordecone, dieldrin, endrin, hexabromobiphenyl, mirex, and toxaphene), with the elimination of others (DDT, heptachlor, HCB, PCBs) planned at a later stage. Finally, the protocol severely restricts the use of DDT, hexachlorocyclohexane (HCH, including lindane), and PCBs, and also obliges the states for which the convention is in force to reduce their emissions of PCDDs, PCDFs, polyaromatic hydrocarbons (PAHs), and HCB below their levels in 1990 (or an alternative year from 1985 to 1995).
The protocol to the Convention on Long-Range Transboundary Air Pollution and the Stockholm Convention are part of the numerous international treaties ratified on the environment in recent years, such as the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal (1992) and the Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides (1998). Many new persistent organic pollutants as a result of actual industrial processes are entering the environment. However, their environmental effects are almost unknown.
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