POPs also are semi-volatile, enabling them to move long distances in the atmosphere. The ability of POPs to persist in the environment and travel long distances has resulted in the presence of POPs all over the world, even in regions where they have never been used. Most of the twelve POPs currently addressed in international negotiations have been banned or subjected to severe use restrictions in many countries for more than 20 years. Many of them, however, are still in use in many countries, and stockpiles of obsolete POPs exist in many parts of the world.
POPs comprise a large number of chemicals that have a wide range of uses.
The twelve targeted POPs are used prima- rily in industry, agriculture, and disease vector control. POPs can be produced cheaply compared to most other industrial chemicals. Social and economic consequences of use of POPs Humans can be exposed to POPs through diet, occupational accidents, and the environment. Exposure to very low doses of certain POPs can lead to cancer, damage to the central and peripheral nervous systems, diseases of the immune system, reproductive disorders, and interference with infant and child development. There is sufficient evidence of harm to wildlife and humans to demonstrate that international action is required to reduce the risk of POPs to health and environment.