Recent studies, however, offer powerful evidence linking these chemicals to disruptions in animals and humans of hormone systems, thus lowering sperm counts and altering sexual and other behavior. Humans can also suffer from weakened immune systems, which increases the risk of infectious diseases and cancer. POPs do not easily degrade or dissolve. They tend to become more concentrated the higher they are in the food chain, accumulating in the fatty tissue of fish, birds and mammals. The best known of these chemicals are DDT, PCBs and dioxins.
POPs spread easily through air and water and are found virtually everywhere.
Inuits and other Arctic populations eat a lot of high-fat sea foods such as seals and fish. Earlier this month, governments met in Australia to recommend actions to reduce or possibly ban POPs. Many POPs are pesticides, according to a study by the Washington, DC-based World Resources Institute. Many of these pesticides are banned in rich nations but widely used in other parts of the world. Until recently, most pesticide production took place in the former.