If not degraded or absorbed into the atmosphere, oil settles into the bottom sediments where it can have long lasting impacts on the marine ecosystem. Estuaries, with shallow water levels and a high presence of young aquatic life highly sensitive to contaminants, are a major area of concern with oil pollution. POPS are easily dispersed into the environment, and are often transported far from their origin, making clean-up difficult. Examples include such chemical compounds such as DDT, chlordane and PCBs. While many of these compounds are no longer manufactured, the existing supply continues to be used in some areas, and they have a long half-life in the environment.
Human exposure comes through the food chain, or exposure to contaminated water or air.
Many of these POPS are carcinogenic and are easily absorbed into body fat tissues of mammals where they cause reproductive failures, immune dysfunction and mortality. Steiner is most noted as being one of the principle coordinators of the environmental clean-up in response to the Exxon Valdez oil spill. Since then he has become an advocate for environmental safeguards. Once oil is in the water, seldom is more than ten percent recovered. While financial compensation can serve as a palliative for some of the human pain, money does not mitigate environmental destruction.