Contaminants in the Upper Mississippi River: historic trends, responses to regulatory controls, and emerging concerns

摘要: We synthesized information on selected contaminants in the Upper Mississippi River, summarized regulatory measures enacted to reduce pollution, and described biotic ecosystem responses actions. Contamination of river with mercury lead rapidly followed settlement basin by European immigrants mid-1800s. Metal contamination peaked 1960s has since decreased substantially. DDT, its degradation product DDE, PCBs biomagnified concentrations that adversely affected wildlife upper trophic levels. National (U.S.A.) environmental regulations from 1972 1991 reduced discharges wastes point sources, improved wastewater treatment, or banned production usage certain chemicals, such as PCBs, lead. Responses these include reductions contamination, exposure, recovery populations. Recovery pollution been slow, however, we conclude proactive approaches focusing prevention are highly preferable reactive management toxic substances. Past successes reducing point-source which is greatest near urban areas, do not extend nonpoint-source given existing framework does adequately address nonpoint sources. The continues receive hundreds recently behavior effects most compounds aquatic ecosystems largely unknown. Emerging discovered mechanisms adverse biological effects, endocrine disruption, pose continuing challenges scientists managers concerned ecological health this riverine ecosystem.