Trends In Levels And Effects Of Persistent Toxic Substances In The Great Lakes

`Are the Great Lakes getting better or worse?' This is the question that the public, scientists and managers are asking the International Joint Commission after a quarter-century of cooperative action by the United States and Canadian governments to clean up the Great Lakes. This volume contains papers from the workshop on Environmental Results, hosted in Windsor, Ontario, by the Great Lakes Science Advisory Board of the International Joint Commission, on September 12 and 13, 1996. The Great Lakes have been through almost a century of severe pollution from the manufacture, use and disposal of chemicals. In the 1960s wildlife biologists started to investigate the outbreaks of reproductive failure in fish-eating birds and ranch mink and to link these to exposure to organochlorine compounds. Human health researchers in the 1980s and 1990s linked growth retardation, behavioral anomalies and deficits in cognitive development with maternal consumption of Great Lakes fish prior to pregnancy. The Great Lakes became the laboratory where the theory of endocrine disruptors was first formulated. Now a group of Great Lakes scientists, hosted by the International Joint Commission, has compiled the story of the trends in the concentrations and effects of persistent toxic substances on wildlife and humans. The technical papers review the suitability of various organisms as indicators, and present the results of long-term monitoring of the concentrations and of the incidence of effects. The evidence shows that there was an enormous improvement in the late 1970s, but that in the late 1990s there are still concentrations of some persistent toxic substances that have stubbornly remained at levels that continue to cause toxicological effects.

This report summarizes what is currently known about the levels and the effects of toxic chemicals in the water, sediments, fish, wildlife and human residents of the Great Lakes basin. A list of critical pollutants is included. Particular attention is paid to the effects of toxic contaminants on double-crested cormorants, bald eagles, herring gulls, common terns, mink, common snapping turtles, and lake trout.

ATSDR's mission is to prevent exposure and adverse human health effects and diminished quality of live associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollutin present in the environnment. The activities described in this report support this mission and are consistent with achieving the health promotion and disease prevention objectives of Healthy People 2000, a national strategy put forth by the U.S. Department of Health and Human Services to significantly improve the health of the nation over the next decade. The ATSDR research program is designed to investigate and characterise the association between the consumption of contaminated Great Lakes fish and short- and long-term harmful health effects.