Dioxins are a group of 210 chemicals with similar properties and structures that are usually found as a "mixture" in the environment. Dioxins are found at low levels in air, soil, water, and sediment as well in foods such meat, dairy, fish, and shellfish. The highest levels are usually found in sediments soil and animal fats. The most toxic chemical in the group is 2,3,7,8-tetrachlorodibenzo-para-dioxin, which is the "standard" to which other dioxins are compared. This paper examines the Michigan Department of Environmental Quality (MDEQ) assessment and remediation efforts in the Tittabawassee River (Michigan, USA) flood plain. Soil and sediment samples indicate higher than "normal" (background) levels of dioxins for soil and sediment, which exceed the Center for Disease Control (CDC) and U.S. Agency for Toxic Substances and Diseases Registry (ATSDR) action level of 1000 parts per trillion. Data presented indicates the difficulties associated with assessing historical dioxin levels in environments such as soil and sediments. Activities associated with these efforts such as dioxin and furan exposure studies, animal toxicology assessments, U.S. Environmental Protection Agency (EPA) enforcement, MDEQ efforts to expedite remediation, as well as future directions for this on-going project are discussed.

Praise for the previous edition: "Editors' Choice Reference Source"—Booklist "Best Reference Source"—Library Journal "Runner-up, General Nonfiction category"—Green Book Festival "Top 40 Reference Titles"—Pennsylvania School Librarians Association "A worthwhile reference for high school students and the general public."—Library Journal "...interesting and helpful...will help readers gain an understanding of major concepts, terms, and events in modern pollution studies. Recommended."—Choice "Definitive yet accessible...notable for reliable information on a topic of interest to both undergraduate and lay audiences, merits high recommendation for high-school, public, and academic libraries."—Booklist, starred review "...fascinating..."—Library Journal "...an excellent addition for all academic libraries and large public libraries."—American Reference Books Annual "This accessible and attractive encyclopedia provides depth, variety and currency and would be valuable for most high school collections."—Pennsylvania School Librarians Association "...recommended...an excellent source of background reading."—Reference Reviews Newly updated, the Encyclopedia of Pollution, Revised Edition is a comprehensive reference designed to address all aspects of pollution and the global impact on the environment in a single source. Containing more than 300 entries and essays interspersed throughout, it uses the most current scientific data to explain the different types of pollutants including properties, production, uses, environmental release and fate, adverse health response to exposure, and environmental regulations on human exposure. It provides the scientific background on the water, soil, and air of environments where the pollutants are released. Coverage also includes pollution regulation, the function of federal regulatory agencies and environmental advocacy groups, and the technology and methods to reduce pollution and to remediate existing pollution problems. Numerous case studies explore the most infamous of pollution events such as the Exxon Valdez oil spill, the Gulf War oil well fires, the Chernobyl disaster, Hurricane Katrina, the World Trade Center disaster, and the Love Canal in New York, among many others—including those that had great impact on legislation or that were used in popular media such as the films Erin Brockovich and A Civil Action. Biographies are provided of some of the leaders and pioneers of pollution study and activism. Other useful features include a detailed glossary, a timeline, and tables.

Although the U.S. Environmental Protection Agency presented a comprehensive review of the scientific literature in its 2003 draft reassessment of the risks of dioxin, the agency did not sufficiently quantify the uncertainties and variabilities associated with the risks, nor did it adequately justify the assumptions used to estimate them, according to this new report from the National Academies' National Research Council. The committee that wrote the report recommended that EPA re-estimate the risks using several different assumptions and better communicate the uncertainties in those estimates. The agency also should explain more clearly how it selects both the data upon which the reassessment is based and the methods used to analyze them.