More than 2500 environmental scientists met in Denver from 30 October to 3 November for the 15th annual meeting of the Society of Environmental Toxicology and Chemistry, The theme-how to interject science into regulatory decisions involving environmental pollutants-figured prominently in many presentations, including three discussed below. One examines the possible role of dioxin and other toxicants in a mass die-off of seals in northern Europe, another looks at how those compounds may pose a continuing threat to fish in the Great Lakes, and a third looks at ways to reduce the amount of dioxin and other pollutants produced in the paper-bleaching process.