Evidence for a Reduction of 2,3,7,8-TCDD Toxic Equivalent Concentrations in White Sucker (Catostomus commersoni) Exposed to Bleached Kraft Pulp Mill Effluent, Following Process and Treatment Improvements

Over a 4-year period from 1990 to 1993, the H4IIE bioassay was used to measure 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentrations (TECs) in the liver tissue of white sucker exposed to bleached kraft mill effluent. During two of the sampling periods, the H4IIE bioassay-derived TECs (BD-TECs) were compared directly with BD-TECs measured by a similar bioassay using a rainbow trout liver cell line (RTL-W1). From 1989 to 1993, …