ABSTRACT
Environmental contamination by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has become a major public health issue. Hyperkeratinization of the epithelium is considered to be responsible for the occurrence of chloracne in humans exposed to polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans. This chapter describes the specificity and sensitivity of the TCDD-induced flat-cell effect in the XBF/3T3 culture system and the application of this effect as a bioassay for the detection of PCDDs and/or related compounds in soot extracts, surface swipes, fish, and other environmental samples. Dioxinlike activity is defined by the induction of the flat-cell effect by 2,3,7,8-TCDD, the most potent and toxic PCDD isomer known. The sensitivity and stability of the XBF/3T3 flat-cell effect for TCDD suggested its application as an assay for dioxin. The potential health hazards associated with human exposure to TCDD are not well understood, but are of major concern.
