Application of an in vitro keratinization assay to extracts of soot from a fire in a polychlorinated biphenyl-containing transformer.

A fire in the State Office Building in Binghamton, New York, involving a polychlorinated biphenyl-containing electrical transformer, resulted in contamination of the structure with soot containing 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran. Benzene extracts of soot collected from various areas of the building were tested for in vitro keratinization-inducing activity by the method of J. C. Knutson and A. Poland (Cell 22, 27-36, 1980). The results, in terms of relative keratinization-inducing activity, are compared to a high-resolution gas chromatographic/mass spectrometric analysis for total polychlorinated dibenzofurans in the same samples. This comparison showed a good correlation and suggests that the in vitro keratinization model has potential for use as a semiquantitative assay for dioxinlike activity.