Symptoms, signs and findings in humans exposed to PCBs and their derivatives.

The records of the health effects caused by some accidental exposure and findings from medical examination in cases exposed to polybrominated biphenyls (PBB) as well as to polychlorinated biphenyls (PCB) and their derivatives polychlorinated dibenzofurans (PCDF) and dibenzodioxins (PCDD) have provided some information for the recognition and classification of their toxicity in humans. The most impressive clinical features have been presented by the yusho episode of exposure. Dermatologic signs are the most persistent indicator of a considerable uptake. Neurological symptoms, respiratory findings and impairment of liver function are further aspects of the contamination. Skin manifestations have been observed also in the newborn infants from mothers exposed to high levels of the substances. However, the available data make it still hard to assess the clinical picture of the effects on humans in cases of acute exposure and even more the effects on reproduction and long-term effects. Furthermore it would still be arbitrary to draw a line between the symptoms which can be referred to PCBs and PBBs alone and those which can be related qualitatively and quantitatively to PCB derivatives (PCDFs, PCDDs, PCQs).