[Polychlorinated diphenyls (PCB) : industrial hygiene and environmental toxicology].

The industrialized countries have been producing, every year from 1929, thousands of tons of polychlorinated biphenyls (PCB). Although it was known from that period the toxic activity of PCB (chlorancne), only from 1966 their presence and persistence in the environment has been detected and their mechanism of bioconcentration studied. Systematic researches to evaluate the mechanism of their toxicity, expecially for long period, have been carried out. The Italian environmental contamination of PCB is quite well defined, but only recently in Italy we have been specifically studying the industrial environment and the professionally exposed workers, to evaluate the exposure levels of PCB, the long term health effects and the possible preventive measures. In particular we are carrying out a research program in a transformer plant in the Roma area in which PCB are used as dielectrics. The methodological approach and the initial results are described.