Effects of some commercial preparations of polychlorinated biphenyls in growing piglets.

Sixty-four piglets were given ad libitum commercial rations containing 250 ppm of polychlorinated biphenyls as Aroclor 1232, Aroclor 1242 and Aroclor 1254 for periods up to 12 weeks. The toxic effects of the polychlorinated biphenyls upon plasma testosterone levels, the blood coagulation system, the gross- and micropathological changes as well as the extent and differences in their distribution and accumulation were studied. Principals given Aroclor 1232, Aroclor 1242 and Aroclor 1254 for the 12 week period gained 30, 10 and 50% more in body weight respectively than did controls. In the context of the present experiment, Aroclors (especially Aroclor 1254) at 250 ppm level in the ration, appeared to act as growth promoting substances. The mode and site of action of this effect is not known. The gross and micropathological examinations of controls and principals gave no evidence of anomalies. Similarly, the data on various parameters of blood coagulation did not reveal any disturbances. However, testosterone levels in plasma were elevated in male piglets given Aroclors. Analyses of polychlorinated biphenyls showed that the highest concentrations were present in adipose tissues of all treated animals. A cumulative tendency was also evident. The levels were relatively high in brain, in some instances higher than in liver of the same group. Levels in hepatic and muscular tissue were, in many instances, of the same magnitude.