Comparative toxicity of PCBs and related compounds in various species of animals.

There are several basic principles that apply to the clinicopathologic syndrome produced by polychlorinated biphenyls (PCBs). They are as follows: The degree of halogenation and position of the halogen atoms determine the potency of PCB, PBB, CDD, CDF and CN; in a given species of animals, the clinicopathologic syndrome induced by PCB is comparable to that induced by polybrominated biphenyls (PBB), chlorinated dibenzo-p-dioxins (CDD), chlorinated dibenzofurans (CDF), and chlorinated naphthalenes (CN) when an equitoxic dose is achieved; The clinicopathologic syndrome is different in each species of animals; Different species of animals vary in their susceptibility to intoxication; intoxication is more readily effected in young animals that in adults; at lethal doses the time between exposure and death is prolonged (greater than 2 weeks).