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The distribution and fate of [14C]heptachlor and the organochlorine compounds closely associated with it in manufacture and use, hexachlorocyclopentadiene, chlordene, and heptachlor epoxide, have been evaluated in food chain organisms in two laboratory model ecosystems and in vitro by sheep liver microsomes. Chlordene and heptachlor undergo epoxidation rapidly and are also hydroxylated at Ci to form the corresponding hydroxy analogs. Heptachlor epoxide, however, is highly stable in biological systems. The rates of conversion and degradation of these compounds are influenced by microsomal oxidases, photolysis, and chemical hydrolysis. The relative balance of the epoxidation, an intoxication, and hydroxylation, a detoxication, determines the magnitude of persisting residues in the environment.

A series of p,p'-disubstituted a-trichloromethylbenzylanilines which closely resemble DDT-type compounds in structure have been synthesized and evaluated for insecticidal activity. These compounds affect insects in a manner indistinguishable from DDT, and the most effective compounds such as a-trichloromethyl-p-ethoxybenzyl-p-methylaniline were of comparable toxicity with DDT to flies and mosquito larvae. The metabolism of W-a-trichloromethyl-p-ethoxybenzyl-p-ethoxyaniline was studied in the housefly, salt-marsh caterpillar, mouse, and in a model ecosystem where the compound was substantially biodegradable. A comparable series of a-trichloromethyl benzyl phenyl ethers was also shown to have DDT-like action.

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