Reductive degradation of dieldrin and endrin in the field using acidified zinc

The reductive dechlorination of dieldrin and endrin was investigated as a possible procedure for field disposal of small quantitites of these pesticides. The objective was to convert the parent compounds to environmentally less objectionable materials. Emulsifiable concentrate formulations of the pesticides in a soil slurry were mixed with powdered zinc, dilute acetic acid, and acetone to facilitate reaction. Analysis of the mixtures by GC-MS indicated essentially complete conversion of endrin and partial conversion of dieldrin to products probably formed by replacement of the bridge anti chlorines with hydrogen. Partial confirmation of the desired anti dechlorodieldrin product was made by nmr. Disappearance of the parent compounds and production of conversion products was monitored for 2 1/2 years by GC in an outside soil plot, and accelerated destruction of parent compounds was achieved by the treatment. By analogy to the bridge anti dechloro products of aldrin and isodrin, the anti dechloro products probably are much less toxic than the parent compounds and are therefore environmentally less objectionable.