An evaluation of serum pesticide residue levels and liver function in persons exposed to dairy products contaminated with heptachlor.

We studied a group of 45 dairy farm family members who had consumed undiluted raw milk products known to be contaminated with residues of the pesticide heptachlor at concentrations as high as 89.2 ppm (fat basis). We compared results of serum pesticide assays for these exposed persons with results for an unexposed group of 94 persons from the same geographic area and the results from the Second National Health and Nutrition Examination Survey. The exposed group had significantly higher mean levels of primary heptachlor metabolites--ie, heptachlor epoxide (0.84 +/- 1.0 vs 0.50 +/- 0.9 parts per billion) and oxychlordane (0.71 +/- 0.8 vs 0.49 +/- 1.1 parts per billion)--than the unexposed group. In the exposed group, 21.2% had elevated serum concentrations of these same metabolites; this rate was significantly greater than the rates in both the unexposed farm family members (heptachlor epoxide, 3.8%; oxychlordane, 6.3%) and the Second National Health and Nutrition Examination Survey sample (2.5% for both metabolites). However, we found no evidence of related acute and/or subacute hepatic effects in these exposed persons regardless of their serum concentrations of pesticide residues.