Assessment of primary vs. secondary toxicity of Aroclor 1254 to mink.

Abstract

Dietary tests were conducted, using mink as a surrogate mammalian wildlife carnivore, to develop and evaluate procedures for the assessment of primary vs secondary toxicity of potentially hazardous chemicals to mammalian carnivores. Test methods included comparison of mortality, body weight change, feed consumption and calculated LC50 values in mink fed diets that contained polychlorinated biphenyls (PCBs),i.e., Aroclor® 1254 (primary toxicity) with mink fed diets that contained the same concentrations of the metabolized xenobiotic (secondary toxicity). Mean feed consumption and body weight gains were lower for the mink fed the metabolized Aroclor 1254 (secondary toxicity) than for mink that received the same concentrations of Aroclor 1254. The tests yielded 28- and 35-day LC50 values of 79.0 and 48.5 ppm (mg/kg) for the primary toxicity test and 47.0 and 31.5 ppm (mg/kg) for the secondary toxicity test, respectively. The results indicated that mink were a suitable carnivorous species for secondary toxicity testing and showed the necessity of using a withdrawal period of appropriate duration.