Effect of chronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on sister chromatid exchange levels in peripheral lymphocytes of the rhesus monkey.

Frequencies of sister chromatid exchanges and chromosomal aberrations were examined in peripheral lymphocytes of Rhesus monkeys which had been fed a diet containing 25 parts per trillion 2,3,7,8-tetrachlorodibenzo-p-dioxin for a period of 4 years. When compared to non-exposed control animals, no significant differences were noted for either of these cytogenetic endpoints. In addition, there was not a significant difference in sister chromatid exchange response to a challenge dose of mitomycin C in cells from 2,3,7,8-tetrachlorodibenzo-p-dioxin exposed animals compared to controls. Our results confirm the lack of genotoxic effects associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure.