Concentration-response curves for ethylene-oxide-induced heritable translocations and dominant lethal mutations

Male mice were subjected to repeated inhalation exposures to different concentrations (165, 204, 250, or 300 ppm) of ethylene oxide (EtO) during an 8.5-week period. Transmitted clastogenic effects of these exposures were measured in terms of induction of dominant lethal mutations and heritable translocations. The concentration-response curves for both endpoints are not linear but are markedly concave upward. Significant increases in dominant lethals were detected at all concentrations, except the lowest one. In comparison, the incidences of heritable translocations were significantly increased at all concentrations.