The present lack of evidence for unique rodent germ-cell mutagens

Abstract

Six chemicals, diethylhexyl phthalate (DEHP), ethanol, cyclohexylamine (CHA), sodium saccharin (NaS), cadmium chloride (CdCl 2) and triflupromazine (TFP), were suggested to be unique germ-cell mutagens (Auletta and Ashbym 1988) by the GeneTox Workgroups of the U.S. Environmental Protection Agency (EPA). If this is correct classification it would have major consequences when screening for mutagenicity and when labelling genotoxic substances. However, our re-evaluation of the GeneTox literature, including some more recent publications, has failed to find substantive evidence that any of these chemicals have been unequivocally established as having unique mutagenic activity in germ cells. For DEHP, NaS and TFP the evidence for genotoxic/mutagenic effects is questionable, in both germinal and somatic cells. Ethanol and CdCl 2 showed clastogenic activity, but it was not restricted to germ cells. Both, ethanol and cadmium salts, appear to induce aneuploidy. The unconfirmed effect of CHA was restricted to rats, but it occurred in both bone marrow and spermatogonia. Therefore, the general observation that rodent germ-cell mutagens are also genotoxic in somatic cells in vivo (Brusick, 1980; Holden, 1982) remains valid.