Genotoxic activity of potassium permanganate in acidic solutions

Abstract

Potassium permanganate (KMnO 4) combined with sulfuric acid is a strongly oxidizing mixture which has been recommended for the destruction and the decontamination of various mutagens/carcinogens in the publication series of the International Agency for Research on Cancer. Evaluation of the genotoxicity of 4 potassium permanganate solutions was performed using a microtechnique of the Ames test with the tester strains TA97, TA98, TA100 and TA102 with and without metabolic activation. Presence of direct-acting mutagens was detected in all the samples with the tester strain TA102 without S9 mix (163–357 revertants/μl of the solutions). Three samples containing either acetone or ethanol as an organic solvent also induced a mutagenic response on tester strain TA100 without S9 mix (167–337 revertants/μl). In addition, DNA damage in human peripheral blood lymphocytes was also measured for one of the mixtures by a new technique: the single-cell gel assay (SCGA). A sample with no organic solvent induced DNA damage in human lymphocytes with a dose-response relationship as determined by SCGA. The major mutagenic agent generated by the permanganate solutions was found to be manganese ion (Mn 2+). Both manganese sulfate (MnSO 4) and manganese chloride (MnCl 2) gave mutagenic dose-response relationships on tester strain TA102 without S9 mix. The mutagenic potencies were 2.8 and 2.4 revertant/nmole for MnSO 4 and MnCl 2 respectively. MnCl 2 also induced DNA damage in human lymphocytes as determined by the SCGA. The genotoxic effects of KMnO 4 in acidic conditions were probably mediated by the conversion of MnO 4 − to Mn 2+. KMnO 4 in alkaline solutions did not produce mutagenic species and may offer an alternative for the degradation of genotoxic compounds.