New studies on the in vitro genotoxicity of sodium molybdate and their impact on the overall assessment of the genotoxicity of molybdenum substances.
The potential of molybdenum substances to cause genotoxic effects has been studied previously. However, a review of existing in vitro data, including an assessment of relevance and reliability, has shown that inconsistent results have been observed in the past. To resolve the inconsistencies, new studies were performed with the highly soluble sodium molybdate dihydrate according to OECD test guidelines. In a bacterial reverse mutation assay sodium molybdate dihydrate did not induce reverse mutations in five strains of Salmonella typhimurium. No mutagenic or clastogenic effect was observed at the tk locus of L5178Y mouse lymphoma cells. In a micronucleus test in cultured human peripheral blood lymphocytes no clastogenic or aneugenic effects were seen. These results can be read across to other inorganic molybdenum substances, that all release the molybdate ion [MoO4]2-under physiological conditions as the only toxicologically relevant species. In summary, a weight of evidence assessment of all available in vitro data shows no evidence of genotoxicity of molybdenum substances.
EBRC Consulting GmbH, Raffaelstr. 4, 30177 Hannover, Germany. Electronic address: a.burzlaff@ebrc.de.
Arne
A
Burzlaff
Genetic Toxicology, Covance Laboratories Limited, Otley Road, Harrogate, North Yorkshire, HG3 1PY, UK.
Carol
C
Beevers
Genetic Toxicology, Covance Laboratories Limited, Otley Road, Harrogate, North Yorkshire, HG3 1PY, UK.
Helen
H
Pearce
Genetic Toxicology, Covance Laboratories Limited, Otley Road, Harrogate, North Yorkshire, HG3 1PY, UK.
Melvyn
M
Lloyd
EBRC Consulting GmbH, Raffaelstr. 4, 30177 Hannover, Germany.
Kevin
K
Klipsch
D000818:Animals; D006801:Humans; D007940:Leukemia L5178; D051379:Mice; D015162:Micronucleus Tests; D008982:Molybdenum / Q000633:toxicity*; D009152:Mutagenicity Tests; D009153:Mutagens; D015203:Reproducibility of Results; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics
D009153:Mutagens; D008982:Molybdenum; C024687:sodium molybdate(VI)
Aneugenicity; Clastogenicity; Genotoxicity; In vitro; Molybdate; Molybdenum; Mutation; Read-across; Review