Genotoxicity studies of heavy metals: lead, bismuth, indium, silver and antimony.

OBJECTIVES Many kinds of heavy metals are used in industry; thus, it is important for us to clarify their toxicity. For example, lead, which is a component of solder, is notorious for its neurotoxicity, and substitute materials have been sought for many years. Therefore, we examined the genotoxicity of lead and also those of metallic bismuth, indium, silver and antimony which are possible substitutes for lead in solder. METHODS Bacterial reverse mutation tests and chromosomal aberration tests in cultured mammalian cells were performed according to standard procedures. RESULTS Antimony showed genotoxicity in both tests, and bismuth also showed positive results in the chromosomal aberration test. In contrast, lead, indium, and silver were considered to be inactive by the criteria of the present study. CONCLUSIONS Although further studies are needed because of the difficulty of genotoxicity evaluation using an in vitro system, sufficient precautions should be made when antimony and bismuth are used.