Carcinogenicity and mutagenicity of chromium compounds: the association between bronchial metaplasia and neoplasia

摘要: Over the last 40 years, experiments with animals and epidemiology of exposed human populations have established that certain hexavalent chromium-containing compounds are capable causing cancer whilst trivalent materials not. More recently, a variety short-term genotoxicity tests (predictive carcinogenicity) clearly demonstrated Cr[VI] is genotoxic per se, all Cr[VI]-containing which been tested genotoxic. What failed to demonstrate clearly, however, myriad industrially available carcinogenic In this long-term study we looked at incidence squamous metaplasia in bronchial epithelium rats range by intrabronchial implantation. Squamous generally considered be transformed state from carcinoma may arise. We shown its increased groups Cr[VI]-materials, reference carcinogen 20-methylcholanthrene. was not Cr[III] materials. Of Cr[VI], only those receiving sparing aqueous solubility developed statistically significant levels. These results strongly support hypothesis although se biologically active, producing effects pathological changes predispose development cancer, seem evoking response.