Inhibition of repair of radiation-induced chromosome breaks: effects of chromium trioxide on cultured human lymphocytes.

MATERIALS AND METHODS Chromium is known to be an essential element1. Epidemiological and experimental studies have, however, demonstrated that some chromium compouds (mainly hexavalent salts) are mutagenic carcinogens2-5) (see ref. 1 for review). Recent studies have also shown that the hexavalent compounds induce dose-related increases in chromosomal aberrations and sister chromatid exchanges in cultured human lymphocytes and mammalian cells exposed to the compounds6-10). In the present study, we examined by dosage fractionation whether the hexavalent compound, chromiunm trioxide, inhibits the repair of radiation-induced chromosome breaks.