Sister-chromatid exchanges after exposure to metal-containing emissions

The effect of in vivo feeding of metal-containing emissions from an aluminum refining plant upon the induction of sister-chromatid exchanges (SCEs) and mitotic delay was investigated in cultured sheep lymphocytes. The experimental animals were given a daily dose of industrial emissions (mostly aluminum and fluoride) of either 0.75 g or 1.5 g/animal, for 1 year. The experiments were aimed at induction of chronic fluorosis under clinical conditions. A significant increase in mean serum fluoride, aluminum, arsenic and cadmium levels between both experimental groups and control was observed from 5 and 7 months on, respectively. The occurrence of SCEs in the experimental groups was higher (reaching statistical significance at a dose of 1.5 g/animal) than that seen in the controls. The emission was found to reduce the proliferation index. A significant heterogeneity of the first, second and third metaphases as compared to the controls was also observed.