Sister chromatid exchanges in human peripheral blood lymphocytes after ingestion of high doses of arsenicals

To evaluate the cytogenetic effects following the ingestion of high doses of arsenicals. Determination of the mean sister chromatid exchange (SCE) frequency and the population of high-frequency cells (HFC, cells with a high SCE frequency) in the peripheral blood lymphocytes in four patients who ingested 150 mg KAsO2, 1 g, 10 g and 20 g As2O3 respectively. Doses of 10 g and 20 g significantly increased the HFC frequency and produced a shift in the distribution of the cells in accordance with the number of SCEs. The mean frequency of SCEs/cell was affected only after the highest dose (20 g). These results strongly suggest that cytogenetic methods are inappropriate for biomonitoring people occupationally exposed to arsenicals.