Application of the alkaline comet assay in human biomonitoring for genotoxicity: a sandy on Croatian medical personnel handling antineoplastic drugs

The alkaline comet assay was used to evaluate the genotoxicity towards peri pheral blood lymphocytes of medical personnel regularly handling various an tineoplastic drugs with different safety precautions. The study population consisted of 50 exposed subjects working in the oncology, pulmology, gynaec ology and haematology units of nine Croatian hospitals and 20 unexposed con trol subjects. Peripheral blood lymphocytes from the subjects were embedded in agarose on a microscope slide and lysed; the DNA was unwound and subjec ted to electrophoresis at pH 13. Staining with a fluorescent dye was used t o identify cells with DNA damage, as judged by increased migration of genet ic material from the cell nucleus. DNA damage was quantified by measuring t he displacement between the genetic material of the nucleus and the resulti ng tail using an image analysis system. Three parameters were used as indic ators of DNA damage: i.e. tail length, percentage of DNA in the tail and ta il moment. Statistically significant differences in all three parameters we re observed between the exposed and control groups. Within the exposed grou p, there were marked differences between individuals in the comet tail para meters. In the majority of exposed subjects an effect on DNA damage of age or duration of occupational exposure could be excluded. In the exposed grou p, the highest level of DNA damage was recorded in subjects who used only l atex gloves in their work with antineoplastic drugs. The observed DNA damag e was lower in exposed subjects who used more than one type of protective e quipment and who worked in a well-ventilated safety cabinet. No statistical ly significant differences were found between the mean values of comet tail parameters for smoking and non-smoking subpopulations from the exposed gro up. In view of the results obtained, the alkaline comet assay, as a simple, rapid and sensitive method, appears to be a promising additional test for biomonitoring purposes in human populations.