Alkaline comet assay as a biomarker of DNA-damage encountered in workers engaged in cigarette manufacturing

Background and Purpose: The aim of this pilot study was to determine possible genotoxic effects of occupational exposure to tobacco dust between workers employed in tobbaco industry and non-exposed population. Subjects and Method: The exposed group consisted of 20 subjects with mena age of 43.4 years. The average duration of their occupational exposure was 19.95 years. The control group consisted of 40 subjects, mean age 40.18 years and was choosen from general Croatian population. The assessment of primary DNA damage hosted by peripheral blood leukocytes was performed using the alkaline comet assay, the tail length and long-tailed nuclei thereby being the primary outcome of the measure. Results and Conclusions: The results showed that group comet tail length mean measured in the exposed workers was 14.39±1.02 mm whereas mean percentage of long-tailed nuclei was 8.20. In the control group, the mean tail length was 13.91±0.66 mm and long-tailed nucleus percentage was 1.88. Mean values for the tail length measured and the percentage of long-tailed nuclei were significantly higher in the exposed group compared to the control one. Within the exposed population, significant inter-individual differences in DNA damage were found (P<0.05). The observed DNA damage frequency characterized the tobacco dust as an undoubted genotoxicant, and the outcome of the alkaline comet assay stressed the importance of biomonitoring of the exposed individuals. INTRODUCTION T the years, cigarette manufacturer have acknowledged both medical and scientific consensus that smoking poses a serious health hazard causing a number of diseases, such as respiratory disease, heart disease and lung cancer. Specific chemicals including nitrosamines, formaldehyde, hydrazine, arsenic, nickel, cadmium, benzapyren, and potassium capable of causing cancer, are mainly contained in tobacco leaves. The processing of tobacco leaves generates a lot of dust and facilitates the release of numerous tobacco components into ambient air. Tobacco also contains nicotine which is readily absorbed in body tissues, including skin, respiratory epithelium, and mucous membranes of the mouth, the nose and the intestines (1). It has been reported previously that hypersensitivity to allergens contained by tobacco leaves causes occupational asthma (2). Tobacco dust is known to VERA GARAJ-VRHOVAC GORAN GAJSKI VLATKA BRUMEN Mutagenesis Unit, Institute for Medical Research and Occupational Health Ksaverska cesta 2, 10000 Zagreb, Croatia Andrija [tampar School of Public Health Medical Faculty, University of Zagreb Rockefellerova 4, 10000 Zagreb, Croatia Correspondence: Vera Garaj-Vrhovac Institute for Medical Research and Occupational Health Mutagenesis Unit Ksaverska cesta 2, 10000 Zagreb, Croatia E-mail: [email protected]