DNA SINGLE-STRAND BREAK ANALYSIS IN MONONUCLEAR BLOOD-CELLS OF PETROLPUMP ATTENDANTS

DNA single strand breaks, including DNA adducts that lead to alkali-la bile sites, were measured in peripheral mononuclear blood cells of 35 petrol pump attendants by alkaline filter elution. Blood samples from petrol pump attendants were taken on Monday and Friday. Additionally, DNA single strand breaks of smoking and non-smoking control persons we re examined. For the smoking (n = 12) and the non-smoking controls (n = 20) a mean normalized elution rate of 1.49 +/- 0.52 (mean value +/- 95% confidence interval) and 1.32 +/- 0.28, respectively, was obtained . The difference between smoking and non-smoking controls was not stat istically significant (U test). An increase in DNA single strand break s from Monday to Friday was detected for nonsmoking petrol pump attend ants with a daily working time of more than 4 h at the pump station. T heir mean normalized elution rate increased from 1.08 on Monday to 1.8 9 on Friday. This difference was statistically significant (P < 0.05; Wilcoxon test for paired data), although the 95% confidence interval w as large on Friday (0.43 on Monday; 1.23 on Friday). However, no signi ficant increase was found for non-smoking petrol pump attendants who w ere on duty for less than 4 h per day at the pump station. No statisti cally significant increase in DNA single strand breaks could be detect ed for smoking petrol pump attendants whether they were pumping gasoli ne for more or for less than 4 h per day.