Lymphocyte DNA damage in bus manufacturing workers in Guangzhou, China

Abstract

AIMS: To study the effect of occupational exposure, smoking, and drinking on lymphocyte DNA damage in bus manufacturing workers. METHODS: 346 employees (106 women and 240 men) from a bus manufacturing factory were included. There were 31 assembling workers, 120 welders, 30 mechanic, 80 painters, 45 auxiliary workers, and 40 managerial workers. DNA damages were measured by the Comet assay. RESULTS: In painting workshops, benzene levels ranged from 0.1 to 138.5mg/m3, toluene from 0.1 to 389.6mg/m3, and xylene from 0.1 to 11.4mg/m3. In welding workshops, welding dust concentrations ranged from 1.1 to 4.4 mg/m3 with manganese dioxide levels ranged from 0.02 to 0.11mg/m3. In lathe workshops, mixed dust concentrations ranged from 1.1 to 2.2 mg/m3. Assembling workshops were clean and not measured. Gender had no effect on tail moment. Age was slightly correlated with tail moment (r=0.11, p=0.051). Significant differences of tail moment among the 6 job categories were found (p=0.003). Painters had the largest tail moment (geometric mean, 95%CI) [3.25(m (2.97-3.55)], followed by mechanics [3.18(m (2.66-3.82)], auxiliary workers [3.13(m (2.82-3.48)], welders [2.89(m (2.63-3.19)], managerial workers [2.54(m (2.22-2.90)], and assembling workers [2.32(m (2.02-2.67)]. Smoking increased tail moment significantly [3.14(m (2.89-3.40) Vs 2.79 (2.63-2.97), p=0.023]. Analysis of covariance showed that occupational exposure (p=0.001) and smoking (p=0.019) had significant effect on tail moment after adjusting for each other, gender, age and drinking. CONCLUSIONS: Smoking and occupational exposure in bus manufacturing factory increased lymphocyte DNA damage. No effect of drinking on tail moment was found.