Lymphocyte DNA damage in cigarette factory workers measured by comet assay

Abstract

Objective To investigate whether there were separate and combined effects of occupational exposure to tobacco dust and smoking on lymphocyte DNA damage. Method 148 workers(107 workers occupationally exposed to tobacco dust from the production department and 41 controls who were managerial workers) were included in the study.The tail moment(TM) of comet assay was used to measure DNA damage.The two groups had similar mean age,mean duration of work and smoking prevalence. Results The exposed workers had a larger TM than that of the control(mean± s ):(43.43±13.77)μm vs. (38.89±8.98)μm,( P <0.05).Smoking could significantly increases TM[(47.25±14.02)μm vs. (38.90±10.75)μm, P <0.001].Analysis of variance after adjustment for age and gender showed that occupational exposure and smoking had a significant and independent effect on TM( P =0.025 vs. P =0.002,respectively) and there was a significant positive two way interaction between the two factors( P =0.019).Age and gender had no significant effect on TM. Conclusion Smoking and tobacco dust exposure can induce lymphocyte DNA damage and there is a synergistic effect of tobacco dust exposure and smoking on DNA damage.