Study On The Effective Biomarkers Of Genetic Damage In Workers Who Occupationally Exposed To Benzene

Objective: Benzene is an ubiquitous environmental contaminant and used extensively in many industries. The main sources of benzene in human are tobacco smoke, food and industrial pollution. The international Agency for Research on Cancer has concluded that there is sufficient evidence to classify benzene into the group 1 human carcinogen category and exposure to benzene is most significantly associated with the development of acute mveloid leukemia. The aim of this study is to explore the effective biomarkers of genetic damage of benzene and to provide experimental data to prevent the exposed population from the carcinogenicity of benzene for the future .Methods: The present situation of manufacture business, the benzene pollution, contacting worker at working shift and distribution situation of occupational exposure to benzene in Jingjiang county were investigated. For all subjects, detailed information on smoking habits and other potential confounders were recorded by questionnaires. The health effect was studied through blood analyses and the subjective symptoms and so on. The time weighted average (TWA) of workers exposed to benzene was detected bypersonal sampling-GC method and got exact exposure dose of workers in a work shift. The monitoring data over the years were gathered, and the accumulative dose was calculated. Alkaline single cell gel electrophoresis assay (Comet assay) was used to indicate the DNA damage and the Chromosome injury was detected by chromosome aberration test. The dose-response relations between exposure dose and biomarkers was got by statistics to ascertained values of benzene. The possibility of application of biomarkers, such as DNA damage as exposure monitoring factors was explored.Results: The higher accumulative exposure dose, the more gravely damage of the nervous system and the blood system and the gall bladder pathological changes may be come into being. The grade of DNA breakage, the tail length of Comet assay, the rate of chromosome aberration and levels of accumulative exposure, TWA were significantly higher in lymphocytes of exposed workers, compared with matched controls (P<0.01). The dose-response relationship was significant in the above three benzene concentrations. According to the time of exposure, 60 workers were classified into 3groups i.e. 0.5 yrs ~, 12.0 yrs -and 22.0 yrs- group, the rate of comet cell and the tail length of Comet assay have rising tendency with the increasing the time of exposure after adjusting the age, sex, smoking.Conclusion : Occupational exposure to benzene might result in acertain genetic damage .Comet assay is a sensitively and more conveniently detect DNA damage induced by benzene in human lymphocytes. It may be a useful tool for bio-monitoring, particularly for the analysis and identifying of environmental mutagens and carcinogens.