ABSTRACT
OBJECTIVES: The aim of this study was to estimate a benchmark dose (BMD) for chromosome damage induced by vinyl chloride monomer (VCM) in VCM-exposed workers in central China and validate the published results in Shanghai. METHODS: VCM-exposed workers who had been exposed to VCM for at least one year (n=463) and matched subjects not exposed to VCM or other toxins (n=273) were asked to participate in this study. Micronucleus (MN) frequency based on the cytokinesis-block micronucleus assay (CBMN) was used as a biomarker for chromosome damage induced by VCM exposure. RESULTS: The MN frequency in the VCM-exposed workers was significantly higher than that in the control group, and multivariate Poisson regression suggested that gender, smoking status and VCM exposure were the significant factors influencing the risk of increased MN frequency. When subjects were further stratified according to gender and smoking status, the results showed that female VCM-exposed workers were more susceptible than the males to the risk of increased MN frequency. The MN frequency of smokers was significantly higher than that of nonsmokers in the control group. Our study also suggested that there was a strong dose-response relationship between VCM CED and the increased risk of MN frequency in the total group, males and females. The BMDL(10) was found to be 630.6, 670.2 and 273.7 mg-year for all VCM-exposed workers, males and females, respectively. CONCLUSIONS: These results invite further scrutiny of the current VCM occupational exposure limits and warrant further study of the risk of VCM genotoxicity and carcinogenicity.
Subject(s)
Air Pollutants, Occupational/analysis , Occupational Exposure/analysis , Vinyl Chloride/analysis , Adult , Age Factors , Air Pollutants, Occupational/standards , Air Pollutants, Occupational/toxicity , Alcohol Drinking/epidemiology , Biomarkers , China , DNA Damage/drug effects , Dose-Response Relationship, Drug , Female , Humans , Male , Micronucleus Tests , Occupational Exposure/adverse effects , Occupational Exposure/standards , Occupational Exposure/statistics & numerical data , Sex Factors , Smoking/epidemiology , Vinyl Chloride/standards , Vinyl Chloride/toxicityABSTRACT
Information concerning exposure to vinyl chloride collected in Occupational Hygiene Departments of Sanitary-Epidemiological Stations were verified. On the basis of the studies performed it was found that about 3700-4000 persons in Poland are occupationally exposed to vinyl chloride; 400 of these workers are employed at the synthesis and polymeryzation of vinyl chloride, and the others at plasticination and processing of polyvinyl chloride. About 200 workers employed in 3 plants of vinyl chloride polymerization and synthesis and about 30 employees of one of the plants processing this compound are exposed to vinyl chloride whose concentration exceeds the hygienic standard accepted in Poland (30 mg/m3).
