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Chromosome Damage and the Damage Repair Capacity in VCM-exposed Workers

Author: SunYuan
Tutor: XiaZhaoLin
School: Fudan University
Course: Occupational and Environmental Health
Keywords: Vinyl chloride Chromosomal damage Cytokinesis block micronucleus test Current Status Follow-up studies DNA damage repair capacity
CLC: R131
Type: Master's thesis
Year: 2011
Downloads: 40
Quote: 0
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Abstract

Vinyl chloride monomer (Vinyl chloride monomer, VCM) as an important chemical raw materials, mainly used for the synthesis of PVC (Polyvinyl chloride, PVC), and in the world there are a large number of occupationally exposed. VCM is determined human carcinogen, can lead to multi-system, multi-organ tumorigenesis. With the deepening understanding of vinyl chloride toxicity countries strictly control the concentration of vinyl chloride in workplace air, previous population-based study found that under the current occupational health standards, VCM can produce a health hazard. Therefore it is necessary to explore the lower VCM exposure concentration, VCM Workers occupational health hazards. Investigation and follow-up of the research and application of occupational epidemiology survey methodology and molecular biology technology and methods, the use of the current situation, to explore the relationship between chromosome damage and vinyl chloride cumulative exposure dose, analysis of vinyl chloride workers exposed during the development of chromosomal damage. While the use of evaluation vinyl chloride workers exposed to DNA damage repair capacity, screening of DNA damage repair capacity reduced ability to repair DNA damage detection method based on micronucleus predisposing factors to analyze the strength of the ability to repair DNA damage and chromosomal damage relations, research VCM contact early sensitive indices provide a scientific basis as well as explore the genotoxic mechanism. Vinyl chloride exposure levels lower a factory in the survey, 96.5% over the years shop air test results in VCM concentrations were below the occupational health standards in China. However, the status of the investigation and follow-up show that current concentrations of vinyl chloride workers exposed to chromosomal damage, and a dose-response relationship. Survey study of the current status of this study is the chemical plant 188 VCM exposed workers as a control, and 68 contact with VCM and other toxic plant's administrative and logistical staff, according to the calendar year, the workshop the air VCM concentration test results, actual contact time and length of service, as well as life vinyl chloride contact to calculate the cumulative exposure dose, according to the vinyl chloride cumulative exposure dose is divided into high, medium and low three groups (cumulative exposure dose ≤ 1378.4mg low-dose exposure group; 1378.4-33166.4 mg in dose exposure group, gt; 33166.4 mg high dose exposure group). The results show that the vinyl chloride workers exposed to peripheral blood lymphocyte micronucleus rate significantly higher than that of the control group was 3.66 times that of the control group, and the low, perchlorethylene cumulative exposure dose group micronucleus rate trend relationship exists. In this study, the follow-up of the plant vinyl chloride workers exposed to six micronuclei 43 2004 normal rate of micronucleus vinyl chloride workers exposed to track micronucleus abnormal rate of occurrence, until 2010, found that the different contact workers in proportion to its abnormal rate of micronucleus dose group, high-dose exposure group micronucleus abnormal rate significantly higher than the low-dose group, the relative risk was 2.28. Vinyl chloride workers exposed to 66 were followed up within the next six years, in 2004, 2007, 2010 three time points micronucleus test, micronucleus test and micronucleus abnormal rate of two indicators of chromosomal damage within six years of change micronucleated cell rate in 2004 compared to 2007 and 2010, micronucleus rates were significantly increased relative risk of 1.11 and 1.45, respectively; 2007, micronucleus abnormalities were significantly higher than in 2010, 2004 a relative risk of 1.15 and 2.45, the rate of micronuclei and micronuclei abnormal rates presents an increasing trend year by year, also has been increasing degree of chromosomal damage to prompt genetic toxicity of vinyl chloride are cumulative. Multivariate analysis found that the influencing factors in a variety of chromosomal damage in addition to vinyl chloride contact of gender on the extent of chromosomal damage and the development process has an impact, compared with men, women chromosomal damage was severe, and chromosomal damage development fast process, and should therefore be to strengthen the protection of women workers. In addition, in the case of exposure concentration is lower than our current occupational health standards, the dual-core micronucleus test can detect chromosomal damage in vinyl chloride workers exposed to reflect the occurrence of chromosomal damage trends, so the dual-core lymphocyte micronucleus rate as sensitive indicators of vinyl chloride contact early genetic damage, and can be used to track research has application value. The simultaneous study of vinyl chloride workers exposed to chromosome damage repair capacity, application-based the micronucleus ability to repair DNA damage detection method to detect chromosomal damage and its repair ability 80 vinyl chloride workers exposed, 30 not in contact with VCM control of the administrative and logistical staff and other toxic plant as damage repair capacity. Perchlorethylene cumulative exposure dose divided into four groups, including a control group and three contact dose group (≤ 231.99 mg cumulative exposure dose for low-dose exposure group; 231.99-6561.99 mg dose exposure group in gt; 6561.99 mg for the high dose contact group), studies have shown that the control group, low, perchlorethylene cumulative exposure dose group 3AB index statistical difference was, respectively, 0.44 ± 0.14,0.43 ± 0.10,0.34 ± 0.12,0.24 ± 0.13, and low in , the 3AB index of cumulative exposure dose group there are certain trends in the relationship between, suggesting that vinyl chloride exposure may affect the ability to repair DNA damage, the higher chloride cumulative exposure dose, DNA damage repair capacity is lower. Multivariate analysis results show that the addition to vinyl chloride cumulative exposure dose, gender vinyl chloride workers exposed to DNA damage repair capacity influential women are low risk factors for DNA damage repair capacity, so prompts should focus on strengthening health surveillance of women workers occupational health services to improve the quality of life of workers exposed to occupational. The study also showed that the chloride exposed workers were divided into three groups according to the the 3AB Index will 3AB index ≤ 0.24 for low-damage repair capacity group; 0.24-0.39 for damage repair capacity in group gt; 0.39 for high damage repair capacity group, the results show that, damage repair capacity, high group micronucleus rate is lower than the low-damage repair capacity group, the FR values ??of 0.74 and 0.56, respectively, high-damage repair capacity micronucleus rate is lower than the damage repair capacity group, which is 0.75 times there are certain trends in the relationship between damage repair capacity and micronucleus rate, suggesting that DNA repair ability and vinyl chloride workers exposed to chromosome damage occurs closely related the worse repair capacity, the higher the risk of chromosome damage. In summary, in the case of exposure concentration lower than China's current occupational health standards, can still result in workers exposed to vinyl chloride contact chromosomal damage, showing cumulative genetic toxicity and hazards. Ability to repair DNA damage and vinyl chloride workers exposed to chromosomal damage occurred close relationship.

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