董一文, 边洪英, 王新刚, 胡伟江. 常用职业健康风险评估方法在氯乙烯生产企业中的应用[J]. 环境与职业医学, 2020, 37(8): 797-803. DOI: 10.13213/j.cnki.jeom.2020.19870
引用本文: 董一文, 边洪英, 王新刚, 胡伟江. 常用职业健康风险评估方法在氯乙烯生产企业中的应用[J]. 环境与职业医学, 2020, 37(8): 797-803. DOI: 10.13213/j.cnki.jeom.2020.19870
DONG Yi-wen, BIAN Hong-ying, WANG Xin-gang, HU Wei-jiang. Application of common occupational health risk assessment methods in vinyl chloride manufacturing factories[J]. Journal of Environmental and Occupational Medicine, 2020, 37(8): 797-803. DOI: 10.13213/j.cnki.jeom.2020.19870
Citation: DONG Yi-wen, BIAN Hong-ying, WANG Xin-gang, HU Wei-jiang. Application of common occupational health risk assessment methods in vinyl chloride manufacturing factories[J]. Journal of Environmental and Occupational Medicine, 2020, 37(8): 797-803. DOI: 10.13213/j.cnki.jeom.2020.19870

常用职业健康风险评估方法在氯乙烯生产企业中的应用

Application of common occupational health risk assessment methods in vinyl chloride manufacturing factories

  • 摘要: 背景

    目前,我国氯乙烯生产企业以电石乙炔法应用最为广泛。因高温高热环境所致氯乙烯单体(VCM)的少量逸散,以及巡视、维修、清釜等岗位的防护措施不佳等因素引发的工人急性中毒或慢性损伤,已成为现今VCM职业接触健康损伤的主要问题。

    目的

    识别VCM生产过程中的重点接触岗位,结合个体接触水平将三种风险评估方法应用于实践并进行比较,了解重点接触岗位的风险水平。

    方法

    通过现场调查和个体接触水平检测了解天津市2家聚氯乙烯(PVC)化工企业(B厂和G厂)中19种VCM相关岗位共35人的接触情况;继而采用半定量综合指数法、半定量接触比值法和定量致癌风险评估法对接触工人开展风险评估,并采用Kappa法对三种风险评估法的结果一致性进行检验。

    结果

    35名重点接触岗位工人均为男性,年龄为(40.04±1.03)岁,工龄为6.0(4.0,9.5)年,分别从事VCM合成、聚合外操、分析、清釜、下料、釜维修等VCM生产相关环节。B厂压缩机外操工、聚合外操工、VCM回收工、糊树脂外操工的时间加权平均质量浓度(后称:浓度)(CTWA)较高(60.90~71.30 mg·m-3),达职业接触限值(COEL=10 mg·m-3)的6~7倍;配制外操工、聚合内操工、合成主控内操工的CTWA为10.50~22.70 mg·m-3,为限值的1~2倍。G厂看釜清釜工在清理反应釜时CTWA达到438.30 mg·m-3,为限值的40余倍,其他岗位的CTWA均低于职业接触限值。半定量综合指数法评估结果显示,各岗位工人处于中等~高风险间;半定量接触比值法评估结果显示,各岗位工人处于低~极高风险间;定量致癌风险评估法结果显示,B厂作业工人处于高~很高风险间,G厂作业工人处于可忽略~很高风险间。一致性检验结果显示,当岗位CTWACOEL时,半定量接触比值法结果与定量致癌风险评估法一致性好(K=0.632,P=0.002)。

    结论

    PVC生产企业中,VCM合成、压缩、聚合、回收、清釜、糊树脂、维修等生产过程中涉及的岗位为VCM重点接触岗位;依据接触水平和所处环境的差异,岗位风险分别处于中等至极高风险之间;三种风险评估方法各具优势及局限性,在评估过程中结合应用将更有利于充分发挥其优势。

     

    Abstract: Background

    Nowadays, calcium carbide craft is one of the most widely used method in China's vinyl chloride factories. Nevertheless, the acute or chronic poisoning induced either by small amount of vinyl chloride monomer (VCM) effusion during high-temperature processes or by inadequate protection in specific operation positions like patrolling, maintenance, and kettle clearing have contributed to a large fraction of VCM related occupational health problems.

    Objective

    The study is conducted to recognize major exposure positions of VCM manufacturing, and understand the occupational health risk levels through the application and comparison of three recommended risk assessment methods.

    Methods

    A total of 35 VCM workers from 19 major positions in 2 polyvinyl chloride (PVC) factories (factory B and factory G) in Tianjin City were investigated through field investigation and individual sampling. The occupational health risk levels were subsequently evaluated by semi-quantitative comprehensive index method, semi-quantitative exposure ratio method, and quantitative risk assessment method for carcinogens. Also, methodological differences among the three methods above were tested by Kappa conformance test.

    Results

    All the 35 workers were male and aged (40.04±1.03) years, with an average working age of 6.0 (4.0, 9.5) years. They were assigned to positions such as VCM synthesis, polymerization, analysis, kettle clearance, material cutting, and machine maintenance. The time-weighted average concentrations (CTWA) in positions like compressor operation, polymerization, VCM recycling, and paste resin in factory B reached very high levels (60.90-71.30mg·m-3) that were 6-7 folds of the national occupational exposure limits (COEL=10mg·m-3); the CTWA in positions of preparation operation, internal polymerization, and synthesis controlling were 1-2 folds of the occupational exposure limits. Meanwhile, the CTWA in factory G was not high, except the concentration in kettle monitoring and clearance position which was as high as 438.3 mg·m-3, over 40 folds of the occupational exposure limit. The results of semi-quantitative comprehensive index method demonstrated that all positions were at medium to high risk levels; the results of semi-quantitative exposure ratio method presented low to extremely high risk levels; the results of quantitative risk assessment method for carcinogens showed positions in factory B were at high to very high risk levels, and positions in factory G were at negligible to very high risk levels. The results of quantitative risk assessment for carcinogens and semi-quantitative exposure ratio method were in a good conformance (K=0.632, P=0.002) when CTWACOEL.

    Conclusion

    Positions involved in processes such as VCM synthesis, compression, polymerization, recycling, kettle cleaning, paste resin, and maintenance are major exposure positions in PVC production enterprises. Their risk ranks are from medium to extreme high risks according to differences in exposure level and workplace environment. Application of the three different risk assessments in a combined way will certainly play to their strengths as limitations and advantages coexist.

     

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