三种半定量风险评估方法在矽尘暴露岗位风险等级划分中的比较

Comparative study of three semi-quantitative risk assessment methods in risk classification of silica dusts exposed posts

目的将三种不同的半定量职业健康风险评估方法应用于矽尘暴露岗位的职业健康风险评估,探索各种方法的应用条件,为准确评估不同矽尘暴露岗位的职业健康风险水平提供可靠依据。方法选取我国西南地区的4家金属矿山企业和1家隧道施工企业中的矽尘暴露岗位,采用现场卫生学调查和检测的方法,应用半定量综合指数法、半定量接触比值法、国际采矿和金属委员会(ICMM)制订的风险评级表法对矽尘暴露岗位的职业健康风险进行评估,利用风险比值标化三种方法的风险评估结果,并采用加权Kappa检验对三种方法的评估结果进行一致性检验。结果矿山开采的打眼和除渣岗位、选矿车间的粗碎和筛选岗位、隧道施工的掘进和装载岗位接触矽尘浓度较高。三种风险评估方法评估结果显示,综合指数法和接触比值法的结果一致性中等(Kappa=0.483,P=0.000),风险评级表法和接触比值法结果一致性较强(Kappa=0.672,P=0.000),综合指数法和风险评级表法结果一致性一般(Kappa=0.302,P=0.002)。矿山开采时的打眼和除渣岗位,选矿的装载、粗碎岗位,隧道施工中的掘进、装载、混凝土搅拌岗位,风险等级为极高风险或高风险。结论对矽尘暴露岗位进行风险评估时,接触比值法和风险评级表法仅需检测限值和结果,风险评级表法在接触浓度超过限值时未再进一步对风险等级进行划分,结果较接触比值法高估;综合指数法较全面,但需要相对准确掌握各项风险因子水平的取值,以使其评估结果更接近劳动者实际暴露风险水平。

Objective Three different semi-quantitative occupational health risk assessment methods were applied to evaluate the risk by silica dust exposure,the application conditions of these methods were also exlored,hereby provide some basis for controlling occupational health risk in different silica dust exposed posts.Methods Four metal mines and a tunnel construction enterprise in southwest China were selected as research objects,using on-site hygienic investigation and detection methods,the semi-quantitative comprehensive index method,semi-quantitative contact ratio method and risk rating method formulated by International Mining and Metal Commission(ICMM)were applied.Risk ratio was used to standardize the risk assessment results of three methods,and weighted Kappa test was used to check the consistency of the risk assessment results.Results The results showed that higher silica dust concentration were those:drilling and slag removal posts in mining,crushing and screening in milling,tunneling and loading in tunnel construction.The consistency test showed:comprehensive index method and contact ratio method had medium consistent(Kappa=0.483,P=0.000),the risk rating table method and the contact ratio method had strong consistency(Kappa=0.672,P=0.000),and the consistency of the comprehensive index method and the risk rating table method were general(Kappa=0.302,P=0.002).The occupational health risks of drilling,slag removal,loading,coarse crushing in mineral dressing,tunneling,loading and concrete mixing were high risk posts.Conclusion The contact ratio method and the risk rating method only need the limits and the test results;the risk rating method will not further classify the risk level when the contact concentration exceeds the limit,therefore,the results may be overestimated by the relative contact ratio method;the comprehensive index method seems more comprehensive,but it requires relatively accurately grasp the value of each risk factor level,so the evaluation results could be closer to actual exposure risk level of the workers.