贝叶斯决策分析法在某电厂输煤系统煤尘及噪声接触评估中的应用

Application of Bayesian decision analysis to coal dust and noise exposure assessment of coal handling system in a power plant

[目的]使用贝叶斯决策分析法对某电厂输煤系统的煤尘和噪声两种职业危害因素进行接触评估,并与常规职业接触评估方法比较,探讨贝叶斯决策分析法的利弊。[方法]选择某电厂的输煤系统作为研究对象,分别使用常规职业接触评估方法和贝叶斯决策分析法对现场巡检人员煤尘(总尘)接触质量浓度(以下简称"浓度")和噪声接触剂量进行评估。[结果]采用常规职业接触评估方法,现场巡检人员煤尘(总尘)接触浓度和噪声接触剂量的检测结果的第95百分位数分别为2.63 mg/m^3和73.0%,均低于相应的职业接触限值(4 mg/m^3和100%),但第95百分位数的单侧95%可信上限却分别达到6.01 mg/m^3和144.0%,均超过相应的职业接触限值。采用贝叶斯决策分析法,直接得出现场巡检人员煤尘(总尘)接触水平有90.7%的可能性低于职业接触限值,噪声接触剂量有80.1%的可能性低于职业接触限值。[结论]贝叶斯决策分析法的评估结果直观、明确,对于检测样本数量较少的职业危害因素,贝叶斯决策分析法较常规职业接触评估方法更加适用。

[Objective] To assess exposure to coal dust and noise of a coal handling system in a power plant using Bayesian decision analysis（BDA）,and discuss the advantages and disadvantages of BDA in comparison with a conventional occupational exposure assessment method.[Methods] A coal handling system in a power plant was selected as the study subject.The coal dust（total dust） exposure concentration and noise exposure dose of patrolling inspectors were assessed using a conventional occupational exposure assessment method and BDA.[Results] By the conventional occupational exposure assessment method,the 95 th percentiles of coal dust（total dust） exposure concentration and noise exposure dose of the patrolling inspectors were 2.63 mg/m^3 and 73.0%,respectively,and both were below the national occupational exposure limits（OELs）（4 mg/m^3 and 100%,respectively）.However,the one-sided 95% upper confidence limits for the 95 th percentiles were 6.01 mg/m^3 and 144.0%,respectively,and both were beyond the OELs.Meanwhile,based on BDA,it was concluded directly with a 90.7% certainty of coal dust（total dust） exposure concentration of the inspectors lower than the OEL,and a 80.1% certainty of noise exposure dose below the OEL.[Conclusion] The results derived by BDA is intuitive and clear.For occupational hazards with a small sample size,BDA is more applicable than the conventional occupational assessment method.