Validation And Optimization Of The Indicator System Of Risk Assessment On Occupational Hazards Of The Chemical Factors

Objective(1) To validate the scientificity and practicability of indicator system (Y=0.383A+0.284B+0.333C) for risk assessment on occupational hazards of chemicals that established in our previous study.(2) To optimize the established indicator system (Y=0.383A+0.284B+0.333C), and provide scientific evidences for promoting the application of indicator system of risk assessment on occupational hazards of chemicals in practical work.(3) To explore the suitable statistical methods for optimizing the indicator system of risk assessment on occupational hazards of chemicals.Methods(1) The indicator system of risk assessment on occupational hazards of chemicals (Y=0.383A+0.284B+0.333C) was applied for assessing the risk of274chemicals in120workplaces of90factories. The correlation analysis was performed to test the correlation between risk assessment score Y and the actual health damage in workplace; Consistency test was performed to analyze the consistency between the risk level and actual health damage level.(2) The indicator system established in our former study was optimized by the combination of stepwise regression and work experiences. The weight coefficients of indexes were adjusted by proportional allocation; the best critical points wer determined by ROC curve. The indicator system was re-established after adjustment for levels of risk.(3) The data of120workplaces was applied to the optimized indicator system. The correlation analysis was performed to test the correlation between risk assessment score Y and the actual health damage in workplace; Consistency test was performed to analyze the consistency between the risk level and actual health damage level.Results(1) The result of correlation analysis demonstrated that the correction between risk assessment score Y and the actual health damage in workplace showed statistically significant in indicator system established in our previous study (r=0.728, P<0.01). The overall coincident rate of occupational diseases incidence was70.83%,(Kappa=0.417, P<0.01); the coincident rate of levels of risk was44.17%(Kappa=0.274, P<0.01).(2) The optimized indicator system consists of three indicators of class A, eleven indicators of class B and twelve indicators of class C. Compared with the original indicator system, the optimal indicator system has reduced by twenty two indicators of class C and one indicator of class B. The weight coefficients of indicators and levels of risk were both adjusted accordingly.(3) The result of correlation analysis showed a significant positive correction between risk assessment score Y and the actual health damage in workplace in optimized indicator system (r=0.734, P<0.01).;the overall coincident rate of occupational diseases incidence was95.00%(Kappa=0.900,P<0.01); the coincident rate of levels of risk was64.17%(Kappa=0.508,P<0.01).Conclusion(1) The indicator system that established in our previous study was scientifically credible, however, the practicability and coincident rate of indicator system was affected by some problems such as tedious calculation, excessive indicators, hardness to obtain specific indicators and so on.(2) The optimized indicator system was simple and practical and suitable for risk assessment on occupational hazards.