Uncertain Water Quality Health Risk Assessment Method And Application Research

Water quality health risk assessment can quantitatively describe the harm caused by water pollutants to human health,which is of great significance for water resources utilization and water environmental protection.However,due to the complexity of the objective environment and the limitations of people’s understanding,a large number of uncertain factors exist in the process of water quality health risk assessment.Neglecting or mishandling the uncertain factors in the water quality health risk assessment may result in consequenses that do not agree with the actual situation,which is not conducive to the decision-making of water environment risk management.This paper analyzes the research status of domestic and foreign scholars in the health risk assessment of surface water,drinking water,and groundwater quality.According to the characteristics of the temporal and spatial uncertainty and evaluation data in the process of water quality health risk assessment,the paper constructs three models:a fuzzy evaluation model of water quality health risk based on fuzzy set theory,interval number operation,a probabilistic evaluation model of water quality health risk based on Monte Carlo Simulation,a spatial uncertainty evaluation model for water quality health risk based on sequential indicator simulation.The research work and results are as follows:(1)In view of the uncertainty caused by the evaluation factor concentration and exposure parameters in the water quality health risk assessment,the paper represents the evaluation factor concentration and exposure parameters based on triangular fuzzy numbers,conducts uncertainty health risk assessment in the water source in Zhongjiang County,and compares with the results of deterministic assessment.The results show that the fuzzy evaluation model based on triangular fuzzy numbers takes the uncertainty of concentration and parameters into account,and the evaluation results can more accurately and comprehensively reflect the health risk level of water quality in the study area.(2)Given the uncertainty quantitative analysis of the evaluation factor concentration and exposure parameters in the water quality health risk assessment,the probability distribution is used to represent the evaluation factors and exposure parameters.The probabilistic health risk assessment is carried out on the upper,middle,and lower reaches of the mainstream of the Minjiang River,and compared with the fuzzy evaluation results based on triangular fuzzy numbers.The results show that Monte Carlo simulation can provide environmental managers with more health risk results and possibilities,help environmental managers to find some extreme risk events in the water environment,and quantify the possibility of their occurrence,so as to avoid harmful environmental accidents.Moreover,additional valuable information can be obtained as a result of the sensitivity analysis,so as to provide a more valuable and accurate scientific basis for water environment risk prevention.(3)Given the spatial uncertainty generated by limited sampling points in the water quality health risk assessment,the paper constructs spatial uncertainty evaluation model based on sequential indicator simulation,characterizes the evaluation factors and parameter uncertainties based on the Monte Carlo simulation.Health risk assessment and grading control area division were carried out for drinking water in Hanyuan area.The results show that sequential instruction simulation can effectively determine different levels of health risk control areas,so as to assist risk management decision makers to formulate more flexible,economical and effective environmental risk management strategies and save management costs.