Water Environment Health Risk Assessment Of Drinking Water Sources

Water is a kind of special resources, supporting the all life. It’s the basic resources in our daily life. With the development of society and the standard of living, human has reached unprecedented levels for the development and utilization of water resources. People all over the world face severe water shortages. About 4.5 billion people living of water around is in the unhealthy state all over the world. The water is polluted of different levels, or draining. If the trend continues, there will be more and more people no available water. The drinking water quality is directly related to people’s physical health, and also reflects the civilization degree of a country.The water environmental health risk assessment linked with human health effect and environmental pollutants, can be more intuitive performance on the dangers of water environment. The domestic and overseas scholars mostly calculated pollutants in water on human health hazards using the water environmental health risk assessment model simply in recent years and ignoring the uncertainty in the evaluation process and the influence on the evaluation results. On the basis of risk assessment "four steps"(i.e., hazard identification, dose-response assessment, exposure assessment and risk characterization) this paper put forward by the United States National Academy of Sciences, and used the Monte Carlo method to analyze the uncertainty in the process of assessment. Combined with the method of loss of life expectancy, we could evaluate water environmental health risk of underground drinking water sources and improve the scientific nature of the evaluation results.The paper selected six underground water sources of drinking water in Panjin as the study area, and collected underground water for groundwater quality indices using water chemical analysis method. We conducted water environmental health risk assessment of groundwater sources on the basis of related information about natural geography and the hydro-geological characteristics in Panjin. Firstly, we introduced the risk assessment "four steps" theory and the water environment health risk model. Secondly, Monte Carlo method was introduced to estimate parameter uncertainty involved in the model of water environment health risk(e.g.adult daily drinking, Weight per capita, exposure frequency, exposure time delay, breathing rate).Finally, we conducted health risk assessment in Panjin based on life expectancy loss method of water environment health risk assessment method. Through the epidemiology and toxicology data, we could receive the distinguished age mortality. And calculated life expectancy and loss of life expectancy exposed in the pollutants or not. We conducted water environment health risk of underground drinking water sources using water environment health risk assessment method and life expectancy loss method.Monte Carlo method simulate the Panjin six sources of drinking water of 10000 groups of carcinogenic risk and non-carcinogenic risk, draw the cumulative distribution curve of health risk of six drinking water sources, and get the statistical data: average risk, maximum, minimum and standard deviation of water environment health risk. Taking Shishan drinking water source for example, the maximum and minimum values of carcinogenic risk are 1.749×10-5, 3.462×10-5, and the maximum and minimum values of non-carcinogenic risk are 1.641×10-9, 3.259×10-9. Through random simulation model parameters could quantify the uncertainty of parameters in the model. Obtained the average life expectancy loss value in Panjin is 0.014 d under the risk of 10-5 by the method of life expectancy loss model. Combined Water environment health risk with life expectancy loss value, we get the water environment total risk loss of six water sources in Panjin: Shishan 1.9088 d, Gaosheng 1.9709 d, Xingyi 2.9475 d, Xingnan 3.0550 d, Pandong 1.9922 d, and Dawa 4.0830 d. Through water environment health risk and life expectancy loss method,we get the carcinogenic risk and non-carcinogenic risk in the same framework. Water environment risk of six sources of drinking groundwater in Panjin decreased in the following order Dawa >Xingnan >Xingyi> Pandong>Gaosheng >Shishan.Water environment health risk assessment aimed that made people’s health and guaranteed the development of economy. Moreover, it could provide effective basis for drinking water sources protection and scientific management. It played a positive role in promoting sustainable utilization of groundwater resources, ecological environment benign circulation and maintenance of human health.