Study On Health Risk Assessment Of Water Quality In Urban Rivers ——Take Yitong River In Changchun As An Example

Rivers are important natural factors affecting the layout of cities.Rivers provide extremely important conditions for urban water,industrial water,agricultural irrigation,fisheries and shipping.Environmental pollutants in the river can enter the human body through skin contact and drinking water,and heavy metal elements in the water will also affect the ecological environment.Therefore,it is of great significance to carry out health risk assessment and ecological risk assessment for the water quality of Yitong River to protect the river and prevent water pollution.The four steps of river health risk assessment mainly include hazard identification,exposure assessment,dose-effect relationship assessment and risk characterization.In this paper,yitong River in Changchun City,Jilin Province is taken as an example to determine the water quality,pollution and possible sources of pollution of Yitong River through field investigation,water sample collection,correlation analysis,principal component analysis and cluster analysis.The heavy metal elements in Yitong River were evaluated by using single factor index method,Nemero comprehensive index method and Hakanson potential ecological risk evaluation model,and the main environmental protection measures for Yitong River were proposed.Research shows that:（1）The water of Yitong River is clear and transparent,with aquatic plants living on the bank and fish in the water without odorous and suspended matter.The sensory judgment of water quality is good.According to the investigation and research around Yitong River,it is found that the main pollution sources around yitong River are living,agricultural non-point source pollution and urban runoff pollution.The total phosphorus and manganese contents in Yitong River are 0.130 mg/L and 0.284 mg/L respectively,which are higher than the standard value,but the water quality varies little with the seasons.In addition,according to the source analysis,the heavy metal elements As,Cd,Pb,Cu,Se,Cr,Zn and Mn in yitong River water may be affected by anthropogenic sources,especially the heavy metal element Mn.（2）The hazard entropy of Mn,Cr,Zn,As,Cd,Pb and Se in water is less than 1 or has a high probability of being less than 1,and its non-carcinogenic risk is small,while the hazard entropy of Cu is more than 1,and its carcinogenic risk is greater than other heavy metals.Ytong,moreover,the heavy metal in water cause the risk of different to different age groups,for the risk for people under age 18 with the trend of decrease after the first increases along with the age growth,has the biggest risk to the value in 1-2years old,at the age of 15 to 18 have minimum risk value,and for over 18 years old,is because of the exposure parameters unchanged,the risk values,The risk is somewhere between maximum and minimum risk..（3）Through the evaluation and analysis of Yitong River by single factor index evaluation method and Hakanson’s potential ecological risk evaluation model,it is found that there is no ecological risk of heavy metals in Yitong River.