Study On The Characteristics Of Groundwater Quality And Health Risk In Rural Areas Of Anhui River

In recent years,the groundwater pollution in China has spread from urban to suburban and rural areas,and the groundwater monitoring in most rural areas is incomplete.As an important connection of"Yangtze River Economic Belt",Wanjiang area is an important region to implement the rise of the central region,and also of the main production areas of agricultural products such as grain,cotton and oil in Anhui province.The rural population in this area is 11.112 million in 2018,and groundwater is one of the important sources of living and drinking water for rural residents in Wanjiang area.It is of great significance to know the quality of groundwater in rural areas for the development of local economy,prevention and control of groundwater pollution and ensuring the safety of rural residents'water safety.In this study,97 groundwater samples were collected,and the contents of NH₄⁺-N,NO₃^--N,NO₂^--N,Se,B,P,p H etc.were detcted.The content characteristics of various indexes of groundwater in the area were studieded,and source apportionment of groundwater were performed using multivariate statistical method.The single factor method,one-vote veto method and Nemerow method were used to evaluate the groundwater quality.Finally,the health risk assessment model was used to evaluate the human health risk of groundwater in the region,the uncertainty of health risk was evaluated based on Monte Carlo method.The main results in this study are as follows:?1?The content characteristics of Cd,Cr⁶⁺,Hg,Pb,Cu,Zn,As,NO₃^--N,NO₂^--N,NH₄⁺-N,B,Se,TDS,Na⁺,K⁺,Ca²⁺,Cl^-,SO₄^2-of groundwater in this regional were determined.The contents of heavy metals,B,Se,NO₃^--N?NO₂^--N?NH₄⁺-N and conventional ions in groundwater were low in most points,while the TDS and NO3-N contents in few points were high or the p H is low.?2?Based on principal component analysis?PCA?,the pollution sources of groundwater was determined,29.79%of the groundwater pollution comes from water-rock interaction,32.91%from agricultural activities and 14.86%from industrial and mining activities.?3?There is no pollution of Hg,Cr⁶⁺,Cd Cu,Pb,Se,B,NO₂^--N in groundwater,and the water quality of As,NH₄⁺-N,NO₃^--N and Se is lower than the national standard III.?4?One-vote veto method and Nemerow method were used to evaluate groundwater quality.The proportion of groundwater quality of Grade III and above?good?is about 80%in the research area.The ratio of excellent water quality evaluated by Nemerow method is slightly higher than one-vote veto method.The poor water quality is generally related to TDS,p H and NO₃^--N.?5?Based on the health risk assessment model,the human health risk of groundwater was evaluated.Drinking water intake is the main approach of groundwater health risk in the region.The carcinogenic risk of adults is higher than that of children,and the non-carcinogenic risk of children is higher than that of adults.Adults and children have 94.2%and 99.3%probability of low and acceptable carcinogenic risk respectively,95.4%and 87%probability no risk of As non-carcinogenic risk,and 100%and 93%probability no risk of NO3-N non-carcinogenic risk.NO₃^--N and As are the key of groundwater health risks control.