Evaluation of Heavy Metal Pollution in Shallow Groundwater of Farmland in Huaibei Plain, China

School of Environment and Surveying Engineering, Suzhou University, Suzhou City, Anhui Province, 234000, China

^* Corresponding author’s e-mail: zhangyong@ahszu.edu.cn

Abstract

In order to understand the characteristics of heavy metal pollution in shallow groundwater in farmland in Huaibei Plain, 69 samples were collected from typical farmland areas in Xiaoxian County to determine the content of heavy metal elements such as Cr, Zn, Cu, Cd, and Ni. The single-factor pollution index method and Nemerow comprehensive index method are used to evaluate and analyze the pollution degree and the health risk assessment method is used to explore the health risk level. The results show that the concentrations of Cr, Zn, Cu, Cd and Ni were respectively 1.27μg∙L^-1~268.78μg∙L^-1, 0.45μg∙L^-1~ 266.1μg∙L^-1, 1.77μg∙L^-1~ 29.8μg∙L^-1, 0.10μg∙L^-1~ 21.54μg∙L^-1 and 0.9μg∙L^-1~ 252.85μg∙L^-1. The Nemerow comprehensive index of each heavy metal element is 0.031~5.507, and the pollution degree is Ni>Cr>Cd>Zn>Cu. The Nemerow comprehensive pollution index of each sampling point is 0.251~9.325, with an average value of 1.934. The overall value is 9.523, and the pollution level is extremely poor. The overall health risk is at a risk-free health level. There are 19 samples which the carcinogenic risk index of the Cr is greater than 10^-4, and the number of samples with health risks accounts for 27.5%. Cr is the main source of heavy metal health risks in shallow groundwater in farmland.