Characteristics of Heavy Metal Contents and Health Risk Assessment Concerning Rural Groundwater in Suzhou City, China

70 groundwater samples were collected from the rural area in Suzhou, Anhui province, and seven heavy metals (including Fe, Mn, Cr, Cd, Cu, Pb and Ni) in each sample were tested. Based on the analysis of heavy metal content characteristics, we carried out quality evaluation on the groundwater samples with Nemerow composite index method, and conducted health risk assessment (HRA) with the recommended model by the United States Environmental Protection Agency (USEPA). The results show that: (1) the descending order of the average concentration of heavy metals in the samples is Mn > Fe > Ni > Pb > Cu > Cr > Cd. Mn and Ni concentrations in excess of the concentration requirements set by the Standards for Drinking Water Quality (GB5749-2006) are 32.85% and 5.71% that of and 2.97 times and 2.28 times higher than the set values, respectively. (2) The comprehensive evaluation score of the groundwater samples according to Nemerow composite index method is 0.2818∼2.1292, with the mean value of 0.6800, and the ground water quality level is “favorable”. (3) For chemical non-carcinogens (Fe, Mn, Cu, Pb and Ni) that are ingested through the mouth, the descending order of their health risk levels is Pb>Cu>Mn>Ni>Fe, and all of their risk scores are below the recommended maximum acceptable value (5.0×10^-5a^-1) of the International Radiation Protection Association (IRPA) and below the recommended health risk standard (1×10^-4 a^-1) of USEPA. This means that the ingestion of the tested groundwater will basically not pose significant hazards to exposed populations. The mean health risk scores of carcinogens (Cd and Cr) by mouth is 9.96×10^-7a^-1 and 1.07×10^-5a^-1, respectively. The risk score of Cr is 10.7 times larger than the recommended maximum acceptable value (1×10^-6a^-1) by the Swedish Environmental Protection Agency, the Ministry of Housing, Spatial Planning and the Environment (Netherlands), and the British Royal Society. Therefore, the plethora of Cr renders it the representative pollutant of the research area such that priority should be given to it.