Evaluation on Heavy Metal Pollution and Potential Ecological Risk of Farmland Soils in a County of Anhui Province, China

• Main Authors: JIANG Hong, MA You-hua, YIN Guo-qing, WANG Qiang, NIE Jing-ru, MA Tie-zheng, HU Hong-xiang
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2017-06-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: farmland soils, heavy metal, potential ecological risk, pollution assessment, Anhui Province
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2017/4/20170407.htm
• ISSN: 2095-6819; 2095-6819

Heavy metal pollutions in the farmland are regarded as serious threats to rural environment in China. Human activities, such as intensive livestock, sewage irrigation, large amounts of agrochemicals input and the rapid urbanization are proved to be the main sources of the heavy metals in farmland. The study area is located in middle and lower reaches of the Yangtze River in Anhui Province, China. The concentrations of Cr, Pb, As, Hg and Cd in the topsoil(0~20 cm) of the farmland in the district were analyzed, and the potential ecological risks of these heavy metals were assessed. It turned out that the average content of Cd, Pb, Cr, As and Hg in soils were 0.302, 61.17, 87.13, 12.89 mg·kg^-1 and 0.139 mg·kg^-1 respectively. According to the second grade in Chinese Standard of the Soil Environment Quality(GB 15618-1995), Cd was the only element that exceeded the limit. However, all the elements were beyond the scope comparing with the background values of the elements in the local soils. Besides, the proportions of samples beyond the standard of limit of the heavy metal elements in soils were as follow respectively:Cd(85.43%), Hg(76.38%), Pb(59.30%), As(26.63%) and Cr(19.60%). The results showed that the pollution rank were Cd > Hg > Pb > As > Cr and the potential ecological risk index of heavy metals in the research area were Hg > Cd > As > Pb > Cr with Hg and Cd took the dominant position. The comprehensive potential ecological risk indexes of the research area were from 83.83 to 6 987.87 with the average value of 250.76 and high risk level for 13.57% of the samples, which should be paid attention by relevant government agencies.