Journal of Geographical Sciences ›› 2010, Vol. 20 ›› Issue (1): 121-134.doi: 10.1007/s11442-010-0121-1

• Environmental Chemistry • Previous Articles     Next Articles

Heavy metal concentrations of agricultural soils and vegetables from Dongguan, Guangdong

CAI Limei1,2,3,4, HUANG Lanchun4, ZHOU Yongzhang4, XU Zhencheng1,2,3, PENG Xiaochun3, YAO Ling'ai3, ZHOU Yang3, PENG Ping'an1,2   

  1. 1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, CAS, Guangzhou 510640, China;
    2. Research Center of the Pearl River Delta Environmental Pollution and Control, Guangzhou 510640, China;
    3. South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China;
    4. Center for Earth Environment and Resources, Sun Yat-sen University, Guangzhou 510275, China
  • Received:2008-11-24 Revised:2009-01-20 Online:2010-02-15 Published:2010-08-16
  • Contact: Xu Zhencheng, E-mail: xzc@scies.com.cn E-mail:xzc@scies.com.cn
  • About author:Cai Limei (1980?), Ph.D, specialized in environmental geochemistry. E-mail: paco801217@163.com
  • Supported by:

    Important National Science & Technology Specific Projects of China, No.2007zx07211; Fund from the Ministry of Environmental Protection of the People’s Republic of China, No.0202043

Abstract:

A total of 118 of agricultural soil and 43 of vegetable samples were collected from Dongguan City, Guangdong, China. The spatial distribution, sources, accumulation characteristics and potential risk of heavy metals in the agricultural soils and vegetables were depicted in details by three different approaches, including total contents of eight metal elements in soils and vegetables, GIS maps and multivariate analysis of heavy metals in soils in the study. The results show that there are higher accumulation of heavy metals such as Cu, Zn, Ni, Pb, Cd and Hg in agricultural soils, and the contents of Pb (65.38 mg kg?1) and Hg (0.24 mg kg?1) are 1.82 and 2.82 times of the background contents of the corresponding heavy metals in soils of Guangdong Province, respectively. There are about 3.4% of Cu, 5.9% of Ni, 1.7% of Cd and 28% of Hg in all collected soil samples from all investigated sites which have overran the contents for heavy metals of the China Environmental Quality Standard for Soils (GB15618-1995, Grade Ⅱ). The pollution characteristics of multi-metals in soils are mainly reflected by Hg. There are different sources to eight metal elements in soils, Cu, Zn, Ni, Cr and As are predominantly derived from parent materials, and Pb, Hg and Cd are affected by anthropogenic activities. The spatial distribution shows that the Cu, Zn, Ni, Cr, Pb, As and Hg contents of agricultural soils are high in the west and low in the east, and Cd contents are high in the northwest, southeast and low in the southwest in Dongguan. The ratios of vegetable samples which Ni, Pb and As concentrations higher than the Maximum Levels of Contaminants in Foods (GB2762-2005) are 4.7%, 16.3% and 48.8%, respectively. The order of bio-concentration factors (BCF) of heavy metals in vegetables is Cd > Zn > Cu > As > Ni > Hg > Cr > Pb. It is necessary to focus on potential risk of heavy metals for food safety and human’s health from agricultural soils and vegetables in Dongguan City, Guangdong Province.

Key words: agricultural soil, vegetable, heavy metal, pollution, spatial distribution, DongguanSciences