Mercury and other metal and metalloid soil contamination near a Pb/Zn smelter in east Hunan province, China Zhonggen Li a , Xinbin Feng a,⇑ , Guanghui Li a , Xiangyang Bi b , Guangyi Sun c , Jianming Zhu a , Haibo Qin a,d , Jianxu Wang a,d a State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China b Key Laboratory of Biogeology and Environmental Geology, Ministry of Education, China University of Geosciences, Wuhan 430074, China c Hei Longjiang Institute of Geological Survey, Harbin 150036, China d Graduate School of Chinese Academy of Sciences, Beijing 100049, China article info Article history: Available online 30 November 2010 abstract The spatial distributions of contaminant metals (Hg, Pb, Zn, Cd, Cu) and a metalloid (As) in vegetable plots and paddy fields located near a large scale Pb/Zn smelter in Hunan province, China, were investigated. Soil located 4 km from the smelter was severely contaminated, with maximum concentrations of Hg, Pb, Zn, Cd, Cu and As as high as 2.89, 1200, 3350, 41.1, 157 and 93 mg kg 1 , respectively. Concentrations of soil metal and As decreased with distance in the dominant wind direction. Single-factor assessment indicated pollution levels of Hg, Pb, Zn and Cd were most severe, while pollution levels for Cu and As were less severe. Results from a potential ecological risk assessment indicated high risk associated with the soil within a 4 km radius, with the contribution for each contaminant calculated as follows: Cd (70.0%), Hg (19.4%), Pb (4.8%), As (3.0%), Cu (1.7%) and Zn (1.1%). The forest soil in the nearby city park was also affected by the atmospheric depositions from smelting activities. Soil profiles demonstrated the pollu- tants were mostly accumulated in the upper 20 cm layer. Contamination of the topsoil with Hg, Pb, Zn, Cd, Cu and As indicated remediation should be considered. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Lead/Zn smelting activities are one of the major sources of con- taminant metals to the environment, especially in China (Nriagu and Pacyna, 1988; Feng et al., 2004; Bi et al., 2006a; Streets et al., 2005). These human activities have resulted in soil pollution, which has led to adverse ecological impacts (Yang et al., 2009). In China, about 20 million hectares (one fifth of the total) of farmland has been contaminated by metals, and 12 million tonnes of grains have been polluted by metals each year (Xiao, 2000). A large por- tion of this pollution has been ascribed to Pb/Zn smelters (Chen et al., 1999). In the past several years, many reports have revealed multi-media environmental pollution near Pb/Zn smelters in dif- ferent parts of China (e.g. Li et al., 2006; Bi et al., 2006b; Zheng et al., 2008; Wei et al., 2009; Wang et al., 2009). Due to the accu- mulation and toxicity of the pollutant metals, soil pollution has gained more and more attention (Verner and Ramsey, 1996; Ull- rich et al., 1999). Hunan province, located in central China, is one of the largest producers of non-ferrous metals in China. In 2005, this province produced 23.7% and 16.9% of the national Zn and Pb output, respectively (The year book of nonferrous metals industry of China, 2006). The area of soil polluted by metals from mining and smelt- ing activities was estimated to be 28,000 km 2 , accounting for 13% of the total area of the province (Guo and Zhu, 2004). Zhuzhou smelter in eastern Hunan province is a large scale Pb/Zn smelter, producing 327 kilotonnes of Zn and 96 kilotonnes of Pb in 2005. It is the largest and fourth largest producer of Zn and Pb in China, respectively. In addition, around 30 tonnes of contaminant metals are emitted form the smelter each year in early 2000s, constituting over 90% of the total emissions in Zhuzhou city (Lei et al., 2008). The contents of Pb, Zn, Cd, Cu and As in the soil around this smelter are some of the highest of nine mining and smelting areas in Hu- nan province (Lei et al., 2008), and are potentially highly bioavail- able (Song et al., 2009). Previous studies, however, did not characterize the spatial distribution of soil pollutants (i.e. horizon- tal and vertical). The smelter is located between the city and coun- tryside. Vegetables and grain grown on the polluted soil are consumed by the local residents, which poses an important toxico- logical risk. In this paper, an attempt was made to identify the spa- tial distribution of metals (Hg, Pb, Zn, Cd, Cu) and a metalloid (As) in the soil around the smelter, and to evaluate the pollution status of the contaminated soil. Since As is one of the pollutants from the Pb/Zn smelter and behaves similarly to the metals, it was included in this assessment. 0883-2927/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.apgeochem.2010.11.014 ⇑ Corresponding author. Tel.: +86 851 5891356; fax: +86 851 5891609. E-mail address: fengxinbin@vip.skleg.cn (X. Feng). Applied Geochemistry 26 (2011) 160–166 Contents lists available at ScienceDirect Applied Geochemistry journal homepage: www.elsevier.com/locate/apgeochem