Journal of Hazardous Materials 186 (2011) 1384–1391 Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat Uptake of metals and metalloids by plants growing in a lead–zinc mine area, Northern Vietnam Nguyen Thi Hoang Ha a , Masayuki Sakakibara a,∗ , Sakae Sano b , Mai Trong Nhuan c a Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan b Department of Geology, Ehime University, Matsuyama 790-8577, Japan c Department of Environmental Geology, Vietnam National University, Hanoi, 334 Nguyen Trai, Hanoi, Vietnam article info Article history: Received 29 July 2010 Received in revised form 14 October 2010 Accepted 6 December 2010 Available online 14 December 2010 Keywords: Metals Northern Vietnam Phytoremediation Phytomining Plants abstract This study was conducted to evaluate the phytoremediation and phytomining potential of 10 plant species growing naturally at one of the largest lead–zinc mines in Northern Vietnam. Total concentrations of heavy metals and arsenic were determined in the plant and in associated soil and water in and outside of the mine area. The results indicate that hyperaccumulation levels (mg kg -1 dry weight) were obtained in Houttuynia cordata Thunb. (1140) and Pteris vittata L. (3750) for arsenic, and in Ageratum houstonianum Mill. (1130), Potamogeton oxyphyllus Miq. (4210), and P. vittata (1020) for lead. To the best of our knowl- edge, the present paper is the first report on metal accumulation and hyperaccumulation by H. cordata, A. houstonianum, and P. oxyphyllus. Based on the obtained concentrations of metals, bioconcentration and translocation factors, as well as the biomass of these plants, the two latter species and P. vittata are good candidates for phytoremediation of sites contaminated with arsenic and multi-metals. None of the collected plants was suitable for phytomining, given their low concentrations of useful metals (e.g., silver, gallium, and indium). © 2010 Elsevier B.V. All rights reserved. 1. Introduction Mining activities generate a large amount of tailings that are generally deposited upon the ground surface [1]. Tailings usually provide an unfavorable substrate for plant growth because of their low pH, high concentrations of toxic metals, and low nutrient con- tent [2]. At the present study site, one of the largest Pb–Zn mines in Northern Vietnam, mining activity started in the 18th century and has continued until the present. Long-term mining operations have generated considerable amounts of sulfide-rich waste materials that have been released directly to the surrounding area without treatment. As a result, soil and water are contaminated with heavy metals and As. Of particular concern, water from the main stream in the study area is directly used for irrigation and domestic supply by rural communities located around the mine [3]. This problem gives rise to the need to remediate the mine tailings and drainage contaminated with heavy metals and As. Soil remediation is primarily accomplished by the physi- cal removal of soils from contaminated sites for landfilling, incineration, or in situ stabilization by chemical treatment [4]. ∗ Corresponding author at: Bunkyo-cho 2-5, Matsuyama 790-8577, Japan. Tel.: +81 89 927 9649; fax: +81 89 927 9640. E-mail address: sakakiba@sci.ehime-u.ac.jp (M. Sakakibara). These technologies are generally costly and in many cases result in significant secondary damage to the environment [4]. In contrast, phytoremediation is considered a cost-effective and environment-friendly technology for the treatment of soils and water contaminated by heavy metals/metalloids [5–7]. Criteria related to the concentration of metals in plant shoots are used to identify those plants with the greatest potential in phytoremedia- tion [8]. Hyperaccumulators are defined as plants with leaves able to accumulate at least 100 mg kg -1 of Cd; 1000 mg kg -1 of As, Cu, Pb, Ni, Co, Se, or Cr; or 10,000 mg kg -1 of Mn or Zn (dry weight) when grown in a metal-rich environment [9,10]. Phytomining has also emerged as an environment-friendly tech- nology to allow economic exploitation of low-grade surface ores or mineralized soils that are too metal-poor for conventional min- ing [11,12]. The use of plant species for both phytoremediation and phytomining appears to be a sustainable approach that would ensure the commercialization of these technologies. It is important to use native plants for phytoremediation because such plants respond better to the stress conditions at the site than would plants introduced from other environments [13]. Previous studies have investigated the concentrations of heavy metals/metalloids in natural vegetation in and around mining areas, as well as the possible use of such plants for phytoremedia- tion [13–19]. However, few studies have evaluated accumulation of useful metals (e.g., In, Ag, and Ga) in plants and the possible use of these plants for the combined phytoremediation and phytomining. 0304-3894/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2010.12.020