| Phytostabilization of Mine Tailings in Arid and Semiarid Environments—An Emerging Remediation Technology Monica O. Mendez and Raina M. Maier Department of Soil, Water, and Environmental Science, University of Arizona, Tucson, Arizona, USA Abstract
Objective: Unreclaimed mine tailings sites are a worldwide problem, with thousands of unvegetated, exposed tailings piles presenting a source of contamination for nearby communities. Tailings disposal sites in arid and semiarid environments are especially subject to eolian dispersion and water erosion. Phytostabilization, the use of plants for in situ stabilization of tailings and metal contaminants, is a feasible alternative to costly remediation practices. In this review we emphasize considerations for phytostabilization of mine tailings in arid and semiarid environments, as well as issues impeding its long-term success. Data sources: We reviewed literature addressing mine closures and revegetation of mine tailings, along with publications evaluating plant ecology, microbial ecology, and soil properties of mine tailings. Data extraction: Data were extracted from peer-reviewed articles and books identified in Web of Science and Agricola databases, and publications available through the U.S. Department of Agriculture, U.S. Environmental Protection Agency, and the United Nations Environment Programme. Data synthesis: Harsh climatic conditions in arid and semiarid environments along with the innate properties of mine tailings require specific considerations. Plants suitable for phytostabilization must be native, be drought-, salt-, and metal-tolerant, and should limit shoot metal accumulation. Factors for evaluating metal accumulation and toxicity issues are presented. Also reviewed are aspects of implementing phytostabilization, including plant growth stage, amendments, irrigation, and evaluation. Conclusions: Phytostabilization of mine tailings is a promising remedial technology but requires further research to identify factors affecting its long-term success by expanding knowledge of suitable plant species and mine tailings chemistry in ongoing field trials. Key words: arid, mine tailings, phytostabilization, remediation, revegetation, semiarid. Environ Health Perspect 116:278–283 (2008) . doi:10.1289/ehp.10608 available via http://dx.doi.org/ [Online 17 December 2007]
Address correspondence to R.M. Maier, Department of Soil, Water, and Environmental Science, University of Arizona, 1177 E. Fourth St., Tucson, AZ 85721-0038 USA. Telephone: (520) 621-7231. Fax: (520) 626-6782. E-mail: rmaier@ag.arizona.edu We thank A.J. Gandolfi of the College of Pharmacy at the University of Arizona for his editorial comments. This research was supported by grant 2 P42 ES04940-11 from the National Institute of Environmental Health Sciences Superfund Basic Research Program, National Institutes of Health. The authors declare they have no competing financial interests. Received 27 June 2007 ; accepted 17 December 2007.
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