title: Occurrence and treatment of arsenic in groundwater and soil in northern Mexico and southwestern USA.
abstract: This review focuses on the occurrence and treatment of arsenic (As) in the arid region of northern Mexico (states of Chihuahua and Coahuila) and bordering states of the southwestern US (New Mexico, Arizona, and Texas), an area known for having high As concentrations. Information assembled and assessed includes the content and probable source of As in water, soil, and sediments and treatment methods that have been applied in the area. High As concentrations were found mainly in groundwater, their source being mostly from natural origin related to volcanic processes with significant anthropogenic contributions near mining and smelting of ores containing arsenic. The affinity of As for solid phases in alkaline conditions common to arid areas precludes it from being present in surface waters, accumulating instead in sediments and shifting its threat to its potential remobilization in reservoir sediments and irrigation waterways. Factors such as oxidation and pH that affect the mobility of As in the subsurface environment are mentioned. Independent of socio-demographic variables, nutritional status, and levels of blood lead, cognitive development in children is being affected when exposed to As. Treatments known to effectively reduce As content to safe drinking water levels as well as those that are capable of reducing As content in soils are discussed. Besides conventional methods, emergent technologies, such as phytoremediation, offer a viable solution to As contamination in drinking water.
authors.affiliation: Center for Inland Desalination Systems, University of Texas at El Paso, 500 West-University Avenue, Room 216, El Paso, TX 79968, USA. lcamacho3@utep.edu
authors.forename: Lucy Mar
authors.initials: LM
authors.lastname: Camacho
authors.forename: Mélida
authors.initials: M
authors.lastname: Gutiérrez
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Alarcón-Herrera
authors.forename: Maria de Lourdes
authors.initials: Mde L
authors.lastname: Villalba
authors.forename: Shuguang
authors.initials: S
authors.lastname: Deng
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation / Q000379:methods; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry; D008800:Mexico; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D015206:Southwestern United States; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*; D018508:Water Purification / Q000379:methods; D014881:Water Supply / Q000032:analysis
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D001151:Arsenic