title: Arsenic in the soils of Zimapán, Mexico.
abstract: Arsenic concentrations of 73 soil samples collected in the semi-arid Zimapán Valley range from 4 to 14 700 mg As kg(-1). Soil arsenic concentrations decrease with distance from mines and tailings and slag heaps and exceed 400 mg kg(-1) only within 500 m of these arsenic sources. Soil arsenic concentrations correlate positively with Cu, Pb, and Zn concentrations, suggesting a strong association with ore minerals known to exist in the region. Some As was associated with Fe and Mn oxyhydroxides, this association is less for contaminated than for uncontaminated samples. Very little As was found in the mobile water-soluble or exchangeable fractions. The soils are not arsenic contaminated at depths greater than 100 cm below the surface. Although much of the arsenic in the soils is associated with relatively immobile solid phases, this represents a long-term source of arsenic to the environment.
authors.affiliation: Oak Hill High School, P.O. Box 400, Sabattus, ME 04280, USA. loisongley@earthlink.net
authors.forename: Lois K
authors.initials: LK
authors.lastname: Ongley
authors.forename: Leslie
authors.initials: L
authors.lastname: Sherman
authors.forename: Aurora
authors.initials: A
authors.lastname: Armienta
authors.forename: Amy
authors.initials: A
authors.lastname: Concilio
authors.forename: Carrie Ferguson
authors.initials: CF
authors.lastname: Salinas
mesh_terms: D001151:Arsenic / Q000032:analysis*; D003300:Copper / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D007220:Industrial Waste; D058085:Iron Compounds / Q000032:analysis; D007854:Lead / Q000032:analysis; D017895:Manganese Compounds / Q000032:analysis; D008800:Mexico; D008906:Mining; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility; D014131:Trace Elements / Q000032:analysis; D014867:Water / Q000737:chemistry; D015032:Zinc / Q000032:analysis
chemical_list: D007220:Industrial Waste; D058085:Iron Compounds; D017895:Manganese Compounds; D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements; D014867:Water; D007854:Lead; D003300:Copper; D015032:Zinc; D001151:Arsenic