title: Derivation of soil-screening thresholds to protect the chisel-toothed kangaroo rat from uranium mine waste in northern Arizona.
abstract: Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat (Dipodomys microps leucotis); risks from radiation exposure were not evaluated. Dietary toxicity reference values were used to estimate soil-screening thresholds presenting risk to kangaroo rats. Sensitivity analyses indicated that body weight critically affected outcomes of exposed-dose calculations; juvenile kangaroo rats were more sensitive to the inorganic constituent toxicities than adult kangaroo rats. Species-specific soil-screening thresholds were derived for arsenic (137 mg/kg), cadmium (16 mg/kg), copper (1,461 mg/kg), lead (1,143 mg/kg), nickel (771 mg/kg), thallium (1.3 mg/kg), uranium (1,513 mg/kg), and zinc (731 mg/kg) using toxicity reference values that incorporate expected chronic field exposures. Inorganic contaminants in soils within and near the mine areas generally posed minimal risk to kangaroo rats. Most exceedances of soil thresholds were for arsenic and thallium and were associated with weathered mine wastes.
authors.affiliation: US Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, USA. jhinck@usgs.gov
authors.forename: Jo Ellen
authors.initials: JE
authors.lastname: Hinck
authors.forename: Greg
authors.initials: G
authors.lastname: Linder
authors.forename: James K
authors.initials: JK
authors.lastname: Otton
authors.forename: Susan E
authors.initials: SE
authors.lastname: Finger
authors.forename: Edward
authors.initials: E
authors.lastname: Little
authors.forename: Donald E
authors.initials: DE
authors.lastname: Tillitt
mesh_terms: D000818:Animals; D001130:Arizona; D004173:Dipodomys; D004784:Environmental Monitoring; D007220:Industrial Waste; D008906:Mining; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry* / Q000633:toxicity*; D014131:Trace Elements / Q000737:chemistry; D014501:Uranium
chemical_list: D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements; D014501:Uranium