title: Health effects following subacute exposure to geogenic dusts from arsenic-rich sediment at the Nellis Dunes Recreation Area, Las Vegas, NV.
abstract: Geogenic dust from arid environments is a possible inhalation hazard for humans, especially when using off-road vehicles that generate significant dust. This study focused on immunotoxicological and neurotoxicological effects following subacute exposure to geogenic dust generated from sediments in the Nellis Dunes Recreation Area near Las Vegas, Nevada that are particularly high in arsenic; the naturally-occurring arsenic concentrations in these surficial sediments ranged from 4.8 to 346μg/g. Dust samples from sediments used in this study had a median diameter of 4.5μm and also were a complex mixture of naturally-occurring metals, including aluminum, vanadium, chromium, manganese, iron, cobalt, copper, zinc, strontium, cesium, lead, uranium, and arsenic. Adult female B6C3F1 mice exposed via oropharyngeal aspiration to 0.01 to 100mg dust/kg body weight, four times, a week apart, for 28days, were evaluated 24h after the last exposure. Peripheral eosinophils were increased at all concentrations, serum creatinine was dose responsively increased beginning at 1.0mg/kg/day, and blood urea nitrogen was decreased at 10 and 100mg/kg/day. Antigen-specific IgM responses and natural killer cell activity were dose-responsively suppressed at 0.1mg/kg/day and above. Splenic CD4+CD25+ T cells were decreased at 0.01, 0.1, 10, and 100mg/kg/day. Antibodies against MBP, NF-68, and GFAP were selectively reduced. A no observed adverse effect level of 0.01mg/kg/day and a lowest observed adverse effect level of 0.1mg/kg/day were determined from IgM responses and natural killer cell activity, indicating that exposure to this dust, under conditions similar to our design, could affect these responses.
authors.affiliation: Department of Pharmacology and Toxicology, East Carolina University, Greenville, NC 27834, USA. Electronic address: dewittj@ecu.edu.
authors.forename: Jamie
authors.initials: J
authors.lastname: DeWitt
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: Brenda
authors.initials: B
authors.lastname: Buck
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA; Department of Earth and Environmental Sciences, KU Leuven, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Goossens
authors.affiliation: Department of Pharmacology and Toxicology, East Carolina University, Greenville, NC 27834, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Chow
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: Winnie
authors.initials: W
authors.lastname: David
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Young
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: Yuanxin
authors.initials: Y
authors.lastname: Teng
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Mallory
authors.initials: M
authors.lastname: Leetham-Spencer
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Lacey
authors.initials: L
authors.lastname: Murphy
authors.affiliation: Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA.
authors.forename: James
authors.initials: J
authors.lastname: Pollard
authors.affiliation: Department of Environmental, Geographical, and Geological Sciences, Bloomsburg University of Pennsylvania, Bloomsburg, PA,17815, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: McLaurin
authors.affiliation: Brooks Rand Labs, LLC, Bothell, WA 98011, USA.
authors.forename: Russell
authors.initials: R
authors.lastname: Gerads
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Keil
mesh_terms: D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000633:toxicity*; D001806:Blood Urea Nitrogen; D001835:Body Weight / Q000187:drug effects; D045424:Complex Mixtures; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004391:Dust / Q000032:analysis / Q000276:immunology*; D004804:Eosinophils / Q000187:drug effects; D005260:Female; D007075:Immunoglobulin M / Q000187:drug effects; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000187:drug effects; D051379:Mice; D016900:Neurofilament Proteins / Q000276:immunology; D009505:Nevada; D009929:Organ Size / Q000187:drug effects; D010316:Particle Size; D013154:Spleen / Q000473:pathology
chemical_list: D045424:Complex Mixtures; D004391:Dust; D007075:Immunoglobulin M; D016900:Neurofilament Proteins; C066858:neurofilament protein NF 68; D003404:Creatinine; D001151:Arsenic
keywords: Geogenic dust; Heavy metals; Immunotoxicity; Lung exposure; Minerals; Neurotoxicity