Soil and vegetation fluoride exposure pathways to cotton rats on a petrochemical-contaminated landfarm

• Published in: Environmental toxicology and chemistry Vol. 18; no. 9; pp. 2028 - 2033
• Main Authors: Schroder, J.L, Basta, N.T, Rafferty, D.P, Lochmiller, R.L, Kim, S, Qualls, C.W. Jr, McBee, K
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01-09-1999; SETAC
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Cotton rat; Ecotoxicology, biological effects of pollution; environmental exposure; Fluorosis; Fundamental and applied biological sciences. Psychology; Petrochemical; Sigmodon hispidus; Soil contamination; soil pollution; Terrestrial environment, soil, air; United States; North America; Oklahoma; America; Vertebrata; Fluorosis; Mammalia; Toxicity; Cultivated soil; Rodentia; Fluorides; Soil pollution; Petrochemical plant; Sigmodon hispidus; Biological monitoring; Chemical contamination
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620180922

Total fluoride (F) content of soils, vegetation, and cotton rats (Sigmodon hispidus) was measured on a landfarm contaminated with petrochemical wastes. A potentially bioavailable form of F was determined by HCl extraction of soils and vegetation. Cotton rats from the landfarm were examined for dental lesions indicative of fluorosis. Exposure pathways including dietary ingestion of unwashed vegetation and nondietary ingestion of soil associated with grooming and burrowing were evaluated. Mean bone F (1,515 mg/kg) and mean soil total F (1,954 mg/kg) from the landfarm site were greater than bone F (121 mg/kg) and soil total F (121 mg/kg) at a reference site. The HCl-extractable F was elevated in landfarm soil (326 mg/kg) compared to the reference site (2.3 mg/kg). About 80% of the cotton rats collected from the landfarm had dental fluorosis. During winter, the dietary pathway consisted of 78.9% of the potential bioavailable exposure (HCl-extractable F) of the two exposure pathways. However, in the summer, the nondietary pathway consisted of 87.9% of the potential bioavailable exposure of the two pathways. Incidental ingestion of soil associated with grooming and burrowing is more important than consumption of unwashed vegetation for cotton rats on the landfarm site in the summer. Fluoride accumulation in the soil from landfarming of petroleum wastes may pose a risk to terrestrial vertebrates. In addition to monitoring petroleum hydrocarbons, land application of petrochemical wastes should consider F and other inorganic contaminant loadings to the soil system.