Olfactory Bulb Uptake and Determination of Biotransfer Factors in the California Ground Squirrel (Spermophilus beecheyi) Exposed to Manganese and Cadmium in Environmental Habitats

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• 作者：Graham Bench ; Tina M. Carlsen ; Patrick G. Grant ; Jim S. Wollett ; Jr. ; Roger E. Martinelli ; Johnnye L. Lewis ; and Kevin K. Divine
• 刊名：Environmental Science & Technology
• 出版年：2001
• 出版时间：January 15, 2001
• 年：2001
• 卷：35
• 期：2
• 页码：270 - 277
• 全文大小：265K
• 年卷期：v.35,no.2(January 15, 2001)
• ISSN：1520-5851

文摘

Manganese (Mn) and cadmium (Cd) profiles in olfactorybulbs of California ground squirrels (Spermophilus beecheyi)trapped at Lawrence Livermore National Laboratory'sSite 300 facility in California were determined with protoninduced X-ray emission (PIXE). As a reference, Mnprofiles in olfactory bulbs from laboratory rats exposedvia nose-only inhalation to 0.53 mg/m³ Mn in the form ofMnCl₂ were also determined with PIXE. Atomic absorptionspectrophotometry was used to measure soil Mn and Cdcontents from the trapping sites and Mn and Cd contents inground squirrel liver and leg muscle tissues. The datafrom laboratory rats revealed that Mn uptake into theolfactory bulb occurs via inhalation exposure. Data fromground squirrels and knowledge of the collection sites indicatethat although several routes of exposure may occur,fossorial rodent olfactory uptake affords a significantexposure route to Mn and Cd in soils. Measured biotransferfactors (ratio of leg muscle tissue metal content to soilmetal content) for Cd in ground squirrels were 10³-foldgreater than exposure modeling estimates based on oral Cduptake data from livestock. The measurements forground squirrel tissues show that when conductingecological risk assessments for natural habitats considerablecare should be taken in selecting transfer factors.Specifically, transfer factors derived from data pertainingto comparable exposure pathways and ecological settingshould be used wherever possible.