Comparison of the bioavailability of elemental waste laden soils using in vivo and in vitro analytical methodology and refinement of exposure/dose model. 1997 annual progress report
'The bioavailability study has made significant progress in developing in vitro methodology, and the authors have completed the time course in vivo studies. The in vitro studies have been conducted to establish the major digestive variables of concern and the values to be used in application of both the saliva/gastric juice and intestinal fluid components of a synthetic digestive extraction. In vitro and in vivo experiments have been conducted on the 575 urn particle fraction of a soil sample collected in a Jersey City State Park. Five Jersey City soil samples were first characterized for physical and chemical characteristics. Based upon the composition of the five soils, one was selected for use in the first series of experiments. The second set of in vivo studies are to be conducted on a standard NIST Montana soil. It has already been examined for bioaccessibility and availability with the in vitro methodology. A sample has been collected in Bayonne to obtain an urban background soil. Surficial soil samples have been acquired from the Savannah River Site of the DOE. These are not radioactive but are contaminated with heavy metals, e.g. arsenic, and are being analyzed by both the in vivo and in vitro methodology. During this past summer a second set of soil samples were collected at Savannah River Site. These contain levels of both heavy metals and radionuclides. Recently, a special extraction laboratory has been constructed at EOHSI, with resources made available from the organization. It will handle the extraction and measurement of the radio activity of the soil, and extracts obtained by the in vivo techniques. It is anticipated that the SRS samples collected this summer will be available for analysis in both the in vivo and in vitro systems this fall. The initial characterization will be for soil, physical and chemical content, and microbial characteristics. The samples will be analyzed for the 5 75 urn particle size fraction, and the total mass 5 250 urn in particle size. Previous experience has suggested a preferential distribution of toxic materials in the small size fraction of soils, and that these particles will define the majority of the potential bioavailabiity of the soil. Initial mass balance experiments have been completed on the in vitro methodology, and they are attempting to optimize the recovery of total mass of each metal or radionuclide present in a soil. The mass balance studies have proceeded with the use of test soils from a home in Califon that has known arsenic contamination, and a lead contaminated soil from Columbia Univ. which has been used in human feeding studies. The plans for next year intend to focus on the analysis of the SRS samples, radioactive and non-radioactive and soils from other DOE sites and pharmacokinetic modeling. The technique development has moved to the point where the applications can be made using a reproducible protocol.'
- Research Organization:
- environmental and Occupational Health Sciences Inst., Piscataway, NJ (US)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM), Office of Science and Risk Policy
- DOE Contract Number:
- FG07-96ER62315
- OSTI ID:
- 13578
- Report Number(s):
- EMSP-54584-97; ON: DE00013578
- Country of Publication:
- United States
- Language:
- English
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