Grantee Research Project Results
1997 Progress Report: Development of Chemical Methods to Assess the Bioavailability of Arsenic in Contaminated Media
EPA Grant Number: R825410Title: Development of Chemical Methods to Assess the Bioavailability of Arsenic in Contaminated Media
Investigators: Basta, Nicholas T. , Rodriguez, Robin R. , Casteel, Stan W.
Institution: Oklahoma State University , University of Missouri - Columbia
EPA Project Officer: Hahn, Intaek
Project Period: November 1, 1996 through October 31, 1999 (Extended to October 31, 2000)
Project Period Covered by this Report: November 1, 1996 through October 31, 1997
Project Amount: $431,677
RFA: Environmental Fate and Treatment of Toxics and Hazardous Wastes (1996) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Safer Chemicals , Land and Waste Management
Objective:
To determine the degree of correlation between chemical speciation and in-vitro methods with in-vivo methods and the ability of chemical methods to provide accurate assessments of the bioavailability of As in contaminated media. To determine if the bioavailability of As in contaminated media is a function of As concentration.Progress Summary:
Research is in progress to satisfy project objectives. Chemical speciation and chemical characterization components have been complete but in-vitro and in-vivo studies are still in progress and expected to be completed within the next year.Accomplishments And Research Results:
Chemical characterization of contaminated media and soils
Chemical analysis show all study soils and media contained elevated levels of arsenic, lead, zinc, copper and nickel. Arsenic occurs in oxide and sulfate based minerals in contaminated samples. Samples contained significant amounts of sulfate and chloride which may influence the solubility and possibly the bioavailability of anionic arsenate.
Chemical speciation of contaminated media
Chemical speciation of arsenic was accomplished by using various extracting solutions to extract As from contaminated soils. In general, the amount of arsenic extracted by extracting solutions of ammonium oxalate > hydroxylamine hydrochloride > phosphate solution > sodium acetate > water soluble is consistent with arsenic solubility in soils and should be directly related to arsenic bioavailability.
In-vivo pig feeding study
Results from pig feeding trials involving two contaminated materials have been conducted. Research is in progress for the remaining contaminated soils.
In-vitro gastrointestinal (GI) methods
Research to measure bioavailable arsenic by using in-vitro GI methods is currently in progress. Arsenic in soil and contaminated media is being extracted by two in-vitro methods that simulate the gastrointestinal system. Arsenic dissolved by simulated stomach and by simulated intestinal processes is being measured for each in-vitro method.
Future Activities:
In-vivo and in-vitro studies will be completed within the next year. Relationships between arsenic bioavailability measured by chemical methods (chemical speciation, in-vitro methods) and bioavailable arsenic measured by in-vivo pig feeding trials will be ascertained. Resulted will be reported at national scientific meetings and in refereed scientific journals.Journal Articles:
No journal articles submitted with this report: View all 20 publications for this projectSupplemental Keywords:
Risk assessment, cleanup levels, remediation endpoints, site-specific bioavailability., Health, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Waste, Water, Susceptibility/Sensitive Population/Genetic Susceptibility, Fate & Transport, Risk Assessments, Chemistry, genetic susceptability, Environmental Chemistry, Contaminated Sediments, Epidemiology, Arsenic, Children's Health, Bioavailability, health effects, toxicity, arsenic mobility, contaminant transport, contaminated sediment, kinetic studies, mining impacted watershed, contaminated mines, ingestion, risk assessment, adverse human health affects, human exposure, dermal contact, chemical contaminants, fate, risk characterization, soil sediment, soils, animal research, sediment transport, hazardous waste, children, fate and transport, ecology assessment models, transport contaminants, chronic health effects, hazardous waste sites, environmental toxicant, superfund site, chemical speciation, human health effects, soil ingestion, exposure assessment, mobility, arsenic exposureProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.