FINAL REPORT Validation of an In Vitro Bioaccessibility Test Method for Estimation of Bioavailability of Arsenic from Soil and Sediment ESTCP Project ER-200916 December 2012 Susan Griffin U.S. EPA Region 8 Yvette Lowney Exponent, Inc. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to the Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) 01-05-2012 Final 2008-2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Validation of an In Vitro Bioaccessibility Test Method for the Estimation of NA the Bioavailability of Arsenic from Soil and Sediment 5b. GRANT NUMBER NA 5c. PROGRAM ELEMENT NUMBER NA 6. AUTHOR(S) 5d. PROJECT NUMBER Griffin, Susan ER-0916 Lowney, Yvette 5e. TASK NUMBER NA 5f. WORK UNIT NUMBER NA 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER USEPA Region 8, 1595 Wynkoop St, Denver CO 80202 Exponent, Inc., 4141 Arapahoe Ave. Suite 101, Boulder CO 80303 NA 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) Environmental Security Technology Certification Program (ESTCP) ESTCP 901 North Stuart Street Suite 303 11. SPONSOR/MONITOR'S REPORT Arlington VA 22203-1821 NUMBER(S) ER-0916 12. DISTRIBUTION/AVAILABILITY STATEMENT Available for public release; distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT A method is described for measuring the in vitro bioaccessibility (IVBA) of arsenic in soil or soil-like media, and using the measured IVBA value to estimate the relative bioavailability (RBA) in swine or monkeys using empiric regression models developed from 20 (swine) or 17 (monkey) calibration soils. The correlation coefficients for the models are high (0.85 for swine, 0.87 for monkey), and the precision of the method is high, both within and between laboratories. This method is the most thoroughly tested, calibrated, and validated IVBA approach for estimation of arsenic RBA that has been described to date. 15. SUBJECT TERMS Arsenic, RBA, IVBA 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF RESPONSIBLE PERSON a. REPORT b. ABSTRACT c. THIS PAGE ABSTRACT OF Susan Griffin PAGES 19b. TELEPHONE NUMBER (Include area code) UUU UU 28 303-312-6651 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................... 1 1.1 BACKGROUND .............................................................................................................. 1 1.2 OBJECTIVE OF THE DEMONSTRATION .................................................................. 3 1.3 REGULATORY DRIVERS ............................................................................................. 3 2.0 TECHNOLOGY .................................................................................................................. 4 2.1 TECHNOLOGY DESCRIPTION .................................................................................... 4 2.2 TECHNOLOGY DEVELOPMENT ................................................................................ 8 2.3 ADVANTAGES AND LIMITATIONS OF THE TECHNOLOGY ............................. 10 3.0 PERFORMANCE OBJECTIVES ..................................................................................... 13 4.0 SITE DESCRIPTION ........................................................................................................ 17 4.1 SITE LOCATION AND HISTORY .............................................................................. 17 4.2 SITE GEOLOGY/HYDROGEOLOGY ........................................................................ 17 4.3 CONTAMINANT DISTRIBUTION ............................................................................. 17 5.0 TEST DESIGN .................................................................................................................. 22 5.1 CONCEPTUAL EXPERIMENTAL DESIGN .............................................................. 22 5.2 BASELINE CHARACTERIZATION ........................................................................... 22 5.3 TREATABILITY OR LABORATORY STUDY RESULTS ....................................... 22 5.4 DESIGN AND LAYOUT OF TECHNOLOGY COMPONENTS................................ 22 5.5 FIELD TESTING ........................................................................................................... 22 5.6 SAMPLING RESULTS ................................................................................................. 22 6.0 PERFORMANCE ASSESSMENT ................................................................................... 24 7.0 COST ASSESSMENT ....................................................................................................... 25 7.1 COST MODEL .............................................................................................................. 25 7.2 COST DRIVERS............................................................................................................ 26 7.3 COST ANALYSIS ......................................................................................................... 26 8.0 IMPLEMENTATION ISSUES ......................................................................................... 28 8.1 REGULATORY ACCEPTANCE.................................................................................. 28 8.2 PROCUREMENT OF IVBA ANALYSES ................................................................... 28 8.3 PROCUREMENT OF ARSENIC SPECIATION DATA ............................................. 28 9.0 REFERENCES .................................................................................................................. 30 ii LIST OF TABLES Table 2-1 Overview of Published IVBA Procedures for Arsenic Table 3-1 Performance Objectives Table 7-1 Cost Model for Conducting an IVBA Test for Estimating the RBA of Arsenic from Soil Table 7-2 Cost Analysis for Conducting an IVBA Study at a Heterogeneous Site (N = 20) LIST OF FIGURES Figure 2-1 IVBA Extraction Device Figure 4-1 Operable Unit 1 Source Areas Figure 4-2 Conceptual Model for OU1 Springs Figure 4-3 Site 2 Sediment Sample Locations LIST OF APPENDICES Appendix A Points of Contact Appendix B Phase Reports Appendix C Standard Operating Procedures iii LIST OF ACRONYMS ABA absolute bioavailability ºC degrees Celsius CSF cancer slope factor DI de-ionized EPA U.S. Environmental Protection Agency g grams g/mL grams per milliliter HAH hydroxylamine hydrochloride HDPE high-density polyethylene IVBA in vitro bioaccessibility IVIVC in vivo-in vitro correlation L liter mg/kg milligrams per kilogram mL milliliter N Normal NIST National Institute of Standards and Technology OU1 Operable Unit 1 ppm parts per million = mg/L or mg/kg RAM relative arsenic mass RBA relative bioavailability RfD reference dose SOP standard operating procedure ug/kg microgram per kilogram ug/L microgram per liter iv ACKNOWLEDGEMENTS The work described in the report was accomplished through the efforts of a team of scientists. The co-investigators for this project were Susan Griffin of the U.S. Environmental Protection Agency, and Yvette Lowney of Exponent, Inc. The co-investigators were supported throughout the study by John Drexler of the University of Colorado at Boulder, who performed all of the in vitro bioaccessibility and speciation analyses, and also provided many valuable discussions and insights. In addition, the project was supported by scientists from SRC, Inc. (William Brattin, Gary Diamond, and Penny Hunter) and from CDM Smith (Lynn Woodbury), who provided ongoing support in data reduction and modeling efforts, as well as authorship of project reports. Contact information for these individuals is provided in Appendix A. v EXECUTIVE SUMMARY Accurate evaluation of the human health risk from ingestion of arsenic in soil or soil-like media requires knowledge of the relative bioavailability (RBA) of arsenic in the soil or soil-like material. Although RBA can be measured using studies in animals, such studies are generally slow and costly. An alternative strategy is to perform measurements of arsenic solubility in the laboratory. Typically, a sample of soil or sediment is extracted using a fluid that has properties that resemble a gastrointestinal fluid, and the amount of arsenic solubilized from the sample into the fluid under a standard set of extraction conditions is measured. The fraction of arsenic that is solubilized is referred to as the in vitro bioaccessibility (IVBA). The IVBA is then utilized to predict the in vivo RBA of arsenic in that sample, usually through an empiric correlation model. The technology developed in this project is an IVBA-based method to accurately predict