Bioaccessibility, Bioavailability, and Chemical Speciation of Arsenic in Contaminated Soils and ...

194 Pages·2016·1.93 MB·English

by  Brooke Stevens

Bioaccessibility, Bioavailability, and Chemical Speciation of Arsenic in Contaminated
Soils and Solid Wastes

DISSERTATION

Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy
in the Graduate School of The Ohio State University

By
Brooke Nan Stevens, B.S.
Graduate Program in Environmental Science

The Ohio State University
2016
Dissertation Committee:
Dr. Nicholas T. Basta, Advisor
Dr. Michael S. Bisesi
Dr. W. Berry Lyons
Dr. Kirk G. Scheckel
Dr. Olli H. Tuovinen
Copyrighted by
Brooke Nan Stevens
2016
Abstract

Arsenic in soil and solid waste is one of the most common contaminants of
concern that exceed risk criteria at many Department of Defense (DoD) sites. Ingestion of
soil contaminated with high levels of As is the primary human health risk driver at many
of the sites. Use of contaminant total content instead of bioavailability in human health
risk assessment is often overly conservative and can result in costly and unnecessary soil
remedial action. The binding mechanisms and speciation of As in soil impact
contaminant bioavailability.
Twenty-seven As contaminated soils and solid wastes that represent a wide
variety of properties and As sources from DoD installations, industrial sites, residential,
and agricultural sites were studied. Total As content ranged from 162 to 12,500 mg As/kg
material with a median value of 464 mg As/kg material. Relative bioavailable (RBA) As
was determined by the adult mouse and the juvenile swine bioassays. Relative
bioavailable As ranged from 6.37 to 81.2%. Swine RBA As was greater than mice RBA
As. However, variability in RBA As was higher for swine than mice. In vitro
bioaccessible (IVBA) As was determined by the U.S. EPA Method 9200 (glycine),
PBET, UBM, OSU IVG, and CAB methods. In vitro bioaccessible As ranged from less
than 1% to 100%. Median and mean IVBA As followed the trend CAB (pH 1.5) was
greater than UBM (pH 1.2), OSU IVG (pH 1.8), PBET (pH 1.8), and glycine (pH 1.5)
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which were approximately equal. In vivo-in vitro correlations (IVIVC) were used to
evaluate the ability of IVBA methods to predict RBA. In vivo-in vitro correlation
analysis showed all of the IVBA methods were predictive of RBA for both the mice and
swine bioassays. Physiology based IVBA methods (UBM and OSU IVG) produced
IVIVC that are more predictive of RBA. The CAB method is more accurate for low RBA
As materials and for materials with high reactive Al and Fe oxides.
Arsenic speciation determined using X-ray absorption spectroscopy was
predictive of 21% and 36% of RBA As determined using the adult mouse and juvenile
swine methods, respectively. Despite As(V) adsorbed to mineral surfaces (i.e., Fe oxides)
being a major component of most soils and solid wastes (>50%), these materials ranged
from ~20-80% in IVBA As and widely ranged in RBA As. Arsenic speciation can
provide a conservative estimate of RBA As. Arsenic speciation is very important to
provide information on IVBA or RBA As results and/or determine a priori if a
bioavailability-based risk assessment is justified.
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To my parents,
Ken and Gail Stevens,
With your love and support I know anything is possible
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Acknowledgments

I wish to thank my advisor, Nick Basta, for taking a chance on the chemistry
major from a smaller university in Virginia. Thank you for providing opportunities to
explore and funding, but more importantly, the guidance, support, patience and friendship
that you have provided over the years.
I would like to acknowledge the funding provided by The Environmental Science
Graduate Program (teaching associate), Parsons Environmental & Infrastructure Group
Inc. (RFP No. 447359-2001), and Strategic Environmental Research and Development
Program (ER-1742).
The success of this research and my Ph.D. was greatly impacted by the time and
teaching of Dr. Kirk Scheckel, Shane Whitacre, and Hunter Anderson. Thank you Kirk,
for taking the time to teach me XAS and being a part of my committee. Also thank you
for being a reference so that I could get the job of a lifetime. Thank you Shane, for
answering all of my questions no matter how many times I asked and welcoming me as
an office mate. Thank you, Hunter for being so helpful and willing to answer all of my
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statistics related questions that were required to make this work complete. Also thank you
for helping send around my CV so that I could get the job of a lifetime.
I would like to thank all of my previous teachers and mentors, there are too many
to name everyone. You exposed me to science and the wonders of chemistry, provided
guidance, mentoring, research opportunities, and friendship that I value on a daily basis.
My parents and family, Ken, Gail, Taylor, and Dakota Stevens you have
supported me through all of my schooling, provided love, laughs, and have always been
my rock through it all. This is as much yours as it is mine. Thank you does not say
enough and I could never repay you.
Finally, I would like to thank Patrick Weaver. Thank you for standing by my side
when I moved away to pursue this degree. You have endured more than a lifetime of
phone calls and messages about courses, self-doubt, nervousness, excitement, and “Hold
on. Let me finish this one last thing.” throughout this whole adventure. Your patience and
understanding is something I am eternally grateful for. You, R, and C have provided
smiles and laughs when I needed them most.

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Vita

October 6, 1990 ..............................................Born, Rochester New York
June 2008 .......................................................Osbourn Park Senior High School
2012................................................................B.S. Chemistry, James Madison University
2012 to present ..............................................Graduate Research Associate, School of
Environment and Natural Resources, The
Ohio State University
2013 to present ..............................................Graduate Teaching Associate,
Environmental Science Graduate Program,
The Ohio State University

Publications

Obrycki, John F., Nicholas T. Basta, Kirk Scheckel, Brooke N. Stevens, and Kristen K.
Minca. 2016. Phosphorus Amendment Efficacy for In Situ Remediation of Soil
Lead Depends on the Bioaccessible Method. J. Environ. Qual. 45:37-44.
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Fields of Study

Major Field: Environmental Science

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Table of Contents
Abstract ............................................................................................................................... ii
Acknowledgments............................................................................................................... v
Vita .................................................................................................................................... vii
Publications ....................................................................................................................... vii
Fields of Study ................................................................................................................. viii
Table of Contents ............................................................................................................... ix
List of Tables ................................................................................................................... xiv
List of Figures .................................................................................................................. xvi
1. Introduction ................................................................................................................. 1
2. Background Information .............................................................................................. 4
Arsenic in the Environment............................................................................................. 4
Bioavailability Adjustments for Human Health Risk Assessment.................................. 6
Arsenic Bioavailability .................................................................................................... 9
Arsenic Bioaccessibility ................................................................................................ 12
Arsenic Speciation......................................................................................................... 17
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