Research Statement James K. Kearns PhD
Summary of Research: The serious effects of common contaminants continue to challenge me to devise better
methods of determination, remediation and to understand how they impact health. My research is focused on
identifying molecules and metals - principally arsenic - in soil and water by improving common field test
methods, broadening their application and obviating subjective assessment of results by assessing them with
digital technology. Arsenic contamination poses a serious health risk to people exposed to very low
concentrations of the toxin. Not only abundant in nature worldwide, it has been widely distributed through the
use of pesticides, wood-treatment, mining, and other anthropogenic processes. Undergraduate and graduate
students are engaged by the broad appeal of the research objective and the opportunities to participate in
individual and group initiatives while learning analytical techniques. Additional topics are being explored to
capture student interest in research.
Past Research:

Using the Hach Kit, the standard methodology for determining As in liquid, I have refined its methods
of sampling in the field by experimenting using a broader range of concentration and extending reaction time. I
also found that by examining results with digital tools – scanners – I achieved quantification of colorimetric
change and could avoid common inaccuracies resulting from subjective assessment of color change on which
the test relies (Kearns, J. Tyson, J. Improving the accuracy and precision of an arsenic field test kit: increased
reaction time and digital image analysis Anal.Methods, 2012, 4, 1693).
Comparison of the measured blue intensities versus concentration of As(III) in µg L-1 at 20 min (), the
Hach color-chart (), 35 °C (), 40 min (), and 24 h (x symbol with vertical line).

Collaborating internationally with scientists in other disciplines, I have worked to determine why arsenic
impacts the health of certain individuals (Banerjee N, Nandy S, Kearns JK, et al. Polymorphisms in the TNF-α
and IL10-gene promoters and risk of arsenic-induced skin lesions and other non-dermatological health effects
Toxicol.Sci. first published online 2011, 2 doi:10.1093/toxsci/kfr046.)

I am in the process of editing a paper - A field portable method for arsenic determination using silver
nitrate - focusing on changing the colorimetric reagent mercuric bromide used in the traditional As test kits
with silver nitrate and discussing the implications of these findings for the analytical performance of such tests
and minimizing interpretation error. It seeks to improve measurement precision by the analysis of the digital
images obtained with a flat-bed scanner. Strategy and Approach: Silver nitrate has the advantage of being
comparatively less toxic compared with other common reagents. This suggested that it was worthwhile to
attempt to increase silver nitrate's sensitivity in this application. Replacing the usual reagents on Hach kit test
strips with a dried solution of silver nitrate seemed the most likely to produce success. Prior to reaction, silver
nitrate appeared as a clear deposit. After being reacted, its color altered with increasing arsenic concentrations
from red to brown, then finally to black with a silvery sheen. Scanner technology and computer software
capably quantified the concentration of arsenic by gauging the brightness and color of the reacted silver nitrate
product. Two quantification techniques were used in the experiments: color and Luma.
Plot of blue pixel value versus concentration of arsenic in water in µg L-1 calibration curves for batch test results
with the measurement of arsine gas with silver nitrate as a reagent.

Current Research: Metal and organic compound measurement, the impact of petroleum drilling in drinking
water in eastern Ecuador on an indigenous community water supply.
A. Statement of Problem: Living at the headwaters of the Amazon basin in Ecuador, the Secoya indigenous
group has been adversely affected by Chevron-Texaco soil and gas drilling practices which resulted in spills and
damage called the “Amazon Chernobyl.” The Secoya, and neighboring groups, now rely on rooftop collection
systems to supply drinking water from rainfall. They adopted this system when the local groundwater was
determined too polluted for human consumption. Unfortunately, the rooftop water may also be polluted by
airborne contaminants released by local petroleum refineries when they “flare,” or burn off, surplus natural gas.
B. Strategy and Approach: In July, 2012, I received permission to visit the tribe and collect both filtered and
unfiltered samples from regional rainwater cisterns and rivers. The samples were analyzed to establish the
effectiveness of the filtration systems and the concentrations of Cr, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Hg, Tl,
and Pb. The results were quantified to determine whether any of the metals present exceed World Health
Organization standards and will be mapped using the GPS coordinates of the collection sites.
C. Relevance and Impact: After communicating the findings, the Secoya community can decide whether it can
continue to rely on rain collection systems for potable water. Further testing is planned. By examination of the
literature and the findings, it may be possible to postulate whether there is a link between exposure to
contaminants and the prevalence of stomach cancers in the community.
D. Targeted Grant Organizations: Maddox Pitt-Jolie Foundation, Rain Forest Action Network, and the National
Science Foundation.

Determination of Arsenic in soils using the Gutzeit Method by undergraduate researchers
A. Statement of the Problem: The Gutzeit method is least expensive method for determining concentrations of
arsenic in liquids. It requires only a Hach Kit which is a portable commercial kit designed to test arsenic
levels in drinking water. Because contaminated soil also exposes animals and humans to arsenic
through the ingestion and inhalation of particulates and the consumption of food grown or grazed on it,
a field portable, inexpensive method for examining soil is necessary.
B. Strategy and Approach: By experimentation I found that by dissolving experimentally contaminated soil
samples in the reaction vessels provided by the kit, following the directions and analyzing the results with a
scanner, I could get an accurate assessment of the amount of Arsenic. Three variables: mass (g), concentration
(mg L-1), and time (t) were examined. As concentrations of arsenic in the contaminated soils increased, the
blue pixel count of the color produced on the test strip decreased. It was found that the most efficient detection
resulted from using 0.1g of soil and running the test for 45 min.
Plot of concentration of blue pixel value versus arsenic for 0.1 grams mass soil at 1-1000 mg kg
for four time periods; 1 h (diamond), 45 min (square), 30 min.(triangle), 20 min (x).
C. Relevance and Impact: Because the Hach Kits are inexpensive and scanners are readily
available, students can readily undertake personal research projects with little expense, supported
by available instrumentation. They document results comparing the accuracy of analysis by the
field portable method enhanced by the using digital equipment and by analysis with laboratory
instrumentation. Rather than examine experimentally contaminating soil samples, they collect
samples in their homes, school and community to evaluate the extent of exposure.
Future Research:

Digital Image Analysis of Reactions for the Measurement of Arsenic in Food Sources.
A. Statement of Problem: Recent news reports of contaminated apple juice and rice have awakened
concern in the U.S. and the demand for accurate testing of this toxin. Because the most effective kits
currently available rely on a color reaction that requires evaluation by the human eye and since
human observation is subject to error, quantification at a sufficiently precise level can be unreliable.
B. Strategy and Approach: Applying digital image analysis methods to improve the accuracy of
current field kits using digital scanners and computer analysis to interrogate the intensity of the
colors generated through the kits’ chemical reactions.
C. Relevance and Impact: Because it is topical, this project engages students in the STEM disciplines,
particularly invoking aspects of medicine, chemistry, geology, ecology, and biology. Students are
trained in the operation of commercial arsenic test kits and how to quantify the results using readily
available image-capturing equipment and color-analyzing computer programs. In the process they
acquire research skills. They are encouraged to explore further refinements, improvements, and
innovations in this form of analysis and to produce papers for publication.
D. Targeted Grant Organizations: National STEM Education Distributed Learning; Cottrell Scholar
Awards; Research Corporation American Society of Mass Spectrometry Research Award. Some
financial resources will be dedicated to the maintenance of any expensive laboratory-based
equipment used in the project.