in Groundwater of Asia
Responsible for the Arsenic-Induced
Largest Mass Poisoning in History
Ben Kocar, Matt
Polizzotto, Jason Stuckey, Sam
Ying, Shawn Benner (Boise State
Univ.), Scott Fendorf
As many as
one hundred million people living in the large
river deltas of South and Southeast Asia (e.g.,
West Bengal – India, Bangladesh, Cambodia,
Myanmar, and Vietnam) routinely consume well
water with unsafe arsenic levels (often 20 to 50
times, and up to more than 100 times, the
recommended limit set by the World Health
Organization). While there is general agreement
that arsenic is naturally derived, the processes
governing aqueous concentrations in groundwater
remain unresolved, limiting our ability to
predict arsenic concentrations in space (between
wells) and time (future concentrations) and to
assess the impact of human activities on the
arsenic problem. Long-term exposure to high
levels of arsenic has resulted in arsenicosis
and cancers. However, because most surface water
sources are contaminated with pathogens, people
continue to drink well water, forced to choose
arsenic poisoning over surface water-borne
In our field work, we seek to determine the hydrologic
and biogeochemical processes operative within
the aquifer systems of Asia.
Integrating our knowledge
gained from laboratory studies with a
determination of the field conditions, we aim to
develop the capacity to predict, spatially and
temporally, shifts in groundwater arsenic
concentration with land use change (e.g.,
irrigation, development, river alterations).
Our main research area is in the Mekong River Delta of
Cambodia where we have established an
approximately 50 square kilometer site in
partnership with Resource
Development International, Cambodia. We are
continuing to measure the distribution of
chemical parameters (including arsenic) of
groundwater and surface water, monitored
hydraulic heads to establish groundwater flow
paths, and analyzed soils and sediments in order
to understand the sources and controls on
arsenic in groundwater.
We are paralleling these efforts with
detail biogeochemical studies of soils and
near-surface sediments, and with an analysis of
land use changes (current and impending).
Fendorf featured in July 24th Nature Podcast
<- Click to listen
Benner, S.G., M.L. Polizzotto, B. D. Kocar, S. Ganguly,
K. Phan, K. Ouch, M. Sampson, and S. Fendorf.
Groundwater flow in an
arsenic-contaminated aquifer, Mekong Delta,
Kocar, B.D., M.L.
Polizzotto, S.G. Benner, S. Ying, M. Ung, K.
Ouch, S. Samreth, B. Suy, K. Phan, M. Sampson,
and S. Fendorf. 2008. Integrated
biogeochemical and hydrologic processes driving
arsenic release from shallow sediments to
groundwaters of the Mekong Delta.
Polizzotto, M. L., S. G. Benner, B. D. Kocar, M.
Sampson, and S. Fendorf.
Near-surface wetland sediments as a
source of arsenic release to groundwater in
Polizzotto, M. L., C. F. Harvey, G.-C. Li, B. Badruzzman,
M. Newville, and S. Fendorf.
2006. Solid-phases and desorption
processes of arsenic within Bangladesh
Polizzotto, M. L., C. F. Harvey, S. R. Sutton, and S.
Processes conducive to the release and
transport of arsenic into aquifers of
Proc. Nation. Acad. Sci.