ENVIRONMENTAL HEALTH
New Hampshire Assesses Exposure to Arsenic and
Uranium from Private Wells
by John Schneider, Toxicologist IV, New Hampshire Public Health Laboratories and Kimberly Aviado, PhD, Toxicologist II,
New Hampshire Public Health Laboratories
New Hampshire is known as “the
Granite State”—but that granite can be
a source of potentially harmful arsenic
in groundwater that poses a significant
public health risk. According to the
US Centers for Disease Control and
Prevention (CDC), New Hampshire has
the highest rate of bladder cancer in the
nation, and exposure to arsenic through
drinking contaminated well water is a
contributing factor. Nearly half of all
residents use a private well as their
primary source of drinking water, and
many of those wells contain naturally-
occurring arsenic and uranium that may
exceed the maximum contaminant level
recommended by the US Environmental
Protection Agency (US EPA) for safe
drinking water.
Arsenic and uranium concentrations
were determined using inductively
coupled plasma-mass spectrometry
(ICP-MS), a highly sensitive technique
for measuring trace metals.
In 2016, BiomonitoringNH launched
an investigation to assess exposure to
arsenic and uranium from private well
water. The primary objectives of this study
were to identify which groups of people
are most at risk for coming into contact
with arsenic and uranium, and to educate
New Hampshire residents on ways to
reduce or eliminate their exposure to
these environmental contaminants. At
the conclusion of the study in October
2018, a total of 566 people from 296
households participated, including a small
comparison population of 50 individuals
on a public water supply (i.e., whose
drinking water is treated to remove
contaminants by their municipality). top: Biosafety cabinet and automatic diluter/dispenser provide
clean environment for urine specimen preparation
Study Design bottom: Example of a water sample and specimen collection
kit from Biomonitoring NH
Participating households were selected
using probability mapping developed by
the US Geological Survey, which identified
25 cities and towns across southern and
southeastern New Hampshire that had
greater than a 35% chance of arsenic
concentrations in groundwater above the
US EPA’s maximum contaminant level
of 10 parts per billion. Program staff,
including the study’s two epidemiologists,
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LAB MATTERS Winter 2019
met one-on-one with each participant to
conduct a health and exposure survey and
provide urine and water collection kits.
The purpose of the well water testing was
two-fold: it provided critical information
about a major exposure route to arsenic
and uranium in the home, and also served
as an incentive for participating in the
study. Through collaboration with the
Water Analysis Laboratory at the New
Hampshire Public Health Laboratories,
participants were offered free well
water testing for a suite of water quality
measurements that included lead,
arsenic, uranium, copper, hardness, iron,
manganese, bacteria and pH. Testing
for additional potential contaminants
provided a more complete picture to well
owners, or, in the case of households on
public water supply, could alert them to
the possibility of contamination from
household plumbing.
Testing and Challenges
Urine specimens collected by each
participating member of a household
were analyzed by biomonitoring program
staff at the New Hampshire Public Health
Laboratories. Arsenic and uranium
concentrations were determined using
inductively coupled plasma-mass
spectrometry (ICP-MS), a highly sensitive
technique for measuring trace metals.
Selectively measuring arsenic in urine
required removing significant mass
spectral interferences caused by salts
present in urine. This was achieved by
pressurizing the ICP-MS collision cell
with inert helium gas, which collides
with interfering ions and allows for their
removal through kinetic energy filtering.
Measuring uranium posed unique
challenges, as it was often present in
urine at extremely low concentrations—
typically parts per trillion—making its
detection and measurement sometimes
difficult. At such low detection levels,
significant measures were taken to avoid
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