United States
Environmental Protection
Agency
Health Effects Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S1-81-064 Feb. 1982
Project Summary
Community Health
Associated with Arsenic in
Drinking Water in
Millard County, Utah
J. W. Southwick, A. E. Western, M. M. Beck, J. Whitley, R. Isaacs, J. Petajan,
and C. D. Hanson
This study evaluates the human
health effects of ingesting drinking
waters with arsenic at levels about
four times the United States Environ-
mental Protection Agency primary
drinking water standard. Examinations
"of 250 cases included dermatological,
neurological, and anemia endpoints.
Hair and urine were tested for arsenic
content. Estimates of water consump-
tion provided the exposure criteria.
One hundred and forty five "ex-
posed" cases drank water with arsenic
at 0.18 - 0.21 mg/liter. One hundred
and five matched controls were
selected from a neighboring commun-
ity with arsenic at 0.02 mg/liter in
their drinking waters. Cases were of
either sex, over five years old, and
residents of the community for the last
five years. Controls were selected by
random number selection from within
age categories to match age and sex
distribution of the exposed population.
No exposure of controls to arsenic by
use of arsenic-containing chemicals
was found.
A clear relationship is shown be-
tween amount of arsenic consumed
and levels in urine and hair. Derma-
tological signs associated with arsenic
exposure were rare and scattered
among exposed and control partici-
pants. Anemia, nerve conduction
slowing, and signs/symptoms of
arsenic intoxication were not found in
the study population. Cancer incidence
or mortality did not show an excess in
the exposed community. No adverse
human health effects were discovered
among this relatively small population
exposed to drinking water with arsenic
at four times the primary drinking
water standard.
This Project Summary was devel-
oped by EPA's Health Effects Research
Laboratory, Cincinnati, OH, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The objective of this study was to
determine if a population consuming
drinking waters with high arsenic will
show more signs and symptoms of
arsenic intoxication than a population
not so exposed The toxicity of arsenic
compounds is highly variable depending
on exposure route, rate and duration of
exposure, compound, species of arsenic,
and animal species, strain and individual
susceptibility. However, the acute
toxicity of arsenic is well established
and includes gastrointestinal damage
and cardiac abnormalities. Chronic
exposure produces a variety of signs
and symptoms which may include
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dermatologic, neuropathy, hematolog-
ical, cancer, and cardiovascular disease.
The ascertainment of signs and symp-
toms due to chronic exposure is made
difficult by their variety, range of
disease susceptibility and additional
exposure to potential disease causing
agents.
Arsenic in drinking waters is limited
by a primary drinking water standard
from the United States Environmental
Protection Agency at 0.05 mg/liter. This
maintained the U.S. Public Health
Service standard from 1962. Chemical
forms of arsenic include trivalent and
pentavalent inorganic and organic
compounds. It is assumed that the
pentavalent inorganic form is the most
common in drinking waters. Inorganic
arsenic is absorbed readily from the
gastro-mtestinal tract, lungs and through
the skin. Inorganic trivalent forms are
slowly oxidized to, the pentavalent form.
Arsenic is excreted via urine, feces,
sweat, and skin. With chronic exposure
arsenic accumulates mainly in bone,
muscle, skin; with some in liver, and
kidneys. Epidemiologic investigations
have provided valuable insight into
potential human health risks associated
with arsenic in drinking waters.
In Taiwan, well water averaged 0.6
mg/liter of arsenic in a community.
Predomrnate signs, symptoms, and
illness reported were hyperpigmenta-
tion, keratosis, skin cancer, and "black-
foot disease." This study showed the
prevalence of skin cancer to increase in
direct proportion to the arsenic content
of the well water consumed. Water from
these wells was used for more than 45
years.
In Antofagasta, Chile mean arsenic
levels of 0.8 mg/liter were found. Signs
and symptoms predominately of children
included weight loss, diarrhea, general
debilitation, anorexia, and scaling of the
skin. Over 80% of the affected population
had abnormal skin pigmentation.
Bronchopulmonary and cardiovascular
disease was also reported. Other studies
have reported neuropathy and anemia.
Cancer (not skin) caused by arsenic
exposure has not been well established.
However, evidence does exist from
occupational studies for an increased
risk due to arsenic exposure.
Drinking water arsenic levels at 0.1
mg/liter in Lane County, Oregon showed
no association to skin cancer, keratosis,
or hyperpigmentation. Levels ranging
from 0.1 to 1.0 mg/liter in Lassen
County, California drinking water were
not associated with any specific illness.
However, levels above 0.05 mg/liter
increased arsenic concentrations in hair.
The National Academy of Sciences has
suggested that dermatologic manifesta-
tions may be a sensitive indicator of
exposure to arsenic compounds at levels
which could prove harmful.
This study utilized an existing condition
of high arsenic levels in drinking waters
to study the potential human health
effects of this exposure. Exposure was
determined by environmental sampling
of air and drinking water; estimating
individual water consumption through
the administration of a questionnaire
given to each participant; and measuring
levels of arsenic in hair and urine
samples. Exposure determination was
conducted in both high exposure (>0.15
mg/liter) and low exposure (<0.025
mg/liter) communities. Health status
was determined by physical examination
which included dermatological signs of
chronic arsenic poisoning, such as
hyperpigmentation, keratosis, vascular
changes, and skin cancer; nerve con-
duction velocities; hematocrits; and a
questionnaire relevant to health status.
Community death rates and cancer
incidence was also determined by
record retrieval.
Results and Conclusions
Arsenic exposure estimates con-
sidered the air route to be insignificant
after monthly sampling for a year. Water
consumption patterns showed similarity
by community and occupation. Highest
consumption of water was by out-of-
door summer workers, ranging higher
than 8 liters per day. (See Table 1)
Estimates of annual arsenic consumed
had a range of 12 - 953 mg in the
"exposed" and 4-135 mg in the "non-
exposed" populations. (See Table 2)
Arsenic levels in hair and urine were
significantly (statistically) associated
with exposure to arsenic in drinking
waters.
Dermatological manifestations were
not evidently associated with arsenic
exposure. The mean values for con-
duction velocity for any given nerve did
not vary significantly with respectto age
or community. However, a slightly
increased proportion of participants
with slowing of nerve conduction were
among the exposed participants. A
trend (not statistically significant) for
anemia in exposed communities was
also found. Cancer incidence and death
rates did not suggest an unreasonable
excess of cancer in the exposed pop-
ulation.
The hypothesis that arsenic in drinking
waters at these levels would result in ill
health was not confirmed by this study.
This could be an effect of the form of
arsenic in the drinking water. The
species of arsenic in the high exposure
areas was determined to be 86% As*5.
Different forms of arsenic may result in
varying degrees of signs and symptoms
after exposure.
In this study no adverse health effects
were found for exposed people averag-
ing more than 150 mg arsenic from
drinking well water per year. This isfour
times the maximum allowed by the
current standard without evidence of
adverse health effects.
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Table 1. Daily summer water consumption for residents of three study
communities.
Water Consumption Rate (Liter/day)
Community
Delta
Hinckley
Deseret
Number of
participants
105
102
43
Mean
2.7
2.9
2.4
Range
0.5 - 12.0
0.3 - 13.0
0.3 - 8.0
Standard
Deviation
1.9
2.0
1.4
Table 2. Annual Arsenic Consumption from Drinking Water for Study
Participants from Three Study Communities.
Arsenic Consumption (mg)
Community Number of
Participants Mean Range Median
Delta (Control)
"Exposed"
Hinckley
Deseret
105
145
102
43
24.2
152.4
135.5
192.5
4- 135
12 - 853
12 - 853
14 - 736
17
119
115
148
U S GOVERNMENT PRINTING OFFICE, 1982 — 559-017/7450
J W. Southwick, A E. Western, M. M. Beck, J. Whitley, R. Isaacs, J. Petajan,
and C D. Hanson are with the Utah State Department of Health, Salt Lake City,
UT 84110.
Daniel G. Greathouse is the EPA Project Officer (see below).
The complete report, entitled "Community Health Associated with Arsenic in
Drinking Water in Millard County, Utah," (Order No. PB 82-108 374; Cost:
$8.00, subject to change) will be available only from-
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Health Effects Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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Environmental Protection
Agency
Center for Environmental Research
Information
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