USDeptHealth_Arsenic_FAQU.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, Public Health Service
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Environmental Medicine ToxFAQsTM August 2007
This fact sheet answers the most frequently asked health questions (FAQs) about arsenic. For more
information, call the ATSDR Information Center at 1-800-232-4636. This fact sheet is one in a series
of summaries about hazardous substances and their health effects. It is important you understand this
information because this substance may harm you. The effects of exposure to any hazardous substance
depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other
chemicals are present.
HIGHLIGHTS: Exposure to higher than average levels of arsenic occur mostly in
the workplace, near hazardous waste sites, or in areas with high natural levels. At
high levels, inorganic arsenic can cause death. Exposure to lower levels for a long
time can cause a discoloration of the skin and the appearance of small corns or
warts. Arsenic has been found in at least 1,149 of the 1,684 National Priority List
sites identified by the Environmental Protection Agency (EPA).
What is arsenic?
Arsenic is a naturally occurring element widely distributed in
the earth’s crust. In the environment, arsenic is combined
with oxygen, chlorine, and sulfur to form inorganic arsenic
compounds. Arsenic in animals and plants combines with
carbon and hydrogen to form organic arsenic compounds.
Inorganic arsenic compounds are mainly used to preserve
wood. Copper chromated arsenate (CCA) is used to make
“pressure-treated” lumber. CCA is no longer used in the
U.S. for residential uses; it is still used in industrial
applications. Organic arsenic compounds are used as
pesticides, primarily on cotton fields and orchards.
What happens to arsenic when it enters the
environment?
‘ Arsenic occurs naturally in soil and minerals and may
enter the air, water, and land from wind-blown dust and may
get into water from runoff and leaching.
‘ Arsenic cannot be destroyed in the environment. It can
only change its form.
‘ Rain and snow remove arsenic dust particles from the air.
‘ Many common arsenic compounds can dissolve in water.
Most of the arsenic in water will ultimately end up in soil or
sediment.
‘ Fish and shellfish can accumulate arsenic; most of this
arsenic is in an organic form called arsenobetaine that is
much less harmful.
How might I be exposed to arsenic?
‘ Ingesting small amounts present in your food and water
or breathing air containing arsenic.
‘ Breathing sawdust or burning smoke from wood treated
with arsenic.
‘ Living in areas with unusually high natural levels of
arsenic in rock.
‘ Working in a job that involves arsenic production or use,
such as copper or lead smelting, wood treating, or pesticide
application.
How can arsenic affect my health?
Breathing high levels of inorganic arsenic can give you a
sore throat or irritated lungs.
Ingesting very high levels of arsenic can result in death.
Exposure to lower levels can cause nausea and vomiting,
decreased production of red and white blood cells, abnormal
heart rhythm, damage to blood vessels, and a sensation of
“pins and needles” in hands and feet.
Ingesting or breathing low levels of inorganic arsenic for a
long time can cause a darkening of the skin and the
appearance of small “corns” or “warts” on the palms, soles,
and torso.
Skin contact with inorganic arsenic may cause redness and
swelling.
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ToxFAQsTM Internet address is http://www.atsdr.cdc.gov/toxfaq.html
Where can I get more information? For more information, contact the Agency for Toxic Substances and Disease
Registry, Division of Toxicology and Environmental Medicine, 1600 Clifton Road NE, Mailstop F-32, Atlanta, GA 30333. Phone:
1-800-232-4636, FAX: 770-488-4178. ToxFAQs Internet address via WWW is http://www.atsdr.cdc.gov/toxfaq.html. ATSDR
can tell you where to find occupational and environmental health clinics. Their specialists can recognize, evaluate, and treat
illnesses resulting from exposure to hazardous substances. You can also contact your community or state health or environmental
quality department if you have any more questions or concerns.
Almost nothing is known regarding health effects of organic
arsenic compounds in humans. Studies in animals show that
some simple organic arsenic compounds are less toxic than
inorganic forms. Ingestion of methyl and dimethyl
compounds can cause diarrhea and damage to the kidneys
How likely is arsenic to cause cancer?
Several studies have shown that ingestion of inorganic
arsenic can increase the risk of skin cancer and cancer in the
liver, bladder, and lungs. Inhalation of inorganic arsenic can
cause increased risk of lung cancer. The Department of
Health and Human Services (DHHS) and the EPA have
determined that inorganic arsenic is a known human
carcinogen. The International Agency for Research on
Cancer (IARC) has determined that inorganic arsenic is
carcinogenic to humans.
How can arsenic affect children?
There is some evidence that long-term exposure to arsenic in
children may result in lower IQ scores. There is also some
evidence that exposure to arsenic in the womb and early
childhood may increase mortality in young adults.
There is some evidence that inhaled or ingested arsenic can
injure pregnant women or their unborn babies, although the
studies are not definitive. Studies in animals show that large
doses of arsenic that cause illness in pregnant females, can
also cause low birth weight, fetal malformations, and even
fetal death. Arsenic can cross the placenta and has been
found in fetal tissues. Arsenic is found at low levels in
breast milk.
How can families reduce the risks of exposure to
arsenic?
‘ If you use arsenic-treated wood in home projects, you
should wear dust masks, gloves, and protective clothing to
decrease exposure to sawdust.
‘ If you live in an area with high levels of arsenic in water
or soil, you should use cleaner sources of water and limit
contact with soil.
‘ If you work in a job that may expose you to arsenic, be aware
that you may carry arsenic home on your clothing, skin, hair, or
tools. Be sure to shower and change clothes before going home.
Is there a medical test to determine whether I’ve
been exposed to arsenic?
There are tests available to measure arsenic in your blood, urine,
hair, and fingernails. The urine test is the most reliable test for
arsenic exposure within the last few days. Tests on hair and
fingernails can measure exposure to high levels of arsenic over
the past 6-12 months. These tests can determine if you have
been exposed to above-average levels of arsenic. They cannot
predict whether the arsenic levels in your body will affect your
health.
Has the federal government made recommendations
to protect human health?
The EPA has set limits on the amount of arsenic that
industrial sources can release to the environment and has
restricted or cancelled many of the uses of arsenic in
pesticides. EPA has set a limit of 0.01 parts per million (ppm)
for arsenic in drinking water.
The Occupational Safety and Health Administration (OSHA)
has set a permissible exposure limit (PEL) of 10 micrograms
of arsenic per cubic meter of workplace air (10 μg/m³) for 8
hour shifts and 40 hour work weeks.
References
Agency for Toxic Substances and Disease Registry (ATSDR).
2007. Toxicological Profile for Arsenic (Update). Atlanta, GA:
U.S. Department of Public Health and Human Services, Public
Health Service.
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