July 1999 |
ToxFAQs™ |
for |
Silver |
(Plata) |
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This fact sheet answers the most frequently
asked health questions about silver. For more information,
you may call the ATSDR Information Center at 1-888-422-8737.
This fact sheet is one in a series of summaries about hazardous
substances and their health effects. This information is important
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.
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HIGHLIGHTS: Silver is an element
found naturally in the environment. At very high levels,
it may cause argyria, a blue-gray discoloration of the
skin and other organs. This chemical has been found in
at least 27 of the 1,177 National Priorities List sites
identified by the Environmental Protection Agency (EPA). |
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What
is silver? |
Silver is a naturally occurring element.
It is found in the environment combined with other elements
such as sulfide, chloride, and nitrate. Pure silver is "silver"
colored, but silver nitrate and silver chloride are powdery
white and silver sulfide and silver oxide are dark-gray to
black. Silver is often found as a by-product during the retrieval
of copper, lead, zinc, and gold ores.
Silver is used to make jewelry, silverware,
electronic equipment, and dental fillings. It is also used
to make photographs, in brazing alloys and solders, to disinfect
drinking water and water in swimming pools, and as an antibacterial
agent. Silver has also been used in lozenges and chewing gum
to help people stop smoking.
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What
happens to silver when it enters the environment? |
- Silver may be released into the air and water through
natural processes such as the weathering of rocks.
- Human activities such as the processing of ores, cement
manufacture, and the burning of fossil fuel may release
silver into the air.
- It may be released into water from photographic processing.
- Rain may wash silver out of soil into the groundwater.
- Silver does not appear to concentrate to a significant
extent in aquatic animals.
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How
might I be exposed to silver? |
- Breathing low levels in air.
- Swallowing it in food or drinking water.
- Carrying out activities such as jewelry-making, soldering,
and photography.
- Using anti-smoking lozenges or other medicines containing
it.
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How
can silver affect my health? |
Exposure to high levels of silver for
a long period of time may result in a condition called arygria,
a blue-gray discoloration of the skin and other body tissues.
Lower-level exposures to silver may also cause silver to be
deposited in the skin and other parts of the body; however,
this is not known to be harmful. Argyria is a permanent effect,
but it appears to be a cosmetic problem that may not be otherwise
harmful to health.
Exposure to high levels of silver in
the air has resulted in breathing problems, lung and throat
irritation, and stomach pains. Skin contact with silver can
cause mild allergic reactions such as rash, swelling, and
inflammation in some people.
Animal studies have shown that swallowing
silver results in the deposit of silver in the skin. One study
in mice found that the animals exposed to silver in drinking
water were less active than unexposed animals.
No studies are available on whether silver
affects reproduction or causes developmental problems in people.
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How
likely is silver to cause cancer? |
No studies are available on whether silver
may cause cancer in people. The only available animal studies
showed both positive and negative results when silver was
implanted under the skin.
The EPA has determined that silver is
not classifiable as to human carcinogenicity.
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Is
there a medical test to show whether I've been exposed to silver? |
Silver can be measured in the blood,
urine, feces, and body tissues of exposed people. Silver builds
up in the body, and the best way to learn if past exposure
has occurred is to look for silver in samples of skin. Tests
for silver are not commonly done at a doctor's office because
they require special equipment. Although doctors can find
out if a person has been exposed to silver by doing these
tests, they cannot tell whether any health effects will occur.
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Has the federal government made recommendations to protect human health? |
The EPA recommends that the concentration
of silver in drinking water not exceed 0.10 milligrams per
liter of water (0.10 mg/L) because of the skin discoloration
that may occur.
The EPA requires that spills or accidental
releases of 1,000 pounds or more of silver be reported to
the EPA.
The Occupational Safety and Health Administration
(OSHA) limits silver in workplace air to 0.01 milligrams per
cubic meter (0.01 mg/m³)
for an 8-hour workday, 40-hour workweek. The National Institute
of Occupational Safety and Health (NIOSH) also recommends
that workplace air contain no more that 0.01 mg/m³
silver.
The American Conference of Governmental
Industrial Hygienists (ACGIH) recommends that workplace air
contain no more than 0.1 mg/m³
silver metal and 0.01 mg/m³
soluble silver compounds.
The federal recommendations have been
updated as of July 1999.
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Glossary |
Carcinogenicity: Ability to cause cancer.
Milligram (mg): One thousandth of a gram.
National Priorities List: A list of the
nation's worst hazardous waste sites.
Soluble: Capable of being dissolved in
water.
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1990. Toxicological Profile for silver. Atlanta, GA: U.S. Department of Health
and Human Services, Public Health Service.
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Where can I get more information? |
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. For more information, contact:
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Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Phone: 1-888-42-ATSDR (1-888-422-8737)
FAX: (770)-488-4178
Email: ATSDRIC@cdc.gov
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