Public Health Statement for Nickel
PDF Versionpdf icon[87.8 KB]
This Public Health Statement is the summary chapter from the Toxicological Profile for Nickel. It is one in a series of Public Health Statements about hazardous substances and their health effects.
A shorter version, the ToxFAQs™, is also available. 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. For more information, call the ATSDR Information
Center at 1-800-232-4636.
This public health statement tells you about nickel and the effects of exposure to it.
The Environmental Protection Agency (EPA)
identifies the most serious hazardous waste sites in the nation.
These sites are then placed on the National Priorities List
(NPL) and are targeted for long-term federal clean-up activities.
Nickel has been found in at least 882 of the 1,662 current
or former NPL sites. Although the total number of NPL sites
evaluated for this substance is not known, the possibility
exists that the number of sites at which nickel is found may
increase in the future as more sites are evaluated. This information
is important because these sites may be sources of exposure
and exposure to nickel may harm you.
When a substance is released either from
a large area, such as an industrial plant, or from a container,
such as a drum or bottle, it enters the environment. Such
a release does not always lead to exposure. You can be exposed
to a substance only when you come in contact with it. You
may be exposed by breathing, eating, or drinking the substance,
or by skin contact.
If you are exposed to nickel, many factors
will determine whether you will be harmed. These factors include
the dose (how much), the duration (how long), and how you
come in contact with it. You must also consider any other
chemicals you are exposed to and your age, gender, diet, family
traits, lifestyle, and state of health.
What is nickel?
Pure nickel is a hard, silvery-white
metal, which has properties that make it very desirable for
combining with other metals to form mixtures called alloys.
Some of the metals that nickel can be alloyed with are iron,
copper, chromium, and zinc. These alloys are used in making
metal coins and jewelry and in industry for making items such
as valves and heat exchangers. Most nickel is used to make
stainless steel. There are also compounds consisting of nickel
combined with many other elements, including chlorine, sulfur,
and oxygen. Many of these nickel compounds are water soluble
(dissolve fairly easily in water) and have a characteristic
green color. Nickel and its compounds have no characteristic
odor or taste. Nickel compounds are used for nickel plating,
to color ceramics, to make some batteries, and as substances
known as catalysts that increase the rate of chemical reactions.
Nickel combined with other elements occurs
naturally in the earth's crust. It is found in all soil, and
is also emitted from volcanoes. Nickel is the 24th most abundant
element. In the environment, it is primarily found combined
with oxygen or sulfur as oxides or sulfides. Nickel is also
found in meteorites and on the ocean floor in lumps of minerals
called sea floor nodules. The earth's core is composed of
6% nickel. Nickel is released into the atmosphere during nickel
mining and by industries that make or use nickel, nickel alloys,
or nickel compounds. These industries also might discharge
nickel in waste water. Nickel is also released into the atmosphere
by oil-burning power plants, coal-burning power plants, and
There are no nickel mining operations
in the United States. Much of our nickel used in industries
comes from recycling nickel-containing alloys or is imported
mainly from Canada and Russia.
What happens to nickel when it enters the environment?
Nickel may be released to the environment
from the stacks of large furnaces used to make alloys or from
power plants and trash incinerators. The nickel that comes
out of the stacks of power plants attaches to small particles
of dust that settle to the ground or are taken out of the
air in rain or snow. It usually takes many days for nickel
to be removed from the air. If the nickel is attached to very
small particles, it can take more than a month to settle out
of the air. Nickel can also be released in industrial waste
water. A lot of nickel released into the environment ends
up in soil or sediment where it strongly attaches to particles
containing iron or manganese. Under acidic conditions, nickel
is more mobile in soil and might seep into groundwater. Nickel
does not appear to concentrate in fish. Studies show that
some plants can take up and accumulate nickel. However, it
has been shown that nickel does not accumulate in small animals
living on land that has been treated with nickel-containing
How might I be exposed to nickel?
Nickel normally occurs at very low levels
in the environment, so very sensitive methods are needed to
detect nickel in most environmental samples. Food is the major
source of exposure to nickel. You may also be exposed to nickel
by breathing air, drinking water, or smoking tobacco containing
nickel. Skin contact with soil, bath or shower water, or metals
containing nickel, as well as, metals plated with nickel can
also result in exposure. Stainless steel and coins contain
nickel. Some jewelry is plated with nickel or made from nickel
alloys. Patients may be exposed to nickel in artificial body
parts made from nickel-containing alloys. Exposure of an unborn
child to nickel is through the transfer of nickel from the
mother's blood to fetal blood. Likewise, nursing infants are
exposed to nickel through the transfer of nickel from the
mother to breast milk. However, the concentration of nickel
in breast milk is either similar or less than the concentration
of nickel in infant formulas and cow's milk.
We often do not know the exact form of
nickel we are exposed to, including at most hazardous waste
sites. Much of the nickel found in air, soil, sediment, and
rock is so strongly attached to dust and soil particles or
embedded in minerals that it is not readily taken up by plants
and animals and, therefore, cannot easily affect your health.
In water and waste water, nickel can exist either dissolved
in water or attached to material suspended in water.
Nickel in air is attached to small particles.
Over a 6-year period (1977-1982) in the United States, average
nickel concentrations in cities and in the country ranged
from 7 to 12 nanograms per cubic meter (ng/m3; 1 ng/m3 is
equivalent to 1 billionth of a gram in a cubic meter of air).
More recently, EPA estimates that the average nickel concentration
in air in the United States has decreased to 2.2 ng/m3, based
on air quality information obtained from 1996.
The concentration of nickel in the water
of rivers and lakes is very low, with the average concentration
usually less than 10 parts of nickel in a billion parts of
water (ppb). The level of nickel in water is often so low
that we cannot measure it unless we use very sensitive instruments.
The average concentration of nickel in drinking water in the
United States is between 2 and 4.3 ppb. However, you may be
exposed to higher-than-average levels of nickel in drinking
water if you live near industries that process or use nickel.
The highest levels of nickel in drinking water, about 72 ppb,
were found near areas of a large natural nickel deposit where
nickel is mined and refined.
Soil usually contains between 4 and 80
parts of nickel in a million parts of soil (ppm; 1 ppm=1,000
ppb). The highest soil concentrations (up to 9,000 ppm) are
found near industries that extract nickel from ore. High concentrations
of nickel occur as dust that is released into air from stacks
during processing and settles on the ground. You may be exposed
to nickel in soil by skin contact. Children may also be exposed
to nickel by eating soil.
Food contains nickel and is the major
source of nickel exposure for the general population. You
eat about 170 micrograms (µg; 1 µg=1 millionth
of a gram) of nickel in your food every day. Foods naturally
high in nickel include chocolate, soybeans, nuts, and oatmeal.
Our daily intake of nickel from drinking water is only about
2 µg. We breathe in between 0.1 and 1 µg nickel/day,
excluding nickel in tobacco smoke. We are exposed to nickel
when we handle coins and touch other metals containing nickel.
You may be exposed to higher levels of
nickel if you work in industries that process or use nickel.
You also may be exposed to nickel by breathing dust or fumes
(as from welding) or by skin contact with nickel-containing
metal and dust or solutions containing dissolved nickel compounds.
A national survey conducted from 1980 to 1983 estimated that
727,240 workers are potentially exposed to nickel metal, nickel
alloys, or nickel compounds.
How can nickel enter and leave my body?
Nickel can enter your body when you breathe
air containing nickel, when you drink water or eat food that
contains nickel, and when your skin comes into contact with
nickel. If you breathe air that contains nickel, the amount
of nickel you inhale that reaches your lungs and enters your
blood depends on the size of the nickel particles. If the
particles are large, they stay in your nose. If the particles
are small, they can enter deep into your lungs. More nickel
is absorbed from your lungs into your body when the nickel
particles can dissolve easily in water. When the particles
do not dissolve easily in water, the nickel may remain in
your lungs for a long time. Some of these nickel particles
can leave the lungs with mucus that you spit out or swallow.
More nickel will pass into your body through your stomach
and intestines if you drink water containing nickel than if
you eat food containing the same amount of nickel. A small
amount of nickel can enter your bloodstream from skin contact.
After nickel gets into your body, it can go to all organs,
but it mainly goes to the kidneys. The nickel that gets into
your bloodstream leaves in the urine. After nickel is eaten,
most of it leaves quickly in the feces, and the small amount
that gets into your blood leaves in the urine.
How can nickel affect my health?
Scientists use many tests to protect
the public from harmful effects of toxic chemicals and to
find ways for treating persons who have been harmed.
One way to learn whether a chemical will
harm people is to determine how the body absorbs, uses, and
releases the chemical. For some chemicals, animal testing
may be necessary. Animal testing may also help identify health
effects such as cancer or birth defects. Without laboratory
animals, scientists would lose a basic method for getting
information needed to make wise decisions that protect public
health. Scientists have the responsibility to treat research
animals with care and compassion. Scientists must comply with strict
animal care guidelines because laws today protect
the welfare of research animals.
The most common harmful health effect
of nickel in humans is an allergic reaction. Approximately
10-20% of the population is sensitive to nickel. A person
can become sensitive to nickel when jewelry or other items
containing nickel are in direct contact and prolonged contact
with the skin. Wearing jewelry containing nickel in ears or
other body parts that have been newly pierced may also sensitize
a person to nickel. However, not all jewelry containing nickel
releases enough of the nickel ion to sensitize a person. Once
a person is sensitized to nickel, further contact with the
metal may produce a reaction. The most common reaction is
a skin rash at the site of contact. In some sensitized people,
dermatitis (a type of skin rash) may develop in an area of
the skin that is away from the site of contact. For example,
hand eczema (another type of skin rash) is fairly common among
people sensitized to nickel. Some workers exposed to nickel
by inhalation can become sensitized and have asthma attacks,
but this is rare. People who are sensitive to nickel have
reactions when nickel comes into prolonged contact with the
skin. Some sensitized individuals react when they eat nickel
in food or water or breathe dust containing nickel. More women
are sensitive to nickel than men. This difference between
men and women is thought to be a result of greater exposure
of women to nickel through jewelry and other metal items.
People who are not sensitive to nickel
must eat very large amounts of nickel to suffer harmful health
effects. Workers who accidentally drank light-green water
containing 250 ppm of nickel from a contaminated drinking
fountain had stomach aches and suffered adverse effects in
their blood (increased red blood cells) and kidneys (increased
protein in the urine). This concentration of nickel is more
than 100,000 times greater than the amount usually found in
The most serious harmful health effects
from exposure to nickel, such as chronic bronchitis, reduced
lung function, and cancer of the lung and nasal sinus, have
occurred in people who have breathed dust containing certain
nickel compounds while working in nickel refineries or nickel-processing
plants. The levels of nickel in these workplaces were much
higher than usual (background) levels in the environment.
Lung and nasal sinus cancers occurred in workers who were
exposed to more than 10 mg nickel/m3 as nickel compounds that
were hard to dissolve (such as nickel subsulfide). Exposure
to high levels of nickel compounds that dissolve easily in
water (soluble) may also result in cancer when nickel compounds
that are hard to dissolve (less soluble) are present, or when
other chemicals that can produce cancer are present. The concentrations
of soluble and less-soluble nickel compounds that were found
to have produced cancers were 100,000 to 1 million times greater
than the usual level of nickel in the air in the United States.
The U.S. Department of Health and Human Services (DHHS) has
determined that nickel metal may reasonably be anticipated
to be a carcinogen and nickel compounds are known human carcinogens.
The International Agency for Research on Cancer (IARC) has
determined that some nickel compounds are carcinogenic to
humans and that metallic nickel may possibly be carcinogenic
to humans. The EPA has determined that nickel refinery dust
and nickel subsulfide are human carcinogens. These cancer
classifications were based on studies of nickel workers and
Lung inflammation and damage to the nasal
cavity have been observed in animals exposed to nickel compounds.
At high concentrations, the lung damage is severe enough to
affect lung function. Long-term exposure to lower levels of
a nickel compound that dissolves easily in water did not produce
cancer in animals. Lung cancer developed in rats exposed for
a long time to nickel compounds that do not dissolve easily
Oral exposure of humans to high levels
of soluble nickel compounds through the environment is extremely
unlikely. Because humans have only rarely been exposed to
high levels of nickel in water or food, much of our knowledge
of the harmful effects of nickel is based on animal studies.
Eating or drinking levels of nickel much greater than the
levels normally found in food and water have been reported
to produce lung disease in dogs and rats and to affect the
stomach, blood, liver, kidneys, and immune system in rats
and mice, as well as their reproduction and development.
How can nickel affect children?
This section discusses potential health effects in humans from exposures
during the period from conception to maturity at 18 years of age.
It is likely that the health effects seen in children exposed
to nickel will be similar to the effects seen in adults. We
do not know whether children differ from adults in their susceptibility
to nickel. Human studies that examined whether nickel can
harm the developing fetus are inconclusive. Animal studies
have found increases in newborn deaths and decreases in newborn
weight after ingesting nickel.
These doses are 1,000 times higher than
levels typically found in drinking water. It is likely that
nickel can be transferred from the mother to an infant in
breast milk and can cross the placenta. The nickel levels
in breast milk are likely to be similar to the levels in cow's
milk-based or soy-milk-based infant formula.
How can families reduce the risk of exposure to nickel?
If your doctor finds that you have been exposed to substantial amounts of nickel, ask whether your
children might also have been exposed. Your doctor might need to ask your state health department to investigate.
People may be exposed to nickel by wearing
jewelry that contains nickel. In some people, wearing jewelry
that contains nickel produces skin irritation. Avoiding jewelry
containing nickel will eliminate risks of exposure to this
source of this metal.
Other sources of nickel exposure are
through foods that you eat and drinking water. However, the
amount of nickel in foods and drinking water are too low to
be of concern.
Is there a medical test to determine whether I have been exposed to nickel?
Measurements of the amount
of nickel in your blood, feces, and urine can be used to estimate
your exposure to nickel. More nickel was found in the urine
of workers who were exposed to nickel compounds that dissolve
easily in water (soluble) than in the urine of workers exposed
to compounds that are hard to dissolve (less soluble). This
means that it is easier to tell if you have been exposed to
soluble nickel compounds than less-soluble compounds. The nickel
measurements do not accurately predict potential health effects
from exposure to nickel.
What recommendations has the federal government made to protect human health?
The federal government develops regulations
and recommendations to protect public health. Regulations
can be enforced by law. The EPA, the Occupational Safety and
Health Administration (OSHA), and the Food and Drug Administration
(FDA) are some federal agencies that develop regulations for
toxic substances. Recommendations provide valuable guidelines
to protect public health, but cannot be enforced by law. The
Agency for Toxic Substances and Disease Registry (ATSDR) and
the National Institute for Occupational Safety and Health
(NIOSH) are two federal organizations that develop recommendations
for toxic substances.
Regulations and recommendations can be
expressed as "not-to-exceed" levels, that is, levels
of a toxic substance in air, water, soil, or food that do
not exceed a critical value that is usually based on levels
that affect animals; they are then adjusted to levels that
will help protect humans. Sometimes these not-to-exceed levels
differ among federal organizations because they used different
exposure times (an 8-hour workday or a 24-hour day), different
animal studies, or other factors.
Recommendations and regulations are also
updated periodically as more information becomes available.
For the most current information, check with the federal agency
or organization that provides it. Some regulations and recommendations
for nickel include the following:
OSHA has set an enforceable limit of
1.0 mg nickel/m3 for metallic nickel and nickel compounds
in workroom air to protect workers during an 8-hour shift
over a 40-hour work week. EPA recommends that drinking water
levels for nickel should not be more than 0.1 mg per liter.
Agency for Toxic Substances and Disease Registry (ATSDR). 2005. Toxicological profile for Nickel. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.