1.1 What is cobalt? |
1.2 What happens to cobalt when it enters
the environment? |
1.3 How might I be exposed to cobalt? |
1.4 How can cobalt enter and leave my
body? |
1.5 How can cobalt affect my health? |
1.6 How can cobalt affect children? |
1.7 How can families reduce the risk of
exposure to cobalt? |
1.8 Is there a medical test to determine
whether I have been exposed to cobalt? |
1.9 What recommendations has the federal
government made to protect human health? |
1.10 Where can I get more information? |
References |
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April 2004 |
Public Health Statement |
for |
Cobalt |
(Cobalto) |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for cobalt. 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 1-888-422-8737.
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This public health statement tells you
about cobalt and the effects of exposure.
The Environmental Protection Agency (EPA)
identifies the most serious hazardous waste sites in the nation.
These sites make up the National Priorities List (NPL) and
are the sites targeted for long-term federal cleanup activities.
Stable cobalt has been found in at least 426 of the 1,636
current or former NPL sites. Radioactive cobalt, as 60Co,
has been found in at least 13 of the 1,636 current or former
NPL sites. However, the total number of NPL sites evaluated
for this substance is not known. As more sites are evaluated,
the sites at which cobalt is found may increase. This information
is important because exposure to this substance may harm you
and because these sites may be sources of exposure.
When a substance is released from a large
area, such as an industrial plant, or from a container, such
as a drum or bottle, it enters the environment. This release
does not always lead to exposure. You are 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.
External exposure to radiation may occur
from natural or man-made sources. Naturally occurring sources
of radiation are cosmic radiation from space or radioactive
materials in soil or building materials. Man-made sources
of radioactive materials are found in consumer products, industrial
equipment, atom bomb fallout, and to a smaller extent from
hospital waste and nuclear reactors.
If you are exposed to cobalt, many factors
determine whether you'll 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 the other
chemicals you're exposed to and your age, sex, diet, family
traits, lifestyle, and state of health.
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1.1
What is cobalt? |
Cobalt is a naturally-occurring element
that has properties similar to those of iron and nickel. It
has an atomic number of 27. There is only one stable isotope
of cobalt, which has an atomic mass number of 59. (An element
may have several different forms, called isotopes, with different
weights depending on the number of neutrons that it contains.
The isotopes of an element, therefore, have different atomic
mass numbers [number of protons and neutrons], although the
atomic number [number of protons] remains the same.) However,
there are many unstable or radioactive isotopes, two of which
are commercially important, cobalt 60 and cobalt 57, also
written as Co 60 or 60Co and Co 57 or 57Co,
and read as cobalt sixty and cobalt fifty-seven. All isotopes
of cobalt behave the same chemically and will therefore have
the same chemical behavior in the environment and the same
chemical effects on your body. However, isotopes have different
mass numbers and the radioactive isotopes have different radioactive
properties, such as their half-life and the nature of the
radiation they give off. The half-life of a cobalt isotope
is the time that it takes for half of that isotope to give
off its radiation and change into a different isotope. After
one half-life, one-half of the radioactivity is gone. After
a second half-life, one-fourth of the original radioactivity
is left, and so on. Radioactive isotopes are constantly changing
into different isotopes by giving off radiation, a process
referred to as radioactive decay. The new isotope may be a
different element or the same element with a different mass.
Small amounts of cobalt are naturally
found in most rocks, soil, water, plants, and animals, typically
in small amounts. Cobalt is also found in meteorites. Elemental
cobalt is a hard, silvery grey metal. However, cobalt is usually
found in the environment combined with other elements such
as oxygen, sulfur, and arsenic. Small amounts of these chemical
compounds can be found in rocks, soil, plants, and animals.
Cobalt is even found in water in dissolved or ionic form,
typically in small amounts. (Ions are atoms, collections of
atoms, or molecules containing a positive or negative electric
charge.) A biochemically important cobalt compound is vitamin
B12 or cyanocobalamin. Vitamin B12 is
essential for good health in animals and humans. Cobalt is
not currently mined in the United States, but has been mined
in the past. Therefore, we obtain cobalt and its other chemical
forms from imported materials and by recycling scrap metal
that contains cobalt.
Cobalt metal is usually mixed with other
metals to form alloys, which are harder or more resistant
to wear and corrosion. These alloys are used in a number of
military and industrial applications such as aircraft engines,
magnets, and grinding and cutting tools. They are also used
in artificial hip and knee joints. Cobalt compounds are used
as colorants in glass, ceramics, and paints, as catalysts,
and as paint driers. Cobalt colorants have a characteristic
blue color; however, not all cobalt compounds are blue. Cobalt
compounds are also used as trace element additives in agriculture
and medicine.
Cobalt can also exist in radioactive
forms. A radioactive isotope of an element constantly gives
off radiation, which can change it into an isotope of a different
element or a different isotope of the same element. This newly
formed nuclide may be stable or radioactive. This process
is called radioactive decay. 60Co is the most important
radioisotope of cobalt. It is produced by bombarding natural
cobalt, 59Co, with neutrons in a nuclear reactor.
60Co decays by giving off a beta ray (or electron),
and is changed into a stable nuclide of nickel (atomic number
28). The half-life of 60Co is 5.27 years. The decay
is accompanied by the emission of high energy radiation called
gamma rays. 60Co is used as a source of gamma rays
for sterilizing medical equipment and consumer products, radiation
therapy for treating cancer patients, and for manufacturing
plastics. 60Co has also been used for food irradiation;
depending on the radiation dose, this process may be used
to sterilize food, destroy pathogens, extend the shelf-life
of food, disinfest fruits and grain, delay ripening, and retard
sprouting (e.g., potatoes and onions). 57Co is
used in medical and scientific research and has a half-life
of 272 days. 57Co undergoes a decay process called
electron capture to form a stable isotope of iron (57Fe).
Another important cobalt isotope, 58Co, is produced
when nickel is exposed to a source of neutrons. Since nickel
is used in nuclear reactors, 58Co may be unintentionally
produced and appear as a contaminant in cooling water released
by nuclear reactors. 58Co also decays by electron
capture, forming another stable isotope of iron (58Fe). 60Co
may be similarly produced from cobalt alloys in nuclear reactors
and released as a contaminant in cooling water. 58Co
has a half-life of 71 days and gives off beta and gamma radiation
in the decay process.
Quantities of radioactive cobalt are
normally measured in units of radioactivity (curies or becquerels)
rather than in units of mass (grams). The becquerel (Bq) is
a new international unit, and the curie (Ci) is the traditional
unit; both are currently used. A becquerel is the amount of
radioactive material in which 1 atom transforms every second,
and a curie is the amount of radioactive material in which
37 billion atoms transform every second. For an overview of
basic radiation physics, chemistry, and biology see Appendix
D of the cobalt profile. For more information on radiation,
see the ATSDR
Toxicological Profile for Ionizing Radiation.
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1.2
What happens to cobalt when it enters the environment? |
Cobalt may enter the environment from
both natural sources and human activities. Cobalt occurs naturally
in soil, rock, air, water, plants, and animals. It may enter
air and water, and settle on land from windblown dust, seawater
spray, volcanic eruptions, and forest fires and may additionally
get into surface water from runoff and leaching when rainwater
washes through soil and rock containing cobalt. Soils near
ore deposits, phosphate rocks, or ore smelting facilities,
and soils contaminated by airport traffic, highway traffic,
or other industrial pollution may contain high concentrations
of cobalt. Small amounts of cobalt may be released into the
atmosphere from coal-fired power plants and incinerators,
vehicular exhaust, industrial activities relating to the mining
and processing of cobalt-containing ores, and the production
and use of cobalt alloys and chemicals. 58Co and
60Co may be released to the environment as a result
of nuclear accidents (i.e, Chernobyl), radioactive waste dumping
in the sea or from radioactive waste landfills, and nuclear
power plant operations.
Cobalt cannot be destroyed in the environment.
It can only change its form or become attached or separated
from particles. Cobalt released from power plants and other
combustion processes is usually attached to very small particles.
Cobalt contained in windborne soil is generally found in larger
particles than those released from power plants. These large
particles settle to the ground or are washed out of the air
by rain. Cobalt that is attached to very small particles may
stay in the air for many days. Cobalt released into water
may stick to particles in the water column or to the sediment
at the bottom of the body of water into which it was released,
or remain in the water column in ionic form. The specific
fate of cobalt will depend on many factors such as the chemistry
of the water and sediment at a site as well as the cobalt
concentration and water flow. Cobalt deposited on soil is
often strongly attached to soil particles and therefore would
not travel very far into the ground. However, the form of
the cobalt and the nature of the soil at a particular site
will affect how far cobalt will penetrate into the soil. Both
in soil and sediment, the amount of cobalt that is mobile
will increase under more acidic conditions. Ultimately, most
cobalt ends up in the soil or sediment.
Plants can accumulate very small amounts
of cobalt from the soil, especially in the parts of the plant
that you eat most often, such as the fruit, grain, and seeds.
While animals that eat these plants will accumulate cobalt,
cobalt is not known to biomagnify (produce increasingly higher
concentrations) up the food chain. Therefore, vegetables,
fruits, fish, and meat that you consume will generally not
contain high amounts of cobalt. Cobalt is an essential element,
required for good health in animals and humans, and therefore,
it is important that foodstuffs contain adequate quantities
of cobalt.
60Co and 58Co are
moderately short-lived, manufactured radioactive isotopes
that are produced in nuclear reactors. Although these isotopes
are not produced by nuclear fission, small amounts of these
radioisotopes are also produced by the neutron interaction
with the structural materials found in the reactor of nuclear
plants, and are produced during the routine operation of nuclear
plants. Small amounts may be released to the environment as
contaminants in cooling water or in radioactive waste. Since
these isotopes are not fission products, they are not produced
in nuclear weapons testing and are not associated with nuclear
fallout. In the environment, radioactive isotopes of cobalt
will behave chemically like stable cobalt. However, 60Co
and 58Co will also undergo radioactive decay according
to their respective half-lives, 5.27 years and 71 days.
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1.3
How might I be exposed to cobalt? |
Cobalt is widely dispersed in the environment
in low concentrations. You may be exposed to small amounts
of cobalt by breathing air, drinking water, and eating food
containing it. Children may also be exposed to cobalt by eating
dirt. You may also be exposed by skin contact with soil, water,
cobalt alloys, or other substances that contain cobalt. Analytical
methods used by scientists to determine the levels of cobalt
in the environment generally do not determine the specific
chemical form of cobalt present. Therefore, we do not always
know the chemical form of cobalt to which a person may be
exposed. Similarly, we do not know what forms of cobalt are
present at hazardous waste sites. Some forms of cobalt may
be insoluble or so tightly attached to particles or embedded
in minerals that they are not taken up by plants and animals.
Other forms of cobalt that are weakly attached to particles
may be taken up by plants and animals.
The concentration of cobalt in soil varies
widely, generally ranging from about 1 to 40 ppm (1 ppm=1
part of cobalt in a million parts of soil by weight), with
an average level of 7 ppm. Soils containing less than about
3 ppm of cobalt are considered cobalt-deficient because plants
growing in them do not have sufficient cobalt to meet the
dietary requirements of cattle and sheep. Such cobalt-deficient
soils are found in some areas in the southeast and northeast
parts of the United States. On the other hand, soils near
cobalt-containing mineral deposits, mining and smelting facilities,
or industries manufacturing or using cobalt alloys or chemicals
may contain much higher levels of cobalt.
Usually, the air contains very small
amounts of cobalt, less than 2 nanograms (1 nanogram=one-billionth
part of a gram) per cubic meter (ng/m3). The amount
of cobalt that you breathe in a day is much less than what
you consume in food and water. You may breathe in higher levels
of cobalt in dust in areas near cobalt-related industries
or near certain hazardous waste sites.
The concentration of cobalt in surface
and groundwater in the United States is generally low-between
1 and 10 parts of cobalt in 1 billion parts of water (ppb)
in populated areas; concentration may be hundreds or thousands
times higher in areas that are rich in cobalt-containing minerals
or in areas near mining or smelting operations. In most drinking
water, cobalt levels are less than 1-2 ppb.
For most people, food is the largest
source of cobalt intake. The average person consumes about
11 micrograms of cobalt a day in their diet. Included in this
food is vitamin B12, which is found in meat and
diary products. The recommended daily intake of vitamin B12
is 6 micrograms (1 microgram=one-millionth part of a gram).
You may also be exposed to higher levels
of cobalt if you work in metal mining, smelting, and refining,
in industries that make or use cutting or grinding tools,
or in other industries that produce or use cobalt metal and
cobalt compounds. If good industrial hygiene is practiced,
such as the use of exhaust systems in the workplace, exposure
can be reduced to safe levels. Industrial exposure results
mainly from breathing cobalt-containing dust.
When we speak of exposure to 60Co,
we are interested in exposure to the radiation given off by
this isotope, primarily the gamma rays. The general population
is rarely exposed to this radiation unless a person is undergoing
radiation therapy. However, workers at nuclear facilities,
irradiation facilities, or nuclear waste storage sites may
be exposed to 60Co or 58Co. Exposures
to radiation at these facilities are regulated and carefully
monitored and controlled.
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1.4
How can cobalt enter and leave my body? |
Cobalt can enter your body when you breathe
in air containing cobalt dust, when you drink water that contains
cobalt, when you eat food that contains cobalt, or when your
skin touches materials that contain cobalt. If you breathe
in air that contains cobalt dust, the amount of inhaled cobalt
that stays in your lungs depends on the size of the dust particles.
The amount that is then absorbed into your blood depends on
how well the particles dissolve. If the particles dissolve
easily, then it is easier for the cobalt to pass into your
blood from the particles in your lungs. If the particles dissolve
slowly, then they will remain in your lungs longer. Some of
the particles will leave your lungs as they normally clean
themselves out. Some of the particles will be swallowed into
your stomach. The most likely way you will be exposed to excess
cobalt is by eating contaminated food or drinking contaminated
water. Levels of cobalt normally found in the environment,
however, are not high enough to result in excess amounts of
cobalt in food or water. The amount of cobalt that is absorbed
into your body from food or water depends on many things including
your state of health, the amount you eat or drink, and the
number of days, weeks, or years you eat foods or drink fluids
containing cobalt. If you do not have enough iron in your
body, the body may absorb more cobalt from the foods you eat.
Once cobalt enters your body, it is distributed into all tissues,
but mainly into the liver, kidney, and bones. After cobalt
is breathed in or eaten, some of it leaves the body quickly
in the feces. The rest is absorbed into the blood and then
into the tissues throughout the body. The absorbed cobalt
leaves the body slowly, mainly in the urine. Studies have
shown that cobalt does not readily enter the body through
normal skin, but it can if the skin has been cut.
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1.5
How can cobalt affect my health? |
To protect the public from the harmful
effects of toxic chemicals and to find ways to treat people
who have been harmed, scientists use many tests.
One way to see if a chemical will hurt
people is to learn how the chemical is absorbed, used, and
released by the body. In the case of a radioactive chemical,
it is also important to gather information concerning the
radiation dose and dose rate to the body. For some chemicals,
animal testing may be necessary. Animal testing may also be
used to identify health effects such as cancer or birth defects.
Without laboratory animals, scientists would lose a basic
method to get information needed to make wise decisions to
protect public health. Scientists have the responsibility
to treat research animals with care and compassion. Laws today
protect the welfare of research animals, and scientists must
comply with strict animal care guidelines.
Cobalt has both beneficial and harmful
effects on human health. Cobalt is beneficial for humans because
it is part of vitamin B12, which is essential to
maintain human health. Cobalt
(0.16-1.0 mg cobalt/kg of body weight) has also been used
as a treatment for anemia (less than normal number of red
blood cells), including in pregnant women, because it causes
red blood cells to be produced. Cobalt also increases red
blood cell production in healthy people, but only at very
high exposure levels. Cobalt is also essential for the health
of various animals, such as cattle and sheep. Exposure of
humans and animals to levels of cobalt normally found in the
environment is not harmful.
When too much cobalt is taken into your
body, however, harmful health effects can occur. Workers who
breathed air containing 0.038 mg cobalt/m3 (about
100,000 times the concentration normally found in ambient
air) for 6 hours had trouble breathing. Serious effects on
the lungs, including asthma, pneumonia, and wheezing, have
been found in people exposed to 0.005 mg cobalt/m3
while working with hard metal, a cobalt-tungsten carbide alloy.
People exposed to 0.007 mg cobalt/m3 at work have
also developed allergies to cobalt that resulted in asthma
and skin rashes. The general public, however, is not likely
to be exposed to the same type or amount of cobalt dust that
caused these effects in workers.
In the 1960s, some breweries added cobalt
salts to beer to stabilize the foam (resulting in exposures
of 0.04-0.14 mg cobalt/kg). Some people who drank excessive
amounts of beer (8-25 pints/day) experienced serious effects
on the heart. In some cases, these effects resulted in death.
Nausea and vomiting were usually reported before the effects
on the heart were noticed. Cobalt is no longer added to beer
so you will not be exposed from this source. The effects on
the heart, however, may have also been due to the fact that
the beer-drinkers had protein-poor diets and may have already
had heart damage from alcohol abuse. Effects on the heart
were not seen, however, in people with anemia treated with
up to 1 mg cobalt/kg, or in pregnant women with anemia treated
with 0.6 mg cobalt/kg. Effects on the thyroid were found in
people exposed to 0.5 mg cobalt/kg for a few weeks. Vision
problems were found in one man following treatment with 1.3
mg cobalt/kg for 6 weeks, but this effect has not been seen
in other human or animal studies.
Being exposed to radioactive cobalt may
be very dangerous to your health. If you come near radioactive
cobalt, cells in your body can become damaged from gamma rays
that can penetrate your entire body, even if you do not touch
the radioactive cobalt. Radiation from radioactive cobalt
can also damage cells in your body if you eat, drink, breathe,
or touch anything that contains radioactive cobalt. The amount
of damage depends on the amount of radiation to which you
are exposed, which is related to the amount of activity in
the radioactive material and the length of time that you are
exposed. Most of the information regarding health effects
from exposure to radiation comes from exposures for only short
time periods. The risk of damage from exposure to very low
levels of radiation for long time periods is not known. If
you are exposed to enough radiation, you might experience
a reduction in white blood cell number, which could lower
your resistance to infections. Your skin might blister or
burn, and you may lose hair from the exposed areas. This happens
to cancer patients treated with large amounts of radiation
to kill cancer. Cells in your reproductive system could become
damaged and cause temporary sterility. Exposure to lower levels
of radiation might cause nausea, and higher levels can cause
vomiting, diarrhea, bleeding, coma, and even death. Exposure
to radiation can also cause changes in the genetic materials
within cells and may result in the development of some types
of cancer.
Studies in animals suggest that exposure
to high amounts of nonradioactive cobalt during pregnancy
might affect the health of the developing fetus. Birth defects,
however, have not been found in children born to mothers who
were treated with cobalt for anemia during pregnancy. The
doses of cobalt used in the animal studies were much higher
than the amounts of cobalt to which humans would normally
be exposed.
Nonradioactive cobalt has not been found
to cause cancer in humans or in animals following exposure
in the food or water. Cancer has been shown, however, in animals
who breathed cobalt or when cobalt was placed directly into
the muscle or under the skin. Based on the animal data, the
International Agency for Research on Cancer (IARC) has determined
that cobalt is possibly carcinogenic to humans.
Much of our knowledge of cobalt toxicity
is based on animal studies. Cobalt is essential for the growth
and development of certain animals, such as cows and sheep.
Short-term exposure of rats to high levels of cobalt in the
air results in death and lung damage. Longer-term exposure
of rats, guinea pigs, hamsters, and pigs to lower levels of
cobalt in the air results in lung damage and an increase in
red blood cells. Short-term exposure of rats to high levels
of cobalt in the food or drinking water results in effects
on the blood, liver, kidneys, and heart. Longer-term exposure
of rats, mice, and guinea pigs to lower levels of cobalt in
the food or drinking water results in effects on the same
tissues (heart, liver, kidneys, and blood) as well as the
testes, and also causes effects on behavior. Sores were seen
on the skin of guinea pigs following skin contact with cobalt
for 18 days. Generally, cobalt compounds that dissolve easily
in water are more harmful than those that are hard to dissolve
in water.
Much of what we know about the effects
of radioactive cobalt comes from studies in animals. The greatest
danger of radiation seen in animals is the risk to the developing
animal, with even moderate amounts of radiation causing changes
in the fetus. High radiation doses in animals have also been
shown to cause temporary or permanent sterility and changes
in the lungs, which affected the animals' breathing. The blood
of exposed animals has lower numbers of white blood cells,
the cells that aid in resistance to infections, and red blood
cells, which carry oxygen in the blood. Radioactive cobalt
exposures in animals have also caused genetic damage to cells,
cancer, and even death.
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1.6
How can cobalt affect children? |
This section discusses potential health
effects from exposures during the period from conception to
maturity at 18 years of age in humans.
Children can be exposed to cobalt in
the same ways as adults. In addition, cobalt may be transferred
from the pregnant mother to the fetus or from the mother to
the infant in the breast milk. Children may be affected by
cobalt the same ways as adults. Studies in animals have suggested
that children may absorb more cobalt from foods and liquids
containing cobalt than adults. Babies exposed to radiation
while in their mother's womb are believed to be much more
sensitive to the effects of radiation than adults.
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1.7
How can families reduce the risk of exposure to cobalt? |
If your doctor finds that you have been
exposed to significant amounts of cobalt, ask whether your
children might also be exposed. Your doctor might need to
ask your state health department to investigate.
Since cobalt is naturally found in the
environment, people cannot avoid being exposed to it. However,
the relatively low concentrations present do not warrant any
immediate steps to reduce exposure. If you are accidentally
exposed to large amounts of cobalt, consult a physician immediately.
Children living near waste sites containing
cobalt are likely to be exposed to higher environmental levels
of cobalt through breathing, touching soil, and eating contaminated
soil. Some children eat a lot of dirt. You should discourage
your children from eating dirt. Make sure they wash their
hands frequently and before eating. Discourage your children
from putting their hands in their mouths or hand-to-mouth
activity.
You are unlikely to be exposed to high
levels of radioactive cobalt unless you are exposed as part
of a radiotherapy treatment, there is an accident involving
a cobalt sterilization or radiotherapy unit, or there is an
accidental release from a nuclear power plant. In such cases,
follow the advice of public health officials who will publish
guidelines for reducing exposure to radioactive material when
necessary. Workers who work near or with radioactive cobalt
should follow the workplace safety guidelines of their institution
carefully to reduce the risk of accidental irradiation.
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1.8
Is there a medical test to determine whether I have been exposed
to cobalt? |
We have reliable tests that can measure
cobalt in the urine and the blood for periods up to a few
days after exposure. The amount of cobalt in your blood or
urine can be used to estimate how much cobalt you had taken
into your body. The tests are not ableto accurately predict
potential health effects following exposure to cobalt.
It is difficult to determine whether
a person has been exposed only to external radiation from
radioactive cobalt unless the radiation dose was rather large.
Health professionals examining people who have health problems
similar to those resulting from radiation exposure would need
to rely on additional information in order to establish if
such people had been near a source of radioactivity. It is
relatively easy to determine whether a person has been internally
exposed to radioactive cobalt.
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1.9
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. Federal agencies that develop regulations
for toxic substances include the Environmental Protection
Agency (EPA), the Occupational Safety and Health Administration
(OSHA), the Food and Drug Administration (FDA), and the U.S.
Nuclear Regulatory Commission (USNRC).
Recommendations provide valuable guidelines
to protect public health but cannot be enforced by law. Federal
organizations that develop recommendations for toxic substances
include the Agency for Toxic Substances and Disease Registry
(ATSDR), the National Institute for Occupational Safety and
Health (NIOSH), and the FDA.
Regulations and recommendations can be
expressed in not-to-exceed levels in air, water, soil, or
food that are usually based on levels that affect animals;
they are then adjusted to help protect people.
Sometimes these not-to-exceed levels
differ among federal organizations because of different exposure
times (an 8 hour workday or a 24 hour day), the use of different
animal studies, or other factors.
Recommendations and regulations are also
periodically updated 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 cobalt include the following:
EPA requires that the federal government
be notified if more than 1,000 pounds of cobalt (as the bromide,
formate, and sulfamate compounds) are released into the environment
in a 24 hour period. OSHA regulates levels of nonradioactive
cobalt in workplace air. The limit for an 8 hour workday,
40 hour workweek is an average of 0.1 mg/m3. The
USNRC and the Department of Energy (DOE) regulate occupational
exposures as well as exposures of the general public to radioactive
cobalt.
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1.10
Where can I get more information? |
If you have any more questions or concerns, please contact
your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Information line and technical assistance:
Phone: 888-422-8737
FAX: (770)-488-4178
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.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 2004. Toxicological
profile for cobalt. Atlanta, GA: U.S. Department of Health
and Human Services, Public Health Service.
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