1
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
This public health statement tells you about barium and barium compounds and the effects of
exposure to these chemicals.
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. Barium and barium compounds have been found in at least
798 of the 1,684 current or former NPL sites; however, the total number of NPL sites evaluated
for these substances is not known. This information is important because these sites may be
sources of exposure and exposure to this substance 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 barium and barium compounds, 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 them. You must also consider any other chemicals you are exposed to
and your age, sex, diet, family traits, lifestyle, and state of health.
1.1 WHAT IS BARIUM?
Barium is a silvery-white metal that takes on a silver-yellow color when exposed to air. Barium
occurs in nature in many different forms called compounds. These compounds are solids,
existing as powders or crystals, and they do not burn well. Two forms of barium, barium sulfate
and barium carbonate, are often found in nature as underground ore deposits. Barium is
sometimes found naturally in drinking water and food. Because certain barium compounds
(barium sulfate and barium carbonate) do not mix well with water, the amount of barium usually
found in drinking water is small. Other barium compounds, such as barium chloride, barium
nitrate, and barium hydroxide, are manufactured from barium sulfate. Barium compounds such
2
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
as barium acetate, barium chloride, barium hydroxide, barium nitrate, and barium sulfide
dissolve more easily in water than barium sulfate and barium carbonate, but because they are not
commonly found in nature, they do not typically end up in drinking water unless the water is
contaminated by barium compounds that are released from waste sites.
Barium and barium compounds are used for many important purposes. Barium sulfate ore is
mined and used in several industries. It is used mostly by the oil and gas industries to make
drilling muds. Drilling muds make it easier to drill through rock by keeping the drill bit
lubricated. Barium sulfate is also used to make paints, bricks, tiles, glass, rubber, and other
barium compounds. Some barium compounds, such as barium carbonate, barium chloride, and
barium hydroxide, are used to make ceramics, insect and rat poisons, and additives for oils and
fuels; in the treatment of boiler water; in the production of barium greases; as a component in
sealants, paper manufacturing, and sugar refining; in animal and vegetable oil refining; and in the
protection of objects made of limestone from deterioration. Barium sulfate is sometimes used by
doctors to perform medical tests and take x-ray photographs of the stomach and intestines.
More information on the chemical and physical properties and use of barium is found in
Chapters 4 and 5.
1.2 WHAT HAPPENS TO BARIUM WHEN IT ENTERS THE ENVIRONMENT?
The length of time that barium will last in air, land, water, or sediments following release of
barium into these media depends on the form of barium released. Barium compounds that do not
dissolve well in water, such as barium sulfate and barium carbonate, can persist for a long time
in the environment. Barium compounds, such as barium chloride, barium nitrate, or barium
hydroxide, that dissolve easily in water usually do not last in these forms for a long time in the
environment. The barium in these compounds that is dissolved in water quickly combines with
sulfate or carbonate that are naturally found in water and become the longer lasting forms
(barium sulfate and barium carbonate). Barium sulfate and barium carbonate are the barium
compounds most commonly found in the soil and water. If barium sulfate and barium carbonate
3
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
are released onto land, they will combine with particles of soil. More information on the
environmental fate of barium is found in Chapter 6.
1.3 HOW MIGHT I BE EXPOSED TO BARIUM?
Background levels of barium in the environment are very low. The air that most people breathe
contains about 0.0015 parts of barium per billion parts of air (ppb). The air around factories that
release barium compounds into the air has about 0.33 ppb or less of barium. Most surface water
and public water supplies contain on average 0.030 parts of barium per million parts of water
(ppm) or less, but can average as high as 0.30 ppm in some regions of the United States. In some
areas that have underground water wells, drinking water may contain more barium than the
2 ppm limit set by EPA. The highest amount measured from these water wells has been 10 ppm.
The amount of barium found in soil ranges from about 15 to 3,500 ppm. Some foods, such as
Brazil nuts, seaweed, fish, and certain plants, may contain high amounts of barium. The amount
of barium found in food and water usually is not high enough to be a health concern. However,
information is still being collected to determine if long-term exposure to low levels of barium
causes any health problems.
People with the greatest known risk of exposure to high levels of barium are those working in
industries that make or use barium compounds. Most of these exposed persons breathe air that
contains barium sulfate or barium carbonate. Sometimes they are exposed to one of the more
harmful barium compounds (for example, barium chloride or barium hydroxide) by breathing the
dust from these compounds or by getting them on their skin. Barium carbonate can be harmful if
accidentally eaten because it will dissolve in the acids within the stomach unlike barium sulfate,
which will not dissolve in the stomach. Many hazardous waste sites contain barium compounds,
and these sites may be a source of exposure for people living and working near them. Exposure
near hazardous waste sites may occur by breathing dust, eating soil or plants, or drinking water
that is polluted with barium. People near these sites may also get soil or water that contains
barium on their skin. More information on how you might be exposed to barium is found in
Chapter 6.
4
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
1.4 HOW CAN BARIUM ENTER AND LEAVE MY BODY?
Barium enters your body when you breathe air, eat food, or drink water containing barium. It
may also enter your body to a small extent when you have direct skin contact with barium
compounds. The amount of barium that enters the bloodstream after you breathe, eat, or drink it
depends on the barium compound. Some barium compounds that are soluble, such as barium
chloride, can enter bloodstream more easily than insoluble barium compounds such as barium
sulfate. Some barium compounds (for example, barium chloride) can enter your body through
your skin, but this is very rare and usually occurs in industrial accidents at factories where they
make or use barium compounds. Barium at hazardous waste sites may enter your body if you
breathe dust, eat soil or plants, or drink water polluted with barium from this area.
Barium that enters your body by breathing, eating, or drinking is removed mainly in feces and
urine. Most of the barium that enters your body is removed within 1–2 weeks. Most of the small
amount of barium that stays in your body goes into the bones and teeth. More information on
how barium enters and leaves your body is found in Chapter 3.
1.5 HOW CAN BARIUM 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 health effects associated with exposure to different barium compounds depend on how well
the specific barium compound dissolves in water or in the stomach. For example, barium sulfate
5
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
does not easily dissolve in water and causes few harmful health effects. Doctors sometimes give
barium sulfate orally or by placing it directly in the rectum of patients for purposes of making x-
rays of the stomach or intestines. The use of this particular barium compound in this type of
medical test is not harmful to people. Barium compounds such as barium acetate, barium
chloride, barium hydroxide, barium nitrate, and barium sulfide that dissolve in water can cause
harmful health effects. Barium carbonate does not dissolve in water, but does dissolve in the
stomach; it can also cause harmful health effects.
Eating or drinking very large amounts of barium compounds that dissolve in water or in the
stomach can cause changes in heart rhythm or paralysis in humans. Some people who did not
seek medical treatment soon after eating or drinking a very large amount of barium have died.
Some people who eat or drink somewhat smaller amounts of barium for a short period may
experience vomiting, abdominal cramps, diarrhea, difficulties in breathing, increased or
decreased blood pressure, numbness around the face, and muscle weakness. One study showed
that people who drank water containing as much as 10 ppm of barium for 4 weeks did not have
increased blood pressure or abnormal heart rhythms. The health effects of barium have been
studied more often in experimental animals than in humans. Rats that ate or drank barium over
short periods had swelling and irritation of the intestines, changes in organ weights, decreased
body weight, and increased numbers of deaths. Rats and mice that drank barium over long
periods had damage to the kidneys, decreases in body weight, and decreased survival. We have
no information about the ability of barium to affect reproduction in humans; a study in
experimental animals did not find reproductive effects.
Some studies of humans and experimental animals exposed to barium in the air have reported
damage to the lungs, but other studies have not found these effects. We have no reliable
information about the health effects in humans or experimental animals that are exposed to
barium by direct skin contact.
Barium has not been shown to cause cancer in humans or in experimental animals drinking
barium in water. The Department of Health and Human Services and the International Agency
for Research on Cancer have not classified barium as to its carcinogenicity. The EPA has
6
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
determined that barium is not likely to be carcinogenic to humans following ingestion and that
there is insufficient information to determine whether it will be carcinogenic to humans
following inhalation exposure.
More information on the health effects of barium can be found in Chapter 3.
1.6
HOW CAN BARIUM AFFECT CHILDREN?
This section discusses potential health effects in humans from exposures during the period from
conception to maturity at 18 years of age.
We do not know whether children will be more or less sensitive than adults to barium toxicity.
A study in rats that swallowed barium found a decrease in newborn body weight; we do not
know if a similar effect would be seen in humans.
1.7
HOW CAN FAMILIES REDUCE THE RISK OF EXPOSURE TO BARIUM?
If your doctor finds that you have been exposed to substantial amounts of barium, ask whether
your children might also have been exposed. Your doctor might need to ask your state health
department to investigate.
The greatest potential source of barium exposure is through food and drinking water. However,
the amount of barium in foods and drinking water are typically too low to be of concern.
1.8
IS THERE A MEDICAL TEST TO DETERMINE WHETHER I HAVE BEEN
EXPOSED TO BARIUM?
There is no routine medical test to determine whether you have been exposed to barium. Doctors
can measure barium in body tissues and fluids, such as bones, blood, urine, and feces, using very
complex instruments. These tests cannot be used to predict the extent of the exposure or
potential health effects. This is normally done only for cases of severe barium poisoning and for
medical research.
7
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
More information on testing for barium exposure is found in Chapters 3 and 7.
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. 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 barium include the following:
The EPA has determined that drinking water should not contain more than 2.0 milligrams (mg)
barium per liter (L) of water (2.0 mg/L).
OSHA has a legally enforceable occupational exposure limit of 0.5 mg of soluble barium
compounds per cubic meter (m
3
) of air averaged over an 8-hour work day. The OSHA 8-hour
exposure limit for barium sulfate dust in air is 15 mg/m
3
for total dust. NIOSH considers
8
BARIUM AND BARIUM COMPOUNDS
1. PUBLIC HEALTH STATEMENT
exposure to barium chloride levels of 50 mg/m
3
and higher as immediately dangerous to life or
health.
More information on government regulations can be found in Chapter 8.
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 contact ATSDR at the address and phone number below.
ATSDR can also tell you the location of occupational and environmental health clinics. These
clinics specialize in recognizing, evaluating, and treating illnesses that result from exposure to
hazardous substances.
Toxicological profiles are also available on-line at www.atsdr.cdc.gov and on CD-ROM. You
may request a copy of the ATSDR ToxProfiles
TM
CD-ROM by calling the toll-free information
and technical assistance number at 1-800-CDCINFO (1-800-232-4636), by e-mail at
cdcinfo@cdc.gov, or by writing to:
Agency for Toxic Substances and Disease Registry
Division
of
Toxicology
and Environmental Medicine
1600 Clifton Road NE
Mailstop
F-32
Atlanta,
GA
30333
Fax:
1-770-488-4178
Organizations for-profit may request copies of final Toxicological Profiles from the following:
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield,
VA
22161
Phone:
1-800-553-6847
or
1-703-605-6000
Web
site:
http://www.ntis.gov/
Document Outline - 1. PUBLIC HEALTH STATEMENT
- 1.1 WHAT IS BARIUM?
- 1.2 WHAT HAPPENS TO BARIUM WHEN IT ENTERS THE ENVIRONMENT?
- 1.3 HOW MIGHT I BE EXPOSED TO BARIUM?
- 1.4 HOW CAN BARIUM ENTER AND LEAVE MY BODY?
- 1.5 HOW CAN BARIUM AFFECT MY HEALTH?
- 1.6 HOW CAN BARIUM AFFECT CHILDREN?
- 1.7 HOW CAN FAMILIES REDUCE THE RISK OF EXPOSURE TO BARIUM?
- 1.8 IS THERE A MEDICAL TEST TO DETERMINE WHETHER I HAVE BEEN EXPOSED TO BARIUM?
- 1.9 WHAT RECOMMENDATIONS HAS THE FEDERAL GOVERNMENT MADE TO PROTECT HUMAN HEALTH?
- 1.10 WHERE CAN I GET MORE INFORMATION?
Dostları ilə paylaş: |