years ago, researchers took tissue samples of fish from the wilds
of Northern Mainewith the idea that laboratory test results from
these samples could be used to reflect natural or background concentrations
of several pollutants accumulated in fish tissues. What they found
were surprisingly high concentrations of mercury. Those findings
prompted more widespread sampling and resulted in the statewide
fish consumption advisory that we have today.
Although industry and agriculture are perhaps the most obvious
sources of mercury in the environment, mercury-containing technologies
and chemicals are prevalent at most health care facilities. As
a result, proper mercury management at your facility is essential
to reducing mercury-related health risks for workers, patients,
the public, and the environment.
This pamphlet can help you better manage mercury and reduce mercury-related
problems. It contains the following information to help your facility:
Identify sources of mercury
Educate staff and purchasers about mercury-containing
Safely clean up mercury spills
Effectively manage mercury waste-streams, and
Find alternatives to mercury containing technologies
As a common, naturally occurring metal, easily obtained by roasting
its principal ore, cinnabar, mercury has a long history with man.
For centuries, powdered cinnabar was the source of the bright
red artist's pigment vermilion. Mercury was also used in such
various roles as a biocide, and a catalyst in gold mining. "Hatters"
in the felt hat industry of the 19th century used mercury
in the hat making process. Further, mercury has a lengthy past
in the folklore of several cultures.
Sometimes called "Quicksilver," mercury is a heavy, silver-colored
liquid in its elemental form. How many of you can remember passing
around a glob of mercury in science class, wondering at its weight
and surface tension? These unusual physical properties have made
it useful in many current technologies, such as pressure gauges
and switches where fluidity and weight are desirable.
Mercury and Today's Health Care Facilities.
Health care facilities use a number of mercury-containing products.
Some examples include:
- Electronic switches and relays
- Blood pressure monitoring devices (sphygmomanometers)
- Mirrored instruments
- Fluorescent light bulbs and high pressure sodium lamps
- Laboratory chemicals, especially histology stains containing
Thimersol, Zenker's Solution, mercuric chloride and mercurochrome
Wastewater streams emanating from hospitals often
show a higher than expected level of mercury. Apparently, the
mercury, being much heavier than water, has deposited itself in
drain traps and pipes over the years. Facilities that have cleaned
or replaced these fixtures have subsequently noticed a drop in
mercury levels in their wastewater. Of course, once the drains
are cleaned or replaced, the facilities face the challenge of
keeping mercury-containing materials from continuing to go down
the drain. Some hospitals have installed sample spigots in their
drains to monitor their wastewater periodically. These sample
ports also make pinpointing sources easier. Hospitals are also
discovering that the spaces between floor tiles and carpet fibers
can accumulate mercury from instrument breakage and chemical spills.
As mercury-containing products are identified, health care facilities
are responsive to finding alternative materials or technologies.
For example, blood pressure monitors and thermometers are now
available in mercury free technologies. Nonetheless, even with
the best of efforts, significant levels of this toxic metal can
still be found in the health care waste stream.
Where should my health care facility begin to address the mercury
There are several approaches that health care facilities can
take to minimize their contribution of mercury to the environment
The first step toward effective mercury management
Keep in mind that Material Safety Data Sheets (MSDS) may not
be particularly useful for this process. Often mercury is present
in relatively small quantities or is a proprietary ingredient,
and therefore is not listed or addressed on the MSDS. This is
especially true for histology laboratory chemicals. Therefore,
checking product labels and developing a mercury-awareness by
your purchasing staff is very important.
The second step toward effective mercury management
An effective training program must emphasize that there is a
difference between mercury-containing waste and biomedical,
or so called "Red-Bag" waste. Mercury-containing waste is a
toxic hazardous waste. Although biomedical waste may contain
trace amounts of mercury, it is by definition a waste that contains
human pathogens of sufficient virulence and in sufficient concentrations
that exposure to them could result in disease. Biomedical waste
is not necessarily a hazardous waste. Mercury waste must be
managed as a hazardous waste, which begins with segregation
and accumulation in a labeled container. The hazardous waste
is then typically shipped offsite using a DEP licensed hazardous
The third step toward effective mercury management
Since mercury-containing waste is often mixed with biomedical
waste, and biomedical waste is not always managed as a hazardous
waste, segregation of waste types is critical.
The final disposition of biomedical waste
is usually incineration, often in small biomedical incinerators
located at health care facilities. These biomedical incinerators
have never been required to utilize advanced afterburner pollution
control technologies. Therefore, they have a greater potential
for introducing pollutants into the environment than do larger
incinerators, such as those of trash-to-energy plants.
Several recent studies aimed at identifying potential sources
of atmospheric mercury pollution have concluded that biomedical
waste incineration is a significant source of atmospheric mercury.
The United States Environmental Protection Agency recently enacted
regulations that will dramaticaly reduce allowable emissions for
several pollutants, including mercury. Retrofitting the biomedical
incinerators will be financially prohibitive. The result of this
action in Maine will be the closure of small incinerators located
Your staff needs to know this to understand why a sharps container
is not an appropriate place for a mercury-containing waste, such
as a broken mercury thermometer. Segregation of mercury-containing
waste from biomedical waste is crucial.
What is the best way to clean up a mercury spill?
Mercury spills, although usually small in volume, present some
unique problems for complete and proper cleanup. Health Care Without
Harm recommends the following procedure:
Ventilate the area. Do not use a vacuum.
Assemble the following materials: gloves, an eyedropper, two
stiff pieces of cardboard, two plastic bags, a large tray, duct
tape, a flashlight and a wide mouth container.
Do not touch the mercury. Remove all jewelry
from your hands as mercury will bond with the metal. Wear rubber
gloves. Use the flashlight to locate the mercury. The light
will reflect off the mercury beads and make them easier to find.
On a hard or tightly woven fabric floor use
the stiff paper to push beads of mercury together. Use the eyedropper
to suction the beads of mercury, or working over the tray to
catch any spills, lift the beads of mercury with the stiff paper.
Carefully place the mercury in a wide mouth container. Pick
up any remaining beads of mercury with sticky tape and place
contaminated tape in a plastic bag along with the eyedropper,
stiff paper and gloves. Place this bag into the other plastic
bag. Label the bag as hazardous waste.
On a carpet or rug, the mercury contaminated
section should be cut out and disposed of as hazardous waste.
Once recovered, the mercury should be accumulated
in a labeled container and stored in a secure area, perhaps
with other hazardous wastes generated by the facility.
After the mercury has been recovered, the spill
area should be washed with a dilute calcium sulfide or nitric
Appropriate personal protective equipment (PPE)
needs to be worn. Consult a Material Safety Data Sheet for the
mercury-containing chemical and cleaning solution to identify
the specific items necessary.
Note: Spilled mercury will release vapors and continue to
do so over time. Remember, material used in spill clean up activities
that is contaminated with mercury is a hazardous waste and must
be managed as such. Some vendors imply that their spill kit materials
may be discarded in the regular trash after use, but to do this
allows the mercury to enter the environment. Maine's Hazardous
Waste Management Rules prohibit this method of disposal.
Are there other ways mercury can become airborne?
Another area of concern is from mercury vapors. Mercury vapor
can be present at any spill, but is of special concern from broken
fluorescent light tubes. Air monitoring at sites where fluorescent
tubes have been broken have documented mercury levels in excess
of health standards. All staff should be trained to carefully
handle these bulbs to minimize breakage. If breakage does occur,
the proper cleanup procedure to follow is the same as for the
liquid mercury spill. Spent lamps can be accumulated for recycling.
Many companies are dramatically reducing the mercury content in
new bulb manufacturing, something that should be considered when
purchasing new bulbs. Contact the DEP for a fact sheet about fluorescent
Do batteries have a lot of mercury in them?
Surprisingly, the typical flashlight and radio batteries, or
alkaline batteries as they are known in the trade, are no longer
a source of mercury. That's because in the last five years, major
manufacturers have dramatically reduced or eliminated the mercury
content in the batteries. Since 1995, the U.S. manufacturers have
stopped adding mercury to alkaline batteries altogether.
Mercury batteries have a zinc anode (the negative terminal that
releases electrons), a mercuric oxide cathode (the positive terminal
that accepts electrons), and an electrolyte containing an aqueous
solution of potassium or sodium hydroxide. The mercuric oxide
cathode is usually 20 to 50 percent mercury by weight, or 400,000
ppm. At the other end of the scale, silver-oxide button batteries
usually contain 25 ppm of mercury. Other types of batteries do
not, as a rule, contain mercury.
Most mercury battery applications have been eliminated. Mercury
batteries are being used less frequently in the health care industry,
although there are still some mercury battery applications in
hospitals that cannot be phased out until expensive equipment
is replaced. Fortunately, the only mercuric oxide battery manufacturer
(Alexander Battery) has a collection program in place for spent
mercury batteries, so there is no reason for them to be discarded
into the waste stream. Alexander Battery can be contacted at
1-888-527-2539 about their take-back program.
Are dental practices a problem for mercury entering the environment?
The major source of mercury in a dental practice is from amalgams.
A dental amalgam is a mixture of powdered silver, tin, copper
and elemental mercury which quickly harden to form a solid mass.
It usually contains approximately 50% mercury. There is some debate
as to the safety of these amalgams, and a small segment of the
population does show symptoms of mercury sensitivity. Present
science states that this mercury is not readily available as a
pollutant once the amalgam is installed in the patient's mouth.
To date, tests performed on amalgams have had mixed results. However,
mercury dust, from replacement filling work and particles, suctioned
from the mouth and discharged down the drain, could be an area
of concern. The screens in the drains catch most of the mercury
fragments. When these drains are cleaned, the amalgam chunks
should be collected and stored as hazardous waste. They should
not be flushed down the drain or entered into either the
biomedical or solid waste streams. Mercury filtering systems are
commercially available. These systems are installed on-line and
have filters that are periodically replaced. Manufacturers claim
that the amount of mercury removed from the wastewater stream
is greater than 90%.
Alternatives do exist, but they have disadvantages, primarily
in the durability of the materials. Two alternatives to amalgams
are ceramic, which is not as durable, and gold, which is more
expensive. However, two techniques under development are showing
promise. One is a cold silver process and the other uses the metal
gallium. Perhaps the best news of all is that with the great strides
accomplished in preventative dentistry, mercury use is decreasing
What are the symptoms of mercury poisoning?
The primary exposure routes of mercury into the human body are
from inhalation and absorption through the skin and eyes. Mercury
tends to pass through the digestive tract and targets the central
nervous system, eyes, skin, respiratory system, liver and kidneys.
Exposure can be either acute or chronic in nature. Chronic
exposure appears to be more common and seems to primarily affect
the central nervous system. Since mercury readily accumulates
in living organisms, it becomes more concentrated in creatures
at the top of the food chain. Here in Maine, that includes
eagles, loons, ospreys, otters and possibly humans.
Early symptoms of mercury poisoning include:
- Hair loss
- General weakness and fatigue
- Loss of appetite and associated weight loss
- Joint pain, particularly in wrists and ankles
If exposure levels are high:
Tremors of fingers, eyelids and lips occur with
progression to general tremors of the entire body.
Psychic disorders become noticeable and include
behavior and personality changes, excitability, memory loss
In severe cases, delirium and hallucinations may occur. It is
this stage that was called "Mad Hatters' Disease" in the 19th
century because of the use of mercury in the hat industry.
Acute exposure targets the eyes and skin. Exposure to high
vapor concentrations is capable of causing:
- Severe respiratory damage
- Difficulty breathing
- Muscle weakness
- Ringing in the ears
- Chest pains
- Inflammation of the mouth
Acrodynia, also known as pink or Swift's disease, is another
manifestation of acute exposure and is characterized by redness
and peeling of the skin on the fingers, toes and nose. This condition
was quite common as recently at the 1950s.
Are there any alternatives to mercury products used in the health
Yes, non-mercury alternatives are available for most products.
See the chart below, which identifies alternatives for commonly
used mercury-containing products.
Where can I call or write for more information?
For more information about mercury, please write or call:
Maine Department of Environmental Protection
17 State House Station
Augusta, Maine 04333-0017
Telephone: (207) 287-2651
Fax: (207) 287-7826
Alternatives for Mercury Uses in the Medical
PRODUCTS (containing mercury)
Lithium, zinc air, and alkaline batteries
Fiber optics, solid state devices, mechanical switches
Miller Abbot tubes
Tungsten tubing (tungsten for weight)
Ordinary glow lights; low sodium vapor tubes (yellow); optical,
high-energy, long-lasting lights1
Electronic vacuum gage, expansion, aneroid2
Electronic (digital), expansion, aneroid
Mercury (II) chloride
Staining solutions and preservatives for such products as
buffers and vaccines:
Thimerosal, Immu-sal, Carbol-fuchin stain, Gram iodine stain,
mercuric, acetate, alum, Hematoxylin "Solution
Replace with a variety of chemical compounds3
Mercury (II) oxide
Mercury (II) chloride
Magnesium chloride/sulfuric acid or zinc formalin, freeze
Mercury (II) sulfate
Silver nitrate/potassium/chromium-(III) sulfate
Mercury nitrate (for corrosion of copper alloys) for antifungal
Ammonia/copper sulfate, neosporin, mycin
- No effective substitute exists for high energy fluorescent lights,
but technology is reducing the volume of mercury required in such
- Mercury thermometers and manometers should be phased out because
good substitutes exist. Mercury recycling should be practiced
for old medical instruments.
- Mercury's use in chemical analysis can be phased out in many
cases, especially in Zenker's solution and histological fixatives.
Some substitutes, such as copper, tin and chromium compounds also
have some risk, but less than the risk associated with mercury.
The total use of mercury remaining in such products as antiseptics,
diuretics and skin preparations is minimal; mercury should not
be used in skin lightening soaps and creams.
* Reproduced from Michigan Department of Environmental Quality
Report on Mercury in the Environment, April, 1996.