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Mercury Hazards


Thermometers in the healthcare setting use mercury to function.
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Mercury is used in many instruments and products in the healthcare setting because of its uniform response to temperature and pressure changes. Sphygmomanometers (blood pressure monitors), laboratory and patient care thermometers, and gastrointestinal devices use mercury to function. Mercury compounds also are used in preservatives, fixatives, and reagents. Mercury from medical applications can enter the environment through sewers, spills, and land disposal of trash.

Workers in medical, dental, or other health services who work with equipment that contains mercury are at risk of being exposed to the toxic metal.

Other workers who might be exposed to mercury, include:

  • electrical equipment manufacturing facilities
  • fluorescent light bulb (CFL) recycling facilities
  • automotive part manufacturing facilities
  • chemical processing plants that use mercury

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1. Why is mercury used in healthcare instruments?

a. Uniform response to temperature and pressure changes
b. Cheaper option
c. Readily available
d. No alternatives

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Occupational Exposure to Mercury

How someone's health may be affected by exposure to mercury depends on several factors.

The most common potential mode of occupational exposure to mercury is via inhalation of metallic liquid mercury vapors. Since mercury vapor is odorless and colorless, people can breathe mercury vapor unknowingly. For liquid metallic mercury, inhalation is the route of exposure that poses the most significant health risk.

Mercury is a neurotoxin. How someone's health may be affected by exposure to mercury depends on several factors which include:

  • form of mercury (for example, methylmercury or elemental metallic mercury)
  • amount of mercury in the exposure
  • age of the person exposed (unborn infants are the most vulnerable)
  • how long the exposure lasts
  • route of exposure (breathing, eating, and skin contact)
  • the health of the person exposed

The effects of mercury exposure can be very severe, subtle, or may not occur at all, depending on the factors above.

2. _____ is the most common potential mode of occupational exposure to mercury.

a. Inhalation of mercury vapors
b. Direct contact
c. Coughing
d. Holding hands

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Health Effects

Mercury is highly toxic, primarily when metabolized into methyl mercury. It may be fatal if inhaled and harmful if absorbed through the skin. Mercury and most of its compounds are extremely toxic and you should always handle it with care. In cases of spills involving mercury, such as from thermometers or sphygmomanometers, use specific cleaning procedures to avoid exposure to mercury.

Mercury exposure can have both acute and chronic health effects.

Acute Exposure

Acute exposure (short-term effects) to mercury may result in many health effects, including:

  • chills
  • nausea
  • general malaise
  • tightness in the chest
  • chest pains
  • dyspnea (shortness of breath)
  • cough
  • stomatitis (inflammation or sore inside the mouth)
  • gingivitis
  • salivation
  • diarrhea

Chronic Exposure

Chronic exposure (long-term effects) to mercury may result in the following:

  • weakness
  • fatigue
  • anorexia
  • weight loss
  • disturbance of gastrointestinal function

3. Which of the following is a symptom of chronic exposure to mercury?

a. Chills
b. Gingivitis
c. Weakness
d. Salivation

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Hierarchy of Controls

hierarchy of controls
Workers can be protected from exposures to mercury by using hierarchy of controls.

The hierarchy of controls should be applied to ensure you use the most effective control method. The hierarchy of controls establishes the following control categories in order of preference: elimination, substitution, engineering, administrative, and personal protective equipment (PPE). Controlling hazards within a workplace help prevent accidents or injuries. Controls, such as elimination, substitution, and engineering, are most effective because they do not rely on human behavior. Administrative and PPE controls are least effective since they may not eliminate the hazard and rely on human behavior and performance. A cost-benefit analysis can help guide decision making when implementing the hierarchy of controls.

Elimination and Substitution

Whenever possible, exposure to potential hazards should be eliminated or reduced by substituting with less hazardous materials. Choosing mercury-free equipment or equipment made with less toxic substances minimizes the potential for worker exposure. For example, replacing mercury thermometers and sphygmomanometers with mercury-free devices eliminate the hazard.

When in the development phase of a new process, implementing elimination or substitution controls may be inexpensive and easy to implement. It may be more difficult and expensive to implement elimination or substitution controls for existing operations.

4. Which control method is most effective at preventing or reducing exposure to a hazard?

a. Engineering controls
b. PPE
c. Elimination or substitution
d. Administrative controls

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Engineering Controls

engineering controls
When elimination or substitution is not possible, engineering controls should be applied.

When elimination or substitution is not possible, engineering controls should be applied. Engineering controls work by physically preventing worker exposure to the hazard. Engineering controls are considered a more effective control method as compared to administrative controls or PPE because they do not rely on worker compliance.

Well-designed engineering controls, such as a sealed container, can be highly effective in protecting workers from mercury. Engineering controls should be independent of worker behavior and interactions.

Potential engineering controls include:

  • Use fume hoods to prevent exposure to mercury vapors
  • Use a process enclosure to prevent exposure
  • Control airflow in the work area with adequately designed ventilation systems

5. Which control method is considered more effective at reducing mercury exposure?

a. Engineering controls
b. PPE
c. Warning signs
d. Administrative controls

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Administrative Work Practice Controls

Administrative controls are policies and procedures established by management to reduce the risk of exposure to a hazard, such as mercury. Administrative controls include implementing work practices, management policies, and training programs to reduce worker risk.

Administrative controls used to protect workers from exposure to mercury include:

  • initial and annual training
  • evaluation and maintenance programs

Use a variety of work practice controls to protect healthcare workers from accidental mercury spills.

  • Use mercury spill kits to help clean up small spills of 25ml or less. Kits should contain gloves, protective glasses, mercury absorbing powder, mercury sponges, and a disposal bag.
  • Put in place procedures to isolate the contaminated area.
    • Be aware that mercury can unknowingly be carried home on clothing, skin, or hair.
  • Be on the look-out for mercury, recognizing that it may be present in various instruments and equipment.
  • Use a Mercury Vapor Analyzer to verify that the area is safe to reenter.
  • Make sure that spills are cleaned up promptly and safely by workers or a team trained in proper procedures.

Do not allow workers who are not trained in proper procedures to attempt to clean up spills.

The last line of defense against exposure to workplace hazards is personal protective equipment (PPE).
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Personal Protective Equipment

The last line of defense against exposure to workplace hazards is personal protective equipment (PPE). Employers are required to provide appropriate PPE when employees are handling hazardous chemicals, such as mercury [29 CFR 1910.132]. PPE is the least effective control method because it relies on employee behaviors and performance to prevent exposure.

Examples of PPE include:

  • coveralls
  • booties
  • gloves
  • face shields
  • safety goggles
  • respirators

6. Why is personal protective equipment (PPE) considered the lease effective control method?

a. Because it is costly
b. It relies on management to implement
c. Because it is challenging and complicated to use
d. It relies on employee behavior and performance

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OSHA Mercury Exposure Requirements

According to OSHA Standards, what should employees never do in an area exposed to mercury?

a. Perform work activities
b. Consume food or beverages
c. Clean and disinfect
d. Evaluate hazards

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Cleaning up Mercury Spills

Mercury Spill Cleanup: Health Effects

Only those who have been properly trained should clean up a mercury spill.

What NEVER to Do After a Mercury Spill:

  • Never use a vacuum cleaner to clean up mercury. The vacuum will put mercury into the air and increase exposure.
  • Never use a broom to clean up mercury. It will break the mercury into smaller droplets and spread them.
  • Never pour mercury down a drain. It may lodge in the plumbing and cause future problems during plumbing repairs. If discharged, it can cause pollution of the septic tank or sewage treatment plant.
  • Never walk around if your shoes might be contaminated with mercury. Contaminated clothing can also spread mercury around.

Prepping for Clean Up of a Broken Mercury Thermometer

  • Have everyone else leave the area; don't let anyone walk through the mercury on their way out.
  • Mercury can be cleaned up easily from the following surfaces: wood, linoleum, tile and any similarly smooth surfaces.
  • If a spill occurs on carpet, curtains, upholstery or other absorbent surfaces, these contaminated items should be thrown away in accordance with proper disposal means discussed in the next section. Only cut and remove the affected portion of the contaminated carpet for disposal.

8. What should you do with items contaminated with mercury after a spill?

a. Throw them away
b. Wash them thoroughly
c. Use soap and water to disinfect
d. Mercury does not contaminate clothing

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Mercury Spill Clean Up Instructions

Mercury Vapors

Remember, only people who are properly trained should cleanup a mercury spill. Here are some other important things to remember:

  • Put on gloves.
  • If there are any broken pieces of glass or sharp objects, pick them up with care. Place all broken objects on a paper towel. Fold the paper towel and place in a zip locking bag. Secure the bag and label it as directed by your local health or fire department.
  • Locate visible mercury beads. Use a squeegee or cardboard to gather mercury beads into small mercury balls. Use slow sweeping motions to keep mercury from becoming uncontrollable. Take a flashlight, hold it at a low angle close to the floor in a darkened room and look for additional glistening beads of mercury that may be sticking to the surface or in small cracked areas of the surface.
  • Use an eyedropper to collect or draw up the mercury beads. Slowly and carefully squeeze mercury onto a damp paper towel. Alternatively, use two pieces of cardboard paper to roll the mercury beads onto the paper towel or into the bag. Place the paper towel in a zip locking bag and secure. Make sure to label the bag as directed by your local health or fire department.
  • After you remove larger beads, put shaving cream on top of small paint brush and gently "dot" the affected area to pick up smaller hard-to-see beads. Alternatively, use sticky tape, such as duct tape, to pick up any remaining small glass fragments. (Peel the tape very slowly from the floor to keep the mercury beads stuck to the tape.) Place the paint brush or duct tape in a zip locking bag and secure. Make sure to label the bag as directed by your local health or fire department.
  • Place all materials used with the cleanup, including gloves, in a trash bag. Place all mercury beads and objects into the trash bag. Place the trash bag outside in a secured area and label it as directed by your local health or fire department.
  • Contact your local health department, municipal waste authority, or your local fire department to find out how to conduct proper disposal in accordance with local, state and federal laws.

After Cleanup

Remember to keep the area well ventilated to the outside (i.e., windows open and fans in exterior windows running) for at least 24 hours after your successful cleanup. You may want to request the services of a contractor who has monitoring equipment to screen for mercury vapors. Consult your local environmental or health agency to inquire about contractors in your area.

9. How long should you ventilate the area after successfully cleaning up a mercury spill?

a. 8 hours
b. 12 hours
c. 24 hours
d. 48 hours

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Choosing a mercury-free instrument can make a tremendous impact in reducing the potential for mercury exposure.
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Alternatives to Mercury

For many years it was thought that mercury is indispensable. Although there are instruments that are alternatives to mercury-containing equipment, their use was never widespread. Both mercury and aneroid sphygmomanometers have been in use for many years. The thinking that aneroid sphygmomanometers do not give accurate readings has no base. Of all mercury instruments used in health care, mercury sphygmomanometers (80–100 g/unit) use the most significant amount of mercury. Their widespread use collectively makes them one of the largest mercury reservoirs in the health care setting. By choosing a mercury-free alternative, a health care institution can make a tremendous impact in reducing the potential for mercury exposure to patients, staff, and the environment. When following proper maintenance protocol, aneroid sphygmomanometers provide accurate pressure measurements.

10. Where is the most significant amount of mercury used in the healthcare setting?

a. Thermometers
b. Sphygmomanometers
c. Vaccines
d. IV needles

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Mercury-Free Healthcare

mercury-free healthcare
There are several strategic steps to help reduce mercury in healthcare settings.

Here are some strategic steps for eventually achieving mercury-free health care:

Short-term: Develop and implement plans to reduce the use of mercury equipment and replace it with mercury-free alternatives. Plans should address clean-up, storage, and disposal of mercury.

Medium-term: Increase efforts to reduce the use of unnecessary mercury equipment in hospitals. Hospitals should have an inventory of their use of mercury. Categorize this inventory into either immediately replaceable and gradually replaceable.

Long-term: Support a ban on mercury-containing devices and promote alternatives. Support countries in developing a national guidance manual for sound management of health care mercury waste. Support countries in the development and implementation of a national plan, policies, and legislation on mercury health care waste. Support the allocation of human and financial resources to ensure the procurement of mercury-free alternatives and sound management of health care waste containing mercury.

Case Study

Butterworth Hospital in Grand Rapids, Michigan, is a 529-bed hospital that has committed to reaching mercury-free status. To help achieve this goal, the hospital is implementing a new purchasing policy that restricts the purchase of mercury-containing devices unless a mercury-free alternative is not available. The hospital estimates there is one and one-half pounds of mercury used per bed in their facility. Here are some of Butterworth’s outstanding mercury reduction efforts:

  • The hospital is in the process of removing all the mercury from the hospital’s sphygmomanometers; they estimate that they will have harvested 290 pounds of mercury when they are finished.
  • The surgery department switched its esophageal dilators.
  • Mercury-containing thermometers and batteries will no longer be purchased.
  • Butterworth no longer sends mercury-containing devices overseas in their humanitarian projects.
  • They found pneumatic tubes that have mercury switches and are changing these out.
  • The hospital is doing drain trap testing to justify lab replacements.
  • A mobile fluorescent lamp recycling unit will go to the hospital to crush the lamps on site.

Butterworth’s mercury reduction activities are not without difficulties. The labs were resistant because the pathologists relied on mercury chloride slide fixatives. The pathologists believe there are no alternatives as precise and accurate.

11. _____ is a short-term strategic step to help reduce mercury in healthcare settings.

a. Increasing efforts to reduce unnecessary mercury equipment
b. Banning mercury-containing devices
c. Developing & implementing a plan
d. Supporting allocation of financial resources

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