Mercury pollution prevention
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Introduction
Mercury is a toxic metal that occurs naturally in the environment. The silvery-white inorganic form is most familiar because of its widespread use in fever thermometers. The properties of inorganic mercury that make it useful in medicine (response to temperature and pressure) also permit vaporization and resulting toxic effects. Organic forms of mercury circulate in the environment and may change from one form to another in the process. Although all forms of mercury are toxic to humans, organic forms generally are much more toxic than inorganic forms. The organic forms are of particular concern when they enter the food chain, since these are primarily neurotoxins that can damage the brain, nervous system, and other organs. The inorganic forms primarily affect the kidneys. The developing brain of a fetus or child is especially vulnerable to organic mercury exposure.
Human exposure to mercury can occur through inhalation, ingestion, or skin contact. The most common routes of exposure in the healthcare setting include inhalation of inorganic mercury vapor after a spill or accidental skin contact with mercury. Accidental spills of liquid mercury can increase the levels of mercury in the air or wastewater of a healthcare facility. Small droplets of spilled mercury may lodge in cracks, mix with dust, or go down drains. Mercury may adhere to fabrics, shoe soles, watches, or jewelry, on which it can be transported to other locations. A small spill of mercury in a carpeted patient room can become a major clean-up challenge. The mercury used in healthcare can have a broad impact on the surrounding community if spills or waste enter the groundwater and work their way into the food chain. For all these reasons, hospitals are working to reduce or even eliminate the use of mercury.
Common uses of mercury in healthcare settings
Mercury-containing products can be found almost anywhere in the healthcare setting. They range from medical instruments and clinical laboratory chemicals to electrical equipment and cleaning solutions. Pharmaceutical manufacturers have used thimerosal, a mercury product, as a common preservative. Following are examples of medical and non-medical uses for mercury in the healthcare setting.
Medical uses:
- Thermometers
- Sphygmomanometers
- Esophageal dilators (also called bougie tubes)
- Cantor tubes and Miller Abbott tubes (used to clear intestinal obstructions)
- Feeding tubes
- Dental amalgam
- Laboratory chemicals (fixatives, stains, reagents, preservatives)
- Medical batteries
Non-medical uses:
- Cleaning solutions with caustic soda or chlorine contaminated with mercury during the production process
- Batteries
- Fluorescent lamps and high-intensity lamps
- Thermostats (non-electronic)
- Pressure gauges
- Some electrical switches used for lights and appliances
Memo of understanding
Hospitals are collaborating to reduce and ultimately eliminate mercury. In June 1998, the Environmental Protection Agency (EPA) and the American Hospital Association (AHA) signed a Memorandum of Understanding (MOU) which has as one of its stated goals the virtual elimination of mercury waste by the year 2005.
Primary voluntary goals:
- Virtual elimination of mercury-containing waste from hospitals' waste stream by 2005.
- The reduction of the overall volume of waste (both regulated and non-regulated) by 33 percent by 2005, and 50 percent by 2010.
- The identification of hazardous substances for pollution prevention and waste reduction opportunities.
Taking the mercury-free pledge
Taking the mercury-free pledge is an excellent way for facilities to begin their mercury pollution prevention efforts. Such a pledge needs senior management support and provides an opportunity for healthcare facilities to gain recognition for their pollution prevention efforts.
Several groups have passed resolutions and adopted environmental management policies that call for mercury elimination. In March 2000, the California Medical Association adopted a resolution that promotes the eventual elimination of mercury and urges medical product suppliers to develop mercury-free replacement products. Catholic Healthcare West has adopted mercury-free language in its purchasing policies.
Solutions and strategies for pollution prevention
The EPA’s approach to pollution prevention is outlined in its educational program (Mercury in Medical Facilities) as a series of priority steps, the first being prevention. The primary strategies include source reduction and recycling or waste minimization. Waste that cannot be recycled must then be treated, and the final and last resort is disposal and release.
Mercury source reduction
The healthcare industry is making progress in eliminating mercury pollution. Fewer healthcare institutions have operating incinerators. Large medical waste disposal companies are relying less on incineration and more on steam sterilization autoclaves and other alternatives. Hospitals and medical waste disposal companies are working to ensure appropriate source separation so that mercury is pulled from the waste stream before it is sent for incineration. Such source separation programs may require significant initial educational and implementation efforts, but they are almost guaranteed to be successful because the mercury load in the waste stream should be essentially eliminated. The few items involving essential uses of mercury would be relatively easy to track and control.
Mercury substitution
There is minimal risk of mercury exposure during the normal use and proper handling of products; however, problems may occur if the mercury in a product is exposed to air, or if a product is not properly discarded.
For most mercury-containing products in the hospital, the preferred management practice is to replace the item with a mercury-free product. However, it may not be possible to replace all of the hospital's mercury products at once, and in a few cases, there may be no reliable, cost-effective substitute. In such cases, the best management practice is to have effective procedures in place for handling and recycling or disposal of the mercury-containing products. Recycling is recommended. Disposal should be the last resort—it is expensive and increases the potential for mercury to be dispersed into the environment.
Strategies for managing mercury in healthcare facilities include:
- Using alternatives for products that contain mercury.
- Recycling mercury-containing products when they can no longer be used.
- Correct handling and disposal of mercury, mercury-containing equipment, and laboratory chemicals.
- Establishing protocols for proper cleanup of spills involving mercury.
- Enforcing compliance with institutional policies.
Mercury spill prevention
Follow proper procedures when cleaning or refilling instruments that contain mercury:
- Clean or refill instruments over a tray to contain any
spills. Never handle mercury over a sink. Reserve the room for
mercury use only. Restrict traffic in the area.
- Clean and calibrate all mercury-containing equipment
according to the manufacturer's recommended handling procedures
and the procedures recommended by your hospital's safety
officer.
- Train all workers who use mercury devices about the properties and hazards of mercury, safe handling procedures, and specific policies related to mercury recycling and disposal.
Minimizing the impact of a spill is part of spill prevention. Mercury devices should be used only in rooms without carpeting or other floor coverings not smooth and easily cleaned. Mercury devices should not be used in units with beds that have high structures or projections that can break wall-mounted sphygmomanometers, or in areas where patients cannot be moved.
Mercuryspill response
- Be prepared for a spill in any area of the hospital where mercury-containing devices are used.
- Have a mercury vacuum cleaner or mercury spill kit readily available to consolidate spilled mercury and limit the amount of mercury released into the air. The mercury vacuum cleaner is designed to clean up liquid mercury spills: an activated carbon filter in the vacuum absorbs and contains the mercury vapors. Never use a regular vacuum cleaner to clean up mercury, as it will vaporize the mercury and blow it into the air.
- In the event of a large spill, patients must be removed from the room during cleanup. The room must remain vacant until the air is free of mercury vapor.
- Staff members must have special training in order to clean up mercury spills.
Healthcare facilities should have mercury spill policies addressing:
- Availability of a competent staff person, trained in mercury spill cleanup, on all shifts.
- Availability of protective equipment and clothing for cleanup staff.
- Incorporation of OSHA requirements.
- The circumstances in which patient(s), visitors, and staff should be evacuated from the area before cleanup.
- Guidelines for determining when the spill has been adequately cleaned and the area can safely be occupied.
- The type of equipment to be used for the size and type of spill and type of flooring (linoleum, carpet, cement).
- Availability of manufacturer's instructions for all equipment to be used for cleanup procedures.
- Strategies for waste disposal.
- Method for documentation of the incident report describing the spill, the cleanup method used, unusual circumstances, employee exposure, and follow-up monitoring.
Additional policies should be developed for:
- Handling mercury spills during a medical procedure.
- Servicing mercury-containing medical equipment.
- Education and training of staff who may come in contact with mercury-containing products.