Steps you can take

Get involved in phasing mercury out of your hospital. EPA's guide lays out the steps.

Read more in our What You Can Do section.

Learn more

Health Care Without Harm information on mercury in medicine

Health Care Without Harm resources on mercury for health care professionals and families

American Nurses Association guidelines on eliminating mercury in health facilities

Hospitals for a Healthy Environment model plan for virtual mercury elimination in hospitals (pdf)

Hospitals for a Healthy Environment report on the status of virtual mercury elimination in the health care setting (pdf)

Hospitals for a Healthy Environment guide to implementing a fluorescent lamp recycling program as a means of reducing mercury waste (pdf)

University of Maryland School of Nursing's EnviRN presentation on mercury in health care settings (pdf)

Healthcare Environmental Resource Center guidelines for implementing a mercury reduction program at your hospital

EPA's materials on eliminating mercury from hospitals (pdf)

OSHA information on health effects and safe handling of mercury

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Summary

Mercury has long been an important component of instruments measuring pressure and temperature, such as thermometers and sphygmomanometers. A typical large hospital could easily have over one hundred pounds of mercury on-site, contained within hundreds of devices throughout the facility, unless it has taken specific steps to replace mercury-containing equipment. Health care workers may be exposed to mercury through spills from broken instruments, or during sterilization of thermometers. When mercury spills, it evaporates and passes very efficiently into the lungs. Once inhaled, mercury enters the central nervous system, where it may cause neurological problems ranging from subtle to severe. The risk of mercury spills is high, and the cost to remedy spills is high as well. For example, a large hospital in Los Angeles documented about 18 mercury spills each year, and estimated cleanup costs as $10,000 per year in labor alone. The cost of replacing mercury-containing devices is modest in comparison. Eighty nine percent of all the mercury in hospitals is found in sphygmomanometers and gastroenterological instruments, which can be replaced easily by devices that don't contain mercury. Non-mercury replacements are usually no more expensive than their mercury-containing counterparts. While numerous government and independent resources exist to help motivated hospital staff eliminate mercury-containing devices from their workplaces, no federal regulations mandate such a phase-out. Instead, OSHA defines acceptable exposure for mercury vapor as 0.1 milligrams per cubic meter of air. This exposure limit is five times the level known to lead to neurological symptoms after several years of occupational exposure.

Uses and Health Concerns

Mercury is a silver-colored, naturally occurring heavy metal that remains liquid at room temperature, and is often used in laboratory and medical instruments. Because of its weight, high boiling point, and relatively low vapor pressure, mercury in its elemental form has long been an important component of instruments measuring pressure and temperature, such as thermometers and sphygmomanometers (blood pressure monitors) (HERC 2004, WHO 1991). Elemental mercury can also be found in gastroenterological devices, electrical switches, lamps, laboratory reagents, and dental amalgams, among other things (EPA 1998, WHO 1991). A typical large hospital could easily have over one hundred pounds of mercury on-site, contained within hundreds of devices throughout the facility, unless it has taken specific steps to replace mercury-containing equipment (HERC 2004).

Virtually all hospital workers have indirect contact with mercury that is contained in medical devices. Health care workers may be exposed to mercury in the workplace through accidental spills from broken thermometers, sphygmomanometers, and other instruments, or during sterilization and centrifugation of thermometers (EPA 2000, OSHA 2006). When elemental mercury is spilled, it evaporates and becomes a toxic gas that passes very efficiently into the lungs (HERC 2004). Thus, the most common source of exposure to elemental mercury is through inhalation (EPA 2000, Monroe 1998). Once inhaled, mercury enters the central nervous system, where it may cause neurological problems ranging from subtle to severe (HERC 2004). In addition, mercury can also be absorbed through the skin or eyes (EPA 2000, OSHA 2000).

Neurological health effects of chronic exposure to elemental mercury may include insomnia, irritability, memory loss, fatigue, nausea, tremors, and a host of other problems (Hayes 1982, Echeverria et al. 1998, Haut et al. 1999, HERC 2004). The diversity in clinical neurological effects suggests more than one mechanism of toxicity involving several areas of the brain (Echeverria et al. 1998). Several studies indicate that mild symptoms of neurotoxicity can be observed among people who have been exposed occupationally to elemental mercury at a concentration of 20 micrograms per cubic meter or higher for several years (FDA 1995, Risher 2003). A study of dental professionals documented association between impaired psychomotor skills and recent exposures to elemental mercury in dental amalgams, measured as mercury levels at or below 55 micrograms per liter in the urine of the dental personnel (Bittner et al. 1998). Another study of dentists and dental assistants indicated that subtle preclinical neurological effects were associated with both recent and chronic exposures to extremely small amounts of elemental mercury, measured as levels at or below 4 micrograms per liter in urine (Echeverria et al. 1998). Such low level exposures are comparable to those observed in the general U.S. population (Echeverria et al. 1998).

Respiratory symptoms of chronic exposure to mercury may include cough, chest pain, bronchiolitis, and pulmonary edema (Haut et al. 1999, Hayes 1982, HERC 2004). Elemental mercury vapor has also been found to cause contact dermatitis in occupational settings (OSHA 2006). Research on animals also suggests kidney damage may result from exposure to elemental mercury (WHO 1991).

Because of the extreme sensitivity of the fetus and children to mercury, exposure in utero to elemental mercury is suggested to cause birth defects, sensory disruptions, and neuro-developmental delays (EPA 2000, NIEHS 2003, FDA 1995). An animal study documented reduced births and increased cranial birth defects in rats exposed to mercury in utero (Steffek et al. 1987).

There is little recent information concerning the health effects of chronic mercury exposure. While older reports have established that long-term exposure to mercury results in neurotoxicity and other detrimental health effects, surprisingly little research is currently conducted on this widespread health care hazard. More information on the effects of chronic occupational exposure to elemental mercury in the medical setting is sorely needed.

Hospital and Government Actions

The risk of mercury spills is high, and the cost to remedy spills has proven to be high as well, with the Environmental Protection Agency (EPA) estimating that cleanup of even tiny spills costs at least $649 (EPA 2002). Data from a large hospital at the University of California at Los Angeles documented around 18 mercury spills each year, and estimated cleanup costs as approximately $10,000 per year in labor, and $34 per pound in disposal (EPA 2002).

The cost of replacing mercury-containing devices is modest in comparison (CADHS 2000). Eighty nine percent of all the mercury found in hospitals is found in sphygmomanometers and gastroenterology instruments (CADHS 2000), which can be replaced easily by devices that don't contain mercury. In 2003, Washington and Maine became the first states to ban mercury blood pressure devices (HCWH 2006). Minnesota, Maryland, Rhode Island, Oregon, Massachusetts, Connecticut, Michigan, Washington, Maine, and Illinois have banned the sale and distribution of mercury thermometers, as have many cities throughout the U.S. (HCWH 2006).

Non-mercury replacements are usually no more expensive than their mercury-containing counterparts (CADHS 2000). Most hospitals have already taken the first step toward mercury reduction by replacing mercury thermometers with digital devices. Sphygmomanometers tend to be more expensive, and those that are mercury-based are more likely to be gradually replaced by aneroid or electronic sphygmomanometers (HERC 2004).

A 2005 survey of hospitals conducted by the American Hospital Association and Hospitals for a Healthy Environment (H2E 2005) highlights many of the positive steps individual medical facilities have taken toward safer, mercury-free alternatives:

• 97 percent of hospital respondents across the country were aware of the problem with mercury and had taken steps to address the issue, including labeling mercury-containing devices and phasing out their purchase in favor of safer, equally effective alternatives;
• 80 percent of respondents had completely eliminated the use of mercury thermometers;
• 73 percent had removed all mercury sphygmomanometers from their facilities, and more than 81 percent currently purchase mercury-free cleaning chemicals;
• 60 percent of respondents had implemented a mercury management policy, and more than 54 percent had established a policy to virtually eliminate mercury facility-wide.

When acquiring mercury-free devices, it is equally important to dispose of the mercury-containing items properly. Unfortunately, every state has different laws and regulations when it comes to the disposal of mercury-containing products and devices. The federal government has so far failed to adopt regulations requiring manufacturers of mercury-containing devices to take responsibility for appropriate disposal of their products. Meanwhile, in Japan, the Appliance Recycling Law requires manufacturers to take back their mercury-containing products at the end of their life cycle at no cost to the consumer, and the European Parliament has adopted two initiatives requiring manufactures to assume full financial and/or physical responsibility for their products at the end of their consumer life cycle (Kuiken 2002). However, some manufacturers have chosen to adopt mercury take-back programs. For example, Honeywell, General Electric, and White-Rodgers established the Thermostat Recycling Corporation to recycle all brands of used, wall-mounted mercury-switch thermostats so that the mercury can be purified for re-use (Kuiken 2002).

In the U.S., the EPA treats mercury as an occupational hazard, and regulates mercury use and disposal. The Occupational Safety and Health Administration (OSHA) defines acceptable exposure for mercury vapor, or the Permissible Exposure Limit, as 0.1 milligrams per cubic meter as an 8-hour, time weighted average (OSHA 2006). Notably, this exposure limit is five times the level described as leading to mild neurological symptoms after several years of occupational exposure (FDA 1995, Risher 2003). The National Institute of Occupational Safety and Health (NIOSH) has recommended reducing the exposure limit by half (NIOSH 1973); OSHA has yet to adopt this more health-protective standard. OSHA lists process enclosure, local exhaust ventilation, and personal protective equipment as the most effective methods for controlling worker exposures to mercury (OSHA 2006).

Where mercury-containing devices are still in use in hospitals and medical facilities, following strict guidelines for containment and cleanup procedures can go a long way to reducing exposures. Most hospitals employ a combination of surveillance (OSHA 2000), biomonitoring, periodic medical evaluations (EPA 2000, OSHA 2000), and protective gear. Respirators must be worn if the ambient concentration of mercury vapor exceeds prescribed exposure limits (OSHA 2000). In addition, workers should be advised to use personal protective clothing and equipment that has been chosen for their effectiveness in preventing skin contact with mercury vapor (OSHA 2000).

Numerous government and independent resources exist to help motivated hospital staff eliminate many mercury-containing devices from their workplaces. Health Care Without Harm and Hospitals for a Healthy Environment provide particularly useful materials that motivated nurses can use to rid their own hospitals of mercury-containing devices. However, this piecemeal reduction of mercury from individual medical facilities typically depends on the presence of an educated hospital administration that is willing to make the necessary changes. To effect change across the country, federal regulations specifying a phase-out of mercury-containing instruments in hospitals are needed.