Elemental Mercury Releases Attributed to Antiques --- New York, 2000--2006

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Metallic (i.e., elemental) mercury, a heavy, silvery odorless liquid, is in common household products such as thermostats and thermometers. Lesser-known household sources of elemental mercury include certain antique or vintage items such as clocks, barometers, mirrors, and lamps. Over time, the mercury in these items can leak, particularly as seals age or when the items are damaged, dropped, or moved improperly. Vacuuming a mercury spill or vaporization from spill-contaminated surfaces such as carpets, floors, furniture, mops, or brooms can increase levels of mercury in the air, especially in enclosed spaces (1). Environmental sampling conducted after releases of elemental mercury have indicated substantial air concentrations that were associated with increases in blood and urine mercury levels among exposed persons (2). In 1990, the Agency for Toxic Substances and Disease Registry (ATSDR) created the Hazardous Substances Emergency Events Surveillance (HSEES) system, a multistate* health department surveillance system designed to help reduce morbidity and mortality associated with hazardous substance events (3). This report describes antique-related mercury releases reported to HSEES, all of which occurred in New York state during 2000--2006.^§ Although none of these spills resulted in symptoms or acute health effects,they required remediation to prevent future mercury exposure. The findings underscore the need for caution when handling antiques containing elemental mercury and the need for proper remediation of spills.

Case Reports

Antique pendulum wall clock, Delaware County, New York. In 2006, as an antique store employee was cleaning, he placed an antique pendulum wall clock on the floor, spilling approximately 150 mL of mercury. The employee then moved the pendulum to a bucket and tried to vacuum the spill with a household vacuum cleaner. He dialed 911, and emergency responders were dispatched. That employee and another employee evacuated the store as the fire department, a hazardous materials (HazMat) team, and the state environmental agency responded. The HazMat team removed carpeting and collected all visible mercury beads. The carpeting and vacuum cleaner were discarded as hazardous waste. Air measurements taken the next day revealed background levels of mercury at floor level in the area that had been cleaned. Air measurements throughout the room indicated mercury in the floorboards beneath a radiator. Plastic was hung over the doorway to contain the room air until a second cleanup was conducted. The floor was mopped with a thiosulfate solution. The cleanup contractor took air samples to confirm that the mercury cleanup was complete.

Antique pendulum clock, Southhold, New York. In 2006, a home was contaminated with approximately 500 mL of mercury when an antique pendulum clock fell and broke on the carpeted floor in the living room. The tenant called the state spill hotline and was referred to the county health department. The county health department and a cleanup contractor responded. The resident evacuated until the cleanup was completed and confirmed by environmental sampling.

Antique clock, New York City, New York. In 2005, 30--330 mL of mercury spilled from a 15-inch column in an antique clock in an antiques store. The fire department and city environmental agency responded. As a precaution, four workers were transported to a medical facility for evaluation. The area was cordoned off while a cleanup contractor removed the spilled mercury and conducted air sampling to verify that the cleanup was complete.

Antique barometer, Great Neck, New York. In 2003, approximately 35 mL of mercury spilled from a newly purchased antique barometer while it was being transported in the trunk of a car. As the barometer was being carried into the buyer's home, some of the spilled mercury was tracked inside. The buyer contacted the local health department for cleanup guidance and then hired a cleanup contractor to remediate the spill. The local health department took air measurements to determine whether cleanup was complete in both the house and car. Although mercury cleanup in the house was complete, air measurements in the car trunk indicated residual mercury. The car was successfully remediated only after the trunk carpeting was discarded.

Antique mirror, Ryebrook, New York. In 2001, approximately 30 mL of mercury leaked from the back of an antique mirror onto the carpet in a home. The resident vacuumed the spilled mercury, contaminating the vacuum cleaner and likely increasing the indoor air levels of mercury. The resident contacted the local health department, which responded. The mirror and vacuum both were bagged for disposal as hazardous waste, and the spill was cleaned up within 1.5 hours of discovery. Air sampling confirmed cleanup.

Antique lamp, Syracuse, New York. In 2000, approximately 35 mL of mercury spilled onto a roadway as an antique lamp was being loaded into a vehicle. The mercury had been used as a weight in the lamp's base. The spill was reported to the local fire department and cleaned up by a HazMat team. Because this spill occurred outdoors and was cleaned up quickly, the risk for inhalation exposure was minimal.

Reported by: RE Wilburn, MPH, JK Ehrlich, MPH, WL Welles, PhD, New York State Dept of Health. DK Horton, MSPH, M Orr, MS, V Kapil, DO, Div of Health Studies, Agency for Toxic Substances and Disease Registry.

Editorial Note:

Short-term exposure to high levels of mercury vapor can cause lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation. Exposure to high levels of mercury vapor can permanently damage the brain, kidneys, and developing fetuses. Mercury exposure is of particular concern for fetuses, infants, and children, who have developing nervous systems, and for persons with medical conditions that might be worsened by exposure to mercury, such as conditions of the nervous system, kidneys, or heart and vascular system (1).

The unique properties of elemental mercury, which are largely attributable to its liquid state at room temperature, prompted its earlier use in certain household items and instruments. For example, in the late 19th and early 20th centuries, certain antique clocks with temperature-compensated pendulums typically contained one or more glass cylinders of mercury as a regulator (4) (Figure).

Beginning in the mid-17th century, certain antique barometers used a glass tube from which the air had been evacuated and replaced by liquid mercury (4). The amount of mercury in barometers can range from 5 ounces to 6 pounds (4). During the 16th through the 19th centuries, mercury's reflectivity led certain craftsmen to create mirrors by layering a thin amalgam of approximately 75% tin and 25% mercury to a backing of flat plate glass (5). A deposit of amalgam or liquid mercury beads can sometimes be found at the base of these mirrors (5). In addition, some antique desk and floor lamp manufacturers used elemental mercury in the lamp base as a weight to provide better stability.

Several factors can affect the risk for exposure from mercury-containing antiques; for example, antiques become more fragile as they age, which can increase the risk for spills from breakage. In contrast, fewer antiques with mercury remain in circulation because the sale of many mercury-added items (e.g., barometers and clocks) has been prohibited in certain states, and increased educational measures directed toward the public (e.g., from government agencies) might be raising awareness about the dangers of mercury. Approximately 12 states, including New York, already have restricted the sale of mercury-added products, which could reduce the risk for exposure to mercury from such items; these restrictions typically apply to the sale of antique barometers containing mercury (6).

The findings in this report are subject to at least two limitations. First, reporting of spills to HSEES state programs is not mandatory; therefore, participating state health departments might not be informed about every mercury spill. Second, the HSEES program is conducted in only 14 states; therefore, HSEES data might not be nationally representative.

Most mercury-containing antiques do not pose a risk for exposure if they are sealed and handled properly. Certain measures can be taken to prevent unintentional releases of mercury from antiques (Box). If a spill of elemental mercury does occur, prompt and proper care must be taken to contain and prevent further spread of the substance to minimize exposure and prevent adverse health effects. Guidelines for proper cleanup are available (7), and several agencies have set reference values for acceptable limits of mercury in air, including the Occupational Safety and Health Administration and the American Conference of Government Industrial Hygienists for workplaces, and ATSDR and the U.S. Environmental Protection Agency for indoor living spaces (1).

References

* HSEES participating states: Colorado, Iowa, New Jersey, New York, Minnesota, North Carolina, Oregon, Texas, Utah, Washington, and Wisconsin (2000--2006); Missouri (2000--2005); Louisiana (2001--2006); Rhode Island (2000--2002); Alabama and Mississippi (2000--2004); and Florida and Michigan (2005--2006).

An HSEES event is defined as one that involves the release or threatened release of a hazardous substance or hazardous substances that meets minimum set criteria. A hazardous substance is one that can reasonably be expected to cause an adverse health effect (3).

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