Elemental Mercury Spills

Sources of elemental mercury (Hg(0)) include old natural gas regulators, manometers, sphygmomanometers, thermometers, and thermostats. Causes of Hg(0) spills include improper storage, container breakage, children playing with Hg(0), the breakage of devices containing Hg(0), and ritualistic use of Hg(0). Inhalation is the primary exposure route for Hg(0). Mercury released into the environment can enter lakes and streams, where bacteria convert it into methylmercury, which bioaccumulates in fish. Chronic exposure to Hg(0) vapors can damage the kidneys and neurologic system. Short-term exposure to high levels of Hg(0) vapors may cause lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation, among other effects. Minimizing Hg(0) dispersal is important after an Hg(0) spill. Tracking by shoes or apparel or vacuuming can spread Hg(0), increasing airborne concentrations and cleanup costs. The Illinois Department of Public Health’s response to an Hg(0) spill depends on the size of the spill. Airborne concentrations after large spills are mapped with a mercury vapor analyzer (MVA). The cleanup begins with the spill site and any hot spots that were identified with the MVA. Hard surfaces can usually be cleaned, but contaminated porous items must be discarded. Leaving marginally contaminated items outdoors for a month or more during warm weather may dissipate the Hg(0). After a cleanup, clearance sampling is conducted to determine if further cleanup is needed. The best way to prevent Hg(0) spills is reduce its use.