Many people may not realize it, but mercury still poses contamination hazards from improper handling and potential health risks from exposure. The Missouri Department of Natural Resources encourages Missourians to be aware of what mercury is and understand the risks from unsafely handling the toxic material. People should know how to prevent mercury spills, what actions to take if a spill occurs and how to safely dispose of mercury-containing devices.
Two recent mercury spills have highlighted the importance of mercury awareness. The two incidents, both in St. Louis-area homes, involved accidental releases of mercury in areas where people could be exposed. In one of the cases, a child dropped and broke an old thermostat on the floor, and the mother tried cleaning it up herself. The other incident involved an adult who dropped and broke a vial of mercury on her patio floor.
Elemental or metallic mercury, the silver fluid that many have seen in science class, is liquid at room temperature and has no odor. When mercury is spilled, some of it will evaporate into the air and can move long distances. Mercury is toxic when inhaled or absorbed through the skin. Improper cleanup easily spreads the mercury and increases exposure risk by dispersing it into the air and onto other surfaces.
Mercury exposure particularly affects children less than 12 years old, pregnant women, women who plan to become pregnant and nursing mothers. If mercury exposure is suspected, contact a healthcare provider immediately.
Mercury is used in many devices such as thermometers, barometers, switches, thermostats and fluorescent lamps. Bulk elemental mercury and laboratory reagents are used in school science labs. Improperly storing or mishandling these items can cause dangerous and costly mercury spills.
Only a small amount of mercury is contained in common thermometers, so a broken device does not present an immediate health risk. However, if not quickly and properly cleaned up and disposed of, the released mercury may present a long-term health risk.
Mercury spills should only be cleaned up by properly trained and equipped professionals. Incorrectly handling a mercury spill can significantly increase the responsible party’s actual cleanup cost and extend the time needed for full remediation. Cleaning up a mercury spill typically requires the contaminated property to be vacated until it is deemed safe.
If a spill occurs, do not try to clean it up and keep everyone away from the spill area. Immediately remove any potentially contaminated clothing and leave them in the same spill location. Leave the home or building and call the department’s Environmental Emergency Response 24-hour hotline at 573-634-2436 for guidance.
People can prevent spills by discontinuing the use of elemental mercury compounds and mercury-containing equipment. Businesses, schools and homes should consider removing and disposing of these materials in accordance with state and federal regulations. Most items that contain mercury can be replaced with mercury-free (or lower-mercury) alternatives. These include spirit-filled or digital thermometers, electronic thermostats and switches, manual blood pressure monitors and other digital devices.
The department encourages citizens to use household hazardous waste facilities as the first option for properly disposing of unwanted devices that contain mercury. A list of permanent household hazardous waste facilities in Missouri is available online.
Households can also dispose of those devices in their trash destined for a sanitary landfill. Double-bagging the items is recommended to help limit human exposure during handling.
Businesses are required to manage wastes noted above as universal or hazardous waste; sanitary landfill disposal is not an option. Mercury-containing laboratory chemicals and jars of elemental mercury cannot be classified as universal waste and must be managed as hazardous waste.
Many other mercury information resources are available at dnr.mo.gov/monitoring/mercury.