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Recent mercury spills underscore contamination hazards and health risks

JEFFERSON CITY, MO, NOV. 19, 2021 - The Missouri Department of Natural Resources is encouraging Missourians to be aware of what mercury is, as well as the contamination hazards and potential health risks from unsafe handling of the toxic material. People should also know how to prevent mercury spills, what actions to take if a mercury spill occurs and how to safely dispose of mercury-containing devices.

Two mercury spills in November highlight the importance of mercury awareness. The two incidents, both in St. Louis area homes, left children hospitalized for mercury exposure. For several days, the families were also displaced from their contaminated homes, which required extensive professional decontamination and cleaning to make them safe to live in again.

Elemental or metallic mercury, the silver fluid that many have seen in science class, is liquid at room temperature and has no odor. When spilled, some of the mercury will evaporate into the air and can move long distances. Mercury is toxic when inhaled or absorbed through the skin. Improper clean up easily spreads the mercury and increases exposure risk by dispersing it into the air and onto other surfaces.

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 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.

Short-term exposure to high levels of mercury vapors may cause serious health effects, including nausea, vomiting, diarrhea and lung damage. It can also cause increased blood pressure or heart rate, skin rashes and eye irritation.

Symptoms from long-term exposure can develop in just a few weeks and include tremors, decreased hand-eye coordination, memory problems, insomnia and irritability. If these symptoms are not correctly identified and further exposure prevented, permanent nervous system damage can occur. The Missouri Department of Health and Senior Services offers more information on mercury health risks their website

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.

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.

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. 

Heating and air conditioning contractors can participate in a collection program through the Thermostat Recycling Corporation, a not-for-profit corporation that facilitates the collection and proper disposal of all wall-mounted mercury-switch thermostats. To find local collection sites and for more information, visit

Many other mercury information resources are available at

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