Metallic mercury, also known as elemental mercury, is a naturally occurring element symbolized as Hg. It exists as a dense, shiny, silver-white liquid without any discernible odor at room temperature. This substance tends to form beads and can transform into metallic mercury vapor when exposed to air or heated.

Industrially, metallic mercury finds its usage in various sectors such as electronics manufacturing, fluorescent lighting production, and the creation of chlorine-caustic soda. Although previously utilized in dental fillings, its use in dentistry is now being phased out. Additionally, metallic mercury is employed in alternative medicine and certain cultural practices, notably in Latin American, Indian, Caribbean, and Vietnamese communities. However, many applications involving metallic mercury, such as in batteries and thermometers, have been discontinued or significantly reduced, including its usage in school science laboratories.

Environmental Impact of Metallic Mercury Metallic mercury can be found in the air, water, and soil through natural processes as well as industrial emissions into the atmosphere and water bodies. Over the past few decades, industrial releases into the air have steadily decreased. It is important to note that mercury does not undergo degradation in the environment. Instead, in air, it can disperse over long distances from its source of release. In water, metallic mercury can evaporate into the air, while in soil, it can adhere to the soil particles and sediments.

Exposure Pathways to Metallic Mercury While environmental levels of metallic mercury are generally low and unlikely to cause immediate health effects, higher exposures can lead to nervous system-related issues. Exposure to metallic mercury in the environment can occur near old mines containing metallic mercury or industries utilizing this element. For the general public, exposure commonly happens indoors, especially when compact fluorescent lightbulbs (CFLs) or glass thermometers break, releasing metallic mercury vapor or gas that can be inhaled. Pregnant women are particularly vulnerable as mercury can pass from the mother's bloodstream to the developing fetus. Furthermore, mercury can be present in breast milk, leading to exposure in infants through breastfeeding. Workers in industries involving metallic mercury may also face exposure risks.

silver liquid mercury

Health Effects of Metallic Mercury Exposure The primary health impact of metallic mercury exposure is on the nervous system. Individuals, including laboratory animals, workers, and the general population exposed to mercury, may exhibit symptoms such as tremors, coordination difficulties, vision problems, learning impairments, hearing issues, memory loss, headaches, and mood changes. In cases of very high exposure to metallic mercury vapor, respiratory problems and even fatalities have occurred. Children are more susceptible to the health effects of metallic mercury due to their developing nervous systems. High levels of exposure in children can result in acrodynia, a reversible condition characterized by reddening and tenderness in the palms and soles, along with mood swings, irritability, sleep disturbances, and muscle or joint pain.

Cancer Risk from Metallic Mercury The potential of metallic mercury to cause cancer in humans has not been evaluated or classified by organizations such as the U.S. Department of Health and Human Services (DHHS), the U.S. Environmental Protection Agency (EPA), and the International Agency for Research on Cancer (IARC).

Testing for Metallic Mercury Exposure Mercury levels can be measured in blood, urine, hair, or toenails. Since most metallic mercury is eliminated from the body through urine, testing urine for mercury is the preferred method to assess exposure. However, this test cannot predict whether an individual will experience health problems. If there are concerns about metallic mercury exposure, consulting a healthcare professional or poison control center is recommended.

Protective Measures Against Metallic Mercury Exposure In daily life, most people do not require specific actions to avoid exposure to metallic mercury. However, contact with spills of metallic liquid mercury should be avoided, and proper cleanup procedures should be followed if a spill occurs indoors. Children should be kept away from areas with metallic mercury contamination, such as hazardous waste sites or old mining locations, to prevent exposure.

Handling Broken Thermometers or Compact Fluorescent Lights (CFLs) If a glass thermometer or CFL breaks, it is essential to avoid using a broom or vacuum cleaner to clean up the mercury. Children and pets should be removed from the area, and the spilled mercury should be carefully collected using methods such as rolling it onto a sheet of paper or using an eye dropper. The contaminated items should be placed in a sealed plastic bag or container, and local health or sanitation departments should be contacted for further guidance.

For additional information on handling metallic mercury safely, resources such as ATSDR's "Don't Mess with Mercury," EPA's guidelines on cleaning up broken CFLs, and EPA's comprehensive information on mercury can be consulted.

This revised content provides a detailed overview of metallic mercury, including its environmental impact, exposure pathways, health effects, cancer risk, testing methods, protective measures, and proper handling procedures for spills or accidents involving metallic mercury-containing items.