Mercury, a naturally occurring element, exists in several forms, each with different effects on the human body. Controlling mercury exposure involves both environmental management and internal biological support. The three primary forms are elemental, inorganic, and organic mercury. Elemental mercury, a liquid metal, becomes a dangerous vapor upon evaporation, while organic methylmercury is highly toxic to the nervous system and accumulates in the food chain. Successfully addressing mercury involves limiting exposure, safely cleaning up environmental spills, and supporting the body’s natural processes for elimination.
Identifying and Limiting Sources of Exposure
Preventing mercury exposure begins with identifying the primary pathways through which the element enters the home and body. The most common source of highly toxic organic methylmercury is the consumption of certain types of fish and shellfish. This form of mercury bioaccumulates, meaning it concentrates in larger, longer-lived predatory fish. Limiting these species is the most effective preventative dietary measure.
Federal agencies advise that individuals, especially those who are pregnant or parents of young children, avoid consuming fish with the highest mercury levels. These species should be replaced with safer alternatives to ensure adequate nutritional intake.
- Tilefish from the Gulf of Mexico
- Shark
- Swordfish
- King mackerel
- Marlin
- Orange roughy
- Bigeye tuna
Low-mercury alternatives that can be safely eaten two to three times per week include salmon, shrimp, canned light tuna, cod, tilapia, and catfish.
Elemental mercury exposure originates from household items that contain the liquid metal. Older products like glass fever thermometers, some thermostats, and certain antique barometers contain elemental mercury that can be released if the item breaks. A less obvious source is inorganic mercury compounds found in some imported skin-lightening creams and soaps. These cosmetic products, which may be labeled with ingredients like “calomel,” “mercuric,” “mercurous,” or “mercurio,” are a direct dermal exposure risk that can lead to systemic toxicity.
Safe Cleanup and Disposal of Elemental Mercury
Environmental cleanup focuses on elemental mercury, which poses a severe inhalation hazard once it vaporizes. Following a small spill, such as from a broken thermometer, the immediate action is to ventilate the area by opening windows and turning off any central heating or air conditioning systems. People and pets should leave the contaminated room for at least 15 minutes before cleanup begins.
Never use a household vacuum cleaner, broom, or mop on the spill. Sweeping or mopping breaks the mercury into smaller droplets, and the heat from a vacuum motor will aerosolize the mercury, significantly increasing the toxic vapor concentration. Instead, wear gloves and use stiff paper or a squeegee to gently gather the visible mercury beads into one small ball. An eyedropper can suction droplets from crevices, and sticky tape is effective for picking up final, fine particles.
All contaminated materials, including gloves, the eyedropper, tape, and collected mercury, must be placed into a sealed, non-porous container. This container should be clearly labeled and taken to a local household hazardous waste collection site for proper disposal. Broken compact fluorescent light (CFL) bulbs, which contain a small amount of elemental mercury, require ventilation and careful cleanup before the debris is sealed and taken to a designated recycling center.
Methods for Reducing Mercury Levels in the Body
Reducing mercury levels in the body begins with accurate medical testing to determine the extent and form of the exposure. Blood tests are primarily used to measure methylmercury and are indicative of recent exposure, providing a snapshot of the mercury currently circulating. Urine testing, conversely, is the preferred method for assessing chronic exposure to metallic and inorganic mercury, as these forms are excreted through the kidneys.
Nutritional adjustments can support the body’s natural detoxification processes. Consuming high-fiber foods, such as whole grains and legumes, helps bind mercury excreted in the bile, preventing its reabsorption in the digestive tract. Selenium, found in foods like Brazil nuts, helps counteract mercury’s toxic effects by forming a complex that is less harmful and easier to eliminate.
For confirmed cases of toxicity, chelation therapy is the standard medical treatment. This therapy involves administering prescription chelating agents, specialized drugs designed to bind to heavy metals within the body. Once the agent attaches to the mercury, the complex is cleared primarily through the urine.
Chelation therapy must be strictly supervised by a medical professional due to the potential for serious side effects. These risks include the depletion of essential minerals like zinc and calcium, kidney damage, and the possibility of mobilizing mercury to other organs if not administered correctly. Chelation is approved only for the treatment of documented heavy metal poisoning, and over-the-counter chelation products or their use for unproven conditions are dangerous.