Mercury Toxicity: Three Forms, Bioaccumulation, and Detection
Three mercury forms: elemental (vapor danger), methylmercury (most toxic, bioaccumulates in fish), inorganic salts (kidney damage). Half-life ~70-80 days. Blood tests for recent, hair for long-term exposure.
Mercury exists in three forms with different toxicity profiles: 1. Elemental mercury (liquid metal): Vapor inhalation is dangerous. Skin contact with liquid mercury is less hazardous than commonly believed — the metal does not readily cross intact skin. 2. Methylmercury (organic): The most toxic common form. Bioaccumulates up the food chain — large predatory fish (tuna, swordfish, shark) concentrate methylmercury from all the smaller organisms they consume. This is why fish consumption advisories exist. 3. Inorganic mercury compounds (salts): Corrosive, cause kidney damage. Different exposure pathway than methylmercury. Bioaccumulation: Mercury is not efficiently excreted by the body. Small repeated exposures accumulate over time, with a biological half-life of approximately 70-80 days for methylmercury in humans. Detection: Blood tests measure recent/ongoing exposure. Hair analysis provides a longer-term exposure history, as mercury is incorporated into hair as it grows. Urine tests are primarily useful for inorganic mercury and elemental mercury vapor exposure.