Mercury is found in everything from dental fillings, glass, batteries, and, though it pains me to say it, CFL light bulbs.
Inorganic mercury is released into the environment through mining, combustion of fossil fuels, and manufacturing. Organic mercury compounds are just as bad and are formed by microscopic organisms in water and soil. Methylmercury is the most prevalent form of organic mercury, and is found in fish and shellfish. This compound is of particular concern because it bioaccumulates which means it is not excreted once it has been absorbed, and it biomagnifies which means that concentrations go up as one moves up the food chain.
Exposure to mercury occurs through food, particularly fish and shellfish. Mercury exposure can also result from spills from thermometers, light bulbs, and other household objects. Recently several cosmetics have been found to contain mercury as well.
Methylmercury is considered by the EPA to be possibly carcinogenic for humans. The nervous system is extremely vulnerable to mercury. Short-term exposure can cause permanent damage to the brain, causing deficits in vision, hearing, memory, and tremors. High-level exposure can also cause lung and kidney damage. Children are more susceptible to mercury than adults, and can be passed from mother to the fetus, where it accumulates.
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