Mercury Contamination of Environment and Food

Mercury is a heavy metal that presents in the earth’s crust and it is methylated by bacteria in aquatic environments to methyl mercury (MeHg) in anaerobic conditions. It is then concentrated by the food chain so predatory fish and other seafood animals may have the highest levels. Most of the mercury that enters the ocean from sources on land or air is just the element mercury, a form that poses little danger because living things can get rid of it quickly. The kind of mercury that accumulates to toxic levels in fish is called monomethylmercury, or simply methylmercuryPeople are exposed to mercury from three major sources: fish (methylmercury), vaccines (ethylmercury), and dental amalgams (elemental mercury in the form of mercury vapor). After inhalation, approximately 70-80% of a mercury vapor (Hg0) dose is absorbed across the alveolar membranes and enters the systemic circulation. Levels of mercury in fish vary depending on factors such as: trophic level in the food chain, size, and habitat location. For this reason, it is important to gather information on mercury levels in different types of fish in various parts of the world. Methylmercury [CH3Hg] is the most toxic form. It affects the immune system, alters genetic and enzyme systems, and damages the nervous system, including coordination and the senses of touch, taste, and sight. Methylmercury is particularly damaging to developing embryos, which are five to ten times more sensitive than adults.

کلیدواژه ها:

Mercury ، Contamination ، Environment ، Food