Health Risks of Mercury

Mercury is a very toxic volatile chemical pollutant and non-essential metal in the human body. Mercury is widely distributed in the environment, present in natural products and various types of medicines. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. The organic form of mercury is most toxic, causing neurological and developmental damage. Inorganic mercury compounds are water soluble and on ingestion, can cause gastrointestinal symptoms. They are mainly accumulated in the kidneys and are the major reason for kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood–brain barrier. It may also enter the brain from the nasal cavity through the olfactory pathway. Emission of mercury from volcanoes, industrial processes, artisanal small-scale gold mining (ASGM), fossil fuels combustions and biomass burning accumulates in soil and water, where it’s ingested by plants and sea animals. This can cause the bioaccumulation and biomagnification of mercury in the food chain. This chapter discusses the mercury toxicity, health risks of mercury and their routes of exposure in the food chain.