Mercury

Mercury intoxication and ophthalmic involvement: An update review

“…Mercury is a toxic metal that exists in three forms with different toxicological properties, as elemental or metallic mercury (mercury liquid and mercury vapor) or as inorganic (mercury salts) and organic compounds (methylmercury and ethylmercury) when combined with other elements (Park and Zheng, 2012;Fowler and Zalups, 2022), and it is considered by the World Health Organization (WHO) as one of the top 10 chemicals or groups of chemicals of major public health concern (World Health Organization, 2017). A significant incident occurred in Minamata, Japan, between 1932 and1968, where a factory dumped waste liquid with high concentrations of methylmercury in the bay which was rich in fish and shellfish, the primary food sources for local and other areas residents, affecting at least 50,000 people and causing neurological symptoms in over 2,000 people (hence the name Minamata disease) (World Health Organization, 2017).…”

“…A significant incident occurred in Minamata, Japan, between 1932 and1968, where a factory dumped waste liquid with high concentrations of methylmercury in the bay which was rich in fish and shellfish, the primary food sources for local and other areas residents, affecting at least 50,000 people and causing neurological symptoms in over 2,000 people (hence the name Minamata disease) (World Health Organization, 2017). Later in 1972, over 6,000 people in Iraq developed methylmercury poisoning from eating baked grain bread treated with methylmercury-based fungicide (Fowler and Zalups, 2022;Posin et al, 2022).…”

“…There are many pathways for intoxication after mercury exposure, including ingestion of contaminated seafood, contact with broken mercury-containing devices such as thermometers, barometers and electrical switches, or inhaling mercury vapor from dental amalgam (which are currently less and less likely because their manufacture has been prohibited) (Fisher, 2003;World Health Organization, 2017;Fowler and Zalups, 2022;Posin et al, 2022). However, most human mercury intoxication occurs in occupational settings when workers inhale odorless and colorless elemental mercury vapors, in mercury and artisanal or small-scale gold mining, physics and pharmaceutical laboratories and some industrial processes such as zinc-mercury amalgam, coalfired power and chloroalkali plants, paint factories, non-ferrous and ferrous metal production, and in fluorescent lamp, batteries and other instruments manufacturing (Fisher, 2003;Rustagi and Singh, 2010;UN Environment, 2019;Fowler and Zalups, 2022). These mercury vapors are absorbed up to 80% through the lungs with rapid diffusion to the blood and later distribution throughout the body.…”

“…These mercury vapors are absorbed up to 80% through the lungs with rapid diffusion to the blood and later distribution throughout the body. In contrast, inorganic mercury is absorbed mainly in the gastrointestinal tract in about 2%-38%, while methylmercury when ingested is almost 100% absorbed in the duodenum, then in the blood combines with glutathione and other amino acids or peptides (Hong et al, 2012;Fowler and Zalups, 2022;Posin et al, 2022).…”

“…Peripheral nerve function, renal function, immune and endocrine systems, and muscle function may also be affected by the three forms (Fowler and Zalups, 2022). To reduce these adverse effects, a global agreement named Minamata Convention on Mercury was adopted in 2013 and entered into force in 2017 to take actions to protect human health and environment from anthropogenic release of mercury (UNEP, 2019).…”