Due to bioaccumulation it works its way up through the food web and thus biomagnifies, resulting in high concentrations among populations of some species. Top predatory fish, such as tuna or swordfish, are usually of greater concern than smaller species. The US FDA and the EPA advise women of child-bearing age, nursing mothers, and young children to completely avoid swordfish, shark, king mackerel and tilefish from the Gulf of Mexico, and to limit consumption of albacore ("white") tuna to no more than 170 g (6 oz) per week, and of all other fish and shellfish to no more than 340 g (12 oz) per week. A 2006 review of the risks and benefits of fish consumption found, for adults, the benefits of one to two servings of fish per week outweigh the risks, even (except for a few fish species) for women of childbearing age, and that avoidance of fish consumption could result in significant excess coronary heart disease deaths and suboptimal neural development in children.Because the process of mercury-dependent sequestration of selenium is slow, the period between exposure to methylmercury and the appearance of symptoms in adult poisoning cases tends to be extended. The longest recorded latent period is five months after a single exposure, in the Dartmouth case (see History); other latent periods in the range of weeks to months have also been reported. When the first symptom appears, typically paresthesia (a tingling or numbness in the skin), it is followed rapidly by more severe effects, sometimes ending in coma and death.
In India, a study by Centre for Science and Environment and Indian Institute of Toxicology Research has found that in the countrys energy capital Singrauli, mercury is slowly entering peoples homes, food, water and even blood. The Minamata Convention on Mercury in 2016 announced that the signing of the "international treaty designed to protect human health and the environment from anthropogenic releases and emission of mercury and mercury compounds" on April 22, 2016—Earth Day. It was the sixtieth anniversary of the discovery of the disease. Infantile acrodynia
Infantile acrodynia (also known as "calomel disease", "erythredemic polyneuropathy", and "pink disease") is a type of mercury poisoning in children characterized by pain and pink discoloration of the hands and feet. The word is derived from the Greek, where άκρο means end or extremity, and οδυνη means pain. Acrodynia resulted primarily from calomel in teething powders and decreased greatly after calomel was excluded from most teething powders in 1954.Acrodynia is difficult to diagnose; "it is most often postulated that the etiology of this syndrome is an idiosyncratic hypersensitivity reaction to mercury because of the lack of correlation with mercury levels, many of the symptoms resemble recognized mercury poisoning." Medicine
Mercury was once prescribed as a purgative. Many mercury-containing compounds were once used in medicines. These include calomel (mercurous chloride), and mercuric chloride.