Seafood mercury exposure

One of the particularly tragic aspects of the Minamata disaster was the effect methyl mercury exposure had on unborn children. Some of the mothers exposed to methyl mercury from the fish and seafood gave birth to babies who were severely affected with a disorder similar to infantile paralysis, suffering cerebral palsy and mental retardation. This occurred even in mothers who showed no symptoms themselves, a classic characteristic of a teratogen. Some babies were born completely paralysed. 

Steuerwald U, Weihe P, Jorgensen PJ, Bjerve K, Brock J, Heinzow B, Budtz-J0rgensen E and Grandjean P (2000) Maternal seafood diet, methyl mercury exposure, and neonatal neurolo cfunction. J Pediatr 136 599-605. 

Despite awareness, mercury exposure and related toxicity are reported in humans. Somces of exposme include environment [174 ], food (especially seafood) [175 ], accident or suicide [176, 177, 178, 179 ], occupation [180 ] and traditional drugs [181 182 ]. The major targets for mercury toxicity include renal [176 ], nervous, cardiovascular, reproductive system, autoimmune disease [183 ] and visual impairments. 

Arsenic is an ancient and well-known hazard and, along with lead and mercury, is an important environmental contaminant. The inorganic form is far more toxic than organic arsenic, which is commonly found in seafood. Arsenic-contaminated drinking water is a worldwide problem that affects millions of people. Human exposure also occurs from arsenic-treated lumber. 

Potential sources of human exposure to mercury include food contaminated with mercury, inhalation of mercury vapors in ambient air, and exposure to mercury through water, soil and sediment. Dietary intake is by far the most important source of exposure to mercury for the general population. Fish and other seafood products are the main source of methylmercury in the diet studies have shown that methylmercury concentrations in fish and shellfish are 10-100 times greater than in other foods, including cereals, potatoes, vegetables, fruits, meats, poultry, eggs, and milk. As of December 1998, mercury was the chemical contaminant responsible, at least in part, for the issuance of 1931 fish consumption advisories by 40 states, including the US territory of American Samoa. Almost 68% of all advisories issued in the United States are a result of mercury contamination in fish and shellfish. Advisories for mercury have increased steadily by 115% from 899 advisories in 1993 to 1931 advisories in 1998. The number of states that have issued mercury advisories also has risen steadily from 27 states in 1993 to 40 states in 1997, and remains at 40 states for 1998. Advisories for mercury increased nearly 8% from 1997 (1782 advisories) to 1998 (1931 advisories). 

Grandjean P, Weihe P, Jorgensen PJ, et al. 1992. Impact of maternal seafood diet on fetal exposure to mercury, selenium, and lead. Arch Environ Health 47(3) 185-195. 

Gilbert, S.G., T.M. Burbacher, and D.C. Rice. 1993. Effects of in utero methylmercury exposure on a spatial delayed alternation task in monkeys. Toxicol. Appl. Pharmacol. 123(1) 130-6. Grandjean, P., P. Weihe, P.J. Jorgensen, T. Clarkson, E. Cemichiari, and T. Videro. 1992. Impact of maternal seafood diet on fetal exposure to mercury, selenium, and lead. Arch. Environ. Health 47(3) 185-195. 

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