Mercury adults, effect

Most of the mercury in muscle is present as MeHg. Barr (1986) reported that adult loons from a site closest to a mercury somce with 1.87 ppm Hg in fish, resulted in a muscle Hg concentration of 4.57 ppm ww and a brain Hg concentration of 1.49 ppm. Those loons had only 20% of territories successful (Barr 1986). Mallard hens receiving 0.5 ppm dietary mercury for 18 months had a muscle Hg concentration of 0.82 ppm compared with brain Hg = 0.50 ppm. Mallard hens receiving 3 ppm for the same period had 5.01 ppm in muscle and 4.57 in brain (Heinz 1976). Based on these assessments, muscle Hg concentration is more representative of brain Hg concentration and correlates better with effect than the more commonly measured fiver residue. It is also possible to sample muscle tissue nonlethally via biopsy, in... 

In utero exposure to mercury did not produce significant adverse effects on adult performance, although gender differences may interact with methylmercury on certain behaviors... 

Gerstenberger, S.L., J. Pratt-Shelley, M.S. Beattie, and J.A. Dellinger. 1993. Mercury concentrations of walleye (,Stizostedion vitreum vitreum) in 34 northern Wisconsin lakes. Bull. Environ. Contam. Toxicol. 50 612-617, Gilbert, S.G., C.D. Munkers, T.M. Burbacher, and D.C. Rice. 1994. Effects of in utero methylmercury exposure on schedule controlled behavior in adult monkeys. Amer. Jour. Primatol. 33 211. 

Mercuric chloride is a potent nephrotoxicant in the adult rat, but has little effect on the newborn [222], There are significant maturational changes in organ, cellular and subcellular distribution of mercury during the first 4 weeks after birth. With increasing age, mercury is redistributed from the renal cytosolic fraction to the nuclear/mitochondrial fraction, where it may be more damaging. 

Selenium is readily available in a variety of foods including shrimp, meat, dairy products, and grains, with a recommended daily intake of 55 to 70 jug. It occurs in several forms with Se+6 being biologically most important. Selenium is readily absorbed by the intestine and is widely distributed throughout the tissues of the body, with the highest levels in the liver and kidney. It is active in a variety of cellular functions and interacts with vitamin E. Selenium appears to reduce the toxic effects of metals such as cadmium and mercury and to have anticarcinogenic activity. Selenium produces notable adverse effects both in deficiency and excess thus recommended daily intake for adults is approximately 70 Jg/day but should not exceed 200 pg/day. 

Children at Risk Very young children are more sensitive to mercury than adults are. Mercury in the mother s body passes to the fetus and can pass to a nursing infant through breast milk. However, the benefits of breast-feeding may be greater than the possible adverse effects of mercury in breast milk.90... 

Lead Lead is the most ubiquitous of the ne-phrotoxicant metals in the environment. Like mercury, the health effects of lead have been recognized for centuries with the nervous system as well as the kidney being a target for certain forms of these metals. Sources of exposure to lead include food ( 100pg or less per day for adults), lead-based paints, industrial emissions, lead dusts and lead-glazed pottery. 

For similar exposure routes and forms of mercury, the harmful health effects seen in children are similar to the effects seen in adults. High exposure to mercury vapor causes lung, stomach, and intestinal damage and death due to respiratory failure in severe cases. These effects are similar to those seen in adult groups exposed to inhaled metallic mercury vapors at work. 

Organic Mercury. Limited information was located regarding respiratory effects in humans after oral exposure to organic mercury. Two boys who died after eating meat from a hog that had eaten seed treated with ethylmercuric chloride developed bronchopneumonia and edematous alveolitis, and required artificial ventilation (Cinca et al. 1979). Bronchopneumonia was also identified as the cause of death in four adults and one infant who died as the result of methylmercury poisoning in Iraq during 1972 (Al-Saleem and the Clinical Committee on Mercury Poisoning 1976). It is unclear whether these respiratory effects were the result of direct effects on the respiratory system or were secondary to other effects. 

Organic Mercury. Extremely limited information was also obtained regarding the hepatic effects of organic mercury exposure. An autopsy of four adults and four infants who died as the result of methyl-mercury poisoning in Iraq in 1972 reported fatty changes in the liver occurred in most cases (Al-Saleem... 

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