Mercury burden

Sheffy, T.B. and J.R. St. Amant. 1982. Mercury burdens in furbearers in Wisconsin. Jour. Wildl. Manage. 46 1117-1120. 

MMHg is UpophiUc, causing it to bioaccumulate and biomagnify through the marine food web. About 85 to 95% of the total mercury in fish is MMHg, most of which is the result of biomagnification. Marine fish consumption accoimts far most of the mercury burden in... 

Hibberd AR, Howard MA, Hunnisett AG. Mercury from dental amalgam fillings studies on oral chelating agents for assessing and reducing mercury burdens in humans. J Nutr Environ Med 1998 8 219-31. 

The authors concluded that efforts should be made to decrease total mercury burden in women of reproductive age Oskarsson et al. (1996). 

For the Swedish population in the study, Oskarsson et al. (1996) reports that there was an efficient transfer of inorganic mercury from blood to breast milk and that mercury from amalgam fillings was probably the main source of mercury in breast milk, while methylmercury levels in blood did not appear to be efficiently transferred to breast milk. Exposure of the infant to mercury in breast milk was calculated to range up to 0.3 g/kg/day of which approximately one-half was inorganic mercury. This exposure corresponds to approximately one-half the tolerable daily intake of total mercury for adults recommended by the World Health organization. The authors concluded that efforts should be made to decrease total mercury burden in women of reproductive age Oskarsson et al. (1996). 

Halbach S. 1994. Amalgam tooth fillings and man s mercury burden. Human Exper Toxicol 13 496-501. 

Drasch, G., I. Schupp, H. Hofl, R. Reinke, and G. Roider. 1994. Mercury burden of human fetal and infant tissues. Eur. J. Pediatr. 153(8) 607-610. 

As previously discussed, the major battery manufacturers in Europe, Japan and the United States had all successfully eliminated mercury from primary batteries by 1993. Consequently the mercury burden on the environment from waste primary batteries has been significantly reduced and continues to reduce year on year. The question remained, at what point in the future would all batteries which were sold before 1993 have been disposed of by the consumer If this date can be ascertained, then all primary recycling operations after that date need only concentrate on resource conservation and not toxic elimination. 

Although it is accepted that atmospheric mercury burdens have increased substantially since the pre-industrial period, it is uncertain whether overall atmospheric mercury levels are currently increasing, decreasing, or remaining stable. Measurements of mercury over remote areas of the Atlantic Ocean show increasing levels up until 1990 and a decrease for the period 1990-1994 (Slemr 1996, Pirrone et al. 2000, Munthe et al. 2001). However, other measurements at remote sites in northern Canada and Alaska show deposition rates... 

Due to these factors, the terrestrial pathway is not expected to be significant in comparison to the consumption of fish by humans and wildlife with regard to exposure to mercury. Not unexpectedly, the wildlife most at risk of a higher mercury burden are piscivorous birds and mammals. 

Inserted amalgam fillings also increase blood mercury levels (Kingman et al. 1998), but this only occurs during the first few days after insertion or removal of dental amalgam (Kremers et al. 1999). In contrast to the urinary concentrations, blood levels monitor predominantly the short-term mercury burden. In burdened populations, mercury concentrations in blood may exceed 100 pg L (Akagi et al. 1995, Drasch et al. 2001). 

Mottet, N.K. and Body. R.L (1974) Mercury burden of human autopsy organs and tissues. Arch. Environ. Health, 29.18-24. 

Atmospheric input of mercury has tripled over the past 150 years. The atmosphere plays an important role in the mobilization of mercury with 25-30% of the total atmospheric mercury burden of anthropogenic origin, although more recent estimates of 67% are significantly higher. As a direct result of human activities, mercury levels in river sediments have increased fourfold since precultural times, and twofold to fivefold in sediment cores from lakes and estuaries. Analysis of sediment cores of North American mid-continental lakes show that mercury deposition rates increased by a factor of 3.7 since 1850, at a rate of about 2% annually. During the past 100 years, more than 500,000 metric tons of mercury entered the atmosphere, hydrosphere, and surface soils, with eventual deposition in subsurface soils and sediments. 

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