Mercury acceptable daily intake

There have been numerous reports of possible allergic reactions to mercury and mercury salts and to the mercury, silver and copper in dental amalgam as well as to amalgam corrosion products Studies of the release of mercury by amalgams into distilled water, saline and artificial saliva tend to be conflicting and contradictory but, overall, the data indicate that mercury release drops with time due to film formation and is less than the acceptable daily intake for mercury in food . Further, while metallic mercury can sensitise, sensitisation of patients to mercury by dental amalgam appears to be a rare occurrence. Nevertheless, there is a growing trend to develop polymer-based posterior restorative materials in order to eliminate the use of mercury in dentistry. 

Halbach (1994) examined the data from 14 independent studies and concluded that the probable mercury dose from amalgam is less than 10 g/day. When combined with the 2.6 g/day background intake estimated by WHO (1990) for persons without amalgam fillings and with an estimated methylmercury intake of 5 g/day from food, Halbach noted that the sum of all those inputs still falls within the WHO s 40 g/day acceptable daily intake (ADI) level for total mercury. For the ADI of 40 g total mercury exposure inhaled, approximately 30 g would be absorbed, assuming 80% absorption (Halbach 1994 WHO 1976). 

FW in whole organism. Mercury concentrations considered acceptable to protect representative species of birds, in mg total mercury/kg FW, include less than <0.5-<1.0 in eggs, <5.0 in feather, <5.0 in liver, and <20.0 in kidneys. Diets of sensitive fisheating birds should contain less than 20.0 jig Hg as methylmercury/kg FW or < 100.0 jig total mercury/kg FW daily intake should not exceed 640.0 xg total mercury/kg body weight. For most species of nonhuman mammals, recommended mercury levels include daily intake of < 250.0 xg total mercury/kg FW body weight, diets that contain <1.1 mg total mercury/kg FW, and <0.002 (xg total mercury in drinking water supply of livestock however, diets of fish-eating mammals should contain < 100.0 (Jtg total mercury/kg FW. Tissue mercury concentrations in sensitive mammals, in mg total mercury/kg FW, should probably not exceed 10.0 in liver, 2.0 in hair, 1.5 in brain, and 0.5 in blood. All these proposed criteria provide, at best, miiumal protection. 

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