revised final - Agency for Toxic Substances and Disease Registry ...

MERCURY 177
2. HEALTH EFFECTS
methylmercury in blood is found in the red blood cells (Kershaw et al. 1980). The mean mercury
concentrations in red blood cells were 27.5 ng/g and 20.4 ng/g in males and females, respectively, exposed
to mercury, primarily from mercury-contaminated fish (Sakamoto et al. 1991). Because of this uniform
distribution in tissues, blood levels are a good indicator of tissue concentrations independent of dose
(Nordberg 1976).
Although distribution is generally uniform, the highest levels of organic mercury are found in the kidneys
(Nielsen and Andersen 1991b; Rice 1989b; Ryan et al. 1991). After a single oral dose of 0.04, 0.2, 1, or
5 mg Hg/kg as methylmercuric chloride administered to mice, mercury was retained mostly in the kidneys
and liver at 14 days postexposure (Nielsen and Andersen 1991a). The deposition of mercury in the carcass
was about 70%, with retention primarily in the skin, hair, and muscles and to a lower degree in the fat and
bones (Nielsen and Andersen 1991b). More than 200 days after cynomolgus monkeys were given
0.025 and 0.05 mg Hg/kg/day as methylmercuric chloride in apple juice for about 2 years, the kidneys
contained 10.18–27.89 ppm mercury in the cortex and 1.12–10.11 ppm in the medulla, compared to