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

MERCURY 121
2. HEALTH EFFECTS
The only information located regarding dermal effects in animals after oral exposure to organic mercury
comes from a study in which rats were exposed to methylmercuric chloride in the diet for 2 years
(Verschuuren et al. 1976). No treatment-related lesions were observed upon histopathological examination
of the skin of rats exposed to 0.1 mg Hg/kg/day.
Ocular Effects
Inorganic Mercury. No information was located regarding ocular effects in humans from ingestion of
inorganic mercury.
No studies were located regarding ocular effects in animals after oral exposure to inorganic mercury.
Organic Mercury. No information was located regarding ocular effects in humans from ingestion of
organic mercury. While visual effects result from methylmercury exposure, they are cortical in origin (see
neurotoxicity below).
The only report of ocular effects in animals after oral exposure to organic mercury comes from a study in
which rats were exposed to methylmercuric chloride via the diet for 2 years (Verschuuren et al. 1976). No
treatment-related lesions were observed upon histopathological examination of the eyes of rats exposed to
0.1 mg Hg/kg/day. As in humans, the visual effects resulting from methylmercury exposure in primates are
considered to be centrally mediated (Rice and Gilbert 1982, 1990).
Body Weight Effects
Inorganic Mercury. No information was located regarding body weight effects in humans from ingestion
of inorganic mercury.
A single dose of mercuric chloride administered to female Sprague-Dawley rats (10/group) at 7.4 or 9.2 mg
Hg/kg in water resulted in no effects on body weight at 14 days postexposure (Lecavalier et al. 1994).
However, a number of animal studies have reported decreases in body weight or body weight gain after
ingestion of mercuric chloride (Chang and Hartmann 1972a; Dieter et al. 1992; NTP 1993). After a 4-week
exposure to mercuric chloride in the food, male Wistar rats had a 21% body weight decrease at 10 mg
Hg/kg/day, and female Wistar rats had a 27% decrease in body weight at 22.2 mg Hg/kg/day. No