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

MERCURY 122
2. HEALTH EFFECTS
significant loss was observed at the next-lower-dose groups of 5 and 11.1 mg Hg/kg/day in males and
females, respectively (Jonker et al. 1993b).
Doses of 14.8 mg Hg/kg/day administered to rats 5 days a week for 2 weeks resulted in a 10% decrease in
male body weight gain (NTP 1993). Much lower doses produced decreases in body weight gain when
administered over longer periods. In rats, decreases in body weight gain of approximately 10% were
observed with doses of 0.93 mg Hg/kg as mercuric chloride when administered by gavage 5 days a week for
6 months (NTP 1993). Mice were less sensitive, showing no effect at 7.4 mg Hg/kg/day and a 26%
decrease in body weight gain at 14.8 mg Hg/kg/day in the same study (NTP 1993).
Organic Mercury. No information was located regarding body weight effects in humans from ingestion of
organic mercury.
A number of animal studies have reported decreases in body weight or body weight gain after ingestion of
methyl or phenyl mercury. A 20–25% decrease in body weight gain in male and female rats was observed
after 5 gavage doses of 8 mg Hg/kg/day as methylmercuric chloride or ethylmercuric chloride (Magos et al.
1985). In intermediate-duration studies with methylmercury, biologically significant decreases in body
weight gain have been observed in rats after exposure to doses as low as 0.8 mg Hg/kg/day for 6 weeks
(Chang and Hartmann 1972a) and in mice after exposure to 1 mg Hg/kg/day for 60 days (Berthoud et al.
1976). No effect on female body weight gain was observed after dietary exposure to 0.195 mg Hg/kg/day
as methylmercuric chloride for 14 weeks (Lindstrom et al. 1991). A 2-year exposure to 0.4 mg Hg/kg/day
as phenylmercuric acetate in the feed resulted in a 10% decrease in body weight gain in rats (Solecki et al.
1991). Gavage administration of methylmercuric chloride to rats for 2 days at 12 mg Hg/kg/day resulted in
a persistent decrease in the body temperature of the rats (Arito and Takahashi 1991).
Other Systemic Effects
Inorganic Mercury. Several children who were treated with mercurous chloride contained in powders or
tablets for constipation, worms, or teething discomfort exhibited low-grade or intermittent fevers (Warkany
and Hubbard 1953).
No studies were located on other systemic effects in animals after oral exposure to inorganic mercury.