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

MERCURY 109
2. HEALTH EFFECTS
chloride for constipation, worms, or teething discomfort had swollen red gums, excessive salivation,
anorexia, diarrhea, and/or abdominal pain (Warkany and Hubbard 1953).
Inflammation and necrosis of the glandular stomach were observed in mice that were given oral doses of
59 mg Hg/kg as mercuric chloride 5 days a week for 2 weeks (NTP 1993). In a 2-year gavage study, an
increased incidence of forestomach hyperplasia was observed in male rats exposed to 1.9 or 3.7 mg
Hg/kg/day as mercuric chloride compared to the control group.
Organic Mercury. Case studies of individuals who were orally exposed to alkyl mercury compounds
(unspecified form) reported diarrhea, tenesmus, irritation, and blisters in the upper gastrointestinal tract
(Lundgren and Swensson 1949). Ingestion of meat from a hog that was fed seed treated with ethylmercuric
chloride resulted in vomiting in two of the family members (Cinca et al. 1979). No quantitative data were
available. Ingestion of flour made from seed grains that had been treated with ethylmercury p-toluene
sulfonanilide also commonly resulted in abdominal pain and vomiting, diarrhea, or constipation (Jalili and
Abbasi 1961).
Pfab et al. (1996) reported a case of a 44-year-old man who ingested 83 mg/kg Thiomersal in a suicide
attempt (5 g/60 kg). Thiomersal is a widely used alkyl-aryl-organomercurial bactericide. The man
developed gastritis, renal tubular failure, dermatitis, gingivitis, delirium, coma, polyneuropathy, and
respiratory failure. Treatment was symptomatic plus gastric lavage and the oral chelation with
dimercaptopropane sulfonate and dimercaptosuccinic acid. The patient's condition was at its worst on day
17; however, the patient recovered completely (after several months). Maximum mercury concentrations
were: blood, 14 mg/L; serum, 1.7 mg/L; urine, 10.7 mg/L; and cerebrospinal fluid, 0.025 mg/L. Mercury
concentration in blood declined with two velocities: first with a half-time of 2.2 days, then with a half-time
of 40.5 days. The decline of mercury concentration in blood, urinary mercury excretion, and renal mercury
clearance were not substantially influenced by chelation therapy.
Exposure of rats to phenylmercuric acetate for 2 years resulted in necrosis and ulceration of the cecum at
doses as low as 4.2 mg Hg/kg/day in drinking water; no effect was observed at 1.7 mg Hg/kg/day in the
feed (Fitzhugh et al. 1950; Solecki et al. 1991). Mice showed ulceration of the glandular stomach after
2 years of dietary exposure to methylmercuric chloride at 0.69 mg Hg/kg/day (Mitsumori et al. 1990). In
contrast, no treatment-related histopathological lesions in the stomach or jejunum were observed in rats
exposed via the diet to 0.1 mg Hg/kg/day as methylmercuric chloride (Verschuuren et al. 1976).