TOXICOLOGICAL PROFILE FOR BARIUM AND COMPOUNDS ...

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2. HEALTH EFFECTS
determine if the reduced blood urea nitrogen was an adverse liver effect.
Results of intermediate and chronic studies involving oral exposure of rats to
barium in drinking water have been negative for hepatic effects (Schroeder and
Mitchener 1975a; Tardiff et al. 1980). In these intermediate and chronic
studies, hepatic effects were assessed by determining hepatic weight and by
performing gross and histopathological examinations of the liver.
Renal Effects. Toxic effects on the kidneys have been observed in
several adult cases of acute barium poisoning. Effects include hemoglobin in
the urine (Gould et al. 1973), renal insufficiency (Lewi and Bar-Khayim 1964;
Phelan et al. 1984), degeneration of the kidneys (McNally 1925), and acute
renal failure (Wetherill et al. 1981).
Renal effects observed in animals following oral barium exposure have
been minor. Increased kidney/body weight ratios have been noted in rats
exposed acutely by gavage to 198 mg barium/kg/day as barium chloride; however,
this change was not associated with gross or microscopic renal lesions
(Borzelleca et al. 1988).
Results of intermediate and chronic studies in which rats have been
exposed orally to barium drinking water have been negative for renal effects
(McCauley et al. 1985; Schroeder and Mitchener 1975a; Tardiff et al. 1980).
In these intermediate and chronic studies, renal effects were evaluated by
determining kidney weight and by performing gross and/or histopathologic
examination of the kidney. Lesions of the renal glomeruli were reportedly
observed in several experiments involving oral exposure of uninephrectomized
rats and salt-sensitive and salt-resistant rats to 150 mg barium/kg/day of an
unspecified barium compound for 16 weeks; however, these particular
experiments are inconclusive regarding renal toxicity because no control
animals were used (McCauley et al. 1985).
Dermal/Ocular Effects. No studies were located regarding dermal/ocular
effects in humans after oral exposure to barium. In studies with Sprague-
Dawley rats, both ocular discharge following acute oral exposure to barium
chloride (Borzelleca et al. 1988) and a nonsignificant increase in retinal
dystrophy following intermediate and chronic oral exposure to an unspecified
barium compound (McCauley et al. 1985) have been observed. Although the
retinal dystrophy was statistically insignificant, a dose-related trend was
observed if different duration exposure groups were combined (McCauley et al.
1985). Both ocular discharge and retinal dystrophy are commonly observed in
Sprague-Dawley rats; consequently, the ocular lesions noted in these animal
studies can not necessarily be attributed to oral barium exposure.
Other Systemic Effects. In one human case study involving accidental
acute ingestion of barium carbonate by an adult female, some degeneration of
the spleen was noted post-mortem (McNally 1925). Body weight has been
monitored in a number of acute, intermediate, and chronic studies in which