TOXICOLOGICAL PROFILE FOR BARIUM AND COMPOUNDS ...

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2. HEALTH EFFECTS
may potentially be toxic when it is introduced into the gastrointestinal tract
under conditions where there is colon cancer (Princenthal et al. 1983) or
perforations of the gastrointestinal tract and barium is allowed to enter the
blood stream.
Barium has been associated with a number of adverse health effects in
both humans and experimental animals. Both human and animal evidence suggests
that the cardiovascular system may be one of the primary targets of barium
toxicity. In addition to cardiovascular effects, exposure of humans and/or
animals to barium has been associated with respiratory, gastrointestinal,
hematological, musculoskeletal, hepatic, renal, neurological, developmental,
and reproductive effects. No data or insufficient data are available to draw
conclusions regarding the immunological, genotoxic, or carcinogenic effects of
barium. Death has been observed in some individuals following acute oral
exposure to high concentrations of barium. The following section evaluates
the significance of existing toxicity data on barium with regard to human
health.
Death. No studies were available regarding death in humans or animals
after inhalation or dermal exposure to barium. However, mortality has been
reported to occur in a number of cases where humans have been exposed acutely
to barium through accidental or intentional ingestion (Das and Singh 1970;
Diengott et al. 1964; McNally 1925; Ogen et al. 1967; Talwar and Sharma 1979).
The observations from human case reports are supported by findings from acute
studies with rodents that indicate barium is toxic by the oral route
(Borzelleca et al. 1988; Tardiff et al. 1980). Reduced lifespan also has been
observed in chronic oral studies with mice (Schroeder and Mitchener 1975b).
The results from human case studies and animal studies suggest that humans who
are exposed orally to high levels of barium may be at increased risk for
mortality.
One death in an adult female due to acute intravasation of barium
sulfate during a barium enema was found in the literature. Direct entry of
barium sulfate into the circulatory system apparently resulted in
cardiorespiratory failure (Cove and Snyder 1974). Acute parenteral
administration of barium compounds to animals has resulted in death. Rate of
administration, total dose, species, and individual differences are all
factors affecting the ability of barium and its compounds to cause death.
Major symptoms leading to death are hypokalemia (Jalinski et al. 1967; Roza
and Berman 1971; Schott and McArdle 1974), muscle paralysis (Roza and Berman
1971; Schott and McArdle 1974), cardiorespiratory failure (Cove and Snyder
1974; Roza and Berman 1971), and convulsions (Segreti et al. 1979; Welch et
al. 1983). Parenteral administration is not a normal route of barium exposure
in humans and only on the rare occurrence of intravasation during barium enema
would it be expected to be a problem. However, many of the symptoms
experienced are the same as those experienced by humans and animals exposed to
acute doses by inhalation and ingestion.