Chemistry Reference
In-Depth Information
4 ENVIRONMENTAL LEVELS
AND EXPOSURES
4.2 Working Environment
Exposure to bismuth and some of its compounds
may occur in the production of metallic bismuth and in
the manufacture of pharmaceuticals, cosmetics, and
industrial chemicals, but no reports are available on
such exposure.
4.1 General Environment
4.1.1 Food
Using pooled samples of food representative of the
main regions in the United Kingdom, Hamilton and
Minski (1972; 1973) estimated the daily intake of bis-
muth as less than 5
5 METABOLISM
g (by SSMS). The concentrations in
individual dietary samples were not reported. Studies
(Hahn
et al
., 1982; Wolnik
et al
., 1981), which analyzed
rice fl our, wheat fl our, spinach, and orchard leaves
certifi ed by the U.S. National Bureau of Standards,
reported values of <0.08/
µ
5.1 Absorption
Bismuth compounds are considered to be slightly
to moderately absorbed through the respiratory and
gastrointestinal tracts, depending on their solubility,
but there are no quantitative data. Absorption through
the skin is of interest in relation to the use of bismuth
compounds in oil-based cosmetics, but again there is
no quantitative information (Sollman and Seifter, 1939;
Sollman
et al
., 1938). The gastrointestinal absorption
of bismuth subnitrate has been reported (Chaleil and
Allain, 1980) to be increased by concomitant admin-
istration of sulfhydryl compounds. Recent studies on
the gastrointestinal absorption and tissue uptake of
bismuth administered as a single oral dose of either
ranitidine bismuth citrate or bismuth citrate to mice
(Larsen
et al
., 2003) showed rapid uptake of Bi into cells
of the gastrointestinal tract and kidneys within hours
of exposure and that with the passage of time, Bi was
found in a number of other organ systems weeks later.
Subcellular distribution studies showed that the lyso-
somal compartment was the primary intracellular site
of deposition.
g/g. Similar values were also
reported for corn, potatoes, and soybeans. According to
Woolrich (1973), the daily intake from food and water
is approximately 20
µ
g
,
but again data on concentra-
tions of bismuth in specifi c food items were not given.
This estimate agrees with the model value for daily bal-
ance of elements in the reference manual (ICRP, 1975).
Jaysinghe
et al
. (2004) have recently reported the con-
centrations of bismuth in muscle and tissues of wild-
fowl with lead shot. They reported liver concentration
in teal and mallards ranging from 0.05-0.09
µ
g Bi/g on
a dry weight basis, respectively. Bismuth is a contami-
nant of lead shot, and consumption of shot by water-
fowl is the apparent route of exposure to this element.
µ
4.1.2 Ambient Air, Water, Soil, and Rocks
The concentrations of bismuth in urban air range
from 1-66 ng/m
3
, and in rural air from 0.1-0.6 ng/m
3
(Division of Atmospheric Surveillance, 1972). The con-
centration of bismuth in respirable fl y-ash (ADD <5/
µ
5.2 Distribution
Four days after intramuscular injection of BiOCl or
BiO(OH) to rats, 14.4% of the dose was found in the
kidney, 6.6% in the liver, 1.5% in bone, 0.6% in mus-
cle, and less than 0.1% in blood. Seventeen days after
administration, only 0.6% remained in the kidney
(Durbin, 1960). Two hours after intravenous injection of
bismuth citrate and sodium bismuth thioglycollate to
dogs and rabbits, approximately 3-5% of the dose was
found in the kidney, 6-10% in the liver, and 0.4% in the
lungs. Within 24 hours the relative concentration in the
kidney increased to 7-120%, and in the liver it decreased
1-4%. Within 1 week, the concentration in the kidney
and liver was reduced to 2.5%. After 4-5 weeks, the con-
centration in the liver was again higher (1%) compared
with the kidney (0.45%) (Sollman and Seifter, 1942).
Oral intubation of tripotassium dicitratobismuthate to
rats for 14 months produced the highest tissue concen-
trations in the kidney (Lee
et al
., 1980). Similar results
m
)
was found to be approximately 4-5 g/kg (Davi-
son
et al
., 1974). The daily intake of bismuth through
inhalation is estimated as <0.01-0.76
µ
g (ICRP, 1975;
Woolrich, 1973).
Concentrations of bismuth in drinking water have
not been reported. Seawater has been reported to
contain approximately 0.2
g Bi/L (Environmental
Studies Board, 1972), but other studies (Lee, 1982) have
reported much lower values in the range of 0.053-
0.63 ng/L for ocean surface waters.
Bismuth levels in soil are approximately l
µ
µ
g /kg,
and in rocks they range from 0.1
µ
g/kg (coal) to 3
µ
g/
kg (sandstone) (Bowen, 1966).
4.1.3 Pharmaceuticals and Cosmetics
Pharmaceuticals and cosmetics are still a source of
more prolonged exposure to bismuth compounds for
specifi c groups of the general population.
