Antimony - Toxicology of Metals - page 348

from the respiratory tract is infl uenced by particle size.
One study showed that 1.6

On the other hand, about 90% of pentavalent antimony
was mainly found in plasma (Edel et al ., 1983). In ham-
sters, trivalent antimony levels increased more rapidly
in the liver than pentavalent antimony levels, whereas
pentavalent antimony was taken up more rapidly by
the skeletal system than trivalent antimony (Felicetti
et al ., 1974a). In rats fed a diet containing 2% antimony
trioxide for 1.5 months, the highest concentrations
of antimony were found in the thyroid and adrenal
glands, values of 88.9 and 67.8 mg/kg, respectively
(wet or dry weight not stated). Spleen, lungs, liver, and
kidneys had concentrations between 6.7 and 18.9 mg/
kg (Westrick, 1953). The highest concentrations of anti-
mony in rats given antimony in drinking water (38

m particles were absorbed
in the upper respiratory tract to a greater extent
than 0.7 or 0.3

µ

µ m particles (Felicetti et al ., 1974b).

The 1.6 m particles were cleared by mucociliary

clearance within a few hours, whereas the smaller
particles were cleared over several weeks (Thomas
et al ., 1973). No differences were seen in body bur-
den between trivalent and pentavalent antimony
tartrate 1 day after exposure (Felicetti et al ., 1974a).
In a study of workers in the lead battery production
industry, pulmonary absorption of antimony trioxide
and stibine were found to be virtually equal (Kentner
et al ., 1995). Although no differences in the rate of
absorption of antimony compounds were noted, it is
likely that there are differences related to solubility
(ATSDR, 1992).

µ

g/
L) for 26 months were found in blood and spleen;
185

µ

g/kg wet weight, respectively
(Edel et al ., 1983). As is the case for arsenic (Chapter
19), there seem to be important species differences
with regard to the metabolism of antimony. Djuric et al .
(1962) noticed that in rats exposed to antimony trichlo-
ride by inhalation, a large proportion of the body bur-
den of antimony was recovered in blood. A couple of
weeks after exposure, about 10% of the body burden of
antimony was found in blood. This was a higher pro-
portion than in any other organ. Comparative studies
with rabbits and dogs intratracheally exposed to anti-
mony trichloride revealed that these animals had less
than 1% of the blood antimony concentrations found
in rats.

µ g/kg and 31.5 µ

5.1.2 Ingestion

No quantitative data on absorption of antimony
from the gastrointestinal tract in humans is available.
In animals, absorption rates for antimony tartrate and
antimony trichloride are estimated at 2-7% (Felicetti
et al ., 1974a; Gerber et al ., 1982). At least 15% of a sin-
gle oral dose of labeled antimony potassium tartrate
(trivalent) given to mice is absorbed (i.e., recovered in
urine and tissues) (Waitz et al ., 1965). Absorption may,
however, be higher, because gastrointestinal excretion
starts immediately after the metal is taken up from
the gut. Thus, Gellhorn et al . (1946) observed a fecal
excretion of 50% of the given dose (0.43 mg) within 24
hours after intraperitoneal administration of antimony
potassium tartrate to hamsters.
The therapeutic doses in humans of antimony and
potassium tartrate that produce a diaphoretic/expec-
torant or emetic response are 2.8 mg and 30-60 mg,
respectively; see Section 3.1. (Martindale, 1941).

5.2.2 Humans

A study conducted in Ireland to establish a refer-
ence range for antimony in serum and urine of infants
in the fi rst year of life found levels of 0.09-0.25 g/L in

serum. Urinary antimony concentration for 95% of the
infants was <2.6 ng/mg creatinine (Cullen et al ., 1998).
An earlier study also detected antimony in very low
levels in both serum and urine of infants in the United
Kingdom (Dezateux et al ., 1997). A Japanese autopsy
study examined the levels of antimony in tissues
in unexposed humans. The mean body burden was
0.7 mg, with the highest levels of antimony found in
skin and hair (Sumino et al ., 1975). Surface body scan-
ning of people given intravenous injections of labeled
antimony as sodium antimony dimercaptosuccinate
revealed the highest amounts in liver, thyroid, and
heart. Forty-three days after the last injection, the liver
still showed values of about 1/6 of the maximum, which
was reached 1 day after the last injection (Abdallah and
Saif, 1962; Abdel-Wahab et al ., 1974). Certain inhaled
antimony compounds seemed to be retained in the
lung for long periods. Gerhardsson et al . (1982) found
that former smelter workers occupationally exposed to

µ

5.2 Distribution

5.2.1 Animals

Antimony given as a single dose or by repeated
injections is found in kidney and liver (Boyd et al ., 1931
[pentavalent antimony to monkeys]; Hassan, 1938 [tri-
valent antimony to dogs and monkeys]; Goodwin and
Page, 1943 [pentavalent antimony to mice]) as well as in
thyroid (Brady et al ., 1945 [trivalent antimony to dogs]).
There are remarkable differences in the distribution of
trivalent and pentavalent antimony in blood of rats.
Two hours after an intraperitoneal injection of trivalent
antimony (3

g), more than 95% of the amount of anti-
mony in blood was incorporated in the red blood cells.

µ