Drinking Water and Health, Volume 5 (1983) / Chapter Skim
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Hexachlorobenzene
Hexachlorobenzene
Pages 49-56
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From page 49... ...
118-74-1 Cl Cl Cl Cl Hexachlorobenzene was evaluated in the first and third volumes of Drinking Water and Health (National Research Council, 1977, pp.
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From page 50... ...
At equivalent concentrations, the amounts in the fetuses of the two species were similar. A preliminary report on the pharmacokinetics of hexachlorobenzene in the beagle dog indicates that an intravenous bolus is rapidly distributed to the highly perfused tissues, but that it quickly disappears between 2 and 8 hours later and more slowly thereafter (Sundlof, 1981~.
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From page 51... ...
Diethyl maleate, which lowers tissue glutathione levels, caused increased hepatotoxicity and porphyria in female rats fed hexachlorobenzene (0.1 To in the diet) (Kerklaan et al., 1979~.
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From page 52... ...
In comparison to the other lobes, the caudate lobe initially had lower porphyrin levels, less depression of uroporphyrinogen decarboxylase, and less elevation of b-aminolevulinate synthetase activity; in the advanced stages of porphyria, no differences were found among the lobes. Mechanism studies in rats given 100 mg/kg concentrations of hexachlorobenzene orally every other day suggest that its porphyrinogenic effects are exerted following conversion to an active form that binds covalently to proteins, resulting in products that inhibit uroporphyrinogen decarboxylase (Koss et al., 1980~.
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From page 53... ...
Body weights of the animals did not differ from those of the controls, and although the relative weight of the liver, spleen, kidneys, and adrenal glands increased during the treatment period, they returned to normal by the end of the 38-week recovery period. Porphyrin, b-aminolevulinic acid, and porphobilinogen levels in the urine were elevated during the exposure, but decreased to normal or near normal levels by the end of the recovery period; however, the porphyrin level in the liver was elevated during both periods.
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From page 54... ...
Pretreatment of male and female Wistar rats and pregnant Wistar rats with intraperitoneal 10 mg/kg doses of hexachlorobenzene resulted in increased mutagenicity of 2,4-diaminoanisole when tested in the Ames Salmonella assay in the presence of the liver S9 fraction derived from the pretreated animals. An increase was also observed with the kidney S9 fraction, but not with the lung or the fetal liver S9 fraction (Dybing and Aune, 1977~.
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From page 55... ...
If one averages the data in Table II-S, the estimated upper 95~o confidence estimate of lifetime risk per ~g/liter is 1.85 X 10-6. This is somewhat different from the 2.9 X 10-s upper 955to confidence estimate of TABLE II-4 Tumor incidence in Mice Exposed to Hexachlorobenzene° Animal Sex Tumor Site Dose Levels, mg/kg/day Tumor Rates Swiss mouse Male Liver 0, 6, 12, 24 Swiss mouse Female Liver 0, 6, 12, 24 0/47, 0/30, 3/29, 7/44 0/49, 0/30, 3/30, 14/41 ° From Cabral e' al., 1979.
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From page 56... ...
lifetime risk per Igniter, which was calculated in the third volume of Drinking Water and Health (National Research Council, 1980, p.
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