Drinking Water and Health, Volume 5 (1983) / Chapter Skim
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1,1-Dichloroethylene
1,1-Dichloroethylene
Pages 32-40
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From page 32... ...
Despite extensive knowledge concerning the metabolism of 1,2-dichloroethane, there is still a need to know the comparative pharmacokinetics in different species, including humans. The knowledge that 1,2-dichloroethane has been shown to have both mutagenic and carcinogenic properties in animals provides further reason to obtain these kinds of data following oral exposure in order to develop better estimates of the risk to humans exposed to low levels.
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From page 33... ...
After the administration of a 50 mg/kg dose, 19% was exhaled unchanged by fed rats and 29% by fasted rats. The two major urinary metabolites excreted within 25 hours following the administration of 1 mg/kg to fed rats were identified as thiodiglycolic acid (22~o of the metabolites)
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From page 34... ...
(1972) reported that a single oral 100 mg/kg dose of 1,1-dichloroethylene in corn oil given to rats caused a decrease in liver glucose-6-phosphatase and an increase in alkaline phosphatase activity but did not cause elevations in plasma alkaline phosphatase and alanine aminotransferase.
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From page 35... ...
daily for 90 days. No changes were obser~red in body weight gain, hematological indices, urine analysis, BUN, serum alkaline phosphatase, serum alanine aminotransferase, gross patholog~y, or organ weights.
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From page 36... ...
There was slightly higher mortality than in the controls for the males in all three treatment groups, but this was not related to dose and was not observed in the females. No differences were observed in organ weights except for a decreased kidney to body weight ratio in the males at the lowest dose levels at the 90-day sacrifice.
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From page 37... ...
Negative results were obtained in an in vitro mammalian mutagenicity assay and in a mouse dominant lethal study. No chromosome breakage was observed in an in vitro study with Chinese hamster cells.
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From page 38... ...
1,1-Dichloroethylene was found to produce skin tumors when applied once to mouse skin, followed by repeated treatments with phorbol myristate acetate. When given alone, it did not produce tumors when applied topically or by subcutaneous injection.
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From page 39... ...
However, the only epidemiological study found by the committee was based on a small population of 139 people exposed to measured levels of 1,1-dichloroethylene where vinyl chloride was not used as a copolymer (Ott et al., 1976~. A more recent analysis of the data did not enable investigators to draw definite conclusions (Apfeldorf and Infante, 1981~.
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From page 40... ...
If present in drinking water, 1,1-dichloroethylene would be rapidly and completely absorbed. At the low levels expected to be present, dose-dependent kinetics involving saturation of the metabolic pathways would not occur, so that nearly all of the compound would undergo metabolic conversion.
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