The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels

Schlatter, J; Lutz, WK

HERO ID

95013

Reference Type

Journal Article

Subtype

Review

Year

1990

Language

English

PMID

2188890

HERO ID 95013
Material Type Review
In Press No
Year 1990
Title The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels
Authors Schlatter, J; Lutz, WK
Journal Food and Chemical Toxicology
Volume 28
Issue 3
Page Numbers 205-211
Abstract Ethyl carbamate is found in fermented foods: bread contains 3-15 ng/g, stone-fruit brandies 200-20,000 ng/g, and about one-third of table-wine samples analysed contained more than 10 ng/g. In animals, ethyl carbamate is degraded to CO2, H2O and NH3, with intermediate formation of ethanol. This degradation has been shown to be inhibited (postponed) in the mouse by ethanol concentrations in the blood of about 0.15% and higher. A quantitatively minor pathway involves a two-step oxidation of the ethyl group to vinyl carbamate and epoxyethyl carbamate, the postulated electrophilic moiety that reacts with DNA. This reaction is probably the mode of the mutagenic action observed in many cellular and animal systems. The fact that only vinyl carbamate, but not ethyl carbamate, is mutagenic in a standard Ames test is probably because there is insufficient production of the intermediate oxidation product in the standard test. Consistent with this metabolism is the carcinogenic activity of ethyl carbamate in various animal species and in different organs; this activity can be seen even after a single high dose in early life. Quantitative analysis of the total tumour incidences after chronic exposure of rats and mice to 0.1-12.5 mg ethyl carbamate/kg body weight/day in the drinking-water showed a dose-related increase. The main target organs were the mammary gland (female rats and mice having similar susceptibilities) and the lung (mice only). On the basis of sex- and organ-specific tumour data and with a linear extrapolation to a negligible increase of the lifetime tumour incidence by 0.0001% (one additional tumour in one million individuals exposed for life), a "virtually safe dose" of 20 to 80 ng/kg body weight/day was estimated. The daily burden reached under normal dietary habits without alcoholic beverages is in the range of about 20 ng/kg body weight/day. Regular table-wine consumption would increase the risk by a factor of up to five. Regular drinking of 20 to 40 ml stone-fruit brandy per day could raise the calculated lifetime tumour risk to near 0.01%.
Doi 10.1016/0278-6915(90)90008-b
Pmid 2188890
Wosid WOS:A1990DE38900007
Url https://linkinghub.elsevier.com/retrieve/pii/027869159090008B
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword urethan; animal experiment; article; breast cancer; carcinogenicity; dna adduct; human; lung cancer; mouse; nonhuman; priority journal; rat; risk assessment; Animal; Carcinogens; Diet; Environmental Exposure; Human; Risk; Urethane; Animalia
Is Qa No