Toxicokinetics and acute effects of MTBE and ETBE in male volunteers

Johanson, G; Nihlén, A; Löf, A

HERO ID

76664

Reference Type

Journal Article

Year

1995

Language

English

PMID

8597131

HERO ID 76664
In Press No
Year 1995
Title Toxicokinetics and acute effects of MTBE and ETBE in male volunteers
Authors Johanson, G; Nihlén, A; Löf, A
Journal Toxicology Letters
Volume 82/83
Page Numbers 713-718
Abstract Methyl tertiary butyl ether (MTBE) is widely used in gasoline as an oxygenator and octane enhancer. There is also an interest in using the ethyl tertiary butyl (ETBE) and methyl tertiary amyl (TAME) ethers. We measured the blood, water, and olive oil/air partition coefficients in vitro of MTBE, ETBE, TAME and tertiary butyl alcohol (TBA), a metabolite of MTBE and ETBE. The results indicate similar uptake and distribution behavior for the three ethers and a slight affinity for fatty tissues. The partition coefficients of TBA indicate that this metabolite is not excreted via the lungs to any great extent and that it is preferentially distributed in body water. Further, we exposed 10 healthy male volunteers to MTBE vapor at 5, 25 and 50 ppm for 2 h during light physical exercise. Uptake and disposition were studied by measuring MTBE and TBA in inhaled and exhaled air, blood and urine. Low uptake, high post-exposure exhalation, and low blood clearance indicate slow metabolism of MTBE relative to many other solvents. A low recovery of TBA in urine (below 1% of uptake) indicates further metabolism of TBA. The concentration of MTBE and TBA in blood was proportional to exposure level suggesting linear kinetics up to 50 ppm. The half life of 7-10 h in blood and urine indicates that TBA would be more suitable than the parent compound as a biomarker for MTBE exposure. Subjective ratings (discomfort, irritative symptoms, CNS effects) and eye (redness, tear film break-up time, conjunctival damage, blinking frequency) and nose (peak expiratory flow, acoustic rhinometry, inflammatory markers in nasal lavage) measurements indicated no or minimal effects of MTBE.
Doi 10.1016/0378-4274(95)03589-3
Pmid 8597131
Wosid WOS:A1995TU51400102
Url http://linkinghub.elsevier.com/retrieve/pii/0378427495035893
Is Certified Translation No
Dupe Override 76664
Comments ECRIB. acute accent over e in Nihlen; umlaut over o in Lof.Toxicol. Lett. 82/83: 713-718.
Is Public Yes
Language Text English
Keyword Adult; Air Pollutants/pharmacokinetics; Ethers/pharmacokinetics/toxicity; Ethyl Ethers/pharmacokinetics/toxicity; Female; Humans; Male; Methyl Ethers/chemistry/pharmacokinetics/toxicity; Middle Aged; Solubility; 0 (Air Pollutants); 0 (Ethers); 0 (Ethyl Ethers); 0 (Methyl Ethers); 1634-04-4 (methyl tert-butyl ether); 637-92-3 (ethyl tert-butyl ether)
Is Qa No