Human inhalation exposure to ethylene glycol.
Two male volunteers (A and B) inhaled 1.43 and 1.34 mmol, respectively, of vaporous (13)C-labeled ethylene glycol ((13)C(2)-EG) over 4 h. In plasma, (13)C(2)-EG and its metabolite (13)C(2)-glycolic acid ((13)C(2)-GA) were determined together with the natural burden from background GA using a gas chromatograph equipped with a mass selective detector. Maximum plasma concentrations of (13)C(2)-EG were 11.0 and 15.8 micromol/l, and of (13)C(2)-GA were 0.9 and 1.8 micromol/l, for volunteers A and B, respectively. Corresponding plasma half-lives were 2.1 and 2.6 h for (13)C(2)-EG, and 2.9 and 2.6 h for (13)C(2)-GA. Background GA concentrations were 25.8 and 28.3 micro mol/l plasma. Unlabeled background EG, GA and oxalic acid (OA) were detected in urine in which the corresponding (13)C-labeled compounds were also quantified. Within 28 h after the start of the exposures, 6.4% and 9.3% (13)C(2)-EG, 0.70% and 0.92% (13)C(2)-GA, as well as 0.08% and 0.28% (13)C(2)-OA of the inhaled amounts of (13)C(2)-EG, were excreted in urine by volunteers A and B, respectively. The amounts of (13)C(2)-GA represented 3.7% and 14.2% of background urinary GA excreted over 24 h (274 and 88 micromol). The amounts of (13)C(2)-OA were 0.5% and 2.1% of background urinary OA excreted over 24 h (215 and 177 micromol). From the findings obtained in plasma and urine and from a toxicokinetic analysis of these data, it is highly unlikely that workplace EG exposure according to the German exposure limit (MAK-value 10 ppm EG, 8 h) could lead to adverse effects from the metabolically formed GA and OA.
Carstens
Jörn
J
Institute of Toxicology, GSF-National Research Center for Environment and Health, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
Csanády
György A
GA
Faller
Thomas H
TH
Filser
Johannes G
JG
D000280:Administration, Inhalation; D000328:Adult; D002849:Chromatography, Gas; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity* / Q000652:urine; D019855:Ethylene Glycol / Q000097:blood / Q000633:toxicity* / Q000652:urine; D006016:Glycolates / Q000097:blood / Q000652:urine; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D019815:Oxalic Acid / Q000097:blood / Q000652:urine; D013997:Time Factors
D004785:Environmental Pollutants; D006016:Glycolates; C031149:glycolic acid; D019815:Oxalic Acid; D019855:Ethylene Glycol