Exponential Modeling, Washout Curve Reconstruction, and Estimation of Half-Life of Toluene and Its Metabolites

Details

• Personal Author:
  Chen Y ; Hurtle W ; Morgan M ; Pierce C
• Description:
  Health risks from ostensible occupational and environmental toxicant exposure are difficult to quantify. Maximal use of limited biological measurements of xenobiotic or metabolite concentration in the body is therefore essential. Elimination rates of exhaled [2H8]toluene and urinary metabolites were analyzed from 33 exposures of males to 50 ppm [2H8]toluene for 2 h at rest. It was hypothesized that the shapes from our decay curves would be applicable to any occupational or environmental toluene exposure. Except for a rapid decline in toluene blood and breath levels in the 0-0.1 h period, this "curve reconstruction" method successfully fit data from published studies. Urinary hippuric acid concentrations were not well fit due to substantial background levels, whereas o-cresol levels were accurately described. Our approach was able to reconstruct data from studies where exposure duration ranged from 10 min to 7 h, and where activity level ranged from rest to 150 W (strenuous exercise). Using this approach, limited biological data following toluene exposure could be back-extrapolated to immediate postexposure concentrations, which in turn could be compared to biological indicators of exposure to determine risk. [Description provided by NIOSH]
• Subjects:
  Biomarkers Chemistry Energy Metabolism Environmental Monitoring Hazardous Substances Hematologic Tests Occupational Health Safety Urine
• Keywords:
  Biologic-half-life Biological-monitoring Blood-analysis Chemical-indicators Chemical-properties Chemical-synthesis Exposure-assessment Exposure-levels Metabolic-rate Metabolic-study Metabolism Metabolites Toxic-materials Urinalysis

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• ISSN:
  1528-7394
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  67
• Issue:
  14
• NIOSHTIC Number:
  nn:20029368
• Citation:
  J Toxicol Environ Health A 2004 Jul; 67(14):1131-1158
• Contact Point Address:
  Crispin H Pierce, PhD, University of Washington, Seattle, WA
• CAS Registry Number:
  Ethyl tert-butyl ether (CAS RN 637-92-3) ; tert-Butanol (CAS RN 75-65-0) ; tert-Butyl methyl ether (CAS RN 1634-04-4)
• Federal Fiscal Year:
  2004
• Performing Organization:
  University of Washington, Seattle WA
• Peer Reviewed:
  True
• Start Date:
  19970930
• Source Full Name:
  Journal of Toxicology and Environmental Health, Part A: Current Issues
• End Date:
  20000929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b6321e201c9192b4d13e5064a13d8543c72fa9654b0e948b3887792b644ec76875c876e3ed76f38e19230be8b0bae83ccfe1bee8fdda563b4d9b0bd7e0d1c4df
• Download URL:
  https://stacks.cdc.gov/view/cdc/190359/cdc_190359_DS1.pdf
• File Type:
  [PDF - 404.64 KB ]