EXTRAPOLATION OF THE BENZENE INHALATION UNIT RISK ESTIMATE TO THE ORAL ROUTE OF EXPOSURE (EXTERNAL REVIEW DRAFT)
Notice - This site contains archived material(s)
Archive disclaimer
Archive
disclaimer
Archived files are provided for reference
purposes only. These files are no longer maintained by the Agency and may be outdated. For
current EPA information, go to www.epa.gov. It is EPA's policy to
support reasonable accommodation to persons with disabilities, pursuant to the Rehabilitation
Act of 1973, 29 U.S.C. 791. If you need assistance with accessing archived files, contact
EPA's Reasonable Accommodations
or submit a request using the Contact Us form.
Abstract
Given the absence of oral dose-response information, the authors propose a simple method for extrapolating benzene-induced cancer risk from the inhalation to the oral route. The method is based on the relative efficiency of benzene absorption across pulmonary and gastrointestinal barriers. Substantial literature on pulmonary absorption in humans and a few laboratory animal species exists. Data on oral absorption in humans are lacking; hence extrapolation is based on gastrointestinal absorption studies in several experimental animal species. A review of the relevant literature suggests absorption efficiencies of 50% and 100% for inhalation and oral routes of exposure, respectively. Application of these absorption factors to the current inhalation unit risk range of 2.2 X 10
Citation
This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
- Extrapolation of the Benzene Inhalation Unit Risk Estimate to the Oral Route of Exposure (PDF) (21 pp, 53 KB, about PDF)
- IRIS Summary (PDF) (5 pp, 14 KB, about PDF)