Estimating human-equivalent no observed adverse-effect levels for VOCs (volatile organic compounds) based on minimal knowledge of physiological parameters. Technical paper
The U.S. EPA advocates the assessment of health-effects data and calculation of inhaled reference doses as benchmark values for gauging systemic toxicity to inhaled gases. The assessment often requires an inter- or intra-species dose extrapolation from no observed adverse effect level (NOAEL) exposure concentrations in animals to human equivalent NOAEL exposure concentrations. To achieve this, a dosimetric extrapolation procedure was developed based on the form or type of equations that describe the uptake and disposition of inhaled volatile organic compounds (VOCs) in physiologically-based pharmacokinetic (PB-PK) models. The procedure assumes allometric scaling of most physiological parameters and that the value of the time-integrated human arterial-blood concentration must be limited to no more than to that of experimental animals. The scaling assumption replaces the need for most parameter values and allows the derivation of a simple formula for dose extrapolation of VOCs that gives equivalent or more-conservative exposure concentrations values than those that would be obtained using a PB-PK model in which scaling was assumed.
- Research Organization:
- Environmental Protection Agency, Research Triangle Park, NC (USA). Health Effects Research Lab.
- OSTI ID:
- 5599016
- Report Number(s):
- PB-89-224588/XAB; EPA--600/D-89/097
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR POLLUTION
BIOLOGICAL MATERIALS
BLOOD
BODY FLUIDS
CHEMICAL ANALYSIS
DOSE-RESPONSE RELATIONSHIPS
MATERIALS
MATHEMATICAL MODELS
MATTER
ORGANIC COMPOUNDS
POLLUTION
TOXICITY
VOLATILE MATTER