Citation:

Pleil, J D. AND D. Kim. THE UNIQUE VALUE OF BREATH BIOMARKERS FOR ESTIMATING PHAMACOKINETIC RATE CONSTANTS AND BODY BURDEN FROM RANDOM/INTERMITTENT DOSE. Presented at Breath Gas Analysis for Medical Diagnostics, Dornbirn, Austria, September 23-26, 2004.

Impact/Purpose:

The objective of this task is to develop state-of-the-art methods for measuring xenobiotic compounds, to include the isolation of the analyte from the appropriate matrix (extraction), preconcentration (typically sorbent-based), and analysis via GC/MS and/or LC/MS. Once established, these methods will be applied in small scale pilot studies or demonstration projects. Particular emphasis will be placed on methods which are readily transferable to other laboratories, including those within the Human Exposure and Atmospheric Sciences Division (HEASD), the National Exposure Research Laboratory (NERL), other EPA Laboratories, Program Offices, Regions, and academic institutions.

Specific objectives of this task include the following:

1) Development of GC/MS and LC/MS methods for the measurement of key xenobiotic compounds and their metabolites (to include the pyrethroid pesticides, perfluorinated organic compounds, and the BFRs) in relevant environmental and biological matrices.

2) Development of efficient low cost methods for the extraction and clean up of these compounds collected from relevant matrices.

3) Determination of xenobiotic compound and metabolite concentrations in samples derived from laboratory and field monitoring studies to help assess exposures and evaluate associated risks.

Description:

Biomarker measurements are used in three ways: 1) evaluating the time course and distribution of a chemical in the body, 2) estimating previous exposure or dose, and 3) assessing disease state. Blood and urine measurements are the primary methods employed. Of late, it has been recognized that collecting exhaled breath is an attractive alternative to blood and urine sampling because it is less invasive, and is not restricted by sample volume or time frame. Breath volume and frequency of sampling are essentially unlimited; the subject never runs out sample and one can collect even adjacent breaths with existing technology. Furthermore, there is a fundamental difference between blood and breath measurement in that blood levels report only the status quo at the time of collection, whereas exhaled breath is reflective of current blood levels as well as an elimination mechanism allowing calculation of real time removal rates. Therefore, from a mathematical standpoint, the time courses of blood and breath are interpreted differently and give complementary information.

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Record Details: