EPA Science Inventory

High Throughput Exposure Estimation Using NHANES Data (SOT)

Citation:

Strope, C., B. Wetmore, W. Setzer, J. Rabinowitz, K. Dionisio, AND J. Wambaugh. High Throughput Exposure Estimation Using NHANES Data (SOT). Presented at SOT, Phoenix, AZ, March 23 - 27, 2014.

Description:

In the ExpoCast project, high throughput (HT) exposure models enable rapid screening of large numbers of chemicals for exposure potential. Evaluation of these models requires empirical exposure data and due to the paucity of human metabolism/exposure data such evaluations include large uncertainty. Wambaugh et al. (2013; ES&T) used CDC National Health and Nutrition Examination Survey (NHANES) as a data source for urinary biomarkers of human chemical exposure and developed an exposure prediction model that had large uncertainties. To reduce the uncertainties, we developed a one-compartment pharmacokinetic (PK) model for relating both serum and urine biomarkers to probable chemical exposures. The PK model was parameterized with metabolic clearance and volume of distribution data compiled from literature sources. This expanded the chemical space explored beyond the urine evaluation chemicals by incorporating serum and blood biomarker concentrations to include environmentally persistent chemicals such as perfluorinated and polychlorinated biphenyl chemicals. Exposures were inferred probabilistically, using Markov Chain Monte Carlo (MCMC) to estimate the distribution of parent chemical exposures consistent with the biomarker data. By incorporating up to 50 additional metabolites from the NHANES data, we reduced the uncertainty in the parent chemical exposure inferences. The incorporation of a more diverse set of metabolites and corresponding reduction in uncertainty in ExpoCast predictions will play a key role in the confident application of exposure models in prioritization and risk assessment contexts. This abstract does not necessarily reflect EPA policy

Purpose/Objective:

Including chemicals collected from serum and blood tests from NHANES will allow the addition of valuable data for exposure prediction.

URLs/Downloads:

CSTROPE_SOT_2014_ABSTRACT_V5.PDF   (PDF,NA pp, 299.133 KB,  about PDF)

SOT2014-CSTROPE-FINAL POSTER.PDF   (PDF,NA pp, 635.937 KB,  about PDF)

Record Details:

Record Type: DOCUMENT (PRESENTATION/POSTER)
Start Date: 03/27/2014
Completion Date: 03/27/2014
Record Last Revised: 08/13/2014
Record Created: 08/13/2014
Record Released: 08/13/2014
OMB Category: Other
Record ID: 283724

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL CENTER FOR COMPUTATIONAL TOXICOLOGY