High-throughput models for exposure-based chemical prioritization in the ExpoCast project.

Journal Article

The United States Environmental Protection Agency (U.S. EPA) must characterize potential risks to human health and the environment associated with manufacture and use of thousands of chemicals. High-throughput screening (HTS) for biological activity allows the ToxCast research program to prioritize chemical inventories for potential hazard. Similar capabilities for estimating exposure potential would support rapid risk-based prioritization for chemicals with limited information; here, we propose a framework for high-throughput exposure assessment. To demonstrate application, an analysis was conducted that predicts human exposure potential for chemicals and estimates uncertainty in these predictions by comparison to biomonitoring data. We evaluated 1936 chemicals using far-field mass balance human exposure models (USEtox and RAIDAR) and an indicator for indoor and/or consumer use. These predictions were compared to exposures inferred by Bayesian analysis from urine concentrations for 82 chemicals reported in the National Health and Nutrition Examination Survey (NHANES). Joint regression on all factors provided a calibrated consensus prediction, the variance of which serves as an empirical determination of uncertainty for prioritization on absolute exposure potential. Information on use was found to be most predictive; generally, chemicals above the limit of detection in NHANES had consumer/indoor use. Coupled with hazard HTS, exposure HTS can place risk earlier in decision processes. High-priority chemicals become targets for further data collection.

Full Text

Duke Authors

Cited Authors

  • Wambaugh, JF; Setzer, RW; Reif, DM; Gangwal, S; Mitchell-Blackwood, J; Arnot, JA; Joliet, O; Frame, A; Rabinowitz, J; Knudsen, TB; Judson, RS; Egeghy, P; Vallero, D; Cohen Hubal, EA

Published Date

  • August 6, 2013

Published In

Volume / Issue

  • 47 / 15

Start / End Page

  • 8479 - 8488

PubMed ID

  • 23758710

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

Digital Object Identifier (DOI)

  • 10.1021/es400482g

Language

  • eng

Conference Location

  • United States