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Evaluating correlations of ECOTOX and ToxCast data through toxicity benchmark derivation
Citation:
Schaupp, C., E. Maloney, J. Olker, AND Dan Villeneuve. Evaluating correlations of ECOTOX and ToxCast data through toxicity benchmark derivation. SETAC North America, Pittsburgh, PA, November 13 - 17, 2022. https://doi.org/10.23645/epacomptox.21561474
Impact/Purpose:
Previous analyses have shown that ToxCast high throughput screening data can provide reasonable lower bound toxicity estimates for a range of organic chemicals, with respect to human health hazard. The present work investigates whether ToxCast data could similarly be used to provide lower bound estimates of ecological toxicity. Correlation between the 5th centile of activity concentration at cutoff from ToxCast was compared with chemical-specific points of departure compiled in the ECOTOX knowledgebase. The results provide insights into the potential applications and limitations of data from new approach methodologies targeted to human health for ecological applications. These results help to inform how OPPT, OW, Regions, and other program offices may wish to use ToxCast data for decision-making in relation to ecological hazards of organic contaminants.
Description:
Large repositories of new approach methodology (NAM)-based data, such as the high-throughput, mammalian-centric in vitro bioactivity data in the EPA’s Toxicity Forecaster (ToxCast), provide a wealth of publicly accessible toxicity information for thousands of chemicals. These data can be used to calculate point-of-departure (POD) estimates via concentration-response modeling that may serve as lower bound, protective estimates of in vivo effect. However, discussions about the utility of these data have largely focused on potential integration into human hazard assessment, and their application to ecological risk assessment remains limited. The goal of the present study was to compare and contrast PODs based on the 5th centile of the activity concentration at cutoff (ACC) in ToxCast with the distribution of in vivo PODs compiled in the Ecotoxicology Knowledgebase (ECOTOX). ECOTOX, “the world's largest compilation of curated ecotoxicity data”, contains thousands of in vivo and in vitro toxicity datapoints relevant to ecological receptors. Preliminary results showed poor overall correlation between ToxCast and ECOTOX PODs for 636 chemicals. However, parsing by chemical classification revealed certain classes of compounds show good correlation (e.g., pharmaceuticals; R = 0.49, p = 0.0037), while others, such as organophosphate insecticides (R = 0.047, p = 0.76), do not. Surprisingly, these trends were mostly unaffected when the derivation of ECOTOX PODs was faceted by apical vs. biochemical endpoints, acute vs. chronic data, and study species. Future analyses will investigate ToxCast and ECOTOX benchmark correlation(s) by mode-of-action. Results of this research help to define potential utility and limitations of ToxCast data for predicting ecological hazards. This abstract neither constitutes nor necessarily reflects USEPA policy.
URLs/Downloads:
DOI: Evaluating correlations of ECOTOX and ToxCast data through toxicity benchmark derivation
SCHAUPP_SETAC2022_TOXCAST_ECOTOX PRESENTATION.PDF (PDF, NA pp, 2237.997 KB, about PDF)