Framework for Optimizing Selection of Interspecies Correlation Estimation Models to Address Species Diversity and Toxicity Gaps in an Aquatic Database

The Chemical Aquatic Fate and Effects (CAFE) database is a tool that facilitates assessments of accidental chemical releases into aquatic environments. CAFE contains aquatic toxicity data used in the development of species sensitivity distributions (SSDs) and the estimation of hazard concentrations (HCs). For many chemicals, gaps in species diversity and toxicity data limit the development of SSDs, which may be filled with Interspecies Correlation Estimation (ICE) models. Optimization of ICE model selection and integration ICE-predicted values into CAFE required a multistep process that involved the use of different types of data to assess their influence on SSDs and HC estimates. Results from multiple analyses showed that SSDs supplemented with ICE-predicted values generally produced HC5 estimates that were within a 3-fold difference of estimates from measured SSDs (58%–82% of comparisons), but that were often more conservative (63%–76% of comparisons) and had lower uncertainty (90% of comparisons). ICE SSDs did not substantially underpredict toxicity (800 new SSDs, increased diversity in SSDs by an average of 34 species, and augmented data for priority chemicals involved in accidental chemical releases.