Ensemble QSAR Modeling to Predict Multispecies Fish Toxicity Lethal Concentrations and Points of Departure
| Autor: | Thomas Y. Sheffield, Richard S. Judson |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Quantitative structure–activity relationship
Fishes Quantitative Structure-Activity Relationship General Chemistry 010501 environmental sciences 01 natural sciences Data type Article Lethal Dose 50 Support vector machine Data set Covariate Statistics Animals Environmental Chemistry Fish Generalizability theory 0105 earth and related environmental sciences Test data Mathematics |
| Zdroj: | Environ Sci Technol |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.9b03957 |
| Popis: | QSAR modeling can be used to aid testing prioritization of the thousands of chemical substances for which no ecological toxicity data is available. We drew on the U.S. Environmental Protection Agency’s ECOTOX database with additional data from ECHA to build a large data set containing in vivo test data on fish for thousands of chemical substances. This was used to create QSAR models to predict two types of endpoints: acute LC(50) (median lethal concentration) and points of departure similar to the NOEC (no observed effect concentration) for any duration (named the “LC(50)” and “NOEC” models, respectively). These models used study covariates, such as species and exposure route, as features to facilitate the simultaneous use of varied data types. A novel method of substituting taxonomy groups for species dummy variables was introduced to maximize generalizability to different species. A stacked ensemble of three machine learning methods—random forest, gradient boosted trees, and support vector regression—was implemented to best make use of a large data set with many descriptors. The LC(50) and NOEC models predicted endpoints within one order of magnitude 81% and 76% of the time, respectively, and had RMSEs of roughly 0.83 and 0.98 log(10)(mg/L), respectively. Benchmarks against the existing TEST and ECOSAR tools suggest improved prediction accuracy. |
| Databáze: | OpenAIRE |
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