Criteria for deviation from predictions by the concentration addition model.
Jun-Ichi Takeshita1, Masanori Seki2, Masashi Kamo1
1Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
Environmental Toxicology and Chemistry
|December 15, 2015
Summary
This study developed criteria to assess if chemical mixtures follow Loewe
Area of Science:
- Environmental toxicology
- Risk assessment
- Chemical mixture toxicity
Background:
- Loewe's additivity model predicts mixture toxicity assuming additive effects.
- Identifying applicable mixtures is crucial for chemical risk assessment.
- Current methods lack criteria for validating model predictions.
Purpose of the Study:
- Develop criteria to evaluate deviations from concentration addition model predictions.
- Establish methods for judging the applicability of the concentration addition model.
- Assess the reliability of toxicity predictions for chemical mixtures.
Main Methods:
- Utilized a log-logit model for individual chemical concentration-effect curves.
- Determined model parameters using maximum-likelihood estimation.
- Defined criteria based on confidence intervals and parameter error estimations.
Main Results:
- Criteria were developed using variances and covariance of log-logit model parameters.
- Applied criteria to a binary mixture of p-n-nonylphenol and p-n-octylphenol in medaka.
- The concentration addition model accurately predicted test results within confidence intervals.
Conclusions:
- The developed criteria effectively validated the concentration addition model's predictions.
- No reasons were found to reject the concentration addition model for the tested mixture.
- Confidence intervals are valuable for assessing chemical mixture toxicity predictions.
Keywords:
Chemical mixture effectConcentration addition modelConfidence intervalDeviation mixture modelsStatistical methodMore Related Videos
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