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In Silico Modeling Method for Computational Aquatic Toxicology of Endocrine Disruptors: A Software-Based Approach Using QSAR Toolbox
Published on: August 28, 2019
Statistical uncertainty in hazardous terrestrial concentrations estimated with aquatic ecotoxicity data.
Laura Golsteijn1, Rosalie van Zelm, A Jan Hendriks
1Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Environmental Science, P.O. Box 9010, 6500 GL, Nijmegen, The Netherlands. L.Golsteijn@science.ru.nl
Chemosphere
|June 6, 2013
Summary
The equilibrium partitioning (EP) method estimates hazardous concentrations (HC50) for soil species using aquatic toxicity data. This study found porewater HC50s were generally higher than freshwater HC50s, but statistical uncertainty was significant.
Area of Science:
- Environmental Chemistry
- Ecotoxicology
- Risk Assessment
Background:
- Ecotoxic effects in soil are linked to pore water concentrations.
- The equilibrium partitioning (EP) method estimates soil hazardous concentrations (HC50) from aquatic data.
- Statistical uncertainty in terrestrial HC50s derived by EP needs analysis.
Purpose of the Study:
- Analyze statistical uncertainty in terrestrial HC50s derived by the EP-method.
- Compare freshwater HC50s from aquatic tests with porewater HC50s from terrestrial tests for 47 organic chemicals.
- Evaluate the ratio of porewater HC50 to freshwater HC50 across different chemical groups.
Main Methods:
- Utilized standard aquatic ecotoxicity tests to derive freshwater HC50s.
- Employed terrestrial ecotoxicity tests to derive porewater HC50s.
- Applied Monte Carlo simulations to propagate probability distributions for uncertainty analysis in HC50s and partitioning coefficients.
Main Results:
- Porewater HC50 values were generally higher (approx. factor of 3) than freshwater HC50 values across most chemical groups.
- Specific ratios varied by chemical type: narcotics (approx. 3.0), reactive (0.8), neurotoxic (2.9), and herbicides-fungicides (2.5).
- Despite observed ratios, 81% of organic chemicals showed no statistical difference between aquatic and terrestrial HC50s due to large uncertainty.
Conclusions:
- Systematic deviations between aquatic and terrestrial HC50s are less significant than overall statistical uncertainty.
- The EP-method's reliability for estimating terrestrial HC50s is influenced by substantial statistical uncertainty.
- Representative species sampling is crucial for accurate HC50 determination, especially for specifically acting chemicals.
Keywords:
Equilibrium partitioning methodHazardous concentration (HC50)Soil–water partitioningStatistical uncertaintyTerrestrial ecotoxicityToxic mode of action (TMoA)More Related Videos
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