Assessing predictive uncertainty in comparative toxicity potentials of triazoles

Abstract

Comparative toxicity potentials (CTPs) quantify the potential ecotoxicological impacts of chemicals per unit of emission. They are the product of a substance's environmental fate, exposure, and hazardous concentration. When empirical data are lacking, substance properties can be predicted. The goal of the present study was to assess the influence of predictive uncertainty in substance property predictions on the CTPs of triazoles. Physicochemical and toxic properties were predicted with quantitative structure-activity relationships (QSARs), and uncertainty in the predictions was quantified with use of the data underlying the QSARs. Degradation half-lives were based on a probability distribution representing experimental half-lives of triazoles. Uncertainty related to the species' sample size that was present in the prediction of the hazardous aquatic concentration was also included. All parameter uncertainties were treated as probability distributions, and propagated by Monte Carlo simulations. The 90% confidence interval of the CTPs typically spanned nearly 4 orders of magnitude. The CTP uncertainty was mainly determined by uncertainty in soil sorption and soil degradation rates, together with the small number of species sampled. In contrast, uncertainty in species-specific toxicity predictions contributed relatively little. The findings imply that the reliability of CTP predictions for the chemicals studied can be improved particularly by including experimental data for soil sorption and soil degradation, and by developing toxicity QSARs for more species.

The QSPR-THESAURUS: The Online Platform of the CADASTER Project

“…The data obtained were uploaded to the website of the CADASTER project. The database provides a collection of 5,440 experimental records for 120 properties, collected from more than 544 sources for four classes of emerging chemicals, and which were also used in publications by the CADASTER project partners (29,30,32,(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56).…”

Isomerization of fenbuconazole under UV‐visible irradiation – chemical and toxicological approaches

“…Its fungicidal effect results from the inhibition of cytochrome P‐450 dependent C14 demethylation of lanosterol, an intermediate in ergosterol biosynthesis. Fenbuconazole is mainly used for preventive and early‐infection treatment for fungal diseases including powdery mildews, rusts, and many leaf‐spotting fungi . Its ability to inhibit enzymes involved in the biosynthesis of steroid hormones makes it a possible candidate for endocrine disruption in mammals .…”

“…Fenbuconazole is mainly used for preventive and early-infection treatment for fungal diseases including powdery mildews, rusts, and many leaf-spotting fungi. [15][16][17] Its ability to inhibit enzymes involved in the biosynthesis of steroid hormones makes it a possible candidate for endocrine disruption in mammals. [18] This pesticide is not genotoxic, it does not induce liver tumor in mice and rats but its presence has been associated with a slight increase in the incidence of liver adenomas in female mice after 18 months of dietary exposure.…”