Enantioselective Behavior of the Fungicide Tebuconazole in Soil
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Enantioselectivity (defined as the enantiomer fraction, EF) in sorption, dissipation and bioaccumulation was assessed for the model compound tebuconazole. Tebuconazole sorption in soils was affected by organic carbon (OC) and clay contents and cation exchange capacity, and appeared to be non-enantioselective for both tested soils, soil components and soil amendments. The bioaccumulation test consisted of two phases: the uptake phase and the elimination phase including the assessment of enantiospecific uptake and elimination rates. Unlike dissipation in soils, bioaccumulation of tebuconazole from these soils was enantioselective for both tested earthworm species (Eisenia andrei and Lumbricus terrestris). Peak-shaped bioaccumulation profiles were observed for all tested earthworm–soil variants with the maximum tissue concentrations reached within 7–10 days of exposure. Bioaccumulation factors ranged from 0.03 to 0.87. EF values of earthworm extracts varied from 0.28 to 0.52 with EF values <0.50 dominating. Enantioselectivity in bioaccumulation resulted from different excretion rates of the enantiomers. The interspecies similarity suggests that enantioselectivity in accumulation is a common phenomenon, and therefore, the risk assessment of tebuconazole should preferentially be evaluated at the enantiomer level. If this is not the case, a chiral correction factor of 2 (based on the enantiomer-specific BAF that differed by up to a factor of 2) may be recommended to account for enantioselectivity in tebuconazole bioaccumulation.
KeywordsTebuconazole Enantioselectivity Sorption Bioavailability Dissipation
The research was financially supported by the Czech Science Foundation (grant No. GJ18-14926Y) and the RECETOX Research Infrastructure (LM2015051 and CZ.02.1.01/0.0/0.0/16_013/0001761), which is greatly acknowledged.
- Edwards C (2004) Earthworm ecology, 2nd ed. CRC Press, Boca Raton, p 456Google Scholar
- EFSA (2008) Conclusion regarding the peer review of the pesticide risk assessment of the active substance tebuconazole. EFSA Sci Rep 176:1–109Google Scholar
- European Commission (2013) Ad-hoc study to support the initial establishment of the list of candidates for substitution as required in Article 80(7) of Regulation (EC) No 1107/2009Google Scholar
- Hvězdová M, Kosubová P, Košíková M, Scherr KE, Šimek Z, Brodský L, Šudoma M, Škulcová L, Sáńka M, Svobodová M, Krkošková L, Vašíčková J, Neuwirthová N, Bielská L, Hofman J (2018) Currently and recently used pesticides in central European arable soils. Sci Total Environ 613–614:361–370CrossRefGoogle Scholar
- Lin Z, Zhen Z, Wu Z, Yang J, Zhong L, Hu H, Luo C, Bai J, Li Y, Zhang D (2016) The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils. J Hazard Mater 301:35–45. https://doi.org/10.1016/j.jhazmat.2015.08.034 CrossRefGoogle Scholar
- Matallo M, Romero E, Sánchez-Rasero F, Peña A, Dios G (1998) Adsorption of mecoprop and dichlorprop on calcareous and organic matter amended soils: comparative adsorption of racemic and pure enantiomeric forms. J Environ Sci Heal Part B 33:51–66. https://doi.org/10.1080/03601239809373129 CrossRefGoogle Scholar
- Van der Wal L, Jager T, Fleuren R, Barendregt A, Sinnige TL, Van Gestel CAM, Hermens JLM (2004) Solid-phase microextraction to predict bioavailability and accumulation of organic micropollutants in terrestrial organisms after exposure to a field-contaminated soil. Environ Sci Technol 38:4842–4848CrossRefGoogle Scholar
- Wang X, Liu Y, Xue M, Wang Z, Yu J, Guo X (2019) Enantioselective degradation of chiral fungicides triticonazole and prothioconazole in soils and their enantioselective accumulation in earthworms Eisenia fetida. Ecotoxicol Environ Saf 183:109491. https://doi.org/10.1016/j.ecoenv.2019.109491 CrossRefGoogle Scholar
- Ye XL, Qiu J, Peng AG, Chai, T, Zhao, H, Ge, X (2013) Enantioselective degradation of tebuconazole in wheat and soil under open field conditions. Advances in Environmental Technologies. Trans Tech Publications, pp 348–356Google Scholar