van Hall Bart G, Meijer Shuan, Pelser Anna C, van Gestel Cornelis A M
Amsterdam Institute for Life and Environment (A-LIFE), Faculty of Science, Vrije Universiteit Amsterdam, HZ, Amsterdam, The Netherlands.
Ecotoxicology. 2025 Apr 26. doi: 10.1007/s10646-025-02889-6.
In Europe, the risk assessment of pesticides to soils organisms is based on standardized laboratory toxicity tests using artificial soil containing kaolin clay. However, kaolin is not the most representative clay type for European agricultural soils, and its use may affect the bioavailability and toxicity of pesticides, potentially leading to an underestimation of the actual risk to soil organisms. In this study, reproduction toxicity tests with the earthworm Eisenia andrei following OECD guideline 222 were performed in artificial soils prepared with kaolin or bentonite clay, using the pesticides carbendazim and imidacloprid. The results showed that the OECD guideline 222 quality criteria could be met in soils prepared with bentonite clay. EC reproduction values (and 95% CIs) in soils prepared with kaolin and bentonite clay were 1.80 (1.02-2.57) and 4.19 (-10.4-18.8) mg kg for carbendazim, and 0.71 (0.06-1.36) and 2.27 (-0.26-4.80) mg kg for imidacloprid. For both pesticides, toxicity (LCx, ECx biomass, ECx reproduction) was higher in soils prepared with kaolin clay, although the differences were not always statistically significant. Differences in toxicity between the soils were likely due to a combination of the bentonite's larger interlayer distance, providing space for the pesticides to enter in between the clay sheets, and the higher cation exchange capacity (7.30 and 22.8 cmol kg for kaolin and bentonite soil, respectively) leading to increased pesticide sorption. Overall, these findings suggest that kaolin is a suitable clay type for standardized artificial soil, as it exhibited the highest toxicity, and thus provided a "worst-case" scenario.
在欧洲，农药对土壤生物的风险评估基于使用含高岭土的人工土壤进行的标准化实验室毒性测试。然而，高岭土并非欧洲农业土壤最具代表性的黏土类型，其使用可能会影响农药的生物有效性和毒性，从而可能导致对土壤生物实际风险的低估。在本研究中，按照经合组织（OECD）准则222，使用高岭土或膨润土制备人工土壤，用多菌灵和吡虫啉这两种农药对安德爱胜蚓进行繁殖毒性测试。结果表明，用膨润土制备的土壤能够满足经合组织准则222的质量标准。高岭土和膨润土制备的土壤中，多菌灵的EC繁殖值（及95%置信区间）分别为1.80（1.02 - 2.57）mg/kg和4.19（-10.4 - 18.8）mg/kg，吡虫啉的分别为0.71（0.06 - 1.36）mg/kg和2.27（-0.26 - 4.80）mg/kg。对于这两种农药，高岭土制备的土壤中的毒性（LCx、ECx生物量、ECx繁殖）更高，尽管差异并非总是具有统计学意义。土壤之间毒性的差异可能是由于膨润土较大的层间距离，为农药进入黏土层间提供了空间，以及较高的阳离子交换容量（高岭土和膨润土土壤分别为7.30和22.8 cmol/kg）导致农药吸附增加这两个因素共同作用的结果。总体而言，这些发现表明高岭土是标准化人工土壤的合适黏土类型，因为它表现出最高的毒性，从而提供了一种“最坏情况”的情景。
