Świątek Zuzanna M, van Gestel Cornelis A M, Bednarska Agnieszka J
Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
Department of Ecological Science, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Ecotoxicol Environ Saf. 2017 Sep;143:151-158. doi: 10.1016/j.ecoenv.2017.05.027. Epub 2017 May 19.
The toxicokinetics of zinc in the earthworm Eisenia andrei was investigated following exposure for 21 days to ionic zinc (ZnCl) or zinc oxide nanoparticles (ZnO-NPs) in Lufa 2.2 soil, followed by 21 days elimination in clean soil. Two concentrations were tested for both ZnCl (250 and 500μg Zn g) and ZnO-NPs (500 and 1000μg Zn g), corresponding to EC and EC for effects on reproduction. Based on the measured internal Zn concentrations in the earthworms over time of exposure, the kinetics parameters k - assimilation rate constant (g g day) and k - elimination rate constant (day) were estimated using a one-compartment model for either total Zn concentrations in the soil or porewater Zn concentrations. In the ZnCl treatments, k was higher for total Zn concentrations in soil, whereas in the ZnO-NP treatments, k was higher for porewater Zn concentrations. The value of k did not differ between the two Zn forms (ZnCl vs ZnO-NPs) for either EC or EC when related to total Zn concentrations in soil, but for EC, k related to porewater Zn concentrations was significantly higher for ZnCl than for ZnO-NPs. It is concluded that differences in kinetic parameters between treatments were connected with exposure concentrations rather than with the form of Zn. Zinc was efficiently regulated by the earthworms in all treatments: a 2-fold increase in exposure concentration resulted in a less than 2-fold increase in internal concentration, and after transfer to uncontaminated soil the internal Zn concentrations in the earthworms returned to ca 111μgg dw in all treatments.
在Lufa 2.2土壤中，将安德爱胜蚓暴露于离子态锌（ZnCl）或氧化锌纳米颗粒（ZnO-NPs）21天，随后在清洁土壤中消除21天，以此研究锌在该蚯蚓体内的毒代动力学。对ZnCl（250和500μg Zn/g）和ZnO-NPs（500和1000μg Zn/g）均测试了两种浓度，这两种浓度分别对应于对繁殖产生影响的EC和EC。根据暴露期间蚯蚓体内锌浓度随时间的测量结果，使用单室模型针对土壤中总锌浓度或孔隙水中锌浓度估算动力学参数k（同化速率常数，g/g·天）和k（消除速率常数，天）。在ZnCl处理中，土壤中总锌浓度的k较高，而在ZnO-NP处理中，孔隙水中锌浓度的k较高。当与土壤中总锌浓度相关时，两种锌形态（ZnCl与ZnO-NPs）在EC或EC下的k值均无差异，但对于EC，与孔隙水中锌浓度相关的k，ZnCl显著高于ZnO-NPs。研究得出结论，各处理间动力学参数的差异与暴露浓度有关，而非与锌的形态有关。在所有处理中，蚯蚓对锌都有高效的调节作用：暴露浓度增加2倍，体内浓度增加不到2倍，并且转移到未受污染的土壤后，所有处理中蚯蚓体内的锌浓度均恢复到约111μg/g干重。
