University of Ljubljana, Biotechnical Faculty, 101 Jamnikarjeva, SI-1000, Ljubljana, Slovenia.
Helmholtz Centre for Environmental Research GmbH - UFZ, Department Bioanalytical Ecotoxicology, Permoserstr. 15, D-04318, Leipzig, Germany.
Environ Pollut. 2019 Nov;254(Pt A):112980. doi: 10.1016/j.envpol.2019.112980. Epub 2019 Aug 2.
Current understanding of how environmental aging of microplastics contributes to their ecotoxicity is low. We investigated whether incubation of microplastics in waters with different organic load and toxic potential alters the toxicity of microplastics to crustacean Daphnia magna, fish embryos Danio rerio and plant Lemna minor. Polyethylene primary microplastics; specifically microbeads from facial scrub; were subjected to 3-weeks incubation in low affected spring water, river water, effluent from the municipal wastewater treatment plant (WWTP) and municipal landfill leachate. Primary microplastics had no acute effect on D. magna mobility and D. rerio embryos development. While high organic load wastewaters; WWTP effluent and landfill leachate; showed evident toxicity for D. magna and D. rerio embryos, microplastics aged in these wastewaters had no effect. This suggests that adsorption of pollutants from wastewaters to microplastic particles was not high enough to induce acute toxicity to D. magna and D. rerio. On the contrary, primary microplastics affected the root growth of L. minor. Interestingly, aging of microplastics in low organic-load waters mitigated the toxicity of microplastics for L. minor, while microplastics aged in high-organic load waters had the same adverse effect as primary microplastics. Partly, these effects can be explained by different extent of coating on microplastics in different water samples. This study suggests that aging of microplastics in wastewaters and natural waters did not significantly enhance the toxicity to selected test species, but further studies on plants may be of interest.
目前对于环境老化的微塑料如何影响其生态毒性的理解还很低。我们研究了在不同有机负荷和毒性潜力的水中孵育微塑料是否会改变微塑料对甲壳类动物大型溞、鱼类胚胎斑马鱼和植物浮萍的毒性。我们使用聚乙烯原生微塑料；具体来说，是来自面部磨砂的微珠；在低影响的泉水、河水、城市污水处理厂（WWTP）和城市垃圾渗滤液中进行了 3 周的孵育。原生微塑料对大型溞的移动性和斑马鱼胚胎的发育没有急性影响。然而，高有机负荷的废水；WWTP 流出物和垃圾渗滤液；对大型溞和斑马鱼胚胎表现出明显的毒性，而在这些废水中老化的微塑料则没有影响。这表明，从废水中吸附到微塑料颗粒上的污染物没有高到足以对大型溞和斑马鱼产生急性毒性。相反，原生微塑料影响了浮萍的根生长。有趣的是，原生微塑料在低有机负荷水中老化减轻了微塑料对浮萍的毒性，而在高有机负荷水中老化的微塑料则与原生微塑料产生了相同的不利影响。部分原因是，这些效应可以通过不同水中微塑料表面覆盖程度的不同来解释。本研究表明，微塑料在废水中和天然水中的老化并没有显著增强对所选测试物种的毒性，但对植物的进一步研究可能会很有趣。
