State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Chengdu Xingrong Environment Co., Ltd, Chengdu 610041, China; Chengdu Drainage Co., Ltd, Chengdu 610011, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrialpollutants, University of Science and Technology Beijing, Beijing 100083, China.
J Hazard Mater. 2023 Oct 15;460:132318. doi: 10.1016/j.jhazmat.2023.132318. Epub 2023 Aug 23.
Biodegradable microplastics (BMPs) and cadmium (Cd) are posing threats to agro-systems especially to plants and current studies mostly used virgin BMPs to explore their ecological effects. However, effects of naturally aged BMPs and their combined effects with Cd on pakchoi are yet to be unraveled. Therefore, this study incubated naturally aged polylactic acid (PLA) MPs through soil aging process and investigated the single and combined effects of Cd and PLA MPs (virgin and aged) on pakchoi (Brassica rapa subsp. chinensis) morphology, antioxidant systems and soil microbial activities. Our results found that after being deposited in soil for six months, aged PLA (PLAa) MPs formed with a fractured surface, demonstrating more detrimental effects on pakchoi than virgin ones. PLA/PLAa MPs and Cd stunted pakchoi growth, caused oxidative stress and altered the biophysical environment in soil, separately. Moreover, co-existence of PLA/PLAa MPs and Cd caused greater damages to pakchoi than applied alone. The co-presence of PLAa MPs and Cd inhibited pakchoi biomass accumulation rate by 92.2 % compared with the no-addition group. The results unraveled here emphasized BMPs, especially aged BMPs, could trigger negative effects on agro-systems with heavy metals. These findings will give reference to future holistic assessments of BMPs' ecological effects.
可生物降解微塑料（BMPs）和镉（Cd）对农业系统构成威胁，特别是对植物。目前的研究大多使用原始 BMPs 来探索它们的生态效应。然而，自然老化的 BMPs 及其与 Cd 的联合效应对小白菜的影响尚未被揭示。因此，本研究通过土壤老化过程孵育了自然老化的聚乳酸（PLA） MPs，并研究了 Cd 和 PLA MPs（原始和老化）对小白菜（Brassica rapa subsp. chinensis）形态、抗氧化系统和土壤微生物活性的单一和联合效应。我们的结果发现，在土壤中沉积六个月后，老化的 PLA（PLAa） MPs 形成了断裂表面，对小白菜的危害比原始 PLA 更大。PLA/PLAa MPs 和 Cd 分别抑制了小白菜的生长，导致了氧化应激并改变了土壤的生物物理环境。此外，PLA/PLAa MPs 和 Cd 的共存对小白菜的损害大于单独使用时的损害。与无添加组相比，PLAa MPs 和 Cd 的共存抑制了小白菜生物量积累率达 92.2%。这里揭示的结果强调了 BMPs，特别是老化的 BMPs，可能会对重金属污染的农业系统产生负面影响。这些发现将为未来对 BMPs 生态效应的综合评估提供参考。
