Department of Biology, Faculty of Science, Universidad Autónoma de Madrid, E-28049, Madrid, Spain.
Department of Chemical Engineering, Universidad de Alcalá, E-28871, Alcalá de Henares, Madrid, Spain.
Chemosphere. 2021 Mar;266:129193. doi: 10.1016/j.chemosphere.2020.129193. Epub 2020 Dec 4.
Despite the large number of recent studies on microplastics (MPs) and their ability to act as carriers of pollutants, the knowledge about the biological effects of MPs loaded with chemicals is scarce. The aim of this study was to evaluate the potential of MPs as vectors for the antimicrobial triclosan (TCS). For it, we tested low-density polyethylene (LDPE), polyamide (PA), polyethylene terephthalate (PET), polyoxymethylene (POM), polypropylene (PP), polystyrene (PS) and the biodegradable polylactic acid (PLA). Thus, chemical analysis of sorption and desorption of TCS by these MPs was evaluated. The effect of TCS-loaded MPs to Anabaena sp. PCC7120, a cyanobacterium model of primary producers in freshwater ecosystems, was investigated. Chemical analyses showed different capacity of sorption depending on the MP type, which was related to some of their physicochemical properties. PA (104.7 μg/g), POM (57.4 μg/g) and LDPE (18.3 μg/g) were the polymers that sorbed the highest amounts of TCS. Glass transition temperature of polymers and their physicochemical interaction with TCS explained the extent of sorption. Significant decreases were found in growth, 22.3%, 94.6% and 81.0%, and chlorophyll a content, 58.4%, 95.0% and 89.6%, of Anabaena when exposed to TCS-loaded LDPE, PA and POM beads, respectively, which were the only MPs displaying significant sorption-desorption of TCS, implying that these MPs could act as vectors of TCS towards freshwater microalgae. This finding is of fundamental relevance as microalgae are at the base of the aquatic trophic chain and support growth of upper organisms.
尽管最近有大量关于微塑料 (MPs) 的研究，以及它们作为污染物载体的能力，但关于负载化学物质的 MPs 的生物效应的知识还很匮乏。本研究旨在评估 MPs 作为抗菌剂三氯生 (TCS) 载体的潜力。为此，我们测试了低密度聚乙烯 (LDPE)、聚酰胺 (PA)、聚对苯二甲酸乙二醇酯 (PET)、聚甲醛 (POM)、聚丙烯 (PP)、聚苯乙烯 (PS) 和可生物降解的聚乳酸 (PLA)。因此，评估了这些 MPs 对 TCS 的吸附和解吸的化学分析。研究了负载 TCS 的 MPs 对淡水生态系统初级生产者模式蓝藻 (Anabaena sp. PCC7120) 的影响。化学分析表明，吸附能力因 MP 类型而异，这与它们的一些物理化学性质有关。PA (104.7μg/g)、POM (57.4μg/g) 和 LDPE (18.3μg/g) 是吸附 TCS 量最高的聚合物。聚合物的玻璃化转变温度及其与 TCS 的物理化学相互作用解释了吸附的程度。当暴露于负载 TCS 的 LDPE、PA 和 POM 珠时，蓝藻的生长分别显著下降了 22.3%、94.6%和 81.0%，叶绿素 a 含量分别下降了 58.4%、95.0%和 89.6%，这是仅有的显示出 TCS 显著吸附-解吸的 MPs，这意味着这些 MPs 可能成为 TCS 向淡水微藻传播的载体。这一发现具有重要意义，因为微藻是水生食物链的基础，为上层生物的生长提供支持。
