Lab of Toxicology, Department of Health Sciences, The Graduate School of Dong-A University, 37, Nakdong-daero 550 beon-gil, Saha-gu, Busan 49315, Republic of Korea.
Department of Applied Chemistry, Kyung Hee University, Yongin-si 17104, Republic of Korea.
J Hazard Mater. 2023 Oct 5;459:132295. doi: 10.1016/j.jhazmat.2023.132295. Epub 2023 Aug 14.
Expanded polystyrene (EPS), also known as Styrofoam, is a widespread global pollutant, and its lightweight floating property increases its chances of weathering by abrasion and ultraviolet (UV) irradiation, resulting in microplastics. Herein, we investigated the effects of particle size ((1 µm versus 10 µm), UV irradiation (pristine versus UV oxidation), and origin (secondary versus primary) on the toxicity of Styrofoam microplastics. The target cells used in this study were selected based on human exposure-relevant cell lines: differentiated THP-1 cells for macrophages, Caco-2 for enterocytes, HepG2 for hepatocytes, and A549 for alveolar epithelial cells. In the differentiated THP-1 cells, the levels of cytotoxicity and inflammatory cytokines showed size- (1 µm > 10 µm), UV oxidation- (UV > pristine), and origin- (secondary > primary) dependency. Furthermore, the intrinsic oxidative potential of the test particles was positively correlated with cellular oxidative levels and toxicity endpoints, suggesting that the toxicity of Styrofoam microplastics also follows the oxidative stress paradigm. Additionally, all microplastics induced the activation of the pyrin domain-containing protein 3 (NLRP3) inflammasome and the release of interleukin-1β (IL-1β). These results imply that weathering process can aggravate the toxicity of Styrofoam microplastics due to the increased oxidative potential and decreased particle size.
可发性聚苯乙烯（EPS），又称聚苯乙烯泡沫，是一种广泛存在的全球性污染物，其质轻、可漂浮的特性增加了其因磨损和紫外线（UV）照射而风化的几率，从而形成微塑料。在此，我们研究了粒径（1 µm 与 10 µm）、UV 照射（原始态与 UV 氧化态）和来源（次生与原生）对聚苯乙烯微塑料毒性的影响。本研究选择了基于人类暴露相关细胞系的目标细胞：分化的 THP-1 细胞作为巨噬细胞、Caco-2 细胞作为肠细胞、HepG2 细胞作为肝细胞和 A549 细胞作为肺泡上皮细胞。在分化的 THP-1 细胞中，细胞毒性和炎症细胞因子的水平表现出尺寸依赖性（1 µm > 10 µm）、UV 氧化依赖性（UV > 原始态）和来源依赖性（次生 > 原生）。此外，测试颗粒的内在氧化潜能与细胞氧化水平和毒性终点呈正相关，表明聚苯乙烯微塑料的毒性也遵循氧化应激模式。此外，所有微塑料均诱导吡喃结构域蛋白 3（NLRP3）炎性小体的激活和白细胞介素-1β（IL-1β）的释放。这些结果表明，由于氧化势增加和粒径减小，风化过程会加剧聚苯乙烯微塑料的毒性。
