Abstract：
Combined toxicity is a critical concern during the risk assessment of environmental pollutants. Due to the characteristics of strong hydrophobicity and large specific surface area, microplastics (MPs) and nanoplastics (NPs) have become potential carriers of organic pollutants that may pose a health risk to humans. The co-occurrence of organic pollutants and MPs would cause adverse effects on aquatic organism, while the information about combined toxicity induced by organophosphorus flame retardants and MPs on human cells was limited. This study aimed to reveal the toxicity effects of co-exposure to triphenyl phosphate (TPHP) and polystyrene (PS) particles with micron-size/nano-size on HepG2 cell line. The adsorption behaviors of TPHP on PS particles was observed, with the PS-NP exhibiting a higher adsorption capacity. The reactive oxygen species generation, mitochondrial membrane potential depolarization, lactate dehydrogenase release and cell apoptosis proved that PS-NPs/MPs exacerbated TPHP-induced cytotoxicity. The particle size of PS would affect the toxicity to HepG2 cells that PS-NP (0.07 μm) exhibited more pronounced combined toxicity than PS-MP (1 μm) with equivalent concentrations of TPHP. This study provides fundamental insights into the co-toxicity of TPHP and PS micro/nanoplastics in HepG2 cells, which is crucial for validating the potential risk of combined toxicity in humans.
摘要：
复合毒性是环境污染物风险评估过程中的关键问题。由于具有疏水性强、比表面积大的特点,微塑料（MPs）和纳米塑料（NPs）已成为有机污染物的潜在载体，可能对人类构成健康风险。有机污染物和MPs的共存会对水生生物造成不利影响,而有关有机磷阻燃剂和MPs对人细胞诱导的联合毒性的信息有限。本研究旨在揭示微米/纳米尺寸的磷酸三苯酯（TPHP）和聚苯乙烯（PS）颗粒共同暴露对HepG2细胞系的毒性作用。观察了TPHP在PS颗粒上的吸附行为,PS-NP表现出较高的吸附能力。活性氧的产生，线粒体膜电位去极化，乳酸脱氢酶释放和细胞凋亡证明PS-NPs/MPs加剧了TPHP诱导的细胞毒性。PS的粒径会影响对HepG2细胞的毒性，即PS-NP（0.07μm）比具有等浓度TPHP的PS-MP（1μm）表现出更明显的组合毒性。这项研究为TPHP和PS微/纳米塑料在HepG2细胞中的共同毒性提供了基本见解，这对于验证人类联合毒性的潜在风险至关重要。
