Photoaging enhances combined toxicity of microplastics and tetrabromobisphenol A by inducing intestinal damage and oxidative stress in Caenorhabditis elegans

• Published in: The Science of the total environment 2024-02, Vol.912, p.169259-169259, Article 169259
• Main Authors: Chen, Haibo, Chen, Xiaoxia, Ding, Ping, Gu, Yulun, Jiang, Yongqi, Li, Xintong, Hu, Guocheng, Li, Liangzhong, Wang, Chen, Yu, Jun, Li, Hui
• Format: Article
• Language: English
• Subjects: Adsorption; Combinational effect; Intestinal injury; Oxidative stress; Photoaged microplastics
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.169259

Microplastics (MPs) are emerging environmental contaminants that often co-exist with tetrabromobisphenol A (TBBPA) in the environment. However, the joint effect of TBBPA and photoaged MPs at ambient concentrations remains unknown largely. In this study, the combined toxicity of ultraviolet-aged polystyrene (UV-PS) and TBBPA was investigated in Caenorhabditis elegans. UV irradiation could change the physical and chemical characteristics of polystyrene (PS), and UV-PS (90.218 μg/g) showed a stronger adsorption capacity than PS of 79.424 μg/g. Toxicity testing showed that 1 μg/L UV-PS enhanced the toxic effect of 1 μg/L TBBPA by reducing body length, locomotion behavior, and brood size in nematodes. Using ROS production, lipofuscin accumulation, and expression of gst-4::GFP as endpoints, the combined exposure of UV-PS and TBBPA induced stronger oxidative stress than TBBPA alone. Joint exposure to UV-PS and TBBPA significantly increased of Nile red and blue food dye in its intestinal tract compared to that in the TBBPA exposure group, indicating that co-exposure enhanced intestinal permeability. After co-exposure to UV-PS and TBBPA, the expression of the associated genes detected increased significantly. Therefore, UV-PS enhances the adverse effects of TBBPA through intestinal damage and oxidative stress in nematodes. These findings suggest that the co-presence of photoaged PS and TBBPA results in high environmental risks. [Display omitted] •Photoaging alters the physicochemical properties of PS.•UV-PS exhibited a stronger adsorption capacity for TBBPA than PS.•Photoaging enhances the combined toxicity of PS and TBBPA in nematodes.•UV-PS enhances toxicity of TBBPA through intestinal damage and oxidative stress.