Evaluation of the potential toxicity of microplastics released from soft beverages packaging under different storage...

Microplastics (MPs), as an emerging pollutant, have drawn much attention due to the possibility that they may be released from certain food packaging and pose potential risks to human health. This study systematically investigated the effects of three storage temperature, mechanical agitation, and light exposure on the release behavior of MPs from commercially soft beverages (soda water, cola, and mineral water), and assessed their toxicity in vitro and in vivo. Light exposure was identified as the most critical factor promoting MP release, with the highest abundance reaching 92.79 ± 7.53 μg/g in cola after UV-A treatment, which significantly altered the surface functional groups of the bottles, enhancing CO groups. Toxicological assessments demonstrated that the MPs isolated from the beverages induced concentration-dependent toxic effects, with MPs released under UV-A treatment reducing Caco-2 cell viability to 58.39 ± 3.99% at 200 μg/mL, and significantly triggering apoptosis and oxidative stress. MPs derived from cola exhibited stronger cytotoxicity compared to those from other beverages. Zebrafish embryo experiments confirmed that MPs led to increased mortality and an imbalance in oxidative stress levels (reactive oxygen species (ROS) and superoxide dismutase (SOD), decreased glutathione (GSH)). Although the zebrafish larvae showed some elimination capacity, MPs remained detectable after the clearance period.