Evaluating the in Vitro Toxicity of 4-MBC and Microplastics: The Role of PE and PVC as Carriers

UV filter, 4-methylbenzylidene camphor (4-MBC) is identified as endocrine disrupting chemical that is frequently detected in the aquatic environment. Due to its hydrophobic nature and stability under UV radiation, the concomitant presence of both 4-MBC and microplastics (MPs) enlightens the possible impacts of their combined effects on human health. Hence, the aim of this research was to evaluate the adsorption capacity of 4-MBC in the presence of two commonly encountered types of MPs in the environment: polyvinyl chloride (PVC), and polyethylene (PE). Having in mind that inhalation is one of the primary exposure routes to MPs, the human embryonic lung fibroblast cell line (MRC-5) was used to study the individual cytotoxicity of 4-MBC, PVC, and PE, as well as their sorbed samples. The equilibrium adsorption capacity of 4-MBC on PE was higher compared to PVC. The combined effects of PVC + 4-MBC as well as PE + 4-MBC exerted non-linear dose-response dynamics. The enhanced cytotoxicity of adsorbed samples was detected. Moreover, more pronounced cytotoxic effect was observed in cells treated with PE + 4-MBC. The cooperative index showed an additive effect for 4-MBC and PVC, while 4-MBC and PE exhibited a synergistic interaction. Based on the obtained results PE can sorb and concentrate a higher amount of 4-MBC compared to PVC.