Long-term Effects of Exposure to Microplastics at Environmentally Relevant Concentrations on Lipidome of the Mouse Heart and Brain

Abstract

Recent studies on biological effects of microplastics (MPs) has been limited to short-term effects under high concentrations which are irrelevant to human exposure conditions. To overcome the limitation, this study investigated the long-term effects of MP exposure on mouse lipidome under environmentally realistic concentrations for human. The realistic concentration of MP was determined based on reported abundances of MPs in foods and their daily consumptions. In the consideration of size-dependent absorption of MPs through the digestive system, only MPs with size less than 10 μm were used for the experiments. MPs were orally introduced to mice through drinking water for 1, 3, and 6 months. Relative quantification of lipid carried out by deuterium oxide labeling for global omics relative quantification (DOLGOReQ). The heart and brain lipids were significantly affected by exposure to MPs for 1 month. Meanwhile, the heart and brain lipids of mice exposed to MPs for 6 months did not show any significant changes. Our results implied that the reported lipid metabolism disorders by MPs could have been overestimated, however, the possibility that MPs-induced lipid metabolism disorders could be greater in young mice has been suggested.