Human Exposure to Dietary Microplastics and Health Risk: A Comprehensive Review

The ubiquity of microplastics (MPs) in natural surroundings leads to inevitable human exposure. MPs are reported to be present in daily food products, viz. bottled water, sea salt, packaged foods, beverages, fruits, crops, fishes, and sea foods, mainly due to their unique physical and chemical characteristics, leading to their human exposure across all age groups. In terrestrial environments, soil serves as a potential route of MP exposure to plant communities through plastic mulching, which can have implications on crops and transfer to human trough food chain. Consumption of MPs by aquatic organisms also causes a potential health hazards along food chain through trophic transfer. MPs are also reported to transfer from mother to child via placenta and breast milk. Additionally, MPs can trigger immune responses and hypersensitivity, and induce cellular, gastrointestinal, and developmental cytotoxicity. The aim of the present review is to provide a comprehensive idea on MP exposure through daily food items and their possible health concerns with plausible toxicity pathways. Future research should be oriented toward examining multi-level trophic transmission of MPs. Further, more in vivo studies should be conducted to understand the underlying mechanisms of MP uptake, retention, and depuration in the human body.