A review on microplastics and nanoplastics in the environment: Their occurrence, exposure routes, toxic studies, and potential effects on human health

Microplastics (MPs) and nanoplastics (NPs) are emerging environmental pollutants, having a major ecotoxico-logical concern to humans and many other biotas, especially aquatic animals. The physical and chemical com-positions of MPs majorly determine their ecotoxicological risks. However, comprehensive knowledge about the exposure routes and toxic effects of MPs/NPs on animals and human health is not fully known. Here this review focuses on the potential exposure routes, human health impacts, and toxicity response of MPs/NPs on human health, through reviewing the literature on studies conducted in different in vitro and in vivo experiments on organisms, human cells, and the human experimental exposure models. The current literature review has highlighted ingestion, inhalation, and dermal contacts as major exposure routes of MPs/NPs. Further, oxidative stress, cytotoxicity, DNA damage, inflammation, immune response, neurotoxicity, metabolic disruption, and ultimately affecting digestive systems, immunology, respiratory systems, reproductive systems, and nervous systems, as serious health consequences.

Automated summary

Microplastics and nanoplastics are emerging environmental pollutants that pose significant ecotoxicological concerns to humans and aquatic animals. However, there is still limited knowledge about the exposure routes and toxic effects of these particles on animal and human health. This review focuses on the potential exposure routes, human health impacts, and toxicity responses of microplastics/nanoplastics, based on studies conducted in vitro and in vivo experiments. It highlights ingestion, inhalation, and dermal contacts as major exposure routes, and identifies oxidative stress, cytotoxicity, DNA damage, inflammation, immune response, neurotoxicity, and metabolic disruption as serious health consequences.