Microplastics and nanoplastics in human health: a comprehensive review of exposure pathways, cellular mechanisms, and toxicological implications

The occurrence and accumulation of plastic in the environment are major issues, and studies show various pathways through which plastic risks human health. This review examines the knowledge of human exposure to microplastics (MPs) and nanoplastics (NPs), their biological fate, and potential health implications. These include consumption of seafood (0.04–3.5 MPs/g), using table salt (0–1700 MPs/kg), and drinking water (325–54,200,000 MPs/L). Additionally, people can inhale (0.4–59 fibres/m3) or come into direct contact with them through their skin. The ability of MPs and NPs to translocate across biological barriers and interact with cellular components shows how they distribute within the human body. This review delves into the molecular and cellular mechanisms that result in toxicity, such as oxidative stress, inflammatory responses, and disruption of the endocrine system. NPs have gotten considerable focus because of their unique properties and cellular uptake; nevertheless, tackling the analytical difficulties preventing the human sample’s dependable characterization and quantification is essential. MPs and NPs may interact with other environmental pollutants, and this review emphasizes critical gaps in our comprehension of their long-term, low-dose effects. Standardized techniques and improved detection techniques need to be developed and established in future studies to address these issues.