MICROPLASTICS AND NANOPLASTICS: A LITERATURE REVIEW ON TOXICITY, EFFECTS ON ORGAN SYSTEMS, AND IMPLICATIONS FOR HUMAN HEALTH

Abstract

This article aimed to critically analyze the scientific evidence regarding human exposure to microplastics and nanoplastics (MNPs), with emphasis on exposure pathways, cellular mechanisms of toxicity, and potential effects on human health. This is a qualitative, systematic literature review based on scientific articles published between 2017 and 2026, identified in the PubMed, Web of Science, ScienceDirect, SpringerLink, and Wiley Online Library databases, using descriptors related to microplastics, nanoplastics, human health, and toxicity. Experimental and clinical studies, as well as reviews addressing mechanisms of toxicity, exposure pathways, and physiological or systemic effects of MNPs, were analyzed. The results demonstrated that these particles are widely distributed in the environment and can be found in water, soil, air, and food, contributing to continuous human exposure. The evidence indicated that MNPs can cross biological barriers and trigger oxidative stress, inflammation, and cellular alterations, with potential impacts on the gastrointestinal, respiratory, cardiovascular, immune, nervous, endocrine, and reproductive systems. It is concluded that chronic exposure to MNPs represents an emerging concern for human health, reinforcing the need for further research, monitoring, and public policies.