The Invisible Threat: Understanding Effects of Micro- and Nano-Plastics on Human Health and Environment

Abstract

Micro- and nano-plastic (MNPs) pollution has now become a global environmental threat that has persisted for the past few decades. Although large-scale experimental research evidence is still lacking, it has been found from a few research works that micro- and nano-plastic (MNPs) pollution has a significant negative impact not only on the environment but also on human health and well-being. This review aims to understand three main routes of human exposure to MNPs: ingestion, inhalation, and dermal contact. It further demonstrates the potential routes through which these MNPs are translocated to different tissues such as the lungs, intestines, and skin, damaging these organ systems. This correlation is significant with the studies conducted on both in vivo animal models and in vitro human-derived cell culture methods. Long-term exposure to MNPs could cause respiratory, excretory, immunogenic, gastrointestinal, and endocrine disruption. Some available reports also suggest that prolonged exposure to MNPs in humans could lead to oxidative stress, cytotoxicity, reproductive problems, congenital deformities of embryos, and even some forms of cancers. Although direct evidence supporting all of these effects of MNPs on human health and wellness is very limited, extensive research works are still needed not only to support these claims quantitatively but also to assess the potential threats for the future that might endanger human health and civilization.