A Systematic Review on the Toxicological Implications of Microplastic to Human Health

Abstract

The environmental, economic, and social impacts of micro and nano plastic (MNPs) pollution have caused significant global concern, which is exacerbated by the MNPs associated chemicals and biological entities that could directly or indirectly impact human health. The systematic review of research accomplished on this issue could enhance the understanding surrounding the toxicological risks of MP and its pathways to the human system. A significant amount of research is available on microplastic; still, the research executed to define the chemical impact and risk scenarios of microplastics on human health is limited. The objective of this study was to catalogue the literature on the toxicological impacts of MNPs on humans and the resulting biological consequences. A total of 95 publications were reviewed following the Cochrane protocol and screened based on the direct and indirect health impacts of MNPs to the human systems using the RevMan 5 software. Processing of collected data resulted in a total of 19 publications (until July 2021) that fulfilled the inclusion criteria and provided evidence of the potential impacts of MNPs, particularly in relation to the average sizes of Large MPs - 5mm - 1mm; MPs - 1mm - 0.1μm; NPs - 1-1000nm. Detailed analysis of data categorized into scenarios of chemical, toxicological, and biological impacts of MNPs on human health indicated that additives and associated contaminants of MNPs would pose a significant risk to human health. This is the first review that streamlines the notion that indirect impacts of MNPs caused due to MNP-associated chemicals are more severe than the direct impacts such as ingestion of MNPs.