Effect of Adsorbed and Endogenous Chemical Pollutants
Fragmented particles with large surface area-to-volume ratios of microplastics and hydrophobicity due to adsorbed hydrocarbons on the surface cause toxicity in humans. Some of the adsorbed hydrocarbons have been found to be carcinogenic, mutagenic and immunotoxic in nature. The additives mixed while manufacturing of plastics can leach out based on concentration gradient . Upon accumulation, microplastics present a new source of chemicals to tissues and body fluids. They are capable of inducing reproductive toxicity, mutagenicity, carcinogenicity and even disruption of hormones . Inhalation and ingestion of household dust is a predominant source of micro- and nanoplastics. Carpets, electronics and upholstery contain polybrominated diphenyl ethers (PBDEs), which are also toxic in nature. Apart from chemical additives, microplastics also contain unreacted monomers, which are classified as mutagenic, carcinogenic or both . In a recent study on mice, it was found that peritoneal dialysis solution contains leached contaminants .
Effect on Microbiome
Microbiome refers to the microbial community living inside or on the body and assisting the host in its physiological well-being . If the microbiomes colonize over microplastics, the balanced composition of the microbes will be hampered, and thus it will impair the physiological functions. Microbiomes have the capacity of metabolizing various environmental toxicants, thus forming colonies over microplastics may affect immunogenic responses . Lungs also host a number of microbial communities; colonization of microbes in gastrointestinal and airway tracts may alter immunogenic responses in such areas. However, colonization has been found to be lower in the respiratory region relative to gastrointestinal region. Thus, colonization may cause a change in the microbial composition in the gastrointestinal tract and lungs, which may lead to oxidative stress.