MICROPLASTICS IN THE FOOD CHAIN: A MULTI-OMICS INVESTIGATION OF CHEMICAL TOXICITY, MICROBIAL VECTOR DYNAMICS, AND GENOTOXIC EFFECTS ON HUMAN HEALTH

Abstract

Nanoplastic and microplastic pollution of international food systems is a new public health issue with multidimensional risks that cannot be considered within the paradigms of conventional toxicology. Through this holistic study, the environmental sampling, chemical profiling, metagenomic characterization, and multi-omics are combined to elucidate the intricate interactions between dietary exposure to microplastic and human health outcomes. Chemical analysis of environmentally weathered microplastic surfaces shows a high degree of polycyclic aromatic hydrocarbons, perfluoroalkyl substances, phthalate esters, and bisphenol analogues accumulation, and extraction tests using physiologically relevant conditions have shown a high degree of contaminant bioaccessibility. Metagenomic profiles of the plastisphere indicate specific enrichment of antibiotic resistance genes, virulence factors, and clinically relevant pathogens compared to natural particulate food sources, defining microplastics as carriers of antimicrobial resistance spread in aquatic and terrestrial food webs. Coordinated pathway dysregulation of oxidative stress response, inflammatory cascades and metabolic networks is shown by integrated transcriptomic, proteomic and metabolomic profiling of exposed human cellular models, and transgenerational epigenetic inheritance of plastic induced phenotypic changes by whole-genome bisulfite sequencing of model organisms. Such a pilot human biomonitoring study has found evidence of increased levels of DNA damage, gene expression signatures, and observable circulating microRNA patterns in occupationally exposed groups, which are candidate biomarkers of exposure assessment and early effects. These observations form a mechanistic model in which microplastic particles act as physical irritants, vectors of chemicals, and microbial substrates in an integrated biological response, which cannot be predicted based on reductionist toxicology. The wider food safety regulation, environmental policy, and One Health governance implications are enormous and require a concerted international response to curb the mounting burden of dietary microplastic exposure and resultant health outcomes.