Microplastics from Food Packaging: Polymer Degradation Pathways, Environmental Distribution, and Effects on the Human Gastrointestinal Tract

Fossil fuels are currently the primary source for plastic production, with global production exceeding 400 million tons annually. The food sector remains the dominant application, particularly in the production of single-use packaging. Commonly used packaging is primarily made from PE, PP, PS, and PET. The versatility of these materials stems from their lightweight, functionality, and ability to extend the shelf life of food products. Unfortunately, constantly growing consumption generates vast amounts of difficult-to-degrade waste, which in the natural environment constantly fragments, generating hazardous microplastics (MPs). MPs readily spread throughout the biosphere and are now commonly detected in the digestive tracts of humans and animals. Current scientific reports indicate their potential contribution to the pathogenesis of numerous diseases such as inflammatory bowel disease, diabetes, obesity, allergic reactions, and cancer. This link is believed to result from mechanisms involving physical toxicity, exposure to chemical substances, and microbiological interactions. The MP problem is global in nature and encompasses the entire life cycle of plastics, from production to accumulation in living organisms. This review aims to provide an up-to-date and comprehensive overview of the toxicological and environmental issues related to MPs, addressing the current research gaps and emphasizing their increasing relevance to human health.