Source, migration path and pollution of microplastics and nano-plastics in food

In this paper, the source, migration path and pollution status of microplastics and nano-plastics in food were reviewed. Microplastics and nano-plastics refer to plastic fragments and particles with diameters less than 5 mm and 1 μm, which enter the food chain through various ways and may eventually accumulate in the human body, posing a potential threat to health. Sources include decomposition of plastic products, direct contact of food with packaging materials, food processing and environmental pollution. The migration path involves the process from environment to food, from food packaging to food, and from food processing to food. The pollution analysis shows that the contents of microplastics and nano-plastics in different foods are different, which are influenced by environmental pollution, production and processing technology, packaging materials, food types and consumption habits. Microplastics and nano-plastics mainly exist in granular and fibrous forms, and may contain a variety of plastic polymers, whose morphology and characteristics affect their absorption, distribution, metabolism and excretion in human body. Health risk research shows that these tiny plastic particles may lead to the damage of intestinal oxidation and inflammation balance, lead to toxic effects such as oxidative stress, inflammation and apoptosis, and may penetrate the epithelial barrier and cause immune response, which has genotoxicity and cytotoxicity. Therefore, this study provides a scientific basis for formulating relevant policies and food safety management, and promotes public attention to microplastics and nano-plastic pollution in food.