Microplastic contamination: a human health concern and an analytical challenge

The pollution caused by plastics, for which demand worldwide is increasing every year, is not only a problem for the environment but also poses risks to food safety and human health. Microplastics (MPs) are polymeric particles with dimensions between 5 mm and 0.1 μm that are generated from degraded plastic as it is subjected to mechanical and atmospheric phenomena. Further degradation leads to the formation of even smaller particles, nanoplastics (NPs), with sizes down to 1 nm. Studies report harmful effects of these anthropogenic particles on marine and terrestrial ecosystems; they can affect soil performance, interfere with photosynthesis, and have toxic effects on animals, undermining survival mechanisms such as reproduction and foraging. Some effects of MPs on human health have been reported; however, their toxicity is still not well-documented. In addition, their negative activity can be linked to their ability to act as a vehicle for pathogens and other known contaminants, thus increasing human exposure to these substances. One of the main routes of human contact with MPs and NPs is by ingestion, therefore, through the food and beverages we consume, which are eventually contaminated. Raman microspectroscopy is one of the most popular analytical techniques, included by the European Union among those to measure MPs in water intended for human consumption. MPs have been reported in various foods and drinks. Among complex matrices, seafood is the most studied due to its connection with the marine environment. The scientific community’s interest in the presence of MPs and NPs in food is steadily increasing, with several food products considered to be growing. Nevertheless, there is still a need for reliable and comparable data and the development of standardized procedures for a greater variety of foods to fill the methodological gaps in this scientific field and enable a proper risk assessment evaluation.