Dietary microplastics: Occurrence, exposure and health implications

The increasing use of plastic materials generates an enormous amount of waste. In the aquatic environment, a significant part of this waste is present in the form of microplastics (MPs)- particles with a diameter of between 0.1 μm and 5 mm. The arrival of these small plastics in the food chain has been recently documented. MPs have been reported in fishery products, drinking water and sea salt among other foods. Their intestinal absorption is considered limited due to their size, however, they contain a mixture of chemicals intentionally added during their manufacture, which could cross the intestinal barrier. Currently there are not enough data to allow an accurate assessment of the risk associated with dietary exposure to MPs. The lack of robust methodologies is undoubtedly one of the main problems. There is limited information on occurrence in dietary sources (drinking water and food), human intake, toxicokinetics and long term toxicity of these contaminants. The present review describes the studies published so far and points to the need for improved knowledge in order to have a more accurate view of the problems posed by MPs.