Microplastics in the Food Chain

The presence of microplastics in the whole trophic network including humans has been documented by a plethora of studies. When microplastics are introduced into the trophic structure, the routine functions of the biotic systems play a role as vectors of contaminants. At each higher level of the trophic structure, the toxic levels are biomagnified. After ingestion, depending on the size, shape, and type of the material, the microplastics may stay in the digestive tracts or be absorbed by the intestinal epithelium and/or distributed through the circulatory system or excreted. When introduced into different tissues, it may trigger a chain of physiological and behavioral responses including physical damage and a reaction to the toxic chemicals of the microplastics and the chemicals adsorbed onto them. Multimodal accumulation of microplastics in humans from air and consumption of contaminated food, bottled water, beverages, and commercial salts are recorded. Studies have also documented that microplastics with a size of ≤20 μm are capable of penetrating into all the organs, cross cell membranes, the blood-brain barrier, and the placenta!