## 1 Introduction  
Micro-nano plastic pollution is a global problem that has generated great interest among scientists and attracted public attention because of the potential health risks associated with exposure to MP/NPs through air [1], water [2, 3], and food [4, 5]. In the past years, we have seen an increase in the number of scientific works regarding the topic with the declared purpose of understanding the mechanisms underlying pathological manifestations in various organs, through the study of toxicity on cells and tissues to extrapolate risks to mammals [6, 7]. This is a very complex topic due to the difficulty involved in analyzing the effects of various types of plastic. In fact, plastic particles discharged into the environment are often contaminated with different chemical pollutants [8, 9] and other contaminants [10; 11; 12; 13], including pathogens [14]. In this regard, in fact, some authors argue that microplastics can act as a vector to convey pathogens from the environment to organisms [15; 16]. Therefore, adverse effects of microplastics and nano plastics may result from a combination of intrinsic toxicity of plastics and ability to absorb, concentrate, and release environmental pollutants into living organisms [17]. In addition, it has become well documented that the different particles sizes exert effects through different physiological pathways, in relation to quantity and quality in different species at different developmental stage and in different tissues [18]. Micro plastics are small synthetic solid particles mostly composed of blends of polymers and functional additives with different chemical compositions, shapes, colors, sizes, and densities. The European Food Safety Authority (EFSA) [19] defined \"micro plastics\" all plastic particles having a diameter < 5 mm. MPs including nano plastics (NPs), which are particles with dimensions below 0.1 \(\upmu\)m (1-100 nm) [20]. They are classified as primary and secondary based on their origin. Primary micro plastics are any plastic particles that are directly released into the environment. These include microfibers, fragments, microbeads, and plastic pellets. Secondary micro plastics, on the contrary, originate from the degradation of larger-sized plastic products once exposed to the marine environment with regular or irregular shape [21]. They are derived from abrasion, mechanical wear as a wave action, photo oxidation and biological degradation of small pieces of plastic [22; 23]. MP/NPs, once released into the environment do not degrade and therefore accumulate in aquatic organisms entering the food chain until they are ingested by humans through food. MPs/NPs acute toxicity are correlated with plastic size [24], concentration [25], and cellular/tissue uptake and accumulation [26]. In general, small size, high dose, and the presence of toxic additives or pollutants in the micro/nano plastics appear to induce cellular toxicity [27]. In fact, small sizes of the microplastics enhance their translocation across the biological membranes with various effects on aquatic organisms via endocytosis-like mechanisms resulting in internalization into cells and tissues with potential adverse consequences on health [20]. In contrast, particles larger than 100 \(\upmu\)m do not have any effect [28; 29]. In terrestrial vertebrates, the main entry route of microplastics into the body, is the digestive pathway through food and water with pathological changes consisting of gut barrier dysfunction, intestinal inflammation, and gut micro biota dysbiosis [30; 31; 32; 33]. In fishes, the absorption routes are various, beyond the digestive way, absorption occurs through the gills and the skin. Therefore, scientists started to document the effects of microplastics on fish [34] and the signs of toxicity observed in these animals are, chain can be illustrated [35].