## 3 Result Statements from the Analysis of the Available Literature
### Joint Effects of Microl plastics and Micropolutants  
The extent of the accumulation of micro-pollutants by sorption onto microplastics not only affects their bioaccumulation in aquatic organisms but also influences their bioavailability and toxicity [112, 113]. The bioavailability of micro-pollutants is a measure of their accessibility to biota in the environment, and it is one of the key factors controlling the uptake of the micro-pollutants adsorbed on microplastics in the bodies of organisms, the transfer of these micro-pollutants, and the magnitude of the toxic effects on exposed organisms [114]. In addition to sorption, biomolecular corona formation, the entrapment of micro-pollutants in flocs, and aggregates of microplastics can cause further alteration of their bioavailability, resulting in altered toxicity, particularly antagonistic effects, in affected organisms [88, 115]. Different interactive toxic effects occurring in the mixtures of microplastics and micro-pollutants in organisms were observed (additive, synergistic, antagonistic, and potentiating), dependent both on the chemical combination and the measured endpoint [115]. An additive effect is generally considered as the interaction in which two or more chemicals or actions used in combination produce a total effect equal to the sum of the individual effects [116], indicating no direct connection between the two substances or actions, and defined as non-interaction or inertism [117]. Deviations from the additive effect can be synergistic or antagonistic [116]. Synergistic interaction between chemicals is indicated by a significantly stronger observed effect of the chemical mixture than that predicted from a single chemical, whereas an antagonistic interaction is indicated by a significantly weaker effect of a mixture than that expected from a single compound [116]. Similar to the synergistic effect, a potentiating effect occurs when the combined effects of two or more chemicals are significantly greater than the sum of the effects of individual chemicals. In addition, potentiation also includes a situation where a chemical that typically has no observed effects per se could enhance the effects of another chemical, leading to an increase in the observed effects of the second chemical [118]. The combination of microplastics and micro-pollutants can exhibit distinct effects under varying conditions and endpoints. The additive effect on oxidative stress and cellular damage was reported in the gills of _Dicentrachus labrax_ juveniles exposed to a combination of microplastics and mercury at a low concentration. However, different tissues with different physiologic systems and  
Figure 2: Factors influencing the bioaccumulation of micropollutants in an organism from exposure to microplastics as a vector. functions show heterogeneity in response to the same chemical exposure, and in this study, synergistic effects could be observed in hepatic tissue [119]. Likewise, the diverse effects from the exposure to florfenicol and microplastic mixtures in different concentrations could be detected in _Corbicula fluminen_. Additive, synergistic, and potentiating effects, i.e., the inhibition of acetylcholinesterase (AChE) activity, the inhibition of feeding, and the reduction of isocitrate dehydrogenase (IDH) activity, respectively, were documented. Furthermore, the toxic synergism of the mixtures was observed in the increase in gill glutathione S-transferase (GST) activity and the foot lipid peroxidation (LPO) level in _C. fluminen_[120]. The chemistry of functional groups in microplastics influences their micro-pollutant sorption capacity, which in turn affects the bioavailability and toxicity of micro-pollutants and implicitly links the altered functional groups of microplastics with changes in micro-pollutant bioavailability and toxicity.