Figure 3.

Summary of the effects of nanoplastics (NPs) on aquatic species, their toxicity in response to the interactions with organismal and environmental parameters, and main research gaps in the field. (Left panel): NPs may accumulate in tissues related to key physiological systems, triggering a cascade of molecular, biochemical, cellular, and physiological processes that can explain many of the observed or predicted ecologically relevant adverse outcomes of NPs. This chain of events may be broken down into seven modes of action (MoAs, please see Section 3.2 for further clarification): (i) organismal fitness, (ii) circulatory and respiratory systems, (iii) behavioral, sensory, and neuromuscular function, (iv) alimentary and excretory systems, (v) microbiome, (vi) metabolism, and (vii) immune system [42]. (Center panel): differences in NPs’ properties and exposure pathways, whether caused by environmental conditions or not, might result in altered behavior, fate, uptake, sorption to pollutants or microorganisms, hydrophobicity, or the formation of reactive oxygen species (ROS). (Right panel): examples of research gaps that may indicate future directions to consider in the field of NPs ecotoxicity (please see Section 4 for clarification). Organs are shown as corresponding to mammalian species for purposes of visualization.