Combined toxicity of micro/nanoplastics loaded with environmental pollutants to organisms and cells: Role, effects, and mechanism

• Published in: Environment international 2023-01, Vol.171, p.107711, Article 107711
• Main Authors: Sun, Ning, Shi, Huijian, Li, Xiangxiang, Gao, Canzhu, Liu, Rutao
• Format: Article
• Language: English
• Subjects: Combined toxicity; Cytotoxic mechanism; Environmental pollutant; Environmental Pollutants - toxicity; Environmental Pollution; Human health; Humans; Micro/nanoplastics; Microplastics - toxicity; Plastics - toxicity; Water Pollutants, Chemical - analysis
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2022.107711

[Display omitted] •Adsorption mechanism is introduced to the discussion of compound toxic effects.•MPs/NPs increase the bioavailability of environmental pollutants through adsorption.•The concentration of MPs/NPs can affect combined toxicity by affecting the adsorption.•The pollutants carried by MPs/NPs are more likely to trigger cancer risk than the MPs/NPs itself.•The PAHs adsorbed by nanoplastics can desorb and cause cellular oxidative stress. Micro/nanoplastics (MPs/NPs) are ubiquitous in the environment and living organisms have been exposed to these substances for a long time. When MPs/NPs enter different organisms, they transport various pollutants, including heavy metals, persistent organic pollutants, drugs, bacteria, and viruses, from the environment. On this basis, this paper summarizes the combined toxicity induced by MPs/NPs accumulating contaminants from the environment and entering organisms through a systematic review of 162 articles. Moreover, the factors influencing toxic interactions are critically discussed, thus highlighting the dominant role of the relative concentrations of contaminants in the combined toxic effects. Furthermore, for the first time, we describe the threats posed by MPs/NPs combined with other pollutants to human health, as well as their cytotoxic behavior and mechanism. We found that the “Trojan horse” effect of nanoplastics can increase the bioaccessibility of environmental pollutants, thus increasing the carcinogenic risk to humans. Simultaneously, the complex pollutants entering the cells are observed to be constantly dissociated due to the transport of lysosomes. However, current research on the intracellular release of MP/NP-loaded pollutants is relatively poor, which hinders the accurate in vivo toxicity assessment of combined pollutants. Based on the findings of our critical review, we recommend analyzing the toxic effects by clarifying the dose relationship of each component pollutant in cells, which is challenging yet crucial to exploring the toxic mechanism of combined pollution. In the future, our findings can contribute to establishing a system modeling the complete load-translocation toxicological mechanism of MP/NP-based composite pollutants.