环境纳米塑料研究进展

Microplastics are emerging pollutants and have become a significant topic in environmental science globally. In recent years, nanoplastics with smaller sizes than microplastics have gained more attention as a distinct area of research. Nanoplastics contain unique physical and chemical properties that differ from microplastics and artificial nanomaterials. When we analyze the environmental behavior of nanoplastics or attempt to extract them from environmental media, it is crucial to consider not only the sizes of these particles but also their multiple physicochemical properties. The polymer components of environmental nanoplastics can be analyzed via spectroscopy and mass spectrometry. Spectroscopy can provide surface information but lacks representative samples. Meanwhile, mass spectrometry can provide mass concentration of environmental nanoplastics but limited polymer type. Although global research on analytical methods for nanoplastics started early, there is still an urgent need to improve the reliability and effectiveness of analyzing environmental samples. Future research should effectively combine the advantages of these two methods. Improvements in analytical techniques are for strengthening our understanding of the fundamental properties and environmental behavior of nanoplastics. For instance, many laboratory exposure experiments do not accurately mimic real-world environments involving high concentrations of polystyrene spheres. Therefore, inferring the impacts on nanoplastics from studies of a single nanomaterial requires careful consideration. The toxicity mechanisms of nanoplastics mostly follow the research ideas of organic chemical pollutants, such as selecting oxidative stress, neurotoxicity and reproductive toxicity as main endpoints. But once similar toxic endpoints are selected, researchers may ignore the environmental behavior of nanoplastics and their interaction with organisms. Compared with microplastics, commercially synthesized spherical polystyrene and widely studied nanomaterials, nanoplastics are more unstable with rougher surfaces and larger specific surface areas. These characteristics play a key role in the environmental behavior and toxicological effects of environmental nanoplastics on other coexisting pollutants. Future toxicity testing studies should strive to simulate the morphological characteristics and exposure environments of nanoplastics as closely as possible. Research methods should be developed to examine the interaction processes between nanoplastics and organisms, covering comprehensive ecotoxicological indices. For instance, the particle properties, chemical leachate, and composite effects need to be highlighted to explore the biological effects and corresponding mechanisms of nanoplastics. Meanwhile, in addition to experimental exploration, emerging technologies such as artificial intelligence, machine learning, and computational toxicology have great application potential in the prediction of nanoplastic environmental behavior, analysis of toxicity mechanisms, and ecological risk assessment. This will also provide new ideas and methodological support for future environmental nanoplastic research. Recently, an increasing number of studies have documented the presence of nanoplastics in human organs and tissues. A potential association between nanoplastics and human illnesses has also been reported. These findings represent significant milestones in establishing a link between nanoplastics and human health, encouraging further research into the potential health risks posed by nanoplastics. However, people should treat these findings with great caution because of doubts regarding the reproducibility of the test populations, low sample size, and potential external contamination. Previous studies were inadequate in demonstrating the causal relationship between the presence of nanoplastics and adverse health outcomes in patients. Hence, it is necessary to conduct further research on the distribution of nanoplastics in the environment, biological and human samples and corresponding ecotoxicity effects. This shift marks the beginning of a new “nano era” in studying plastic pollution at the nanoscale level. If future studies confirm the widespread presence of nanoplastics in humans and their significant association with diseases, the health risks posed by nanoplastics could exceed current predictions, thus requiring the implementation of stricter regulations to effectively address and manage plastic pollution.