Microplastics sampling methods and standardization requirements in atmospheric environment—a critical review

The widespread use of plastics has greatly improved people's daily lives, but at the same time, it has also brought serious environmental challenges. Microplastics (MPs) pose a serious threat to ecosystems and human health due to their potential toxicity and ability to carry other pollutants. Especially MPs suspended in the atmosphere, which humans continuously inhale during daily breathing. The atmosphere, as an important link in the Earth's ecosystem, plays a crucial role in the global spread of MPs. Therefore, the research on atmospheric MPs has become a hot topic of global concern. Researchers used passive or active sampling methods to obtain atmospheric MPs samples, but there were significant differences in the sampling details among various studies. The inconsistency of sampling strategies and the non standardized sampling process limit the comparability and credibility of relevant research data. This review reviews the development history of atmospheric MPs and analyzes the sampling methods used to collect atmospheric MPs in 92 articles published between 2015 and 2023, including key factors such as sampling tools, time settings, sampling locations, sources, and intake flow rates. The focus was on comparing the advantages and disadvantages of different methods and evaluating the potential impact of the sampling process on the research results. To promote in-depth research on global atmospheric MPs pollution, it is urgent to establish standardized sampling methods to ensure the accuracy and comparability of data. Highlights Analyze and compare different sampling methods for atmospheric MPs. Establish a standardized sampling method for global atmospheric MPs. Non standardized sampling methods can affect the credibility and comparability of observation results. Summarize the current research status of global atmospheric MPs pollution. The atmosphere is the main transport pathway for MPs.