The high degree of integration between cities has made urban agglomerations one of the key carriers of global economic development. However, the rapid economic growth; industrial restructuring; and subsequent adoption of new technologies, materials, and products, coupled with high-intensity human activities in urban agglomerations, have led to increasingly serious issues of environmental emissions and the accumulation of contaminants of emerging concern (CECs). The complexity, diversity, migration, transformation, accumulation, and ecological risks of CECs in surface environments have made them a central scientific issue in surface environmental process research. This article systematically elaborates on the spatiotemporal differentiation characteristics and migration mechanisms of CECs in urban agglomerations across multimedia, summarizes research progress on the source emissions and contributions of CECs in urban agglomerations at home and abroad, reviews the models of multimedia fate of CECs in urban agglomerations and the methods for ecological health risk assessment, discusses the shortcomings of research on CEC contamination in urban agglomerations, and proposes key scientific issues that need to be addressed in future research.
Micro- and nanoplastics (M-NPs) are ubiquitous in the natural environment and have become a topic of concern. However, due to the lack of key data on human exposure to M-NPs, our understanding of the potential health risks posed by the entry of M-NPs into the human body is still limited. Current research indicates that M-NPs are commonly found in various parts of the human body. However, the experimental analysis techniques for M-NPs in the human body have not yet been standardized, with the main differences lying in sample pretreatment and detection methods. This increases the difficulty of conducting systematic research on the distribution, transfer, accumulation, and excretion of M-NPs in the human body. In addition, the study of nanoplastics (< 1 μm) still faces insurmountable technical obstacles. The experimental research results of M-NPs standard samples, although instructive, do not fully reflect the exposure risks of M-NPs in the real environment, and thus, do not have universal scientific significance. This review aims to provide direction for the standardization of experimental analysis and risk assessment for M-NPs in the human body.
This article reviews the advancements in bio-tracking and imaging techniques for microplastics (MPs). Currently, fluorescent labeling, metal labeling, and isotope labeling are commonly employed, with fluorescent tracers being the most widely used method. Hyperspectral imaging, surface-enhanced Raman imaging, and polarized light imaging are also used due to the spectral characteristics of plastics. Combined with high-resolution imaging technology, tissue clearing made it possible to visualize three-dimensional (3D) imaging, providing a new perspective for in-depth research on the biological effects of MPs. Using various tracking technologies and imaging methods combined with 3D processing and analysis software will elucidate the distribution of microplastics in different organs and even individual organisms in the future. This comprehensive analysis method is expected to provide a stronger scientific foundation for the environmental risk assessment and management of MPs.
The detection method for perfluorinated compounds (PFASs) and the sample pretreatment process for complex environments were optimized using solid-phase extraction in conjunction with ultra-high performance liquid chromatography–tandem mass spectrometry. This optimized method allowed concurrent extraction and identification of 41 PFASs in diverse environmental matrices. Optimal ion pairs and mass spectrometry parameters for the targets were determined through manual tuning of single standards for instrument optimization. The optimal chromatographic mobile phase was identified as a combination of 2 mmol/L ammonium acetate solution and methanol. Higher recovery rates and shorter extraction times compared to accelerated solvent extraction in the context of sample extraction and purification were found for ultrasonic extraction of solid samples at 30°C for 10 minutes. The use of a parallel quantitative concentrator for nitrogen evaporation resulted in an average recovery rate of 104.3%, with a process time half as long as the time required for the traditional water bath method. The average recovery rates were 108.2% and 105.5% when using 2 mmol/L ammonium acetate solution (pH = 3) and 1 mL of 0.5% ammonia methanol solution for solid-phase extraction column elution and washing, respectively. The optimized method was applied to actual samples (soil, sediment, and water), achieving detection limits of 0.01 ~ 0.34 ng, matrix spiking recovery rates of 67.9% ~ 174.9%, and relative standard deviations for parallel samples of 0.03% ~ 28.10%. Overall, the optimized sample preparation method is more time- and solvent-efficient than previous methods, offers better sensitivity and recovery rates, and thus provides a solid technical foundation for large-scale environmental sample detection.
This study utilized comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-TOFMS) to perform a non-targeted qualitative analysis of organic compounds in farmland soils (n = 8) near roads of varying grades in Shanghai. After applying blank filtering and spectral library matching with a similarity threshold in excess of 700, more than 1000 mass spectrum peaks were identified across all samples, with 275 ~ 341 compounds exhibiting an retention index (RI) deviation within ±2% of the library values. Sixty-six organic compounds were found consistently at each sampling location, with the most prevalent being polycyclic aromatic hydrocarbons, phthalates, phenols, thiophenes, and tetrachloroethanes, all of which had notably high signal-to-noise ratios. Fisher ratio (FR) analysis identified 29 compounds with marked differences across road grades, with FR values ranging from 22.6 to 60.3, which were derived primarily from chemical products, biomedicine, and personal care items. These discrepancies were likely attributable to local industrial activities, sewage irrigation practices, and residential emissions. Elemental composition analysis indicated that CHO and CH were the predominant constituents of the detected organic compounds, representing 39.9% ~ 59.1% and 30.2% ~ 45.8% of the total peak area, respectively. Additional classification of anthropogenic contaminants highlighted alkanes, polycyclic aromatic hydrocarbons, and phthalates as the primary pollutants in high concentrations within the roadside farmland soils of Shanghai. This indicated that impacts on roadside farmland soil quality from emissions from traffic sources, such as gasoline and diesel combustion, tire wear, and lubricant evaporation and leakage, cannot be ignored. In summary, the application of comprehensive two-dimensional technology enabled precise qualitative screening of numerous previously overlooked organic contaminants in farmland soils, offering a scientific foundation for future environmental management strategies.
中国综合性科技类核心期刊(北大核心)
