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 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.

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.

This study determined concentrations of more than twenty organophosphate ester (OPE) congeners in road dust samples collected from urban/suburb, agricultural, and forest regions in Hangzhou, and elucidated their spatial trends. Tris (1-chloro-2-propyl) phosphate was the predominant congener. Additionally, significant regional-specific variations in the dust-associated OPE residues were observed. High OPE concentrations were generally found in the road dust sampled from sites with high human population densities and adjacent to trunk roads, highlighting the substantial contributions of anthropogenic activities and vehicular emission to the OPE burdens. Moreover, the OPE exposure rate for the local cohorts via ingestion of and dermal contact with road dust was estimated. The estimated values of OPE exposure were at least 3-4 orders of magnitude lower than the documented reference doses, suggesting that the associated health risks to Hangzhou residents were negligible.

The presence of a variety of environmental contaminants in the soils of steelworks seriously threatens the safety of urban soil and groundwater. Emerging pollutants in deep soils, such as antibiotics and antibiotic resistance genes (ARGs), have not been studied extensively and require timely monitoring and treatment. In this study, the Mingfang Iron and Steel Plant in Handan, Hebei Province, was selected as the research area, and three 4-meter soil columns were collected. The contents of 17 antibiotics in four categories (sulfonamides, fluoroquinolones, macrolides, and tetracyclines) were detected by ultra-performance liquid chromatography-tandem mass spectrometry. The types and abundances of ARGs in the soil at different depths were investigated by metagenomic sequencing. The results showed that the total antibiotic concentrations ranged from 2593.2 to 4279.5 ng/g, among which sulfonamide antibiotics (SAs) were 166.1 to 1103.8 ng/g, fluoroquinolone antibiotics (FQs) were 993.3 to 1330.4 ng/g, macrolide antibiotics (MLs) ranged from 4.0 to 104.8 ng/g, and tetracycline antibiotics (TCs) ranged from 1269.5 to 2077.6 ng/g, with mild to moderate levels of contamination. Soil profile analysis demonstrated that the percentage of SAs were higher in the topsoils (0—150 cm) than in the deep soils (150—400 cm). Contrastingly, MLs accumulated more in deep soils (350—400 cm). The percentages of TCs and FQs were higher in all soil layers and they were the main antibiotic classes detected. The abundance of ARGs corresponding to the four classes of antibiotics decreased with increasing soil depth. The relative abundance of macrolide ARGs was the highest, with the read number of the detected sequences ranging from 0.92 × 10⁵ to 1.44 × 10⁵. The statistical chart of species contributions indicated that Actinobacteria made the greatest contribution to the abundance of ARGs in all four major categories. In conclusion, this study revealed the distribution and migration characteristics of antibiotics in the site soils. Deep soil pollution by ARGs is a matter of concern as it may lead to groundwater contamination and the increased distribution of antibiotic-resistant bacteria.

Estuaries are important convergence areas of antibiotic resistance genes (ARGs), but the geographical pattern and main drivers of ARGs in estuarine environments are poorly understood. Therefore, high-throughput quantitative polymerase chain reaction (HT-qPCR) was used to study the prevalence of ARGs in 16 estuaries of China in dry and wet seasons, and statistical analysis was utilized to reveal the influence of various factors on the prevalence of ARGs. The results showed that the abundance of ARGs was higher in the dry season than the wet season, and the abundance of ARGs increased with latitude. Human activities, mobile genetic elements, gut microbes, antibiotic concentrations, physicochemical properties, and climate variables had significant effects on the prevalence of ARGs. Climate variables and human activities had the most significant influence on ARGs. The most important climate variable affecting ARGs was temperature, with an increasing temperature reducing the abundance of ARGs. This study confirmed that human activities and climate factors jointly drive the changes in ARG abundance in estuaries. These findings provide a basis for the development of control policies for ARGs in the context of climate change and socio-economic development in the future.

This research investigated multi-media occurrences of organophosphate esters (OPEs) in sediments, surface and bottom water sampled from the Yangtze River Estuary, and elucidated their spatio-vertical trends and partitioning behavior across typical aquatic interfaces. Additionally, we determined the key factors affecting the estuarine fate of OPEs and the associated environmental implications. Various OPEs were ubiquitous in the study region, and the peak water-borne residues were often found adjacent to the sites with more intense anthropogenic activities. Moreover, the estuarine hydrodynamic features also increased the OPE burden in water and sediments at the outlet of the Yangtze River. The moderate-to-high ecological risks suggested by risk quotients were mainly generated by tris(2-ethylhexyl) phosphate and bisphenol A-bis(diphenyl) phosphate. The annual fluxes via the water flow and sediment deposition of the Yangtze River towards the East China Sea were predicted to be approximately 150 t and 290 kg, respectively, rivalling or exceeding those reported for many well-studied organic contaminants. Our results highlight the prevalence and abundance of OPEs in a representative urbanized estuary in China and the substantial ecological risks they pose to aquatic ecosystems.

The occurrence of microplastics (MPs) during anaerobic and aerobic treatment processes of kitchen waste was investigated using case studies from the prominent waste treatment facilities of Shanghai Liming Resources Recycling Co., Ltd. and Shanghai Wenxin Biotechnology Co., Ltd. The presence of MPs in the resulting organic fertilizers and the agricultural soils fertilized with these products were further tracked to reveal the pollution characteristics and environmental fate of MPs. Results showed that MPs were present in both anaerobic and aerobic kitchen waste treatment processes, primarily as transparent or black fibers under 1 mm in size and composed predominantly of polyethylene terephthalate (PET) or Rayon. Before anaerobic treatment, the average abundance of MPs in the samples ranged from 40.0 to 546.7 items/kg, whereas, after treatment, the average abundance of MPs in the biogas slurry and biogas residue decreased significantly by 75.53% and 54.41%, respectively. The average abundance of MPs in waste and rice husks before aerobic treatment ranged from 53.3 to 493.3 items/kg and 66.7 to 566.7 items/kg, respectively, whereas, that in organic fertilizers was increased by 46.84%. The average abundance of MPs in the soil with organic fertilizers was (176.7 ± 34.8) items/kg, which was 137% higher than that of the soil without organic fertilizers. These results indicate that MPs can be produced in the process of municipal food waste treatment, and the pollution of soil MPs can be exacerbated through organic fertilizers.

In this study, a coupled Weather Research and Forecasting-Community Multiscale Air Quality (WRF-CMAQ) model was developed to analyze the atmospheric transport of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in the megacity of Shanghai, and the population’s exposure to them. The results showed that 69.88% of the simulated values are within 0.5 to 2 times the observed values, indicating good accuracy. In 2019, the highest PCDD/Fs pollution levels in Shanghai’s atmosphere were observed in winter, followed by fall and spring. The lowest levels occurred in summer, with respective mass concentrations of 847.08, 629.53, 588.38, and 406.96 fg/m³ and respective TEQ concentrations of 59.29, 44.46, 40.80, and 28.08 fg I-TEQ/m³. The areas most polluted with atmospheric PCDD/Fs were Yangzi, Yangzhou, and Shanghai. Fs were found in Yangpu, Hongkou, Huangpu, Jing'an, Baoshan, Jinshan, and Songjiang. The respiratory exposure of Shanghai residents to PCDD/Fs followed the trend of adolescents > elderly > middle-aged people, with 10.67, 8.86, and 8.47 fg I-TEQ/(kg·d), and the risk of exposure was within the acceptable range. The contribution of local emission sources is much larger than that of foreign emission sources, indicating that local industrial production processes and combustion activities mainly cause atmospheric PCDD/Fs pollution in Shanghai.

As the ultimate destination of antibiotics in rivers, the mechanism and change law of migration from rivers to oceans have not been fully and systematically studied. In this study, surface water samples were collected in the Yangtze River Estuary and its offshore areas in the wet season and dry season of 2023. Solid-phase extraction and high performance liquid chromatography-mass spectrometry were used to identify 20 antibiotics in five categories. This analysis was conducted to assess the concentrations, temporal and spatial distribution, and potential ecological risks. The results showed that the concentrations of 20 antibiotics ranged from not detected ~ 63.32 ng·L^–1, and showed a decreasing trend from inland to marine areas from the mouth-adjacent section (average 108 ng·L^–1) to the estuary section (average 50 ng·L^–1), to the coastal section outside the mouth (average 40 ng·L^–1), and the coastal area (average 29 ng·L^–1). The concentrations of the five types of antibiotics from high to low were chloramphenicols > macrolides > sulfonamides > quinolones > tetracyclines. The categories and amount of detected antibiotics showed significant seasonal differences. The seasonal-change pattern showed that the ML concentration season was significantly higher in the dry than the wet season, while the concentrations of TCs were significantly higher in the wet season than the dry season. Antibiotics, such as Sulfamethoxazole, Ciprofloxacin, Chlortetracycline, Erythromycin, Chloramphenicol, Ofloxacin, posed a significant threat to the water in the study area, and the ecological risks should not be overlooked.

This article provides a review of the impacts and potential ecological risks of antibiotics and resistance genes in livestock and poultry farming environments. Through systematic research on the relevant literature, the use of antibiotics in livestock and poultry farming in different regions was summarized. The study found that the residual concentrations of antibiotics and resistance genes in soil after returning livestock and poultry manure to the field varied due to factors such as manure type, region, farm scale, and management measures. Moreover, the migration and transformation of antibiotics and resistance genes in soil are influenced by the soil type and fertilization methods. This study specifically explored the impact of the spreading of resistance genes through mechanisms such as horizontal gene diffusion by soil microorganisms and systematically elucidated the ecological risks of antibiotics and resistance genes. Finally, based on the current pollution situation of returning livestock manure to the field, a summary and outlook on reducing the accumulation and diffusion of antibiotics and resistance genes in the environment were prepared. The work is expected to provide strong support for a comprehensive understanding of the environmental impacts and ecological risks of antibiotics and resistance genes in livestock and poultry farming.

The contents of halogenated flame retardants (HFRs) in 31 surface soil samples collected from different areas of Hefei City were measured by gas chromatography-mass spectrometry. Their composition characteristics, spatial distribution, and sources were explored. The results showed that the mean concentrations of ∑₂₃PBDEs, ∑₂₂ABFRs, and ∑₁₁DECs in the surface soils of Hefei City were (6.490 ± 13.221), (26.375 ± 101.928), and (0.815 ± 0.760) ng/g, respectively. DBDPE is the main homologue among alternative flame retardants, accounting for 84.4%. In terms of spatial distribution, the hotspots of HFRs were mostly located in manufacturing concentrated areas, such as urban development zones and high-tech zones. Source analysis revealed that the use of commercial polybrominated diphenyl ethers and alternative flame retardants in the study area were the main emission sources, followed by the production, transportation, and environmental degradation process of HFRs. Non-carcinogenic risk assessment was carried out based on hazard index method. The results showed that the non-carcinogenic risk index of the target objects in the study area were less than 1, which were within the acceptable range, indicating that there was no non-carcinogenic risk.

The spatial distribution characteristics and potential health risks of hexabromocyclododecane (HBCD) in 34 farmland soils in Shanghai were investigated using the variance analysis and hazard quotient (HQ) methods. Three HBCD homologs (α-, β- and γ-HBCD) were detected in all samples. The total concentration of HBCD (∑HBCDs) ranged from 0.30 to 25.4 ng/g, with an average value of 1.78 ng/g. The ∑HBCDs in agricultural soils exhibited significant spatial variation, of which Baoshan District and Jiading District had notably higher average ∑HBCDs compared to other areas (p < 0.05). It was concluded that HBCDs mainly originated from the combined influence of industrial and vehicular emissions. The proportions of α-, β- and γ-HBCD in Shanghai agricultural soils were 2.90% ~ 73.4%, 5.23% ~ 63.8%, and 6.95% ~ 85.5%, respectively. The proportion of γ-HBCD was lower in 91.2% of the sampling sites than in commercial products, indicating the presence of isomeric interconversion. Daily exposure to ∑HBCDs, combining oral and dermal ingestion, ranged from 3.17 × 10^–4 to 1.57 × 10^–1 ng/(kg·d), peaking in infants. Oral ingestion contributed more to daily exposure than dermal contact across age groups. The HQs indicated that the current HBCD concentrations posed a minimal risk to all populations.

Rivers serve as the primary corridors for transporting plastics to the sea. To understand the sources, pathways, and fate of plastic pollution, this paper provides an inductive analysis and computational optimization of plastic flux into rivers. Additionally, given the limited research on ultraviolet (UV) absorbers in plastics and the absence of quantitative data on UV absorbers leaching from plastics into rivers, this paper synthesizes and refines methods for calculating plastic riverine fluxes. It also proposes an equation for estimating the transport flux of UV absorbers through river systems. The results showed that the Rhine River in Europe has the highest mass flux of total plastics (including both microplastics and macroplastics), followed by the Ganges River in India. Among the five commonly studied types of UV absorbers, benzotriazole UV absorbers (213.40 kg/a) and benzophenone UV absorbers (192.95 kg/a) exhibited the highest riverine fluxes. Predictions based on a biotoxicity model indicated that benzotriazoles have significant potential biotoxicity, highlighting the need for further studies on their environmental behavior, fate, and ecological impacts. This paper aims to summarize and analyze global plastic associated UV absorbers fluxes into rivers, providing a foundation for developing effective prevention and control strategies to address UV absorber pollution and protect aquatic ecosystem health.