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.
中文核心期刊
