Jianjiang Lu

As a widespread emerging pollutant, microplastics (MPs) have become one of the most significant threats to global ecosystems. Bosten Lake, the largest inland freshwater lake in China, represents a typical lake in an arid zone. To provide a theoretical basis for MPs pollution control in such regions, this study systematically investigated the characteristics, distribution, and ecological risks of MPs in Bosten Lake. Results show that MPs were widely present in the lake, with abundances in surface water ranging from 1.33 to 9.43 n/L (mean: 4.8 ± 1.78 n/L) and in sediments ranging from 151.55 to 953.31 n/kg dry weight (dw) (mean: 479.11 ± 210.22 n/kg), suggesting the presence of certain levels of pollution when compared to domestic and international studies. White (54.09 ± 5.14%) and black (30.07 ± 4.28%) MPs dominated, with fibers and fragments comprising over 70% of the forms. Polypropylene particles (0.1–0.5 mm) were the predominant type. Potential sources include residential activities, tourism, agriculture, and fisheries. Seasonal variations were observed in ecological risk, with the potential ecological risk index indicating an overall high-risk level. These findings highlight the need for dynamic management strategies for Bosten Lake and provide a scientific basis for monitoring MPs and assessing their ecological impacts in arid lake environments.

As emerging global contaminants, microplastics (MPs)’ environmental fate and risks have expanded from marine to freshwater systems, yet semi-closed arid lakes remain understudied. This study systematically evaluates MPs pollution in Bosten Lake, revealing abundances of 1.33–9.43 n/L (surface water) and 151.55–953.31 n/kg (sediments) with pronounced spatiotemporal heterogeneity. Spatial hotspots correlated with functional zones: pastoral (B8), transportation (B2, B10), and tourism areas (B11, B12) were primary sources, driven by agricultural plastics, tire wear particles, and tourism debris. Temporally, dry season MPs in water increased by 32.4% due to prolonged hydraulic retention. White (54.09%) and black (30.07%) are the dominant components of MPs in Lake Bosten, with 0.1–0.5 mm, fibrous polypropylene MPs being the most common. Ecological Risk Index (RI) showed seasonal divergence: 92.3% of wet season sediment sites exhibited extreme risks (RI > 1000, e.g., inflow area B13), while dry season RI declined to moderate levels (e.g., B8 decreased from 1335.13 to 188.22) via reduced terrestrial inputs and degradation. This highlights dual “hydrological-anthropogenic” drivers, necessitating dynamic controls during tourism peaks, fishing, and traffic surges to mitigate MPs risks in arid closed-basin lakes.

This study investigates the microregulatory mechanisms governing seasonal variations in particle-bound organic nitrates (PBONs) accumulation on pine needle surfaces. Using scanning electron microscopy, atomic force microscopy, and high-resolution mass spectrometry across five sites in the Changbai Mountain Nature Reserve, we revealed that seasonal transformations in epicuticular wax properties directly control PBON retention. Winter conditions produced maximum wax thickness (5.82 ± 0.47 μm) and PBON concentrations (142.6 ± 18.3 ng/g), while summer showed minimums for both (2.73 ± 0.55 μm; 56.4 ± 9.7 ng/g). We identified temperature as the dominant environmental factor (r = −0.81) with a previously unreported threshold effect at 4.8 ℃, below which PBON accumulation rates accelerate significantly. Structural equation modeling revealed that seasonal conditions influence PBON accumulation through both direct atmospheric pathways and surface-mediated mechanisms. The findings demonstrate that microstructural changes in sampling surfaces are crucial for interpreting seasonal biomonitoring data and understanding pollutant dynamics in forest ecosystems.

PM_2.5 in the air can adsorb a wide range of substances, and due to their small size, they can carry toxic and hazardous substances into the human body through inhalation, which can be harmful to human health. PM_2.5 samples were collected in Shihezi for one year from September 2021 to August 2022 to characterise the distribution of 13 metallic elements in PM_2.5 and their potential sources. The findings revealed that the concentrations of PM_2.5 surpassed the national threshold of 35 μg/m³, alongside elevated levels of crustal elements. To assess the potential sources of the 13 metallic elements, present in PM_2.5, a comprehensive analysis was conducted utilizing Enrichment Factor analysis, principal component analysis (PCA), and Backward Trajectory Modelling. The Enrichment Factors analysis revealed that five elements were significantly influenced by anthropogenic activities, with cadmium exhibiting particularly high levels of enrichment. PCA indicated that the metal elements were predominantly sourced from coal combustion, vehicular emissions, dust, fossil fuel combustion and industrial activities. Backward trajectory cluster analysis demonstrated that pollutant concentrations are substantially affected by both long-range transport mechanisms and localized anthropogenic sources. The assessment of health risks associated with metallic elements suggests a low risk to human health. These findings offer a crucial scientific foundation for air pollution management strategies in the SHZ region.