A total of 106 24-h PM₂.₅ aerosol samples were collected in an urban area (Shijiazhuang, SJZ) and a suburban area (Liulihe, LLH, Fangshan County, Beijing) in the Beijing-Tianjin-Hebei (BTH) region in 2 periods: the first is from 10 July to 10 August, which is before Sept. Third Parade (Period I); the second is from 20 Aug. to 6 Sept. 2015, which is during Sept. Third Parade (Period II). Polar organic tracers, including isoprene, α-pinene, β-caryophyllene and toluene oxidation products, as well as sugars and carboxylic acids were measured. In Period II, rigorous emission-reduction measures were taken in the BTH region. With the anthropogenic emission being cut down significantly, the average concentrations of isoprene, α-pinene, β-caryophyllene and toluene oxidation products and all carboxylic acids (except tetradecanoic, palmitic, and stearic acids), were lower in Period II than those in Period I in LLH, indicating that the SOA tracers were decreased with precursor emission volumes and yields in the atmosphere. Moreover, sugar compounds were shown with comparable levels during the two periods in LLH, suggesting that no measures were taken to reduce the intensities of the biogenic sources. On the contrary, tetradecanoic, palmitic, and stearic acids were shown with obviously higher concentrations in Period II than those in Period I, demonstrating that cooking fumes increased during Sept. Third Parade period.The positive matrix factorization (PMF) model combining with tracer-based method was applied to explore the sources of secondary organic carbon (SOC). It reveals that the sources of SOC include isoprene, α-pinene, β-caryophyllene and toluene oxidation products, fossil fuel combustion, cooking fumes and regionally transferred aged aerosols. These sources accounted for 11.3%, 9.0%, 15.5%, 10.9%, 29.2%, 2.9%, 21.1% of SOC for SJZ, and 12.7%, 11.2%, 9.7%, 14.4%, 25.3%, 0%, 26.7% of SOC for LLH, during the whole sampling periods respectively.

Facile modification is a common, but effective, option to improve the uptake removal capacity of of activated carbon (AC) against diverse target volatile organic compounds (VOCs; e.g., benzene) in gaseous streams. To help design the routes for such modification, this research built strategies to generate three types of modified ACs by incorporating amine/sulfur/amino-silane groups under solvothermal or microwave (MW) thermal conditions. The adsorption performance has been tested using a total of six types of AC sorbents (three modified + three pristine forms) for the capture of 1 Pa benzene (1 atm and 298 K). The obtained results are evaluated in relation to their textural properties and surface functionalities. Accordingly, the enhancement of AC surface basicity (e.g., point of zero charge (PZC) = 10.25), attained via the silylation process, is accompanied by the reduced adsorption of benzene (a weak base). In contrast, ACs amended with amine/sulfur (electron-donating) groups using the MW technique are found to acquire high surface acidity (PZC of 5.99–6.05) to exhibit significantly improved benzene capturing capability (relative to all others). Their uplifted performance is demonstrated in terms of key performance metrics such as breakthrough volume (BTV10%: 163 → 443 L g⁻¹), adsorption capacity (Q10%: 4.82 → 13.6 mg g⁻¹), and partition coefficient (PC10%: 0.516 → 1.67 mol kg⁻¹ Pa⁻¹). Based on the kinetic analysis, the overall adsorption process is found to be governed by pore diffusion as the main rate-determining step, along with surface interaction mechanisms. The results of this research clearly support the critical role of surface chemistry of AC adsorbents and their textural properties in upgrading air/gas purification systems.

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed rigorous restrictions, which resulted in great reductions in pollutant emissions. This study examines the characteristics of air pollutants, including PM₂.₅ (particles with aerodynamic diameters < 2.5 μm), gas pollutants, water-soluble ions (WSIs), black carbon (BC) and elements, as well as the source apportionment of PM₂.₅ in Suzhou before, during and after the Chinese New Year (CNY) holiday of 2020 (when China was under an unprecedented state of lockdown to restrict the COVID-19 outbreak). Compared to those before CNY, PM₂.₅, BC, SNA (sulfate, nitrate and ammonium), other ions, elements, and NO₂ and CO mass concentrations decreased by 9.9%–64.0% during CNY. The lockdown policy had strong (weak) effects on the diurnal variations in aerosol chemical compositions (gas pollutants). Compared to those before CNY, source concentrations and contributions of vehicle exhaust during CNY decreased by 72.9% and 21.7%, respectively. In contrast, increased contributions from coal combustion and industry were observed during CNY, which were recorded to be 2.9 and 1.7 times higher than those before CNY, respectively. This study highlights that the lockdown policy that was imposed in Suzhou during CNY not only reduced the mass concentrations of air pollutants but also modified their diurnal variations and the source contributions of PM₂.₅, which revealed the complex responses of PM₂.₅ sources to the rare, low emissions of anthropogenic pollutants that occurred during the COVID-19 lockdown.

Fish Embryo Acute Toxicity (FET) test was proposed as an alternative to the traditional test methods using larval or adult fish. However, whether fathead minnow (Pimephales promelas) embryo is appropriate for FET remains uncertain. In the present study, ecological threshold of toxicological concern (ecoTTC) values and uncertainty factors (UFs) for each Verhaar et al. category in P. promelas were identified by employing probabilistic ecological risk assessment (PERA) approach with chemical toxicity distributions (CTDs). The sensitivity among different life stages and toxicity among different mode of actions (MOAs) classes were comprehensively compared by CTD comparisons. The results showed that embryo exhibited the less or similar sensitivity compared to larva or adult for Verhaar et al. MOA classes (1-4) while adults were more sensitive, followed by embryo than larval for non-classified chemicals. Considering growth effect as endpoint to class 1, class 3, and non-classified chemicals on P. promelas embryo and larva was more sensitive than mortality. Non-classified chemicals especially inorganic compounds were most toxic to P. promelas embryo for the four concerned Verharr et al. MOA-specific chemical classes. This study also derived uncertainty factors (UFs) as 26.5 (9.8, 109) for embryo-to-larva, 6.26 (3.94, 11.0) for embryo-to-adult, 15.6 (10.1, 36.1) for mortality-to-growth, and 3.03 (1.86, 7.08) for mortality-to-reproduction, which can be applied for extrapolations of life stage-to-life stage and effect-to-effect to reduce the underestimating and overestimating risk by the use of default UF such as 10, 100 or 1000. Our findings are vital for feasibility of FET test of P. promelas for ecotoxicity testing and ecological risk assessment for chemicals with different MOAs.

Microplastics and nanoplastics are distributed in the environments universally. The interrelationship between vascular plants and micro/nanoplastics began to attract attention in recent years. Based on the relevant literatures collected from various databases, this review focuses on two topics: 1) the effect of vascular plants on the fate of micro/nanoplastics; 2) the effects of micro/nanoplastics on vascular plants. The review of the available studies reveals that vascular plants can act as sinks for microplastics and nanoplastics as their surfaces can adsorb these plastics; moreover, nanoplastics can be internalized by plants. Plastics on the surfaces and in the interiors of vascular plants can cause various phytotoxicity effects, including impacts on growth, photosynthesis, and oxidative stress. Furthermore, the results and mechanisms of phytotoxicity effects caused by microplastics or nanoplastics can be very different. However, knowledge gaps still exist in the relationships between micro/nanoplastics and vascular plants based on the analysis of available studies; thus, potential subjects for future studies were proposed, including the fates, analysis methods, influencing factors, mechanisms of phytotoxicity, and further influences of microplastics and nanoplastics in the vascular plant ecosystems. This study presents a review of micro/nanoplastics–vascular plant research and reaches a basis for future research.

During the last years, ingestion of microplastics (MPs) has been quantified in marine species both with an ecological and commercial interest at sea and under experimental conditions, highlighting the importance to assess MP ingestion in commercially and aquaculture important species such as gilthead seabream (Sparus aurata) fish. In order to study the ingestion of MPs in a commercially valuable species, gilthead seabreams were exposed to an enriched diet with virgin and weathered low-density polyethylene (LDPE) pellets for three months followed by a detoxification period of one month of no exposure to MP enriched diets. Our results indicate that MP ingestion in these fishes increased with exposure time, and differences were found between treatments, showing the highest ingestion values after three months of exposure to MP enriched diets and in the weathered treatment. However, after one month of detoxification, no MPs were found in the gastrointestinal tracts of fish, reflecting no long-term retention of MPs in Sparus aurata digestive system. According to results from this study, exposure of fish to MP enriched diets does not affect fish size neither the Fulton’s condition index as both parameters increased with time in all treatments (control, virgin and weathered). Both carbon and nitrogen isotopic signatures decreased with fish size in all treatments which could be related to an increase of nitrogen deposition efficiency in fish muscle with a high protein assimilation during the first months of Sparus aurata.

Pollution in soil by petroleum hydrocarbon has become a global environmental problem. The bioremediation of petroleum hydrocarbon-contaminated soil was enhanced with the combination of an isolated indigenous bacterial consortium and biosurfactant. The biodegradation efficiency of total petroleum hydrocarbon (TPH) was increased from 12.2% in the contaminated soil to 44.5% and 57.7% in isolated consortium and isolated consortium & 1.5 g sophorolipid (SL)/kg dry soil, respectively. The half-life of TPH degradation process was decreased from 32.5 d in the isolated consortium reactor to 20.4 d in the isolated consortium & 1.5 g SL/kg dry soil. The addition of biosurfactant into contaminated soils improved the TPH desorption from solid matrix to the aqueous solution and the subsequent solubilization, which ultimately improved the bioavailability of TPH in contaminated soils. Biosurfactant also served as carbon sources which contributed to the stimulation of cell growth and microbial activity and accelerated the biodegradation process via co-metabolism. The enzyme activities and quantities of functional genes were demonstrated to be incremented in SL reactors. The biosurfactant improved the TPH bioavailability, stimulated the microbial activities and participated in the co-metabolism. The combination of bioaugmentation and SL benefitted the bioremediation of petroleum hydrocarbon-contaminated soil.

Tributyltin (TBT), a bioaccumulative and persistent environmental pollutant, has been proposed as a metabolism disruptor and obesogen through targeting peroxisome proliferator-activated receptor gamma (PPARγ) receptor pathway. However, it remains unknown whether this biological effect occurs in macrophage, a cell type which cooperates closely with hepatocytes and adipocytes to regulate lipid metabolism. This study for the first time investigated the effect of TBT on PPARγ pathway in macrophages. Our results indicated that nanomolar levels of TBT was able to strongly activate PPARγ in human macrophages. TBT treatment also markedly increased the intracellular lipid accumulation, and enhanced the expression of lipid metabolism-related genes in macrophages, while these effects were all significantly down-regulated in PPARγ-deficient macrophages, confirming the involvement of PPARγ in TBT-induced lipogenesis. Next, a mouse model that C57BL/6 mice were orally exposed to TBT with the doses (250 and 500 μg/kg body weight) lower than NOAEL (no observed adverse effect level) was used to further investigate the in vivo mechanisms. And the in vivo results were consistent with cellular assays, confirming the induction of PPARγ and the increased expression of lipogenesis-regulating and lipid metabolism-related genes by TBT in vivo. In conclusion, this study not only provided the first evidence that TBT stimulated lipogenesis, activated PPARγ and related genes in human macrophages, but also provided insight into the mechanism of TBT-induced metabolism disturbance and obesity through targeting PPARγ via both in vitro cellular assays and in vivo animal models.

Mangrove sediment is a major sink for phenanthrene in natural environments. Consequently, this study investigated the effects of seasonal variation on the biodegradation rates of low (150 mg kg⁻¹), moderate (600 mg kg⁻¹), and high (1200 mg kg⁻¹) phenanthrene-contaminated mangrove sediments using a microcosm study and identified potential key phenanthrene-degrading bacteria using high throughput sequencing of 16 S rRNA gene and quantitative-PCR of the PAH-ring hydroxylating dioxygenase (PAH-RHDα) genes. The biodegradation rates of phenanthrene in all treatments were higher in the wet-season sediments (11.58, 14.51, and 8.94 mg kg⁻¹ sediment day⁻¹) than in the dry-season sediments (3.51, 12.56, and 5.91 mg kg⁻¹ sediment day⁻¹) possibly due to higher nutrient accumulation caused by rainfall and higher diversity of potential phenanthrene-degrading bacteria. The results suggested that the mangrove sediment microbiome significantly clustered according to season. Although Gram-negative phenanthrene-degrading bacteria (i.e., Anaerolineaceae, Marinobacter, and Rhodobacteraceae) played a key role in both dry and wet seasons, distinctly different phenanthrene-degrading bacterial taxa were observed in each season. Halomonas and Porticoccus were potentially responsible for the degradation of phenanthrene in the dry and wet seasons, respectively. The knowledge gained from this study contributes to the development of effective and rationally designed microbiome innovations for oil removal.

1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH) is a brominated flame retardant used in commercial and industrial applications. The use of DBE-DBCH containing products has resulted in an increased release into the environment. However, limited information is available on the long-term effects of DBE-DBCH and its effects in aquatic invertebrates. Thus, the present study was aimed at determining how DBE-DBCH diastereomers (αβ and γδ) affects aquatic invertebrates using Daphnia magna as a model organism. Survival, reproduction, feeding, swimming behavior and toxicogenomic responses to environmental relevant concentrations of DBE-DBCH were analyzed. Chronic exposure to DBE-DBCH resulted in decreased lifespan, and reduced fecundity. Expression of genes involved in reproductive processes, vtg1 and jhe, were also inhibited. DBE-DBCH also induced hypoxia by inhibiting the transcription of genes involved in heme biosynthesis and oxygen transport. Furthermore, DBE-DBCH also inhibited feeding resulting in emptiness of the alimentary canal. Increased expression of the stress response biomarkers was observed following DBE-DBCH exposure. In addition, DBE-DBCH diastereomers also altered the swimming behavior of Daphnia magna. The present study demonstrates that DBE-DBCH cause multiple deleterious effects on Daphnia magna, including effects on reproduction and hormonal systems. These endocrine disrupting effects are in agreement with effects observed on vertebrates. Furthermore, as is the case in vertebrates, DBE-DBCH γδ exerted stronger effects than DBE-DBCH αβ on Daphnia magna. This indicate that DBE-DBCH γδ has properties making it more toxic to all so far studied animals than DBE-DBCH αβ.