Both Ca deficiency and metal exposure may affect physiological and nutritional condition of breeding females altering their ability to deposit essential resources (e.g. Ca, antioxidants) into the eggs. This effect of the maternal investment into egg quality is not strictly limited to the embryonic period, but may persist after hatching, since nutrient levels in yolks can compromise nestling antioxidant status, growth and fledging success. The goal of this study was to investigate how metal pollution and Ca availability during the breeding season affect oxidative stress biomarkers and plasma biochemistry in adult female pied flycatchers (Ficedula hypoleuca). In addition, we aim to evaluate how maternal antioxidant status and body condition relate to breeding parameters and offspring oxidative balance. Females breeding in a metal-polluted area in SW Finland showed higher metal concentrations compared to the control area, although current levels were below the toxic level able to affect female physiology. In addition, Ca availability was not constraining female oxidative status and general health in the study area. Interestingly, our results suggested that antioxidant response to metals was better when Ca concentrations were high enough to cover the physiological Ca requirements in breeding females. There seems to be a subtle balance between the concentrations of Ca in the organism and the tolerance to metal-related effects that requires further research. This study supports that offspring oxidative balance and nestling development are affected by maternal body condition and antioxidant status.

It is very important to explore the potential harm and underlying mechanism of fluoride due to the extensive distribution and the significant health risks of fluoride in environment. The objective of this study to investigate whether fluoride can induce mitochondrial impairment and mitophagy in testicular cells. For this, 40 male mice were randomly divided into four groups treated with 0, 0.6, 1.2, 2.4 mM NaF deionized water, respectively, for 90 days continuously. The results showed that mitophagy was triggered by F in testicular tissues, especially in the Leydig cells by transmission electron microscopy and mitophagy receptor PHB2 locations by immunofluorescence. Furthermore, TM3 Leydig cells line was employed and treated with 0, 0.125, 0.25, and 0.5 mM NaF for 24 h. The mitochondrial function indicators and mitophagy maker PHB2, COX IV and regulator PINK1 in transcript and protein levels in Leydig cells were examined by the methods of qRT-PCR, western blotting, and immunofluorescence co-localization. The results showed that fluoride decreased the mitochondrial membrane potential with a concomitant increase in the number of lysosomes. Meanwhile, fluoride exposure also increased the expressions of PINK1 and PHB2 in TM3 Leydig cells. These results revealed that fluoride could induce mitochondrial impairment and excessive PINK1/Parkin-mediated mitophagy in testicular cells, especially in Leydig cells, which could contribute to the elucidation of the mechanisms of F-induced male reproductive toxicity.

Mercury (Hg) is commonly extracted from solid phase samples using aqua regia for total Hg (tHg) analysis. However, uncertainties exist regarding the complete extraction of Hg by aqua regia, especially from carbonaceous materials. To investigate whether aqua regia can completely extract Hg from biochars, batch-style experiments were carried out to evaluate extraction efficiency of aqua regia with respect to Hg-loaded biochar and to characterize the residual Hg speciation and spatial distribution. Different types of biochars (raw, FeCl₃-modified, and FeSO₄-modified, prepared at different temperatures) were reacted with Hg-spiked solution before the digestion experiments. Adsorption analyses indicate the biochars were successfully loaded with Hg and that the Hg content was higher in biochars pyrolyzed at higher temperature (900 versus 300 or 600 °C). The results of digestion experiments indicate Hg could not be completely extracted from the biochars tested, with a greater percentage of residual Hg in biochars pyrolyzed at 600 (60 ± 15%) and 900 (75 ± 22%) than 300 °C (7 ± 2%). Furthermore, the fraction of residual Hg in FeSO₄-modified biochars after aqua regia digestion was significantly lower than in FeCl₃-modified and unmodified biochars. Confocal micro-X-ray fluorescence imaging (CMXRFI) showed residual Hg in biochars is concentrated on surfaces prior to digestion, but more homogeneously distributed after digestion, which indicates Hg on biochar surface is more easily digested. Hg extended X-ray absorption fine structure (EXAFS) spectra modelling showed residual Hg in biochars mainly exists as Hg(II)–Cl. These results indicate extra caution should be paid for tHg determinations using aqua regia digestion method in soil (especially in forest), sediment, and peat samples containing black carbon, activated carbon, or biochar.

Facing serious air pollution problems, the Chinese government has taken numerous measures to prevent and control air pollution. Understanding the sources of pollutants is crucial to the prevention of air pollution. Using numerical simulation method, this study analysed the contributions of the total local emissions and local emissions from different sectors (such as industrial, traffic, resident, agricultural, and power plant emissions) to PM₂.₅ concentration, backward trajectory, and potential source regions in Tangshan, a typical heavy industrial city in north China. The impact of multi-scale meteorological conditions on source apportionment was investigated. From October 2016 to March 2017, total local emissions accounted for 46.0% of the near-surface PM₂.₅ concentration. In terms of emissions from different sectors, local industrial emissions which accounted for 23.1% of the near-surface PM₂.₅ concentration in Tangshan, were the most important pollutant source. Agricultural emissions were the second most important source, accounting for 10.3% of the near-surface PM₂.₅ concentration. The contributions of emissions from power plants, traffic, residential sources were 2.0%, 3.0%, and 7.2%, respectively. The contributions of total local emissions and emissions from different sectors depended on multi-scale meteorological conditions, and static weather significantly enhanced the contribution of regional transport to the near-surface PM₂.₅ concentration. Eight cluster backward trajectories were identified for Tangshan. The PM₂.₅ concentration for the 8 cluster trajectories significantly differed. The near-surface PM₂.₅ in urban Tangshan (receptor point) was mainly from the local emissions, and another important potential source region was Tianjin. The results of the source apportionment suggested the importance of joint prevention and control of air pollution in some areas where cities or industrial regions are densely distributed.

Understanding how essential and toxic elements are distributed in cereal grains is a key to improving the nutritional quality of cereal-based products. The main objective of this work was to characterize the distribution of Cd and of nutrients (notably Cu, Fe, Mn, P, S and Zn) in the durum wheat grain. Laser ablation inductively coupled mass spectrometry and synchrotron micro X-ray fluorescence were used for micro-scale mapping of Cd and nutrients. A dissection approach was used to quantitatively assess the distribution of Cd and nutrients among grain tissues. Micro X-ray absorption near-edge spectroscopy was used to identify the Cd chemical environment in the crease. Cadmium distribution was characterized by strong accumulation in the crease and by non-negligible dissemination in the endosperm. Inside the crease, Cd accumulated most in the pigment strand where it was mainly associated with sulfur ligands. High-resolution maps highlighted very specific accumulation areas of some nutrients in the germ, for instance Mo in the root cortex primordia and Cu in the scutellum. Cadmium loading into the grain appears to be highly restricted. In the grain, Cd co-localized with several nutrients, notably Mn and Zn, which challenges the idea of selectively removing Cd-enriched fractions by dedicated milling process.

Rapid urbanization and industrialization in China stimulated the great increase of energy consumption, which leads to drastic rise in the emission of anthropogenic waste heat. Anthropogenic heat emission (AHE) is a crucial component of urban energy budget and has direct implications for investigating urban climate and environment. However, reliable and accurate representation of AHE across China is still lacking. This study presented a new machine learning-based top–down approach to generate a gridded anthropogenic heat flux (AHF) benchmark dataset at 1 km spatial resolution for China in 2010. Cubist models were constructed by fusing points-of-interest (POI) data of varying categories and multisource remote sensing data to explore the nonlinear relationships between various geographic predictors and AHE from different heat sources. The strategy of developing specific models for different components and exploiting the complementary features of POIs and remote sensing data generated a more reasonable distribution of AHF. Results showed that the AHF values in urban centers of metropolises over China range from 60 to 190 W m⁻². The highest AHF values were observed in some heavy industrial zones with value up to 415 W m⁻². Compared with previous studies, the spatial distribution of AHF from different heating components was effectively distinguished, which highlights the potential of POI data in improving the precision of AHF mapping. The gridded AHF dataset can serve as input of urban numerical models and can help decision makers in targeting extreme heat sources and polluters in cities and making differentiated and tailored strategies for emission mitigation.

The present work reported a high-throughput strategy for the analysis of 21 perfluorinated compounds (PFCs) in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvent (SUPARS) vortex-mixed microextraction combined with high performance liquid chromatography-Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS). The SUPRAS without heating assistance is less solvent-consumption, meeting the requirements for green environmental protection and sustainable development. Parameters in the microextraction such as volume of dodecanol and tetrahydrofuran (THF), vortexing extraction and centrifugation time, salt concentration were investigated. The optimal extraction conditions were 250 μL of undecanol, 1.0 mL of THF and 20.0% (w/v, 4 g) NaCl. Under the optimum conditions, method limit of detection and method limit of quantitation in the ranges of 0.01–0.08 μg/L and 0.03–0.25 μg/L, good recoveries (72.5–117.8%) and intra-day precision (1.1–11.2%, n = 6), high enrichment factors (48–78) were obtained. The developed method was successfully applied for analysis of PFCs in 13 drinking water, tap water, river water and plant effluent samples collected from southern China. Perfluorobutane sulfonic acid was detected in one river water with concentration of 0.48 μg/L and 1H,1H,2H,2H-Perfluorooctane sulfonic acid was detected in one river water and two plant effluent samples with concentrations in the range of 0.14–0.67 μg/L.

Lipid metabolism could be used as a biomarker for environmental monitoring of metal pollution, including Cu. Given the potential role of the Wnt/β-catenin signaling pathway and acetylation in lipid metabolism, the aim of this study was to investigate the mechanism of Wnt signaling and acetylation mediating Cu-induced lipogenesis. Grass carp Ctenopharyngodon idella, widely distributed freshwater teleost, were used as the model. We found that waterborne Cu exposure increased the accumulation of Cu and lipid, up-regulated lipogenesis, suppressed Wnt signaling, reduced β-catenin protein level and its nuclear location, reduced the sirt1 mRNA levels and up-regulated the β-catenin acetylation level. Further investigation found that Cu up-regulated lipogenesis through Wnt/β-catenin pathway; Cu regulated the β-catenin acetylation, and K311 was the key acetylated residue after Cu incubation. SIRT1 mediated Cu-induced changes of acetylated β-catenin and played an essential role in nuclear accumulation of β-catenin and Cu-induced lipogenesis. Cu facilitated lipid accumulation via the regulation of Wnt pathway by SIRT1. For the first time, our study uncovered the novel mechanism for Wnt/β-catenin pathway and β-catenin acetylation levels mediating Cu-induced lipid deposition, which provided insights into the association between Cu exposure and lipid metabolism in fish and had important environmental implications for monitoring metal pollution in the water by using new biomarkers involved in lipid metabolism.

Manure pH may vary depending on its inherent composition or additive contents. However, the effect of pH on the fate of antibiotics and antibiotic resistance determinants in manure remains unclear. This work demonstrated that pH adjustment promoted the removal of different sulfonamide antibiotics (SAs) within swine manure under incubation conditions, which increased from 26–60.8% to 75.0–86.0% by adjusting the initial pH from neutral (7.4) to acidic (5.4–4.8). Acidification was also demonstrated to inhibit the accumulation of antibiotic resistance genes in manure during incubation. Acidified manure contained both lower absolute and relative abundances of sul1 and sul2 than those at a neutral pH like 7.4. Further investigation indicated that acidification promoted the reduction of sul genes in manure by restricting sulfonamide-resistant bacteria (SRB) proliferation and inhibiting IntI1 accumulation. Furthermore, pH adjustment significantly influenced the composition of the manure bacterial community after incubation, which increased Firmicutes and decreased Proteobacteria. Close relationships were observed between pH-induced enrichment of the Firmicutes bacterial phylum, enhanced SAs degradation, and the fates of antibiotic resistance determinants. Overall, lowering the pH of manure promotes the degradation of SAs, decreases sul genes and SRB, and inhibits horizontal sul gene transfer, which could be a simple yet highly-effective manure management option to reduce antibiotic resistance.

Per- and polyfluoroalkyl substances (PFASs) contamination in the Bohai Sea and its surrounding rivers has attracted considerable attention in recent years. However, few studies have been conducted regarding the distribution of PFASs in multiple environmental media and their distributions between the suspended particles and dissolved phases. In this study, surface water, surface sediment, and air samples were collected at the Bohai Sea to investigate the concentration and distribution of 39 targeted PFASs. Moreover, river water samples from 35 river estuaries were collected to estimate PFAS discharge fluxes to the Bohai Sea. The results showed that total ionic compound (Σi-PFASs) concentrations ranged from 19.3 to 967 ng/L (mean 125 ± 152 ng/L) in the water and 0.70–4.13 ng/g dw (1.78 ± 0.76 ng/g) in surface sediment of the Bohai Sea, respectively. In the estuaries, Σi-PFAS concentrations were ranged from 10.5 to 13500 ng/L (882 ± 2410 ng/L). In the air, ΣPFAS (Σi-PFASs + Σn-PFASs) concentrations ranged from 199 to 678 pg/m³ (462 ± 166 pg/m³). Perfluorooctanoic acid (PFOA) was the predominant compound in the seawater, sediment, and river water; in the air, 8:2 fluorotelomer alcohol was predominant. Xiaoqing River discharged the largest Σi-PFAS flux to the Bohai Sea, which was estimated as 12,100 kg/y. Some alternatives, i.e., 6:2 fluorotelomer sulfonate acid (6:2 FTSA), hexafluoropropylene oxide dimer acid (HFPO-DA), and chlorinated 6:2 polyfluorinated ether sulfonic acid (Cl-6:2 PFESA), showed higher levels than or comparable concentrations to those of the C8 legacy PFASs in some sampling sites. The particle-derived distribution coefficient in seawater was higher than that in the river water. Using high resolution mass spectrometry, 29 nontarget emerging PFASs were found in 3 river water and 3 seawater samples. Further studies should be conducted to clarify the sources and ecotoxicological effects of these emerging PFASs in the Bohai Sea area.