The importance of hydrochar properties for soil application is well known, but the effects of natural aging on hydrochar properties remain ambiguous. The present study aimed to determine the shift patterns in the physicochemical properties of hydrochar through a 16-month soil column aging experiment conducted in a rice-wheat rotation system with hydrochars derived from a wheat straw at 220 °C and 260 °C. Obvious decreasing hydrophilic/polarity indices and increasing porosity, ash content, and stability occurred in aged hyrdrochar, which were due to the dissolved organic matter (DOM) leaching and the interaction with mineral content and fertilizer during the 16-month aging process. Besides, fewer C–OH, slightly more CO, and higher aromaticity (C–C/CC) in aged hydrochar were observed. Meanwhile, the relative abundance of the compounds containing only C, H, and O atoms in water extract of aged hydrochar decreased, while that of the compounds containing C, H, O, and N atoms increased during aging; these findings were attributed to the less labile DOM and microbial degradation and the retention of some plant-derived dissolved organic carbon, respectively. This study provided 16-month aging characterization data regarding alteration in hydrochar physicochemical properties, which was conducive to make a better understanding of the use of hydrochars as sustainable soil amendments from agroecosystems and environmental perspective.

Lake water pollution has caused many serious ecological issues globally. An emerging public concern over water quality deterioration in lakes has heightened the need to evaluate the water quality of lakes at long-term scales, particularly for those with high hydrological alterations. This study combines the Mann–Kendall (M–K) test and self-organising map (SOM) to characterise and evaluate water quality trends in Dongting Lake, China, from 1991 to 2018, before and after the inauguration of the Three Gorges Dam (TGD). Herein, six water quality parameters were selected, namely pH, permanganate index (CODMₙ), ammonia nitrogen (NH₃–N), total nitrogen (TN), total phosphorus (TP), and the five-day biochemical oxygen demand (BOD₅). Our results show that the concentrations of TN and BOD₅ increase significantly throughout the study period (|Z| ≥ 1.96). The number of abrupt change points for the six water quality parameters in the post-TGD period was greater than that in the pre-TGD period, which indicates an increased risk of water deterioration in the post-TGD period. The SOM results show that the pH values ranged from 7.64 to 7.85 among the four clusters; besides, the concentrations of the remaining water quality parameters from 1991 to 1997 and 2000 to 2003 were relatively lower, suggesting that the water quality in the pre-TGD period was better. The classification of TN and TP ranged from Level Ⅳ–Ⅴ among the clusters, which did not satisfy the level Ⅲ standard for potable water, thereby posing a higher ecological risk to the Dongting Lake. These results indicate the deterioration of the water quality in Dongting Lake during the post-TGD period under the influences of pollution load and hydrological regulation. Therefore, strict controls on the external nutrient loading and hydrological regulations should be considered for water quality management.

Air pollution has been an important risk factor for female reproductive health. However, epidemiological evidence of ambient air pollution on the predictor for ovarian reserve (antral follicle count, AFC) is deficient. We aim to comprehensively evaluate the association of long-term exposure to ambient air pollution with AFC among women of reproductive age in Shanxi of north China. 600 women with spontaneous menstrual cycle, not using controlled ovarian stimulation, were enrolled in the retrospective study. Two distinct periods of antral follicle development were designed as exposure windows. Generalized linear model was employed to estimate the change of AFC associated with exposure of atmospheric pollutants (SO₂, NO₂, PM₁₀, PM₂.₅, CO and O₃). Stratification analysis based on age (<30, ≥30 years), university degree (yes, no), years of exposure (2013–2016, 2017–2019) and duration of infertility (<2, 2–5, >5 years) along with two pollutants model were employed to further illustrate the association. We found every 10 μg/m³ increase in SO₂ concentration level during the entire development stage of antral follicle was associated with a −0.01 change in AFC (95% confidence interval: −0.016, −0.002) adjusting for the confounders including age, BMI, parity and infertility diagnosis factors. The significant association of increased SO₂ level with decreased AFC was particularly observed during the early transition from primary follicle to preantral follicle stage by 10 μg/m³ increase in SO₂ exposure level with a −0.01 change (95% CI: -0.015, −0.002) in AFC. The negative association was pronounced among women aged ≥30 years old, and also significant in two pollutants model after adjusting the confounders. No significant associations between other air pollutants and AFC were observed. Our finding suggests that long-term exposure to air pollutant SO₂ is associated with lower AFC, raising our concern that atmospheric SO₂ exposure may have potential adverse impact on women ovarian reserve.

Low molecular weight organic compounds are ubiquitous in the atmosphere. However, knowledge on their concentrations and molecular distribution in fresh snow remains limited. Here, twelve fresh snow samples collected at eight sites in China were investigated for dicarboxylic acids and related compounds (DCRCs) including oxocarboxylic acids and α-dicarbonyls. Dissolved organic carbon (DOC) concentrations in the snow samples ranged from 0.99 to 14.6 mg C L⁻¹. Concentrations of total dicarboxylic acids were from 225 to 1970 μg L⁻¹ (av. 650 μg L⁻¹), while oxoacids (28.3–173, av. 68.1 μg L⁻¹) and dicarbonyls (12.6–69.2, av. 31.3 μg L⁻¹) were less abundant, accounting for 4.6–8.5% (6.2%), 0.45–1.4% (0.73%), and 0.12–0.88% (0.46%) of DOC, respectively. Molecular patterns of dicarboxylic acids are characterized by a predominance of oxalic acid (C₂) (95.0–1030, av. 310 μg L⁻¹), followed by phthalic (Ph) (9.69–244, av. 69.9 μg L⁻¹) or succinic (C₄) (23.8–163, av. 63.7 μg L⁻¹) acid. Higher concentrations of Ph in snow from Beijing and Tianjin than other urban and rural regions suggest significant emissions from vehicular exhausts and other fossil fuel combustion sources in megacities. C₂ constituted 40–54% of total diacids, corresponding to 1.5–2.6% of snow DOC. The total measured DCRCs represent 5.5–10% of snow DOC, which suggests that there are large amounts of unknown organics requiring further investigations. The spatial distributions of diacids exhibited higher loadings in megacities than rural and island sites. Molecular distributions of diacids indicated that the photochemical modification was restrained under the weak solar radiation during the snow events, while anthropogenic primary sources had a more significant influence in megacities than rural areas and islands.

The health impact of changes in particulate matter with an aerodynamic diameter <2.5 μm (PM₂.₅) pollution associated with the COVID-19 lockdown has aroused great interest, but the estimation of the long-term health effects is difficult because of the lack of an annual mean air pollutant concentration under a whole-year lockdown scenario. We employed a time series decomposition method to predict the monthly PM₂.₅ concentrations in urban cities under permanent lockdown in 2020. The premature mortality attributable to long-term exposure to ambient PM₂.₅ was quantified by the risk factor model from the latest epidemiological studies. Under a whole-year lockdown scenario, annual mean PM₂.₅ concentrations in cites ranged from 5.4 to 68.0 μg m⁻³, and the national mean concentration was reduced by 32.2% compared to the 2015–2019 mean. The Global Exposure Mortality Model estimated that 837.3 (95% CI: 699.8–968.4) thousand people in Chinese cities would die prematurely from illnesses attributable to long-term exposure to ambient PM₂.₅. Compared to 2015–2019 mean levels, 140.2 (95% CI: 122.2–156.0) thousand premature deaths (14.4% of the annual mean deaths from 2015 to 2019) attributable to long-term exposure to PM₂.₅ were avoided. Because PM₂.₅ concentrations were still high under the whole-year lockdown scenario, the health benefit is limited, indicating that continuous emission-cutting efforts are required to reduce the health risks of air pollution. Since a similar scenario may be achieved through promotion of electric vehicles and the innovation of industrial technology in the future, the estimated long-term health impact under the whole year lockdown scenario can establish an emission–air quality–health impact linkage and provide guidance for future emission control strategies from a health protection perspective.

The effects of fabric filters and desulfurization systems during secondary copper smelting on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations, emission coefficients, and profiles were studied in an oxygen-rich smelting furnace and an anode furnace. In the anode furnace, the toxic equivalent (TEQ) concentration ranges were 0.106–1.04 ng World Health Organization (WHO)-TEQ/m³ at the fabric filters inlet and 0.027–0.17 ng WHO-TEQ/m³ at the outlet. For the oxygen-rich smelting furnace, the TEQ concentration ranges were 1.21–1.93 and 0.010–0.019 ng WHO-TEQ/m³ at the desulfurization system inlet and outlet, respectively. The TEQs in the outlet stack gases of the desulfurization system from the anode furnace were 0.0041–0.016 ng WHO-TEQ/m³. It is likely that PCDD/Fs that were taken away from the stack gases were adsorbed by the fly ash and gypsum. Solid residues were the dominant release routes for PCDD/Fs. PCDD/Fs congener and homologue profiles of stack gases from different smelting stages were similar. The contributions of more chlorinated homologues from the anode furnace decreased observably after the stack gases passed through the fabric filters. However, the desulfurization process did not greatly change the PCDD/Fs homologue profiles. Overall, both the fabric filters and desulfurization systems showed excellent removal efficiencies for PCDD/Fs in the stack gases, which reduced the TEQ emissions to well below the 0.5 ng WHO-TEQ/m³ to achieve standard discharge.

Cadmium (Cd) was an environmental pollutant, which could result in germ cell apoptosis in testes. Sertoli-germ cell communication was vital for germ cell development and maturity. However, little was known about the effect of Sertoli cell autophagy on Cd-induced germ cell apoptosis. Here, we used male Amh-Cre+/Atg5ᶠˡᵒˣ/ᶠˡᵒˣ (Atg5⁻/⁻) mice, loss of autophagy-related gene 5 (Atg5) in testicular Sertoli cells, to explore the obscure effects. Atg5⁻/⁻ and Wild-type (WT) mice were given with cadmium chloride (CdCl₂, 2.0 mg/kg) for 0–24 h. Our results showed that Cd triggered testicular germ cell apoptosis, as evidenced by the increment of TUNEL-labeled germ cells, cleaved caspase3 and cleaved poly (ADP-ribose) polymerase protein level. Additionally, Cd induced testicular autophagy, as determined by elevating the level of autophagy-related proteins, including Atg5, Atg7, LC3B-II, and the gathering of LC3 puncta. 3-methyladenine, a specific autophagy inhibitor, exacerbated Cd-caused germ cell apoptosis. Inversely, rapamycin, an autophagy inducer, relieved Cd-stimulated germ cell apoptosis. Interestingly, we found that autophagy in Sertoli cells was activated in Cd-treated WT mouse testes as evidenced by the increment of LC3 puncta surrounding SOX9, a specific Sertoli cell marker. More importantly, loss of autophagy in Sertoli cells aggravated Cd-triggered germ cell apoptosis. Taken together, these data indicate that autophagy in Sertoli cells alleviates Cd-triggered germ cell apoptosis in mouse testes.

The search for optimal catalysts to improve the working efficiency of ozonation has always been an important issue in the research field of advanced oxidation processes. In this study, a novel catalyst, ferrosilicon, was selected as the catalyst in heterogeneous catalytic ozonation to degrade ibuprofen (IBP) in water and treat real pharmaceutical wastewater. During the procedure, 45#ferrosilicon exhibited the best catalytic activity. Under the optimized experimental conditions, the IBP removal reached 75%, which was a great improvement compared to the 37% removal by ozone alone. The 45#-ferrosilicon-catalysed ozonation also achieved 68% TOC removal for real pharmaceutical wastewater, which was 31% higher than that by ozone alone. The degradation pathway of IBP was proposed using GC/MS. The EPR test proved that the main active species in the system were free active radicals •OH, and the measured accumulative •OH amount was 102 μmol. The characterization results show that the nascent metallic oxides, hydroxides, and hydroxyoxides on the ferrosilicon surface facilitated the decomposition of ozone molecules and generation of free active radicals. The removal of target organic contaminants in the water was mainly attributed to the oxidization of these highly active species.

Seabird eggs are considered a favourable matrix for monitoring marine pollutants and are widely used as higher trophic level indicators. Persistent organic pollutants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other organochlorine compounds (OCs) as well as metals have been shown to have deleterious impacts on seabirds. The Northern Gannet Morus bassanus is an avian sentinel; the largest breeding seabird in Ireland and an obligate piscivore. Gannet eggs were collected from two island colonies off the east coast of Ireland in locations with divergent history of industrialisation. Contaminant levels were measured and differences in concentrations between colonies compared. Stable isotope ratios of carbon (δ₁₃C) and nitrogen (δ₁₅N) were measured in each egg to understand the influence of diet and trophic position on contaminant levels detected. Significantly higher levels of Σ14PCBs, Σ7PBDEs and total mercury were detected in Gannet eggs from Lambay Island near Dublin (Ireland’s industrialised capital city) compared to Great Saltee Island. No differences were observed in levels of other OCs (HCB, ΣHCH, ΣCHL, ΣDDT) between the two colonies. Though Gannets travel significant distances when foraging for food, tracking studies have demonstrated that birds from proximal breeding colonies maintain exclusive feeding areas. Stable isotope ratio analysis in this study demonstrated that Gannets at both locations occupy similar dietary niches, indicating that dietary differences may not be the driver of differing contaminant levels between colonies. Levels of persistent pollutants in the Gannet eggs fall below most existing thresholds for adverse effects and are within internationally reported values. Recent population growth and range expansion of Gannets in Ireland suggest that persistent pollutants are not having an immediate impact on the Gannet population. This study will inform potential monitoring programmes that can help Ireland achieve good environmental status under the European Union’s Marine Strategy Framework Directive.

Evidence has shown associations between air pollution and traffic-related exposure with accelerated aging, but no study to date has linked the exposure with age at natural menopause, an important indicator of reproductive aging. In this study, we sought to examine the associations of residential exposure to ambient particulate matter (PM) and distance to major roadways with age at natural menopause in the Nurses’ Health Study II (NHS II), a large, prospective female cohort in US. A total of 105,996 premenopausal participants in NHS II were included at age 40 and followed through 2015. Time-varying residential exposures to PM₁₀, PM₂.₅₋₁₀, and PM₂.₅ and distance to roads was estimated. We calculated hazard ratios (HR) and 95% confidence intervals (CIs) for natural menopause using Cox proportional hazard models adjusting for potential confounders and predictors of age at menopause. We also examined effect modification by region, smoking, body mass, physical activity, menstrual cycle length, and population density. There were 64,340 reports of natural menopause throughout 1,059,229 person-years of follow-up. In fully adjusted models, a 10 μg/m³ increase in the cumulative average exposure to PM₁₀ (HR: 1.02, 95% CI: 1.00, 1.04), PM₂.₅₋₁₀ (HR: 1.03, 95% CI: 1.00, 1.05), and PM₂.₅ (HR: 1.03, 95% CI: 1.00, 1.06) and living within 50 m to a major road at age 40 (HR: 1.03, 95%CI: 1.00, 1.06) were associated with slightly earlier menopause. No statistically significant effect modification was found, although the associations of PM were slightly stronger for women who lived in the West and for never smokers. To conclude, we found exposure to ambient PM and traffic in midlife was associated with slightly earlier onset of natural menopause. Our results support previous evidence that exposure to air pollution and traffic may accelerate reproductive aging.