Heavy metal pollution is a serious environmental problem globally, particularly in mines and tailings ponds. In this study, based on laboratory and field tests, the migration of heavy metal contaminants in a tailings pond and the retention behavior of a compacted bentonite engineered barrier system on the heavy metal contaminants were analyzed by a numerical simulation. The results demonstrate that the hydraulic conductivity of compacted bentonite is lower than that of the tailings from the laboratory tests. The hydraulic conductivity of the tailings sand decreased with an increase in the dry density and increased with an increase in the concentration of the chemical solution, which could be attributed to the large amounts of fine-grained soil contained in the tailings, according to the grain size distribution test. The hydraulic conductivity of the tailings from the engineering geological survey was between 2.0 × 10−6 and 9.0 × 10−5 m/s, and followed the order: tail coarse sand ＞ tail silty sand ＞ tail medium sand ＞ tail fine silt. The numerical simulation of the seepage could satisfactorily describe the actual working condition of the tailings dam. With the groundwater seepage, the migration range of the heavy metal contaminant in the researched tailings pond reached a maximum of 45 m for 5 years. The retention efficiencies of the 0.2 m engineered barrier against the heavy metal contaminant for 15 and 30 years were 45.4% and 57.2%, respectively. Moreover, the retention efficiency would exceed 87% when the engineered barrier thickness is increased to 0.5 m. The results of model validation show that the calculated results are in good agreement with the measured ones. These findings can provide effective ideas for the prevention and control of environmental pollution in mines and tailings ponds.

Glyphosate-based herbicides (GBH) are the most widely used pesticides in the world. The extensive use of them increases the potential human health risk, including the human inhalation toxicity risk. We studied the effect of the most famous GBH Roundup® (RDP) in the concentration range from 50 to 125 μg/mL on Mitochondria-Associated apoptosis and DNA damage in Human alveolar carcinoma cells (A549 cells). Alkaline comet assay, immunofluorescence assay and Flow Cytometric Analysis assay were employed to detect DNA damages and apoptosis of A549 cells. We found RDP caused concentration-dependent increases in DNA damages and proportion of apoptotic cells in A549 cells. RDP induced the DNA single-strand breaks and double-strand breaks; the collapse of mitochondrial membrane by increasing Bax/Bcl-2, resulting in the release of cytochrome c into cytosol and then activated caspase-9/-3, cleaved poly (ADP-ribose) polymerase (PARP) in human lung tissue cells. The results demonstrate that RDP can induce A549 cells cytotoxic effects in vitro at the concentration lower than the occupational exposures level of workers, which means RDP has a potential threat to human health.

The N-TiO2/g-C3N4@diatomite (NTCD) composite has been prepared through a simple impregnation method, using titanium tetrachloride as precursor and urea as nitrogen-carbon source. Then the effects of calcination temperature on structure, surface property and photocatalytic activity of the catalysts were investigated. And XRD, TEM, XPS, FTIR and UV–vis diffuse adsorption spectroscopy were used to characterize the obtained powders. The photocatalytic activity of the NTCD was evaluated through the reduction of aqueous Cr (VI) under visible light irradiation (λ > 400 nm). The results demonstrated that the nano-TiO2 particles ranging from 15 to 30 nm in the crystal of anatase are well deposited on the surface of diatomite in the NTCD-500 which calcined at 500 °C for 2 h. Furthermore, the g-C3N4 with the lay thickness of 0.92 nm was attached to the surface of nano-TiO2. The N-doped TiO2 and g-C3N4 doped catalysts could co-enhance response in the visible light region and reduce band gap of NTCD-500 (Eg = 3.07 eV). And the NTCD-500 sample exhibited nearly 100% removal rate within 5 h for photocatalytic reduction of Cr (VI) which was higher activity than P25, crude TiO2@diatomite and g-C3N4@diatomite.

Fine particulate matter (PM₂.₅) is an essential risk factor of chronic obstructive pulmonary disease (COPD). Recent studies showed weak association between PM₂.₅ and COPD incidence, but smokers who exposed to higher PM₂.₅ concentration had more opportunity to gain COPD. Cigarette smoking is the most important risk factor of COPD. Thus, we hypothesized: the role of PM₂.₅ played on cigarette-inflamed airways was more significant than normal airways. The study firstly established an animal model of C57BL/6J mice with cigarette smoke exposure and PM₂.₅ orotracheal administration. After calculating pathological scores, mean linear intercept and mean alveolar area, we found PM₂.₅ aggravated pathological injury of cigarette-inflamed lungs, but the injury on normal lungs was not significant. Meanwhile, inflammatory factors as T-bet, IFN-γ and IL-1α were tested using qRT-PCR and ELISA. The results showed PM₂.₅ aggravated inflammation of cigarette-inflamed lungs, but the effect on normal lungs was not significant. The most important pathogenesis of COPD is abnormal apoptosis in airway epithelium, due to oxidative stress following long-term exposure to cigarette smoke. Then, apoptotic responses were detected in lungs. TUNEL analysis demonstrated that PM₂.₅ promoted DNA fragmentation of cigarette-inflamed lungs, but the effect on normal lungs was not significant. Western-blot and immunohistochemistry showed caspase activated significantly in PM₂.₅-cigarette smoke exposed lungs and activated caspase 3 located mainly on bronchial epithelium. Next, human bronchial epithelial cells were cultured treated with cigarette smoke solution (CSS) with or without PM₂.₅. Z-VAD-FMK, a pan-caspase inhibitor, was used to suppress the activation of caspases. After analyzing cell viability, DNA fragmentation, mitochondrial activities and caspase activities, the results clarified that PM₂.₅ aggravated apoptosis in cigarette-inflamed bronchial epithelial cells and the responses could be suppressed by Z-VAD-FMK. Our results gave a new idea about the mechanism of PM₂.₅ on COPD and inferred cigarette-inflamed airways were more vulnerable to PM₂.₅ than normal airways.

Few studies have reported the association between greenspace and academic performance at school level. We examined associations between both residential and school greenspace and individual school grades in German adolescents.German and maths grades from the latest school certificate, residential and school greenspace, and covariates were available for 1351 10 and 15 years old Munich children and 1078 Wesel children from two German birth cohorts – GINIplus and LISA. Residential and school greenspace was assessed by the Normalized Difference Vegetation Index (NDVI), tree cover, and (in Munich only) proportion of agricultural land, forest, and urban green space in 500-m and 1000-m circular buffers. Longitudinal associations between each exposure-outcome pair were assessed by logistic mixed effects models with person and school as random intercepts and adjusted for potential confounders.No associations were observed between any of the greenspace variables and grades in Wesel children. Several statistically significant associations were observed with German and maths grades in Munich children, however associations were inconsistent across sensitivity analyses.There is no evidence of an association of higher greenspace at residence, school or combined with improved academic performance in German adolescents from the GINIplus and LISA longitudinal studies.

The laboratory reproduction test with the predatory mite Hypoaspis aculeifer is currently a mandatory test in the new EU data requirements for prospective environmental risk assessment of Plant Protection Products (PPPs). However, the low sensitivity often shown by this mite towards PPPs, when compared to other invertebrates (namely Folsomia candida and Eisenia fetida), makes the test with this species not very useful in the lower tier test battery. However, the current test protocol only considers exposure to contaminants via contaminated soil, disregarding exposure via contaminated food and does not take into account the fact that H. aculeifer is a predatory species. Therefore, through this protocol, the toxicity of contaminants to soil mites might be underestimated and, thus, an adaptation of the test performance, by including exposure via contaminated food, may be necessary. With this aim, two reproduction tests with H. aculeifer were performed using copper chloride as model substance, artificial soil as test substrate and cheese mites as food. The OECD guideline was followed but, while in one test cheese mites from normal laboratory breeding cultures (clean prey mites) were provided, in the other test, cheese mites previously exposed to copper (Cu pre-exposed prey mites) were provided. Predatory mites were affected at lower concentrations in tests using Cu pre-exposed prey compared to test with clean-prey (NOEC = 1225 and 1508 mg kg⁻¹ and EC₁₀ = 1204 and 1903 mg kg⁻¹ using Cu pre-exposed and clean prey, respectively). However, this higher sensitivity was not detected by EC₅₀ values (EC₅₀ = 2634 and 2814 mg kg⁻¹ using Cu pre-exposed and clean prey, respectively). Further tests are needed in order to (i) investigate the relevance of oral exposure to different PPPs, (ii) optimize the contamination of prey mites according to the chemical properties of each substance and (iii) substantiate a proposal to adapt the standard protocol.

In this study, we develop a new composite material of Fe-Cu/D407 composite via using nanoscale zero-valent iron (nZVI) with copper deposited on chelating resin (D407) to remove nitrate from the water. The experimental results show that a remarkable nitrate removal and the selectivity of N₂ are 99.9% and 89.7%, respectively, under the anaerobic conditions of Cu/Fe molar ratio of 1:2, pH = 3.0. Even without of inert gas and adjusting the initial pH of the solution, the removal rate of nitrate by Fe-Cu/D407 reached to 85% and the selectivity of nitrogen reached to 55%. Meanwhile, the Fe-Cu/D407 maintained preferable removal efficiency of nitrate (100% - 92%) over a wide pH range of 3–11. In addition, the removal rate of the drinking water, lake water and wastewater from the Fe-Cu/D407 is still very high and the reactivity of Fe-Cu/D407 was relatively unaffected by the presence of dissolved ions in the waters tested. Moreover, the synergetic effect of Fe, Cu and D407 in the composite Fe-Cu/D407 were well investigated for the first time according to the analyses of TPR, XPS and EIS. The catalytic mechanism and denitrification routes were also proposed.

Based on long-term systematic sampling, information is currently limited regarding the impacts of different air pollution levels on variations of bacteria, fungi and ammonia-oxidizing microorganisms (AOMs) in fine particulate matter (PM₂.₅), especially their interactions. Here, PM₂.₅ samples were weekly collected at different air pollution levels in Beijing, China during one-year period. Microbial composition was profiled using Illumina sequencing, and their interactions were further investigated to reveal the hub genera with network analysis. Diversity of bacteria and fungi showed obvious seasonal variations, and the heavy- or severe-pollution levels mainly affected the diversity and composition of bacteria, but not fungi. While, the community structure of both bacteria and fungi was influenced by the combination of air pollution levels and seasons. The most abundant bacterial genera and some genera with highest abundance in heavy- or severe-pollution days were the hub bacteria in PM₂.₅. Whereas, only the dominant fungi in light-pollution days in winter were the hub fungi in PM₂.₅. The complex positive correlations of bacterial or fungal pathogens would aggravate the air pollution effects on human health, despite of their low relative abundances. Moreover, the strong co-occurrence and co-exclusion patterns of bacteria and fungi in PM₂.₅ were identified. Furthermore, the hub environmental factors (e.g., relative humidity and atmospheric pressure) may play central roles in the distributions of bacteria and fungi, including pathogens. Importantly, AOMs showed significant co-occurrence patterns with the main bacterial and fungal genera and potential pathogens, providing possible microbiological evidences for controlling ammonia emissions to effectively reduce PM₂.₅ pollution. These results highlighted the more obvious air pollution impacts on bacteria than fungi, and the complex bacterial-fungal interactions, as well as the important roles of AOMs in airborne microbial interactions webs, improving our understanding of bioaerosols in PM₂.₅.

Aluminum is a widely distributed metal that has been reported to have embryotoxicity and fetotoxicity in animal studies. However, there has been no study of the association between prenatal aluminum exposure and newborn mitochondrial DNA copy number (mtDNAcn). We aimed to investigate the effect of prenatal aluminum exposure on newborn mtDNAcn. A total of 762 mother-newborn pairs were recruited between November 2013 and March 2015 in Wuhan city, China. We measured maternal urinary aluminum concentrations at three trimesters of pregnancy. Relative mtDNAcn was measured in DNA extracted from umbilical cord blood samples. We used generalized estimating equations to assess the relationship between prenatal aluminum exposure and newborn mtDNAcn. The geometric means of creatinine corrected aluminum concentrations were 31.0 μg/g Cr (95% CI: 27.6, 34.7), 40.9 μg/g Cr (95% CI: 35.7, 46.8) and 58.4 μg/g Cr (95% CI: 51.2, 67.4) for the first, second and third trimesters, respectively. After adjustment for potential confounding factors, a doubling of maternal urinary aluminum concentrations during the second and third trimesters was related to 3.16% (95% CI: 0.88, 5.49) and 4.20% (95% CI: 1.64, 6.81) increases in newborn mtDNAcn, respectively, while the association between maternal urinary aluminum concentration during the first trimester and newborn mtDNAcn was not significant (percent difference: 0.70%, 95% CI: −2.25, 3.73). Prenatal aluminum exposure during the second and third trimesters was positively associated with newborn mtDNAcn. Further studies are essential to elucidate on the potential health consequences of newborn mtDNAcn.

Cyanobacterial blooms are of global concern due to the multiple harmful risks they pose towards aquatic ecosystem and human health. However, information on the fate of organic pollutants mediated by cyanobacterial blooms in eutrophic water remains elusive. In the present study, endocrine disruptive potentials of phytoplankton samples were evaluated throughout a year-long surveillance in a large and eutrophic freshwater lake. Severe cyanobacterial blooms persisted during our sampling campaigns. Estrogenic agonistic, anti-estrogenic, anti-androgenic, and anti-glucocorticogenic effects were observed in the phytoplankton samples using in vitro reporter gene bioassays. 27 endocrine disrupting chemicals (EDCs) of different modes of action were detected in the samples via UPLC-MS/MS system. Results from mass balance analysis indicated that the measured estrogenic activities were greater than the predicted estrogenic potencies from chemical analysis, demonstrating that chemical analysis of targeted EDCs is unable to fully explain the compounds responsible for the observed estrogenicities. Results from Spearman's correlation analysis concluded that the concentrations of ten EDCs in phytoplankton samples were negatively correlated with cyanobacterial biomass, suggesting the potential occurrence of biomass bio-dilution effects of EDCs due to the huge biomass of cyanobacteria during bloom seasons. The present study provided complementary information about the potential endocrine disruptive risks of cyanobacterial blooms, which is important for understanding and regulating EDCs in eutrophic lakes.