It is vital for the development and application of heavy metal stabilization/solidification (S/S) agents to reveal the mechanism of the reaction between water-soluble thiourea formaldehyde (WTF) resin and heavy metal and evaluate its repairing effect. Based on the density functional theory analysis of the WTF resin structure, the mechanism analysis and scanning electron microscope (SEM) showed that the three-dimensional network structure with thiocarbonyl and hydroxyl groups is very conducive to the capture of Cd²⁺. The reduction rate of Cd²⁺ in soil added WTF resin could reach 70.6%–86.0%. The result of BCR’s sequential extraction also proved that the 86.4%–94.1% of Cd in the soil repaired by WTF resin changed from acid-soluble state to residue state. Enzyme activity analysis and 16sRNA sequencing experiments showed that such a structure does not harm soil health. The urease and phosphatase tests showed the nitrogen and phosphorus cycle of the soil added WTF resin was repaired. Even compared with the remediation agents Na₂S and hydroxyapatite, WTF resin still performed better in repairing soil health. These findings provide valuable insights into the efficient causes of WTF resin and its harmless effects on soil. The results obtained provide a critical reference for the future application of practical and gentle heavy metal S/S agents.

One of the major challenges in understanding the dynamics of the ocean’s health and functioning is the potential impact of the increasing presence of plastic. Besides the verified and macroscopic effects on marine wildlife and habitats, micro and macroplastics offer potential sites for microbial activity and chemical leaching. Most marine plastic is found initially in the upper meters of the water column, where fundamental biogeochemical processes drive marine productivity and food web dynamics. However, recent findings show a continuum of potential effects of these new marine components on carbon, nutrients and microbial processes. In the present analysis, we develop a common ground between these studies and we identify knowledge gaps where new research efforts should be focused, to better determine potential feedbacks of plastics on the carbon biogeochemistry of a changing ocean.

Soil ecological risk caused by compound pollutants is a topic that deserves increasing attention, and soil risk early warning is a more in-depth discussion on this topic. In this study, we collected soil samples from Changchun, a typical industrial city, and determined the contents of 13 heavy metals (HMs) (0.00 mg kg⁻¹-6380 mg kg⁻¹), 16 polycyclic aromatic hydrocarbons (PAHs) (0.00 mg kg⁻¹-27.7 mg kg⁻¹), 7 polychlorinated biphenyls (PCBs) (0.30 μg kg⁻¹-168 μg kg⁻¹), and 8 organochlorine pesticides (OCPs) (0.00 mg kg⁻¹-4.52 mg kg⁻¹). The soil ecological risks of compound pollutants were assessed. The results showed that PAHs were the greatest risk pollutants, followed by PCBs and HMs, and OCPs were the smallest risk pollutants. Most of the ecological risks of compound pollutants were classified as “moderate severity” level according to the (contamination severity index) CSI evaluation criteria. With the help of modern industrial economic theory, through the analysis of the annual accumulation of pollutants, it is possible to predict the future pollutant content in Changchun, and the soil risks could be forewarned. The results showed that if active measures were not taken to reduce the accumulation of PAHs in Changchun soil, the CSI-PAHs would be classified as “ultra-high severity” level in 2035.

Engine oil-derived ash particles emitted from internal combustion (IC) engines are unwanted by-products, after oil is involved in in-cylinder combustion process. Since they typically come out together with particulate emissions, no detail has been reported about their early-stage particles other than agglomerated particles loaded on aftertreatment catalysts and filters. To better understand ash formation process during the combustion process, differently formulated engine oils were dosed into a fuel system of a gasoline direct injection (GDI) engine that produces low soot mass emissions at normal operating conditions to increase the chances to find stand-alone ash particles separated from soot aggregates in the sub-20-nm size range. In addition to them, ash/soot aggregates in the larger size range were examined using scanning transmission electron microscopy (STEM)-X-ray electron dispersive spectroscopy (XEDS) to present elemental information at different sizes of particles from various oil formulations. The STEM-XEDS results showed that regardless of formulated oil type and particle size, Ca, P and C were always contained, while Zn was occasionally found on relatively large particles, suggesting that these elements get together from an early stage of particle formation. The S, Ca and P K-edge X-ray absorption near edge structure (XANES) analyses were performed for bulk soot containing raw ash. The linear combination approach & cross-checking among XANES results proposed that Ca₅(OH)(PO₄)₂, Ca₃(PO₄)₂ and Zn₃(PO₄)₂ are potentially major chemical compounds in raw ash particles, when combined with the STEM-XEDS results. Despite many reports that CaSO₄ is a major ash chemical when ash found in DPF/GFP systems was examined, it was observed to be rarely present in raw ashes using the S K-edge XANES analysis, suggesting ash transformation.

The quality characteristics of urban green spaces (UGS) have been suggested to play a critical role in their use and their potentials to exert health effects. However, epidemiological studies evaluating such a role are scarce. These studies have generally focused on a limited number of quality dimensions. We studied the association between 10 UGS quality dimensions, assessed through a comprehensive multidimensional tool, and physical activity, overweight/obesity, and UGS use. Our study was based on 2053 adults participating in the Barcelona Health Survey (2016) and the quality of 149 UGS located in Barcelona, Spain. For each participant, we abstracted the average and maximum quality score separately for each of the 10 quality dimensions and an overall quality score for the UGS within 300 m of the participant’s residential address. Data on the study outcomes were obtained through face-to-face interviews. We developed logistic regression and negative binomial models to assess our evaluated associations and conducted mediation analyses between the different outcomes. We observed that the overall quality of UGS was associated with higher likelihood of engaging in moderate-to-vigorous physical activity (OR:1.13; 95% CI:1.00–1.27), lower risk of overweight/obesity (OR: 0.88; 95% CI: 0.79–0.98), and increased use of UGS (exponentiated regression coefficient: 1.08; 95% CI:1.01–1.15). For the quality dimensions, we observed different patterns of associations depending on the outcome; however, bird biodiversity and amenities seem to be relevant to all of our evaluated outcomes. The mediation analysis suggested that UGS use mediate the association between quality and physical activity, while physical activity mediates the association between quality and overweight/obesity. The novel results from this study will allow decision-makers better design UGS and directly pinpoint relevant quality dimensions to promote physical activity, reduce the risk of overweight/obesity and boost the use of UGS amongst citizens.

After decades of imposed regulations about reducing the primary emissions of persistent organic pollutants (POPs), these pollutants are still present in the environment. Soils are important repositories of such persistent semivolatile organic contaminants (SVOCs), and it is assumed that SVOCs sequestered in these reservoirs are being re-mobilized due to anthropogenic influence. In this study, concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in soil and air, their fugacities, fluxes and the soil-air partition coefficient (KSA) were determined for three different land cover types (glacial, remote/mountainous and urban) of the Lesser Himalayan Region (LHR). The concentrations of OCPs, PCBs and PBDEs in soils and air ranged between 0.01 and 2.8, 0.81–4.8, 0.089–0.75 ng g⁻¹; 0.2–106, 0.027–182, and 0.011–7.26 pg m⁻³, respectively. The levels of SVOCs in the soil were correlated with soil organic matter (SOM) indicating that SOM is a substrate for the organic pollutants in soils. The Clausius-Clapeyron plots between ln P and inverse of temperature (1000/T) suggested that long range atmospheric transport was the major input source of PBDEs and higher chlorinated PCBs over the LHR. The uneven and wide distribution of local sources in LHR and up-slope enrichment of SVOCs explained the spatial variability and altitudinal patterns. The soils near mountain and urban lakes act as local sinks of SVOCs such as β-HCH, pp΄-DDT, CB-28, -118, −153, BDE-47, -99, and −154, with soil-air exchange fluxes tending more toward deposition. However, the soils near glacial lakes acted as local sources of more volatile congeners of α-HCH, γ-HCH, op′-DDT, pp′-DDE and lower to medium chlorinated PCBs such as CB-18, -28, −53, −42 and BDE-47, -99, with soil-air exchange tending more toward volatilization flux.

The high global consumption of ibuprofen and its limited elimination by wastewater treatment plants (WWTPs), has led to the contamination of aquatic systems by this common analgesic and its metabolites. The potentially negative environmental and public health effects of this emerging contaminant have raised concerns, driving the demand for treatment technologies. The implementation of bacteria which mineralize organic contaminants in biopurification systems used to decontaminate water or directly in processes in WWTPs, is a cheap and sustainable means for complete elimination before release into the environment. In this work, an ibuprofen-mineralizing bacterial strain isolated from sediments of the River Elbe was characterized and assayed to remediate different ibuprofen-polluted media. Strain RW412, which was identified as Sphingopyxis granuli, has a 4.48 Mb genome which includes plasmid sequences which harbor the ipf genes that encode the first steps of ibuprofen mineralization. Here, we confirm that these genes encode enzymes which initiate CoA ligation to ibuprofen, followed by aromatic ring activation by a dioxygenase and retroaldol cleavage to unequivocally produce 4-isobutylcatechol and propionyl-CoA which then undergo further degradation. In liquid mineral salts medium, the strain eliminated more than 2 mM ibuprofen within 74 h with a generation time of 16 h. Upon inoculation into biopurification systems, it eliminated repeated doses of ibuprofen within a few days. Furthermore, in these systems the presence of RW412 avoided the accumulation of ibuprofen metabolites. In ibuprofen-spiked effluent from a municipal WWTP, ibuprofen removal by this strain was 7 times faster than by the indigenous microbiota. These results suggest that this strain can persist and remain active under environmentally relevant conditions, and may be a useful innovation to eliminate this emerging contaminant from urban wastewater treatment systems.

Acid sulfate soils are a major problem in modified coastal floodplains and are thought to have substantial impacts on estuarine species. In New South Wales, Australia, acid sulfate soils occur in every estuary and are thought to impact important fisheries species, such as Eastern School Prawn (Metapenaeus macleayi). These fisheries have experienced declining productivity over the last ten years and increasing occurrence of catchment-derived stressors in estuaries contribute to this problem. We evaluated the effect of pH 4–7.5 on School Prawn survival at two salinities (27 and 14.5), pH 5, 6 and 7.5 on the predation escape response (PER) speed at two salinities (27 and 14.5), and pH 4 and 7.5 on respiration rates. While mortality appeared to be greater in the high salinity treatment, there was no significant relationship between proportional survival and pH for either salinity treatment. Respiration was significantly slower under acidic conditions and the average PER was almost twice as fast at pH 7.5 compared to pH 5 (p < 0.05), indicating prawns may fall prey to predation more easily in acidic conditions. These findings confirm the hypothesised impacts of acidic water on penaeid prawns. Given that the conditions simulated in these experiments reflect those encountered in estuaries, acidic runoff may be contributing to bottlenecks for estuarine species and impacting fisheries productivity.

Nonylphenol (NP), an environmental estrogen, is actually a complicated mixture of isomers, although it is commonly considered to be a single compound. There are many routes for crops to come into contact with NP; however, little is known about the plant uptake and metabolism of NP, especially at the isomer level. This study comparatively evaluated the uptake and in-planta metabolism of 4-n-NP and its 10 isomers using both carrot cells and intact plants. The rapid metabolism of 4-n-NP was observed in the callus tissues and intact plants with half-lives of 2 h and 4.72 d, respectively. Six conjugates of 4-n-NP were identified in the cell extracts using high resolution mass spectrometry. The primary transformation pathway was found to be the direct conjugation (Phase II metabolism) with the parent compound at the hydroxyl. Furthermore, 4-NP isomers with short side chains and/or bulky α-substituents were more resistant to plant metabolism and showed a greater tendency for accumulation. The influence of the side chains to the isomer selectivity was verified by the molecular docking between glycosyltransferase and 4-NP isomers. This study highlighted the necessity to consider isomer-specificity in the plant accumulation of NP and the environmental and human health implications of NP conjugates.

Precious metal mining activities have left complex environmental legacies in lakes around the world, including some sites in climatically sensitive regions of the Canadian sub-Arctic. Here, we examined the long-term impacts of past regional gold mining activities on sub-Arctic lakes near Con Mine (Yellowknife, Northwest Territories) based on sediment core analysis (paleolimnology). In addition to receiving metal(loid)s from roaster stack emissions, the study lakes were also influenced by salt-rich mine drainage from Con Mine tailings. Water samples from these lakes had some of the highest concentrations for salinity-related variables (e.g. Ca²⁺, Cl⁻, Na⁺) and metal(loid)s (e.g. As, Cu, Ni, Sb) in the Yellowknife area. Furthermore, the presence of halophilic diatom (Bacillariophyceae) taxa (Achnanthes thermalis and Navicula incertata) in the recent sediments of Keg and Peg lakes suggest that the extreme saline conditions are strongly influencing the present biota, more than 10 years after the cessation of gold mining activities at Con Mine. The sedimentary metal(loid) profiles (e.g. As, Cu, Ni) of Kam Lake tracked the influence of regional gold mining activities, particularly those at Con Mine, while the algal assemblages recorded the biological responses to salinization and metal(loid) pollution (e.g. marked decreases in diatom species richness, Hill’s N2 diversity, and chrysophyte cyst:diatom valve ratio). At Kam Lake, the algal assemblage changes in the post-mining era were indicative of climate-mediated changes to lake thermal properties (e.g. rise in planktonic diatoms), nutrient enrichment related to urbanization (e.g. increase in eutrophic Stephanodisucs taxa), and/or a combination of both stressors. The lack of biological recovery (i.e. return to pre-mining assemblages) is consistent with investigations of mine-impacted lakes in temperate regions where elevated contaminant levels and emerging stressors (e.g. climate warming, land-use changes) are influencing lake recovery.