Science of the Total Environment最新文献

2-Ethylhexyl diphenyl phosphate (EHDPHP) is a widely used organophosphorus flame retardant and plasticizer easily released into the environment. Its biological toxicity is of great concern. The lung is considered a possible target organ for EHDPHP, but currently, there are limited studies on the biotoxicity of EHDPHP in poultry lungs. Therefore, the lungs were selected as the target organ to study the toxic effects of EHDPHP on chicks and their mechanisms of action. In this study, 7-day-old chicks were gavaged with different concentrations of EHDPHP, and lung samples were collected at 14, 28, and 42 days after intragastric administration. Lung histopathological and ultrapathological changes were examined by paraffin section-HE staining and transmission electron microscopy. The levels of lung damage markers (LDH) and oxidative stress markers (GSH-Px, SOD, and MDA) were detected by applying the kit. In contrast, lung cell pyroptosis-related factors (NLRP3, ASC, NF-κB, Pro-Caspase-1, IL-18, and IL-1β) and inflammatory factors (IL-6 and TNF-α) were assessed by using the qRT-PCR, Western blot and ELISA techniques. The results showed that EHDPHP induced pathological morphological changes and elevated LDH content in chick lungs, decreased lung antioxidant enzymes (GSH-Px and SOD) activities, increased peroxidation product MDA content and up-regulated the expression levels of cellular pyroptosis factors (NLRP3, ASC, NF-κB, Pro-Caspase-1, IL-18, and IL-1β), and the synthesis and secretion of inflammatory factors (IL-6 and TNF-α) were promoted. The above changes were EHDPHP dose-dependent. The results indicated that EHDPHP induced oxidative stress in chick lungs, resulting in oxidative damage to the lungs, and, intriguingly, the cellular pyroptosis pathway was activated, which was also involved in the process of EHDPHP-induced inflammatory damage in chick lungs. The results of this study revealed for the first time the damaging effects and mechanisms of EHDPHP on chick lungs. Also, they provided a scientific basis for further exploring the mechanisms of toxicity damage, safe use, and pollution control of EHDPHP.

Tropical peatlands are significant sources of methane (CH₄), but their contribution to the global CH₄ budget remains poorly quantified due to the lack of long-term, continuous and high-frequency flux measurements. To address this gap, we measured net ecosystem CH₄ exchange (NEE-CH₄) using eddy covariance technique throughout the conversion of a tropical peat swamp forest to an oil palm plantation. This encompassed the periods before, during and after conversion periods from 2014 to 2020, during which substantial environmental shifts were observed. Draining the peatland substantially lowered mean monthly groundwater levels from -20.0 ± 14.2 cm before conversion to -102.3 ± 31.6 cm during conversion and increased slightly to -96.5 ± 19.3 cm after conversion. Forest removal increased mean monthly soil temperature by 2.3 to 3.1 °C, reducing net radiation (R_n) and raising vapor pressure deficit (VPD). Following the tree removal, controlled burning temporarily warmed air temperature by 8 °C, increased VPD and significantly attenuated R_n, resulting in negative values owing to radiation interception by smoke and increased surface warming. Contrary to expectations that drainage would lower CH₄ emissions, the site remained a consistent net source, with even higher emissions observed during and after conversion. The mean monthly NEE-CH₄ during conversion (23.3 ± 8.6 mg C m^-2 d^-1) was about 2-times higher than before conversion (12.1 ± 5.3 mg C m^-2 d^-1) and about 1.5-times higher than after conversion (16.3 ± 4.1 mg C m^-2 d^-1). The heightened CH₄ release is likely attributable to emissions from drainage ditches, underscoring their significant role in post-conversion CH₄ dynamics. Despite its short duration, controlled burning substantially elevated NEE-CH₄, ranging from 0.04 to 0.91 mg C m^-2 s^-1. Our findings highlight the substantial impact of land conversion on peatland CH₄ dynamics, emphasizing the need for accurate flux measurements across various conversion stages to refine global CH₄ budgets.

Polychlorinated biphenyls (PCBs), a typical type of persistent organic pollutants (POPs), were previously widely employed as insulating and heat exchange fluids in transformers and capacitors. Despite knowledge of its adverse effects, the precise mechanism underlying PCB77 toxicity remains enigmatic. In this study, we utilized zebrafish as a model organism to explore the toxic effects of various concentrations of PCB77 (10, 200, and 1000 μg/L) and its molecular toxicity mechanisms. Upon exposure to dosages of PCB77 throughout embryonic and larval stages, the zebrafish exhibited adverse phenotypic manifestations, including deformities, decreased heart rates, increased distances between the bulbus arteriosus (BA) and sinus venosus (SV) and reduced locomotor ability. Transcriptome analysis revealed the common enriched pathways across all PCB77 concentration groups, such as retinol metabolism, steroid hormone biosynthesis, and metabolism of xenobiotics by cytochrome P450, which are closely related to the activity of cytochrome P450 (cyp1a) enzymes. Furthermore, Adverse Outcome Pathway (AOP) framework which integrates AOPs and dose-dependent transcriptomics to predict PCB77-induced adverse outcomes (AOs) revealed that aryl hydrocarbon receptor (AhR) associated AOPs triggered by PCB77 exposure may increase early-life stage mortality and decrease cardiac development, indicating that the primary toxic pathways of PCB77 in zebrafish may involve AhR-mediated signaling. Besides, molecular docking modeling demonstrated that PCB77 could bind to the groove within the AhR domain, suggesting that PCB77 induces embryotoxicity in zebrafish through its interaction with AhR. Collectively, these findings not only deliver a thorough examination of PCB77-induced developmental toxicity as well as the underlying mechanisms, but also validate the efficacy of the analytical approach leveraging AOP framework in unraveling toxicity mechanisms of environmental contaminants, which holds promise for risk assessment associated with novel environmental pollutants.

Selective recovery of rare earth elements (REEs) from environmental waste is strategically significant. Herein, Ce(III) imprinted EDTA modified chitosan-magnetic graphene oxide (IIP-EDTA-CS-MGO) was prepared for selective recovery of Ce(III). Furthermore, adsorption mechanism was clarified based on versatile adsorption fittings and spectroscopic tests. Result presents, adsorption reaches its peak at pH = 7 in 25 min with maximum adsorption capacity 353.28 mg·g^-1. Functional groups C(=O)NH, CN and C-O-C in IIP-EDTA-CS-MGO provide heterogeneous affinity for Ce(III) to induce chemical adsorption. Thermodynamic calculation suggests spontaneous, endothermic and entropy increasing adsorption. Owing to Ce(III) imprinting, IIP-EDTA-CS-MGO demonstrates selectivity coefficients 3.09, 3.19, 14.10, 12.65 towards Ce(III) for binary solutions Ce/Eu, Ce/Dy, Ce/Cu, Ce/Cr, respectively. By virtue of its paramagnetic property, IIP-EDTA-CS-MGO can be readily recovered via magnetic separation for cyclic adsorption, thereby retaining adsorption quantity 116.58 mg·g^-1 for Ce(III) in five consecutive cycles. This work provides a new approach for fabricating magnetic bio-adsorbent towards selective recovery of Ce(III).

Based on the potential bactericidal properties of borate, we synthesized controlled-release borate (CRB) as a novel biocide to inhibit microbial proliferation in a recirculating cooling water system (RCS). In this study, toxicity experiments of CRB were conducted on the dominant bacteria and algae isolated from an actual RCS. The effects of CRB on biocidal performance and genotoxicity were evaluated in a simulated RCS. Our results showed that the inhibition rates of CRB on bacteria and algae reached 80.4-84.0 % and 55.0 %, respectively. CRB achieved a complete release of antibacterial factor, boron, within 20 days in the simulated RCS. The number of heterotrophic bacteria (HB) was reduced to 3.8 × 10³ CFU/mL (day 30), which met the requirement of the Chinese standard (GB/T 50050-2017). 16S/18S rRNA gene sequencing showed that CRB achieved a significant reduction of the predominant phyla, including Pseudomonadota and Chlorophyta. Flow cytometry analysis demonstrated that the algae-inhibiting behavior of CRB was mainly reflected in the inhibition of nucleic acid synthesis and photosystem II activity. Metatranscriptomic analysis revealed that the downregulated key genes were primarily annotated in the "photosynthesis-antenna proteins" and "large/small subunit ribosomal protein" pathways. It indicated that CRB might deteriorate microbial photosynthetic activity and protein synthesis, interfering with microbial growth. Additionally, CRB was associated with negative effects on reactive oxygen species metabolism and regulation of cell size. Moreover, CRB exhibited excellent scaling and corrosion inhibition properties. The determination of the biocidal mechanism of CRB will help enhance the practical application of multi-functional water treatment agents in the RCS.

Environmental justice (EJ) mapping tools are geographic information system (GIS)-based digital maps that integrate environmental, socioeconomic, health, and demographic data to identify areas experiencing environmental injustices. These tools are increasingly used to guide investments toward disadvantaged communities. This review examines 25 EJ tools, describing their functionalities, coverage, and indicator types, ranging from biological susceptibilities to socioeconomic and environmental factors. We discuss the tools' resolutions, update frequencies, and data breadth, emphasizing their role in informing EJ interventions. However, gaps exist, particularly in the underrepresentation of U.S. territories and the limited inclusion of communicable diseases and climate impacts. This underscores the need for more comprehensive tools that consider diverse health risks and socio-environmental factors. Cumulative impact assessments should be integrated into EJ tools, incorporating a broad spectrum of indicators to capture the multifaceted nature of environmental injustices. Community engagement is also crucial in developing and updating EJ tools to ensure they accurately reflect community needs and conditions. By addressing these recommendations, EJ tools can better serve as effective instruments for highlighting and mitigating environmental disparities, supporting broader environmental justice and health equity goals.

Environmental characteristics drastically shape the host-parasite associations under natural conditions. This is the case of parasites such as avian haemosporidians which naturally infect birds and are transmitted by insect vectors. Landscape characteristics are known to determine the epidemiology of transmission of these parasites in the wild, but the strength of these factors may differ at different spatial scales. We studied the effects of the landscape structure and environmental variables on the prevalence and richness of lineages of avian haemosporidian parasites (genera Plasmodium, Haemoproteus and Leucocytozoon) infecting birds in a highly diverse area of Antioquia, Colombia. We screened blood samples from 678 individuals across 90 bird species for number of infections, prevalence and richness of haemosporidian lineages in sites surrounding three hydroelectric dams. We obtained environmental and landscape structure variables around the bird sampling points at different spatial scales (from 50 to 500 m radii, every 50 m) and selected the most important ones. We modelled the relationships between parasite infection variables and landscape structural and environmental characteristics. Effects of landscape structure on variables reflecting haemosporidian infections varied according to the selected scale of analyses. The scale of the effect of landscape structure was larger for the number of infections and prevalence (Average = 350 and 425 m radius) than for lineage richness (Average = Plasmodium 219 m, Haemoproteus 244 m). Agricultural patch density notably increased number of infection rates (pseudo-R² = 0.68). The number of infections and the richness of Haemoproteus lineages correlated with agricultural connectivity at larger scales (500 m). Haemosporidian prevalence was primarily linked with proportion forest and agricultural covers. Haemoproteus richness was influenced by connectivity and NDVI - Normalized Difference Vegetation Index (pseudo-R² = 0.83), while Plasmodium richness was affected by anthropogenic density, edge density, forest proportion, and temperature (pseudo-R² = 0.79). Changes in parasite infection and prevalence remain difficult to predict, as each parasite-host system is susceptible to many unaccounted variables. This study found that transformed landscapes, particularly density of anthropogenic and agricultural patches nearby increases haemosporidian parasites at different scales. These findings underscore the complex interplay between landscape structure and haemosporidian infections in avian hosts in tropical ecosystems.

The Baltic Sea, a semi-enclosed marginal sea with a catchment area four times its size, acts as a sink and continues to show detectable levels of persistent organic pollutants (POPs) in its sediments. This is attributed to the synthesis and industrial use of commercial polychlorinated biphenyls (PCB) products, as well as the widespread use and discharge of certain chlorinated pesticides into the natural environment during the last century. Our study investigates chlorinated hydrocarbon pollutants, the polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolites as well as hexachlorobenzene (HCB) in sediments based on several short sediment cores from different basins covering almost the entire Baltic Sea. In this study, we document the decline of PCB, HCB and DDT metabolites in Baltic Sea sediments, visible in a sevenfold reduction of pollution levels over a period of 50 years since their maximum production in the mid-eighties of the last century. We reflect the pollution levels against the global regulations, especially the worldwide ban of the POPs at the beginning of the 21st century. Based on our results, we are now able, for the first time, to evaluate the fate of POPs in Baltic Sea sediments and to provide further explanation for the detection of POPs in previous and future studies.

Conversion of caustic red mud (RM, Alumina industry waste) into building materials becoming one of the viable solution for its large scale utilization. The building materials developed using RM often results in efflorescence due to its high alkalinity, which is detrimental for the structural integrity of the buildings. The X-ray shielding tiles developed through ceramic route using the mixtures of RM, BaSO₄ and kaolin clay also suffers from severe Na₂SO₄ efflorescence when sintered above 1000 °C. The XRD analysis confirms the formation of Na₂SO₄ through the solid-state reaction that occurs between BaSO_4, Na₂Fe₂Ti₆O₁₆ and NaAlSiO₄ at above 1000 °C. The formation of Na₂SO₄ was reduced by adding KOH with the mixtures, which reacts with RM and BaSO₄ and form stable K₃NaS₂O₈ and KAlSiO₄ phases, as revealed through Rietveld refinement. Eventually, the wt% of Na₂SO₄ was found to decrease from 3.2 % to 0.2 % while adding 8 % of KOH. Subsequently, the efflorescence has decreased from 90 % to 2 %. Moreover, the KOH addition assist to increase the density of the shield from 2.8 g/cc to 3.6 g/cc. It eventually increases both the mechanical strength and X-ray attenuation characteristics of the shield. The flexural strength of the tile has increased from 16.46 N/mm² to 19.46 N/mm² while adding 8 % KOH. The 15 mm thick tile possess the attenuation equivalent to 2 mm lead at 100 kV.