Efficient Photoreduction of CO2 to CO with 100% Selectivity by Slowing Down Electron Transport.

It remains challenging to obtain a single product in the gas-solid photocatalytic reduction of CO2 because CO and CH4 are usually produced simultaneously. This study presents the design of the I-type nested heterojunction TiO2/BiVO4 with controllable electron transport by modulating the TiO2 component. This study demonstrates that slowing electron transport could enable TiO2/BiVO4-4 to generate CO with 100% selectivity. In addition, modifying TiO2/BiVO4-4 by loading a Cu single atom further increased the CO product yield by 3.83 times (17.33 µmol·gcat-1·h-1), while maintaining 100% selectivity for CO. Characterization and density functional theory (DFT) calculations revealed that the selectivity was mainly determined by the electron transport of the support, whereas CO2 was efficiently adsorbed and activated by the Cu single atom. Such a two-step regulation strategy of combining heterojunction with single atom enhances the possibility of simultaneously obtaining high selectivity and high yield in the photocatalytic reduction of CO2.

Associations of Bisphenols Exposure and Hyperuricemia Based on Human Investigation and Animal Experiments.

Hyperuricemia is characterized by elevated blood uric acid (UA) levels, which can lead to certain diseases. Epidemiological studies have explored the association between environmental contaminant exposure and hyperuricemia. However, few studies have investigated the role of chemical exposure in the development of hyperuricemia. Here, we sought to investigate the effects of bisphenol exposure on the occurrence of hyperuricemia. Fifteen bisphenol chemicals (BPs) were detected in human serum and urine samples collected from an area with a high incidence of hyperuricemia in China. Serum UA levels positively correlated with urinary bisphenol S (BPS), urinary bisphenol P (BPP), and serum bisphenol F (BPF). The effects of these three chemicals on UA levels in mice were explored at various exposure concentrations. An increase in serum UA levels was observed in BPS- and BPP-exposed mice. The results showed that BPS exposure increased serum UA levels by damaging the structure of the kidneys, whereas BPP exposure increased serum UA levels by disturbing purine metabolism in the liver. Moreover, BPF did not induce an increase in serum UA levels owing to the inhibition of guanine conversion to UA. In summary, we provide evidence of the mechanisms whereby exposure to three BPs disturbs UA homeostasis. These findings provide new insights into the risks of exposure to bisphenol chemicals.

Comprehensive Toxicological Assessment of Halobenzoquinones in Drinking Water at Environmentally Relevant Concentration.

Halobenzoquinones (HBQs), an emerging unregulated category of disinfection byproduct (DBP) in drinking water, have aroused an increasing concern over their potential health risks. However, the chronic toxicity of HBQs at environmentally relevant concentrations remains largely unknown. Here, the occurrence and concentrations of 13 HBQs in drinking water from a northern megacity in China were examined using ultrahigh performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS). Four HBQs, including 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ), 2,6-dibromo-1,4-benzoquinone (2,6-DBBQ), 2,3,6-trichloro-1,4-benzoquinone (TriCBQ), and 2,5-dibromo-1,4-benzoquinone (2,5-DBBQ), were detected beyond 50% occurrence frequency and at median concentrations from 4 to 50 ng/L. The chronic toxicity of these four HBQs to normal human colon and liver cells (FHC and THLE-2) was investigated at these concentrations. After 90 days of exposure, 2,5-DBBQ and 2,6-DCBQ induced the highest levels of oxidative stress and deoxyribonucleic acid (DNA) damage in colon and liver cells, respectively. Moreover, 2,5-DBBQ and 2,6-DCBQ were also found to induce epithelial-mesenchymal transition (EMT) in normal human liver cells via the extracellular signal regulated kinase (ERK) signaling pathway. Importantly, heating to 100 °C (boiling) was found to efficiently reduce the levels of these four HBQs in drinking water. These results suggested that environmentally relevant concentrations of HBQs could induce cytotoxicity and genotoxicity in normal human cells, and boiling is a highly efficient way of detoxification for HBQs.

Effects of oilfield-produced water discharge on the spatial patterns of microbial communities in arid soils.

Recently intensified oil exploitation has resulted in the discharge of large amounts of wastewater containing high concentrations of organic matter and nutrients into the receiving aquatic and soil environments; however, the effects of oilfield-produced water on the soil microbiota are poorly understood. In this study, we conducted a comprehensive analysis to reveal the composition and diversity of the microbial community at horizontal and vertical scales in a typical arid soil receiving oilfield-produced water in Northwest China. Oilfield-produced water caused an increase in microbial diversity at the horizontal scale, and the communities in the topsoil were more variable than those in the subsoil. Additionally, the microbial taxonomic composition differed significantly between the near- and far-producing water soils, with Proteobacteria and Halobacterota dominating the water-affected and reference soil communities, respectively. Soil property analysis revealed that pH, salt, and total organic content influenced the bacterial communities. Furthermore, the oil-produced water promoted the complexity and modularity of distance-associated microbial networks, indicating positive interactions for soil ecosystem function, but not for irrigation or livestock watering. This is the first detailed examination of the microbial communities in soil receiving oilfield-produced water, providing new insights for understanding the microbial spatial distributions in receiving arid soils.

Highly sensitive response to the toxicity of environmental chemicals in transparent casper zebrafish.

The response sensitivity to toxic substances is the most concerned performance of animal model in chemical risk assessment. Casper (mitfaw2/w2;mpv17a9/a9), a transparent zebrafish mutant, is a useful in vivo model for toxicological assessment. However, the ability of casper to respond to the toxicity of exogenous chemicals is unknown. In this study, zebrafish embryos were exposed to five environmental chemicals, chlorpyrifos, lindane, α-endosulfan, bisphenol A, tetrabromobisphenol A (TBBPA), and an antiepileptic drug valproic acid. The half-lethal concentration (LC50) values of these chemicals in casper embryos were 62-87 % of that in the wild-type. After TBBPA exposure, the occurrence of developmental defects in the posterior blood island of casper embryos was increased by 67-77 % in relative to the wild-type, and the half-maximal effective concentration (EC50) in casper was 73 % of that in the wild-type. Moreover, the casper genetic background significantly increased the hyperlocomotion caused by chlorpyrifos and lindane exposure compared with the wild-type. These results demonstrated that casper had greater susceptibility to toxicity than wild-type zebrafish in acute toxicity, developmental toxicity and neurobehavioral toxicity assessments. Our data will inform future toxicological studies in casper and accelerate the development of efficient approaches and strategies for toxicity assessment via the use of casper.

The critical role of microplastics in the fate and transformation of sulfamethoxazole and antibiotic resistance genes within vertical subsurface-flow constructed wetlands.

Constructed wetlands (CWs) are reservoirs of microplastics (MPs) in the environment. However, knowledge about the impact of MPs on antibiotic removal and the fate of antibiotic resistance genes (ARGs) is limited. We focused on sulfamethoxazole (SMX) as a representative compound to examine the effects of MPs on SMX removal and the proliferation and dissemination of two SMX-related ARGs (sul1 and sul2) in vertical subsurface-flow CW (VFCW) microcosm. The presence of MPs in the substrate was found to enhance the proliferation of microorganisms owing to the large specific surface area of the MPs and the release of dissolved organic carbon (DOC) on MP surfaces, which resulted in a high SMX removal ranging from 97.80 % to 99.80 %. However, the presence of MPs promoted microbial interactions and the horizontal gene transfer (HGT) of ARGs, which led to a significant increase in the abundances of sul1 and sul2 of 68.47 % and 17.20 %, respectively. It is thus imperative to implement rigorous monitoring strategies for MPs to mitigate their potential ecological hazards.

Development of an Automated Morphometric Approach to Assess Vascular Outcomes following Exposure to Environmental Chemicals in Zebrafish.

BACKGROUND: Disruptions in vascular formation attributable to chemical insults is a pivotal risk factor or potential etiology of developmental defects and various disease settings. Among the thousands of chemicals threatening human health, the highly concerning groups prevalent in the environment and detected in biological monitoring in the general population ought to be prioritized because of their high exposure risks. However, the impacts of a large number of environmental chemicals on vasculature are far from understood. The angioarchitecture complexity and technical limitations make it challenging to analyze the entire vasculature efficiently and identify subtle changes through a high-throughput in vivo assay. OBJECTIVES: We aimed to develop an automated morphometric approach for the vascular profile and assess the vascular morphology of health-concerning environmental chemicals. METHODS: High-resolution images of the entire vasculature in Tg(fli1a:eGFP) zebrafish were collected using a high-content imaging platform. We established a deep learning-based quantitative framework, ECA-ResXUnet, combined with MATLAB to segment the vascular networks and extract features. Vessel scores based on the rates of morphological changes were calculated to rank vascular toxicity. Potential biomarkers were identified by vessel-endothelium-gene-disease integrative analysis. RESULTS: Whole-trunk blood vessels and the cerebral vasculature in larvae exposed to 150 representative chemicals were automatically segmented as comparable to human-level accuracy, with sensitivity and specificity of 95.56% and 95.81%, respectively. Chemical treatments led to heterogeneous vascular patterns manifested by 31 architecture indexes, and the common cardinal vein (CCV) was the most affected vessel. The antipsychotic medicine haloperidol, flame retardant 2,2-bis(chloromethyl)trimethylenebis[bis(2-chloroethyl) phosphate], and tert-butylphenyl diphenyl phosphate ranked as the top three in vessel scores. Pesticides accounted for the largest group, with a vessel score of ≥1, characterized by a remarkable inhibition of subintestinal venous plexus and delayed development of CCV. Multiple-concentration evaluation of nine per- and polyfluoroalkyl substances (PFAS) indicated a low-concentration effect on vascular impairment and a positive association between carbon chain length and benchmark concentration. Target vessel-directed single-cell RNA sequencing of fli1a+ cells from larvae treated with λ-cyhalothrin, perfluorohexanesulfonic acid, or benzylbutyl phthalate, along with vessel-endothelium-gene-disease integrative analysis, uncovered potential associations with vascular disorders and identified biomarker candidates. DISCUSSION: This study provides a novel paradigm for phenotype-driven screenings of vascular-disrupting chemicals by converging morphological and transcriptomic profiles at a high-resolution level, serving as a powerful tool for large-scale toxicity tests. Our approach and the high-quality morphometric data facilitate the precise evaluation of vascular effects caused by environmental chemicals. https://doi.org/10.1289/EHP13214.

Special Distribution of Nanoplastics in the Central Nervous System of Zebrafish during Early Development.

There is growing concern about the distribution of nanoplastics (NPs) in the central nervous system (CNS), whereas intrusion is poorly understood. In this study, fluorescent-labeled polystyrene NPs (PS-NPs) were microinjected into different areas of zebrafish embryo to mimic different routes of exposure. PS-NPs were observed in the brain, eyes, and spinal cord through gametal exposure. It indicated that maternally derived PS-NPs were specially distributed in the CNS of zebrafish during early development. Importantly, these NPs were stranded in the CNS but not transferred to other organs during development. Furthermore, using neuron GFP-labeled transgenic zebrafish, colocalization between NPs and the neuron cells revealed that NPs were mostly enriched in the CNS surrounded but not the neurons. Even so, the intrusion of NPs into the CNS induced the significant upregulation of some neurotransmitter receptors, leading to an inhibited effect on the movement of zebrafish larvae. This work provides insights into understanding the intrusion and distribution of NPs in the CNS and the subsequent potential adverse effects.

Immobilization of laccase on magnetic PEGDA-CS inverse opal hydrogel for enhancement of bisphenol A degradation in aqueous solution.

Endocrine disruptors such as bisphenol A (BPA) adversely affect the environment and human health. Laccases are used for the efficient biodegradation of various persistent organic pollutants in an environmentally safe manner. However, the direct application of free laccases is generally hindered by short enzyme lifetimes, non-reusability, and the high cost of a single use. In this study, laccases were immobilized on a novel magnetic three-dimensional poly(ethylene glycol) diacrylate (PEGDA)-chitosan (CS) inverse opal hydrogel (LAC@MPEGDA@CS@IOH). The immobilized laccase showed significant improvement in the BPA degradation performance and superior storage stability compared with the free laccase. 91.1% of 100 mg/L BPA was removed by the LAC@MPEGDA@CS@IOH in 3 hr, whereas only 50.6% of BPA was removed by the same amount of the free laccase. Compared with the laccase, the outstanding BPA degradation efficiency of the LAC@MPEGDA@CS@IOH was maintained over a wider range of pH values and temperatures. Moreover, its relative activity of was maintained at 70.4% after 10 cycles, and the system performed well in actual water matrices. This efficient method for preparing immobilized laccases is simple and green, and it can be used to further develop ecofriendly biocatalysts to remove organic pollutants from wastewater.