Environmental Research最新文献

Per- and polyfluoroalkyl substances (PFASs) have attracted considerable attention because of their toxicity, persistence and bioaccumulation potential. With the construction of the Hainan Free Trade Port and the rapid development of economy, environmental pollution on Hainan Island is becoming increasingly prominent. PFASs have been detected in the seawater and sediments of mangrove ecosystems on Hainan Island. As the receiving water of wastewater treatment plants (WWTPs) and industrial wastewater, rivers are inevitably contaminated by PFASs. However, few studies have focused on PFAS pollution in three large rivers (the Nandu, Changhua, and Wanquan rivers) on Hainan Island. In the present study, the pollution status, potential sources, and ecological risks of PFASs in these three major rivers were explored. Perfluorobutanonic acid (PFBA) (48.7%) was found to be the major PFASs in the surface waters, and perfluoroundecanoic acid (PFUnDA) (19.7%) was the major PFASs in the sediments of the three major rivers. The concentrations of ∑PFASs in the upper-midstream region were low due to minimal human influence and increased in the middle-lower reaches with increasing industrial activity and urbanization, whereas decreased at downstream sites near estuaries where river water was diluted with seawater. WWTP effluent, industrial wastewater discharge, the application and discharge of aqueous fire-fighting foam, storm runoff and landfill leachate were the major sources of PFASs in the three major rivers. In surface water, perfluorooctanoic acid (PFOA), perfluorooctane sulfonamide (PFOSA) and perfluorooctadecanoic acid (PFODA) posed low-moderate risks at 5.71-85.6% of the sampling sites. PFASs in the sediment posed no ecological risk. This study provides key data regarding the pollution status and potential sources of PFASs in large rivers on subtropical islands.

Background: The association between per- and polyfluoroalkyl substances (PFAS) and mitochondrial DNA copy number (mtDNAcn) in children, and the potential impact of estimated glomerular filtration rate (eGFR) on this association, remains unclear.

Methods: We conducted a panel study with up to 3 surveys over 3 seasons in Weinan and Guangzhou, China. A total of 284 children aged 4-12 years were available, with 742 measurements of 11 PFAS and mtDNAcn. Linear mixed-effect (LME), quantile g-computation (qgcomp), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were used to investigate the associations of individuals and a mixture of PFAS with mtDNAcn, and the modifying effect of eGFR on these associations.

Results: Legacy PFAS, including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorooctane sulfonate (PFOS) and emerging PFAS, 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA), were significantly associated with decreased mtDNAcn in a linear dose-response manner (FDR <0.05). The multiple PFAS model showed each doubling increase in PFOA related to a 6.36% (95%CI: -10.22%, -2.34%) decrement in mtDNAcn. Meanwhile, the PFAS mixture was dose-responsive related to decreased mtDNAcn, with PFOA being the largest contributor, followed by PFUnDA and PFNA. Notably, eGFR modified the inverse association between PFOA and mtDNAcn (P-int = 0.039), with a more pronounced decrement in children with an eGFR below the 20^th value (101.71 mL/min/1.73m²). In addition, age significantly modified the relationship between PFOA and decreased mtDNAcn (P-int = 0.028), with a stronger association in those aged 7 years or older.

Conclusion: Both individual and the mixture of legacy and emerging PFAS exposure were associated with decreased mtDNAcn in children, with PFOA as the main contributor and modification of eGFR.

Electrogenic biofilm formation has been shown to be induced by intracellular c-di-GMP signaling and extracellular quorum sensing, but their interactions have been rarely explored. This study explored the effects of quorum quenching (induced by adding acylase) on electrogenic biofilm development and its underlying mechanisms. Quorum quenching impaired the electricity generation and electroactivity of electrogenic biofilms as indicated by dye decolorization rate. It significantly decreased the proportion of typical exoelectrogen Geobacter from 62.0% to 36.5% after 90 days of operation, and enriched some other functional genera (e.g., Dysgonomonas and Sphaerochaeta) to ensure normal physiological function. Moreover, metagenomic analysis revealed that the addition of acylase weakened the potential of chemical communication, as indicated by the decrease in the abundance of genes encoding the production of AHL and c-di-GMP, and the increase in the abundance of aiiA and pvdQ genes (encoding quorum quenching) and cdgC gene (responsible for c-di-GMP breakdown). Functional contribution analysis indicated that Geobacter was a major contributor to hdtS gene (encoding AHL synthesis). These findings demonstrated that quorum quenching adversely impaired not only quorum sensing but also intracellular c-di-GMP signaling, ultimately inhibiting the development of biofilm. This work lays the foundation for regulating electrogenic biofilm development and improving the performance of microbial electrochemical system using signal communication strategy.

Coumarin, a synthetic chemical and phytotoxin, exhibits hepatotoxicity and carcinogenicity, posing threats to both human health and environmental safety. Microbial degradation effectively mitigates environmental contamination. In this study, a coumarin-degrading bacterial consortium designated as XDS-7 with Pseudomonas as the key degrader was obtained. However, there is a lack of comprehensive perspective on the key role of the genus Pseudomonas involved in coumarin degradation. We employed the consortium XDS-7 as a model system to investigate the critical role of the genus Pseudomonas involved in coumarin degradation. Metagenomic binning analysis indicated that bin 14 (Pseudomonas sp.) contains the full complement of genes required for coumarin degradation. A coumarin-degrading bacterium, Pseudomonas sp. strain X4, was isolated from consortium XDS-7 using a traditional enrichment method supplemented with chloramphenicol. Genomic analysis demonstrated that strain X4 carries a suite of genes to completely degrade coumarin. Bioinformatics analysis revealed that putative coumarin-degrading bacteria are widely distributed across diverse bacteria of the genus Pseudomonas. In addition, strain X4 completely removed 100 mg kg^-1 of coumarin from contaminated soil within 48 h and 100 mg L^-1 of coumarin from contaminated wastewater within 4 h. This study will greatly enhance our understanding and utilization of these valuable bioresources.

To alleviate situation caused by azo dyestuff and antibiotics, a series of CdS/sulfur doped carbon nitride (GCNS) S-scheme heterojunction photocatalysts have been successfully fabricated by a pretty facile solid-state diffusion (SSD) method,. Under visible light, the optimal sample called CdS/GCNS-1:2 presented the best photodegradation rate of nearly 100% over methyl orange (MO), of which the reaction constant k was about 9.67 and 5.39 times higher than that of pure GCNS and CdS, respectively. Degradation rate of 91% over tetracycline hydrochloride (TCH) was achieved within 60 min as well. The DFT calculations, XPS and charge flow tracking tests clarified the surge of C-S linkages and the construction of interfacial S-scheme heterojunction. The former promoted the fixation and conversion of adsorbed oxygen, while the latter accelerated the separation/transport of charge carriers. These tuning eventually collaborates on the promotion of •O₂^- reactive species, which confirmed as the predominant role of photoreaction. Furthermore, the plausible degradation pathways of MO/TCH and photocatalytic optimization mechanism were thoroughly elucidated.

Fish and seafood are considered a major source of human dietary exposure to per- and polyfluoroalkyl substances (PFAS). In this study, we examined levels of 35 PFAS in fish samples of brown trout and mottled sculpin, which occupy different trophic positions, collected in 2014 from East Canyon Creek in Utah, USA. We observed 20 PFAS with ∑₂₀PFAS ranging from 0.46-63.9 ng/g and from

Biochar loaded with MgO is a promising adsorbent for the removal and recovery of phosphate from aqueous solutions. However, its phosphate adsorption capacity is unsatisfactory, especially at low phosphate concentrations. Loading nanoscale MgO onto biochar is an effective strategy. Here, ultrafine MgO nanoparticles and MgO nanosheets were loaded onto biochar from steam-exploded straw (UMB and SMB) via an impregnation-precipitation-pyrolysis method. The crystal sizes of ultrafine MgO nanoparticles and MgO nanosheets were about 6-8 nm and 10-16 nm, respectively. The phosphate adsorption capacity of UMB at C₀ = 100 mg P L^-1 was 219.4 mg P g^-1, which was higher than that of SMB (164.9 mg P g^-1). The results suggest that surface precipitation was the dominant adsorption mechanism and the hydration process and the smaller particle size of MgO may play a key role in the superior phosphate removal by UMB. Removal tests in real low-concentration phosphate water samples showed that 0.05 g L^-1 UMB could reduce the phosphate concentration from 0.17 mg P L^-1 to 0.01 mg P L^-1. In addition, phosphate could be desorbed from UMB in varying environments, and therefore has the potential to be used in fertilizer production or directly as a slow-release fertilizer.

Lignocellulose is the most abundant, sustainable, and comparatively economical renewable biomass containing ample fermentable sugars for bio-based chemical production, such as lactic acid (LA). LA is a versatile chemical with substantial global demand. However, the concurrent utilization of mixed sugars derived from lignocellulose, including glucose, xylose, and arabinose, remains a formidable challenge because of the metabolic regulation of carbon catabolite repression (CCR), in which glucose is preferentially utilized over non-glucose sugars, resulting in the loss of carbon resources and a decrease in biorefinery efficacy. Most current studies on CCR have concentrated on elucidating the principles and their impact on specific bacterial species using mixed carbon sources. However, there remains a notable dearth of comprehensive reviews summarizing the underlying principles and corresponding mitigation strategies across other bacterial strains encountering similar challenges. In light of this, this article delineates the possible factors that lead to CCR, including signal transduction and metabolic pathways. Additionally, the fermentation conditions and nutrients are described. Finally, this study proposes appropriate mitigation strategies to overcome the aforementioned obstacles and presents new insights into the rapid and simultaneous consumption of mixed sugars to bolster the production yields of biofuels and chemicals in the future.

Background: Female sexual function is important for sexual well-being, general health, fertility, and relationship satisfaction. Distressing impairments in sexual function, clinically recognized as female sexual dysfunction (FSD), can manifest as issues with interest/desire, arousal, orgasm, and pain during vaginal penetration. Some evidence suggests that exposure to endocrine-disrupting chemicals may adversely affect female sexual function, but associations for per- and polyfluoroalkyl substances (PFAS) have not been previously evaluated.

Objective: We investigated associations between serum PFAS concentrations and female sexual function among U.S. pregnancy planners.

Methods: We used cross-sectional data from participants from Pregnancy Study Online (PRESTO), a prospective preconception cohort study. Participants reported sexual function and distress at baseline on two validated measures: a modified version of the Female Sexual Function Index-6 (FSFI-6) and the Female Sexual Distress Scale (FSDS). We quantified PFAS serum concentrations in samples collected in the preconception period (i.e., at baseline) using solid phase extraction-high performance liquid chromatography-isotope-dilution-mass spectrometry. Participants reported sociodemographic information on structured baseline questionnaires. We included 78 participants with complete PFAS and sexual function data and fit multivariable linear regression models to estimate mean differences in FSFI-6 scores (β) or percent differences (%) in FSDS scores per interquartile range (IQR) increase in PFAS concentrations, adjusting for age, annual household income, years of education, parity, and body mass index. We further investigated effect measure modification by parity (parous vs. nulliparous) in stratified models.

Results: An IQR increase in perfluorohexanesulfonic acid was associated with a 1.0-point decrease (95% CI = -1.8, -0.1) in reported FSFI-6 scores, reflecting poorer sexual function. PFAS were consistently associated with lower FSFI-6 scores among parous participants. PFAS were also associated, though imprecisely, with greater sexual distress.

Conclusion: Some PFAS were associated with poorer sexual function among U.S. pregnancy planners, but future studies are needed to clarify the extent to which PFAS influences female sexual health.

In this study, we collected 177 soil samples from major tea-producing areas in China, systematically investigated the spatial distribution characteristics of the polycyclic aromatic hydrocarbons (PAHs) in the soil of these tea plantations and discussed the environmental factors influencing of the PAHs in tea garden soil. The feature ratio method and source analysis methods were used to determine the PAHs source in tea garden soil, and the potential risk of PAHs in tea garden soil was also evaluated. The results showed that the concentrations of the 16 PAHs in 177 samples ranged from 6.21 to 4068.91 ng g^-1, with an average of 257.00 ng g^-1. The majority of PHAs in tea garden soils predominantly contained a 5-6 ring pattern, and the highest content was indeno (1,2,3-cd) pyrene (InP, 23%) and benzo (b) fluoranthrene (BbF, 16%). In addition, 10.16% of the PAHs in tea plantation soils contained a 2-3-ring pattern, with naphthalene (NAP) having the highest content. PAH source in Chinese tea garden soil was predominantly mixed combustion, such as incomplete biomass combustion, petroleum combustion, coal combustion and wood combustion. The PAHs distribution was mainly affected by the industrial structure, geographical location of tea plantation, climatic conditions, soil properties and other factors in different regions. According to the Dutch Maliszewska-Kordybach grading standard, 79% of the soil samples from Chinese tea plantations were classified as unpolluted, 13% as mildly polluted, and 2% and 6% as moderately and severely polluted, respectively. Although the PAH pollution in tea plantations was generally low, BaP and InP pose significant ecological risk in some areas. Therefore, strategies such as effective guidelines and environmentally friendly technologies, must be developed to reduce the risk of PAH pollution in tea plantation soils.