Environmental Science & Technology Letters Environ.最新文献

Water desalination by capacitive deionization techniques has often suffered from the relegating performance of carbon-based non-Faradaic electrode materials. To overcome the rate-limiting charge transfer kinetics and weak ion adsorption tendency, a metal–organic framework (MOF)-derived hybrid electrode with an exceptional flow capacitive deionization performance is reported here. Using MIL-88(FeNi) as a sacrificial template, we synthesized a porous graphitic framework decorated with nanosized spinel NiFe₂O₄ (NiFe₂O₄@PC-500) electrodes, maintaining a parent rod-shaped morphology with a large surface area of 1227 m²/g. The synergistic interaction of NiFe₂O₄ nanoparticles with the mesoporous graphitic framework exhibited remarkable desalination performance with a salt adsorption capacity of ∼34 mg/g and ∼89% salt removal at 1.2 V, surpassing those of traditional carbon-based electrodes. Moreover, NiFe₂O₄@PC-500 maintained its desalination capacity and structural integrity over prolonged desalination cycles with a specific capacitance of ∼206 F/g and capacitive retention over 500 cycles. This study presents a universal approach for strategically implementing MOF-derived heterostructures as potent flow electrode materials.

Excess gadolinium (Gd) in the environment, originating from Gd-chelating contrast agents present in hospital wastewater, has been extensively studied as a micropollutant. However, the source of excessive lanthanum (La) levels in the environment remains unclear. In this study, we analyzed rare earth elements (REEs) in treated water from 12 wastewater treatment plants (WWTPs) and sewage sludge/incinerated ash from two sludge treatment centers in Sapporo, Japan, during 2019–2020. We found that the annual discharge of excess Gd and La in a treatment area positively correlated with the number of hospitals in that area. The excess Gd concentration in the treated water increased by an order of magnitude late at night Monday, whereas the excess La concentration remained constant. Sequential extraction experiments on sewage sludge revealed that excess La is predominantly incorporated in phosphate, not silicate, as in zeolite catalysts. We identified lanthanum carbonate tablets (e.g., Fosrenol), prescribed daily to kidney patients to prevent hyperphosphatemia, as the source of excess La. Due to its low solubility, most of the anthropogenic lanthanum settles as sewage sludge in WWTPs, and only a small percentage is released into treated water. This raises concerns about the potential degradation of natural REE patterns in the environment.

Quaternary ammonium compounds (QACs) are widely used as disinfectants in consumer and medicinal products that contribute to widespread human exposure. We determined 7 benzylalkyldimethylammonium (BACs), 6 dialkyldimethylammonium (DDACs), 6 alkyltrimethylammonium (ATMACs), and 8 metabolites of BACs (BACm) in paired human urine and feces. We found QACs in human feces at total concentrations (∑All) ranging from 170 to 8270 ng/g dry weight (dw) (median: 746 ng/g dw). BACs were dominant among the four classes of QACs analyzed, accounting for 49% of ∑All, followed by DDACs (40%), BACm (9%), and ATMACs (2%). In urine, only ω-carboxyl (COOH−) metabolites of BACs were frequently found, with a median concentration of ∑BACm at 0.49 ng/mL. QACs measured in human feces exhibited positive correlations, suggestive of the usage of these chemicals as a mixture. The cumulative daily intakes (CDIs) were calculated based on QAC concentrations measured in feces, through a reverse dosimetry approach. The average CDI of QACs was estimated to be 551 ng/kg body weight (BW)/day for adults, which was 3 orders of magnitude below the toxicity reference dose (RfD) suggested for BACs (0.44 mg/kg BW/day) and DDACs (0.1 mg/kg BW/day). This study provides important quantitative information about human exposure to and fecal elimination of QACs.

There is a growing awareness of the health impacts of ethylene oxide (EtO) and its role as a carcinogenic and mutagenic air contaminant of concern. Given the need to better understand EtO emissions and associated health effects, it is imperative to overcome the significant challenges associated with EtO measurement in complex air matrices such as combustion emissions. This work focused on addressing these challenges by evaluating the utility of widely used canister-based EtO ambient measurement approaches, EPA Methods TO-15 and TO-15A, to investigate the presence of EtO in heavy-duty diesel vehicle (HDDV) exhaust. Chassis dynamometer testing was performed on two HDDVs and emissions samples were collected and analyzed following TO-15/TO-15A. Initial testing utilizing TO-15 led to the identification of a diesel exhaust constituent, ethyl nitrite, that coeluted with EtO during analysis and contributed a large positive bias. An optimized TO-15A analytical approach was developed and utilized to measure EtO in diesel exhaust from two HDDVs in additional dynamometer tests. Using this optimized approach, EtO was not detected in the HDDV exhaust in these tests. This work highlights the importance of utilizing this optimized approach to accurately quantify EtO in mobile source exhaust and may also be needed for testing other combustion sources.

Precise determination of the elemental composition of metal-containing nanoparticles (MCNPs) emitted from coal combustion is imperative for evaluating their health implications. Utilizing single-particle ICP time-of-flight MS, this study analyzed elemental compositions of individual MCNPs in coal combustion byproducts (CCPs) collected from a typical coal-fired power plant (CFPP). Vast Ti-, Fe-, Zn-, and Pb-containing NPs were identified in CCPs, with the fly ash escaping through the stack (EFA) exhibiting the highest particle number concentrations. Notably, 65%–100% of these MCNPs were multimetals ones. Zn and Pb were predominantly present in mass fractions below 10% within individual particles, indicating their adsorption onto MCNPs. Al, Si, and Fe were the dominant components of MCNPs. Volatile toxic metals associated with these MCNPs increased with dust removal stages and reached the highest in EFA. Compared to MCNPs in the first dust removal stage, oxidative stress and cytotoxicity of MCNPs in EFA increased by 78% and 32%, respectively. Cytotoxicity was approximately 14 times higher than that of PM_2.5 emitted from CFPPs. Iron in Al-rich NPs and Fe-rich NPs emerged as the top significant factors regulating intracellular oxidative stress, while trace metals (especially Pb) associated with MCNPs played the most important role in lung cell viability toxicity.

Environmental pollutants pose significant health risks and elevate the likelihood of developing diseases. Organoid-based models offer the potential to transform environmental toxicology by offering platforms that closely mimic human physiology for precise toxicological assessments. Here, we discuss recent studies utilizing human-derived organoids as a preferable in vitro model for screening environmental toxins. We also address the persistent challenges arising from the pluripotent nature of their cellular origin. Furthermore, we emphasize future perspectives regarding the utility of organoids in understanding the intricate interactions between environmental pollutant exposure and human health by considering both ad hoc modifications and post hoc analyses. Overall, exploring human-organoid-based in vitro models holds promise for environmental toxicology, offering reproducible, reliable, and relevant data comparable to those from in vivo studies.

Decades-long emissions and long-range transport of chlorinated paraffins (CPs) have resulted in their pervasive presence in the global environment. The lack of an understanding of the global distribution of short-, medium-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) hinders us from quantitatively tracing their origins in remote regions. Using the BETR-Global model and historical emission estimates, we simulate the global dispersion of CPs from 1930 to 2020. Whereas contamination trends in the main contaminated regions (East Asia, Europe, North America, and South Asia) diverge, CP concentrations in the Arctic, Antarctica, and the Tibetan Plateau all increase. By 2020, East Asian, European, and North American emissions contributed 38%, 26%, and 18% of CP contamination in the High Arctic, respectively, while Southern hemispheric emissions and emissions around the Tibetan Plateau primarily contribute to CP contamination in central Antarctica and on the Plateau, respectively. Our results emphasize the important contribution of (i) European and North American emissions to historical CP contamination in remote regions and current MCCP and LCCP contamination in the High Arctic and (ii) East Asian emission to current SCCP and MCCP contamination of all three remote regions. These results can help to evaluate the effectiveness of potential global and regional CP emission-reduction strategies.

Hair is a valuable, non-invasive material for human biomonitoring. However, little is known about polluting contaminants in hair, particularly regarding the relationship between biocomponents and contaminant levels in hair. We measured the concentrations of 42 contaminants, including 11 phosphorus flame retardants (PFRs), 13 bisphenols (BPs), and 18 perfluoroalkyl and polyfluoroalkyl substances (PFAS), while simultaneously measuring the levels of keratin, melanin, and eight sphingolipids in hair samples. Long-chain sphingolipids (C20CER) were negatively associated with levels of PFRs, PFAS, and BPs, while C12CER and C14CER (short-chain) were positively associated with levels of PFRs and BPs. Furthermore, we observed an overall negative association between ∑₇PFRs and endogenous biocomponents but a positive dose–effect relationship with ∑₅BPs and biocomponents using Bayesian kernel machine regression models. Among the biocomponents, C20CER and C14CER contributed the most to the negative and positive associations, respectively. Specifically, a change in Ln C20CER (Z-score) concentration from the 25th to 75th percentile was associated with a decrease in ∑₇PFRs of 47.0%-SD (−61.8%, −32.3%) when other biocomponents were at their median values. These findings provide new insights into the relationships between biocomponents and contaminants in hair, which is an essential step for the advancement of hair as a biomonitoring material.

Prospective influenza A (IAV) RNA monitoring at 190 wastewater treatment plants (WWTPs) across the US identified increases in IAV RNA concentrations at 59 plants in spring 2024, after the typical seasonal influenza period, coincident with the identification of highly pathogenic avian influenza (subtype H5N1) circulating in dairy cattle in the US. We developed and validated a hydrolysis-probe RT-PCR assay for quantification of the H5 hemagglutinin gene. We applied it retrospectively to samples from four WWTPs where springtime increases were identified and one WWTP where they were not. The H5 marker was detected at all four WWTPs coinciding with the increases and not detected in the WWTP without an increase. Positive WWTPs are located in states with confirmed outbreaks of highly pathogenic avian influenza, H5N1 clade 2.3.4.4b, in dairy cattle. Concentrations of the H5 gene approached overall influenza A virus gene concentrations, suggesting a large fraction of influenza virus inputs were H5 subtypes. At all four H5 positive WWTPs, industrial discharges containing animal waste, including milk byproducts, were permitted to discharge into sewers. Our findings demonstrate that wastewater monitoring can detect animal-associated influenza contributions and highlight the need to consider industrial and agricultural inputs into wastewater. This work illustrates wastewater monitoring’s value for comprehensive influenza surveillance, including for influenzas that currently are thought to be primarily found in animals with important implications for animal and human health.