Environmental Science & Technology Letters Environ.最新文献

Conventional filter-only exhaust sampling misses gas-phase and semivolatile nitrated phenols (NPs), biasing vehicular emission estimates low. We deployed a tandem quartz filter-polyurethane foam (filter-PUF) sampler downstream of dilution to quantify 19 NPs from in-use diesel (China III–VI) and gasoline vehicles (China IV–V), and found that filter-only protocols underestimate total NPs (sum of filter and PUF retained under specified dilution) by 66–76% (diesel) and 66–71% (gasoline). Corrected fuel-based NP emission factors declined sharply with tighter standards (up to 97% lower from China-III to -VI), and the mixture was dominated by 4-nitrophenol and its methylated derivatives (∼50–63%). Applying the corrected factors to China’s 2023 fleet yields vehicular NP emissions of 528 Mg, which is comparable in magnitude to previous estimates for biomass burning (∼670 Mg, based on filter-only data) and potentially larger than that for residential coal (∼178 Mg, based on filter-only data). This suggests that vehicular emissions may rank similarly to, or even surpass, these sources when accounting for nonfilter-retained NPs. Recognizing and correcting this filter-only artifact with a drop-in filter-PUF fix enables more accurate inventories and will improve assessments of NPs’ impacts on urban air quality, HONO budgets, and brown carbon.

Levels of fine particulate matter (PM_2.5) air pollution in the United States have declined substantially in recent decades, yielding substantial benefits to public health. This study evaluates emission reductions across five key economic sectors─electricity, industrial, transportation, agriculture, and residential─and their impact on air quality and health. We employ a recently developed sector-specific inventory that provides emissions and their spatial disaggregation across time in a self-consistent framework. Using a national source-receptor matrix, we estimate annual PM_2.5-attributable mortality and its variability spatiotemporally and by sector. We find that annual PM_2.5-attributable mortality decreased 51% between 2002 (197,000 deaths) and 2019 (96,000 deaths). The largest reductions were from electricity and transportation, especially secondary PM_2.5 from NO_x, SO_x, and VOC emissions. Emissions reductions from industrial and residential sectors were more modest. In contrast, agricultural emissions, especially NH₃, increased over time; the importance of agriculture among the five sectors increased from second-smallest (2002) to the largest (2019). While the reductions in PM_2.5-attributable mortality have been large (approximately a factor of 2), future progress may need to focus greater attention on agricultural emissions, in addition to traditionally dominant sources such as transportation and industry.

Side-chain fluorinated polymers (SCFP) are a class of per- and polyfluoroalkyl substances (PFAS) that are extensively used in functional textiles as water and stain repellents. The potential for environmental contamination through the release of SCFP into aqueous waste streams during textile manufacturing is poorly understood. In this study, SCFP in textile wastewater were characterized using targeted analysis, total oxidizable precursor (TOP) and total hydrolyzable precursor (THP) assays, ultrafiltration, and asymmetric-flow field-flow fractionation (AF4). An investigation into point sources of PFAS precursors in Burlington, NC’s wastewater treatment plant (EBWWTP) using the TOP assay revealed a significant PFAS burden stemming from textile manufacturing operations within the city’s sewershed (max: 12,000,000 ng/L after oxidation), far outweighing domestic contributions. TOP and THP profiling of textile manufacturing wastewater showed that the dominant precursors contained 6:2 fluorotelomer functionality, and ultrafiltration and AF4 showed them to be colloidal in size (hydrodynamic diameter: ∼100 nm), resulting in the determination of SCFP in textile wastewater. PFAS mass loading analysis showed that most SCFP exiting the EBWWTP were associated with sludge rather than effluent, where ∑PFAS concentrations up to 150,000 ng/g were measured using the direct TOP assay; thus, the land application of SCFP-contaminated biosolids may represent a significant route of environmental contamination.

Pesticide gestational exposure may contribute to the development of allergies in childhood, yet evidence on its health impact on urban populations remains limited. This study investigates the association between prenatal exposure to individual and mixed pesticides and allergic outcomes, including asthma, wheezing, and eczema, at age 6 in 387 mother-child pairs from the German prospective cohort LiNA. Forty pesticides and metabolites were detected in urine during pregnancy through nontargeted screening, and 11 were selected (detection rate ≥ 17%) for further analysis. Multivariable logistic regression models adjusted for covariates revealed statistically significant associations between dihydroxy-pyrimethanil and asthma (aOR = 1.35, 95% CI: 1.02–1.79), and fluazifop-desbuthyl and wheezing (aOR = 1.14, 95% CI: 1.01–1.30). No significant associations were observed for eczema. The weighted quantile sum (WQS) regression showed that higher pesticide coexposures significantly increased wheezing odds (aOR = 2.08, 95% CI: 1.21–3.56). The main components of the WQS index were fluazifop-desbuthyl, flonicamid, hydroxy-metazachlor, and terbuthylazine, accounting for 67% of the overall mixture effect. These findings suggest that prenatal exposure to pesticides, likely from dietary sources, may increase the risk of childhood asthma and wheezing. Replication studies in populations with comparable pesticide exposures, along with experimental mechanistic validation, will strengthen the understanding of the observed associations.

The co-occurrence of microplastics and heavy metals poses significant environmental risks. However, conventional analytical methods are ex situ, destructive, and unable to capture real-time adsorption dynamics. We present a low-field nuclear magnetic resonance (LF-NMR) technique that enables the in situ, nondestructive, time-resolved quantification of paramagnetic metal adsorption onto microplastics. We applied this method to monitor the adsorption of Cu(II) and Cr(III) onto poly(vinyl chloride) and polystyrene microplastics under diverse water chemistry conditions. Validation using inductively coupled plasma mass spectrometry confirmed the excellent accuracy of the proposed method, which exhibited high linearity (R² > 0.99), an average recovery of 100.7%, and detection limits of approximately 0.1 mg L^–1. The method showed robust sensitivity and stability across varying salinity (0–250 mM) and pH (3.5–6.5) with minimal interference. LF-NMR revealed a two-stage adsorption mechanism characterized by rapid surface binding followed by slower intraparticle diffusion. Critically, the nondestructive nature preserved the microplastic–paramagnetic metal complexes for subsequent characterization, overcoming the limitations of conventional destructive techniques. This real-time approach bridges quantitative detection with mechanistic understanding, providing a powerful tool for elucidating microplastic–metal interactions and showing strong potential for nanoplastic and aging studies.

Natural attenuation (NA) and propane biostimulation (PB) are effective and cost-efficient in situ techniques for remediating 1,4-dioxane (dioxane)-contaminated groundwater. We designed and validated three primer/probe sets capable of distinguishing among three clusters of group-6 propane monooxygenases (PRMs) and evaluated their correlation with dioxane degradation in microcosms mimicking NA and PB treatments. These biomarkers demonstrated exclusive specificity and high sensitivity (500–1600 copies/mL groundwater). Microcosms prepared with groundwater at seven monitoring wells across two sites exhibited significant dioxane removal, particularly where active propane biosparging was implemented. Using Taqman-based qPCR assays, prmAI and prmAIII were most dominant, while prmAII and thmA were absent, indicating the pivotal roles of Cluster I and III PRMs in the observed dioxane biodegradation. Moreover, the average abundance of total prmA, as well as prmAI and prmAIII individually, correlated significantly with the dioxane degradation rates. Correlation and regression analyses highlighted a stronger association of prmAIII than prmAI, suggesting a greater influence of Cluster III PRMs under tested conditions. Samples with total prmA below 10^4.5 copies/mL groundwater exhibited negligible dioxane removal, suggesting a practical threshold for assessing the bioremediation potential. These findings establish cluster-specific group-6 PRM biomarkers as effective tools for predicting and monitoring dioxane biodegradation in impacted aquifers.

The understanding of the toxic effect of environmental nanoparticle exposure at the cellular level is critical. We surprisingly discovered that environmental nanoparticle endocytosis inadvertently transports a small volume of the surrounding extracellular fluid into the cells, without disruption of the cell membrane. Although the volume of engulfed fluid is relatively small, the corresponding Ca²⁺ influx is rather considerable. Nanoparticles, along with their “hijacked” extracellular fluid, accumulate in the lysosomes. Therefore, the elevated Ca²⁺ levels were observed in the lysosomes, accompanied by certain lysosomal damage. In contrast, inhibiting the influx of extracellular Ca²⁺ or activating the lysosomal calcium ion channel TRPML1 significantly mitigated lysosomal calcium overload. Overall, this study may be beneficial for nanoparticles-related ecotoxicological examination and risk assessment.

The USEPA developed an Aquatic Life Screening Value (ASLV) of 11 ng/L for 6PPD Quinone (6PPD-Q), a breakdown product of 6PPD, an antiozonant in automobile tires. Because some coho populations are listed, “Take” requires that no individuals be harmed. The question asked in the present study is whether the ASLV for 6PPD-Q is protective for coho salmon. To answer this question, a concentration–response regression was developed for juvenile coho salmon from the raw data used to generate the three published acute mortality studies. The % mortality from the ASLV was read from the concentration–response regression resulting in a mean predicted mortality (95% confidence limits) of 2% (1–14%). Because of the Take restriction on harming a threatened or endangered species, the protective concentration of 6PPD-Q in coho-bearing streams should be set below the concentration–response curve. The LC1 and 95% CL are 8.5 (1.3–17.8) ng/L. The lower CL is 8.5 times lower than the EPA ASLV. A concentration of 6PPD-Q that does not result in mortality of one individual coho salmon should be below the lower 95% CL of the LC1 (approximately 1 ng/L). Results of this study show that the EPA ASLV is not protective for coho.

Ionic liquids (ILs) are widely used in diverse scientific and industrial fields, yet many of these substances exhibit significant cytotoxicity, challenging their classification as “green solvents”. To facilitate access to established experimental cytotoxicity data on ILs, we present ILToxDB - a curated, open-access database containing 3844 cytotoxicity assay entries for 1224 ILs tested across 154 cell lines and extracted from 152 scientific publications. Each entry includes detailed experimental context, such as the assay type, cell line characteristics, and compound structure (including SMILES), allowing flexible search and analysis. ILToxDB offers a user-friendly web interface and supports advanced structure-based queries. The database is designed to support toxicological assessment, green chemistry development, and machine learning applications for safer IL design. ILToxDB is freely available at https://iltox.ananikovlab.ai/.