Environmental Science & Technology Letters Environ.最新文献

Hydroperoxyl radicals (HO₂) play a central role in atmospheric oxidation and secondary pollutant formation, yet their direct detection remains limited. Peroxynitric acid (HO₂NO₂), a reservoir species in the HO₂–NO₂–HO₂NO₂ equilibrium system, offers an alternative pathway for HO₂ quantification under equilibrium assumptions. In this study, we deployed nitrate-CIMS, I-CIMS, and LIF instruments during field campaigns in summer Nanjing (2023) and springtime Lulang (2021), spanning a wide temperature range (265 to 308 K). We assessed the feasibility of using HO₂NO₂ observations as a proxy for HO₂ and examined the impact of ambient temperature and reagent-ion chemistry on proxy performance. Our results show that at warmer temperatures (>295 K), the fast thermal decomposition of HO₂NO₂ maintains the equilibrium, enabling accurate inference of HO₂ from nitrate-CIMS observations with strong agreement to LIF data (R² = 0.70). However, at colder temperatures (e.g., Lulang), the prolonged HO₂NO₂ lifetime (>60 s) leads to significant deviations from equilibrium, resulting in systematic overestimation of HO₂. Furthermore, intercomparison between nitrate-CIMS and I-CIMS highlights that nitrate-based detection is more robust under high-humidity conditions, where I-CIMS tends to underestimate HO₂NO₂ due to reagent-ion clustering. These findings establish both the temperature applicability limit (∼295 K) for equilibrium-based HO₂ inference and the superior humidity resilience of Nitrate-CIMS, providing critical guidance for future field deployments of HO₂ proxies in diverse atmospheric environments.

Reactive bromine species play an important role in atmospheric oxidation, the ozone budget, and mercury transformation, yet their abundance and sources outside polar regions remain poorly characterized. Here we report measurements of episodic plumes of molecular bromine (Br₂) in a high-tech industrial park in eastern China, with mixing ratios up to 23.4 ppt at night. The alignment of wind direction of high Br₂ mixing ratios with the location of the pharmaceutical facilities, along with strong correlations with brominated organics and methylating agents, suggests pharmaceutical processes as the probable source. The elevated Br₂ occasionally persisted after sunrise, contributing approximately 20% to the oxidation of isoprene in the morning. Based on national bromine consumption data and conservative emission factors, we estimate that Br₂ emissions from the pharmaceutical industry could rival those from residential coal combustion by 2030. These findings highlight a previously unrecognized industrial source of reactive bromine with potentially significant implications for regional air quality.

The unprecedented scale and pace of chemical development challenges human and ecosystem health unless new chemicals are developed using safe-by-design approaches. Therefore, tools for efficient environmental persistence assessment─among other critical assessment capabilities─are urgently needed, as outlined in the European Commission’s Safe and Sustainable by Design (SSbD) framework and the European Chemical Agency (ECHA)’s 2025 report on key regulatory challenges. Current persistence tests require large sample amounts and extended timelines making them unsuitable for early stage chemical development. We developed and validated a miniaturized, higher-throughput biotransformation assay using municipal activated sludge as the source of microbial inoculum. For 33 pesticides and pharmaceuticals, biotransformation rate constants showed strong correlation with large volume controls (R² > 0.84) and consistent relative biotransformation rankings across time and different sources of activated sludge (Spearman correlations > 0.8). Our 24-well plate test requires 2 mL per test (vs hundreds of mL in standard tests) and provides biotransformation data within 48 h (vs weeks or months) due to the dense biomass and high bioavailability of substrates in our targeted substance space (i.e., log K_oc ≲ 4). This miniaturized test lends itself to further automation and enables persistence assessment during chemical design, directly supporting SSbD principles.

Granular activated carbon (GAC) is widely employed for the removal of per- and polyfluoroalkyl substances (PFAS) from aqueous systems. However, the safe management of spent, PFAS-laden GAC remains a pressing environmental challenge. Mechanochemical ball milling has recently emerged as a novel treatment paradigm for PFAS destruction under ambient conditions, typically requiring co-milling reagents such as SiO₂, KOH, or boron nitride. In this study, we report an unprecedented finding that PFAS adsorbed on GAC can be degraded by milling with stainless steel (SS) balls in SS jars, without the need for additional reagents. In this process, the SS balls and jars not only provide mechanical energy but also act as electron donors, transferring electrons to the carbon substrate that subsequently mediates PFAS defluorination. This approach achieved degradation of PFOS spiked on Calgon Carbon Filtrasorb 400, accompanied by quantitative fluorine recovery (∼100% defluorination efficiency). Beyond laboratory-prepared samples, the strategy demonstrated universal applicability in degrading diverse PFAS species on field-collected GAC, achieving PFAS degradation regardless of chain length or headgroup. Furthermore, leaching tests confirmed that no residual PFAS was released from the milled GAC, supporting the feasibility of its safe landfill disposal.

Janus electrocatalytic membranes (JEMs), with their bifunctional interfaces that enable synergistic multireaction pathways, show great potential for advanced water treatment. This study reveals a novel and critical insight: the inherent asymmetric hydraulic behavior between the feed- and permeate-sides of JEMs fundamentally determines the spatial variations in the electrochemical activity. Importantly, the strategic deployment of active interfaces to leverage this asymmetry maximizes the catalytic performance without requiring additional energy or material input. Herein, we experimentally observed that simply positioning the dominant active interface on the hydraulically advantageous feed-side enhanced pollutant degradation by 4- to 10-fold under identical conditions. Numerical simulations revealed significant asymmetric hydraulic behaviors in convection, bypass, and concentration diffusion between the feed- and permeate-side. This asymmetry resulted in enhanced mass transfer, larger electroactive area, and faster electron transfer on the feed-side. Furthermore, life cycle assessment and environmental life cycle costing analyses demonstrate that rationally positioning active interfaces in JEMs not only enhances performance but also achieves superior environmental sustainability and cost-effectiveness compared to conventional strategies that increase the current density and catalyst loading. In summary, this study presents an innovative and resource-efficient design principle to maximize the performance of JEMs by leveraging their asymmetric hydraulics.

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP), a widely used chlorinated flame retardant, is ubiquitous in dust, water, and biota. Parental exposure of Caenorhabditis elegans to environmentally relevant TDCPP (0.1–10 μg/L) reduced mean lifespan by 14.9–20.9% in parental nematodes and 8.07–28.2% in offspring. Multiomics analyses (transcriptomics and lipidomics) uncovered a previously unrecognized lipid-centered mechanism by which TDCPP impaired organismal health. Specifically, TDCPP suppressed the expression of daf-16 and downstream fatty acid desaturase (fat-5/6), leading to depletion of unsaturated lipid species, including triglycerides, diacylglycerols, lysophospholipids, and glycosphingolipids. This disruption was corroborated by phenocopy experiments showing that genetic deletion of fat-5/6 or dietary supplementation with saturated fatty acids (positive control) mimicked TDCPP-induced aging phenotypes. Moreover, TDCPP downregulated aak-2 and cpt-1, impairing mitochondrial β-oxidation and energy metabolism. These findings identified a novel daf-16–fat-6–AMPK–CPT-1 signaling axis, providing mechanistic insight into how the environmental pollutant TDCPP disrupts lipid homeostasis to promote aging and transgenerational toxicity.

Anthropogenic chemicals and their transformation products are increasingly found in the environment, with persistence being a major driver of chemical risk. Methods for predicting biotransformation products and dissipation kinetics are needed to help regulators identify potentially persistent chemicals and prevent their release to the market and eventually to the environment. Leveraging machine learning and artificial intelligence is a promising avenue to tackle this problem. However, predictive models are only as good as the data used to train them, calling for large, high-quality data sets of biotransformation pathways and kinetics, which are currently lacking. The objectives of this Global Perspective are to (i) emphasize the importance of effectively communicating biotransformation data on chemical contaminants in the environment, (ii) describe specific components of reporting biotransformation pathways in a findable, accessible, interoperable, and reusable (FAIR) format, and (iii) provide a standardized tool for researchers to use for reporting their biotransformation data, with the intent to boost the quality and quantity of available biotransformation data. We demonstrate the application of our reporting tool for the case of perfluoroalkyl and polyfluoroalkyl substances (PFASs) as a means to develop a PFAS biotransformation database, thereby illustrating how the research community could profit from standard biotransformation data reporting.

Mineral dust particles are omnipresent in the atmosphere all over the globe. Nitrogen dioxide (NO₂) can be adsorbed on the dust surface and converted to nitrous acid (HONO), which in turn represents one of the most important sources of hydroxyl radicals (OH) driving the oxidation capacity of the atmosphere. Here, we evaluate the conversion of NO₂ to HONO on mineral dust samples from different regions of the world. We reveal that the synergistic effects of relative humidity (RH), UV-light, titanium dioxide (TiO₂), and microbes present on the mineral dust surface are responsible for the observed high HONO yields. The light-induced uptake coefficients of NO₂ on mineral dust surface are 1 order of magnitude higher than the uptakes measured in the dark. Intriguingly, the uptakes of NO₂ are higher in the absence of water vapor; however, the HONO yields increase with the increase of RH (0–90%), the NO₂ concentration (10–50 ppb), and the light intensity (19–50.4 W m^–2). Our findings demonstrate that mineral dust contributes to atmospheric HONO through light- and RH-dependent processes with high HONO yields (up to 80.3%) under realistic conditions. Global models must account for both uptake coefficients and HONO yields to accurately quantify this source, particularly in dust-prone regions.

Fine particulate matter (PM) poses a major threat to public health, with organic aerosol (OA) being a key component. Major OA sources, hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and oxygenated OA (OOA), have distinct health and environmental impacts. However, OA source apportionment via positive matrix factorization (PMF) applied to aerosol mass spectrometry (AMS) or aerosol chemical speciation monitoring (ACSM) data is costly and limited to a few supersites, leaving over 80% of OA data uncategorized in global monitoring networks. To address this gap, we trained machine learning models to predict HOA, BBOA, and OOA using limited OA source apportionment data and widely available organic carbon (OC) measurements across Europe (2010–2019). Our best performing model expanded the OA source data set 4-fold, yielding 85 000 daily apportionment values across 180 sites. Results show that HOA and BBOA peak in winter, particularly in urban areas, while OOA, consistently the dominant fraction, is more regionally distributed with less seasonal variability. This study provides a significantly expanded OA source data set, enabling better identification of pollution hotspots and supporting high-resolution exposure assessments.

Valley fever is a lung infection caused by the inhalation of infectious spores from the fungus Coccidioides spp. Coccidioides is a genus of soil dwelling fungi endemic to the arid regions of the southwestern United States, Mexico, and Central and South America. Few Valley fever studies have focused on detecting Coccidioides spores in airborne respirable particles, which is the primary infection vector. This study looks at the presence of Coccidioides in air at a highly soil positive site in Mesa, Arizona. Aerosol samples were collected for 24 h every 6 days, following the Environmental Protection Agency sampling schedule. Meteorological data were collected from a nearby weather station. Coccidioides were detected in ∼68% of the aerosol samples. Bulk PM₁₀ did not have a statistically significant relationship with presence of Coccidioides; however, there was a significant relationship between the amount of crustal material in the aerosols and presence of Coccidioides. Previous studies link the presence of Coccidioides in air with bulk PM₁₀ concentrations; however, we found that bulk PM₁₀ concentrations give an incomplete story. Additionally, there were statistically significant relationships with the presence of Coccidioides and meteorological parameters, including relative humidity, temperature, and wind speed. This study emphasizes the importance of dust entrainment in the transmission of Coccidioides.