Environmental Science & Technology Letters Environ.最新文献

Sulfidation of nanoscale zerovalent iron (nZVI) toward substantially enhancing electron selectivity to trichloroethene (TCE) and its degradation efficiency to benign end products has been a major breakthrough. However, the electron transfer from S-nZVI to TCE or water also results in leaching of Fe²⁺, and the mitigation of this reaction has not been addressed. Anaerobic corrosion of 1.2 g/L S-nZVI during TCE degradation led to high dissolved Fe, up to 353 ± 26 mg/L under electron-excess conditions and 427 ± 30.2 mg/L under electron-limited conditions, thus compromising treated water quality during (ground)water treatment. In this study, a dittmarite-S-nZVI (DS-nZVI) composite yielded efficient TCE degradation with the continuous sequestration of released Fe. S-nZVI was well-dispersed on the dittmarite (NH₄MgPO₄·H₂O) nanosheets. DS-nZVI yielded faster and complete dechlorination and a ∼1000-fold decrease in Fe leaching (<0.3 mg/L) compared to S-nZVI (353 ± 26 mg/L) under electron excess conditions, and >90% iron removal under electron-limited conditions with TCE degradation capacity of 1.46 × 10²³ molecules per mol of Fe⁰. Continuous exchange of Fe²⁺ with Mg²⁺ ions and complexation with phosphate ions was followed by structural transformation to crystalline baricite, (Fe, Mg)₃(PO₄)₂·8H₂O, leading to a more sustainable TCE degradation approach for groundwater remediation.

Hindered amine light stabilizers (HALSs) are polymer additives that are widely used in plastics, synthetic fibers, and adhesives. However, research on the environmental presence and related exposure risk of HALSs remains limited. In this study, a wide range of HALSs were analyzed in indoor and outdoor dust from multiple environments, and nine HALSs were detected. Relatively high concentrations of HALSs were detected in the dust of automotive repair shops (median = 1.05 × 10⁵ ng/g), while urban residential apartments (median = 1.53 × 10³ ng/g), rural houses (median = 301 ng/g), and the rural outdoors (median = 75.9 ng/g) showed much lower concentrations. The estimated daily intake of ΣHALSs via dust ingestion for automotive repair workers under median exposure scenarios reached 35.4 ng (kg of body weight (bw))⁻¹ day^–1, which was 80 times higher than that for residential exposure. Despite elevated exposure in repair shops, current HALS concentrations do not appear to pose a significant threat to human health via dust ingestion. This is the first study to report the presence of HALSs in automotive repair shops and rural environment settings. Moreover, three HALSs, 2,2,6,6-tetramethyl-4-piperidinyl stearate, N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexane-1,6-diamine, and 4-hydroxy-1-(2-hydroxyethyl)-2,2,6,6-tetramethylpiperidine, are reported for the first time in the environment.

Organophosphorus pollutants pose significant threats to both human health and natural ecosystems due to their widespread use and toxicological effects. In addition to the well-known organophosphorus pesticides and organophosphate esters, quaternary phosphonium compounds (QPCs) are widely utilized, highly productive, and toxic. However, their environmental presence and behavior are not well understood. Using the cheminformatics toolkit in Python, 25 QPCs were screened as target analytes from a chemical industry database based on their characteristic structural features. Among them, 16 QPCs were detected in soil (range: 2.61–5.84 × 10³ ng/g), and 11 QPCs were found in indoor dust (range: 4.89–1.71 × 10³ ng/g) near a manufacturing plant. A point-source distribution pattern was observed in the soil, while indoor dust concentrations showed a distance-dependent attenuation. The spatial distribution suggests that the manufacturing plant is a significant source of QPCs in the surrounding area, with eight QPCs being reported for the first time. Human exposure assessment via dust ingestion indicated estimated daily intakes well below acceptable thresholds, suggesting limited immediate risk. This study highlights QPC manufacturing plants as a significant source of environmental contaminants and underscores the need for greater attention to plant-released QPCs and their potential health effects.

Monitoring thousands of environmental chemicals in microliter blood volumes is now possible by chemical exposomics and high-resolution mass spectrometry (HRMS). As these technologies advance toward higher throughput to support human exposome studies with millions of participants, parallel implementation of higher-frequency blood collection methods must be considered to capture the highly dynamic nature of individual exposomes. Blood microsampling devices offer a less invasive way to collect quantitative, replicate, and repeated blood samples outside the clinic, overcoming limitations of traditional venepuncture and dried blood spots. Here we critically evaluate seven popular commercial microsampling devices for their potential use in chemical exposomics by considering previous use in molecular profiling, collection volumes, compatibility with various blood fractions, and conditions for shipping, storage, and analysis. We furthermore present the first data on extractable chemical interferences leaching from six of these devices in simulated blood sampling. Nontargeted HRMS revealed greatly different chemical backgrounds between devices, with implications for method sensitivity and false-positive discovery of exogenous and endogenous molecules. The unique advantages of each microsampler should be weighed against these chemical backgrounds, and in all cases, a systematic quality control program including field and simulated collection blanks is advised for future exposome studies utilizing these emerging devices.

New pathogens and contaminants that threaten public health and the environment continually emerge. While major advancements have been made in high-throughput analysis methodologies, the current “one-contaminant-at-a-time” approach to quantifying risk that continues to prevail in policy analysis is not sufficient to keep pace. Assessing coexposures and their associated synergisms, antagonisms, or other effects with respect to risk is needed to move beyond this approach. Leveraging concepts from computational toxicology and chemical risk assessment, we propose a roadmap for the integration and advancement of quantitative microbial risk assessment (QMRA) to be bigger, better, and faster. The integrated risk assessment paradigm focuses on (1) integrating microbial omics tools into QMRA including broadening hazard considerations to combinations of pathogens and expressed genes, (2) combining chemical, nonchemical, and pathogen stressors in a common framework for informing cost and sustainability trade-offs in risk management decisions, and (3) advancing actionable risk assessment tools. This approach will promote transdisciplinary, practical risk management solutions by enabling decision-makers to rapidly predict and respond to health risks from complex modern environments.

Inorganic ultraviolet (UV) filters in mineral sunscreens (MSCs) are known to generate reactive oxygen species (ROS), including transient free radicals, under light exposure. Recent findings indicate that these filters (titanium dioxide [TiO₂] and zinc oxide [ZnO]) also assist in generating long-lived free radicals. The photochemical formation of these radicals during routine sunscreen use and as they enter the environment remains unknown, highlighting the need for studies to inform safer sunscreen formulation, reduce adverse health risks, and protect aquatic ecosystems. Here, we provide the first evidence that all commercial sunscreen formulations we used in this study generated substantial amounts of persistent free radicals (PFRs), which remain long after light exposure ends. Both MSCs and organic chemical sunscreens (OSCs) yielded PFRs, though MSCs generated higher levels overall. In most formulations, water exposure significantly reduced PFRs, except in MSC with ZnO-only content, where PFR yields increased. ZnO-only MSCs formed substantial levels of PFRs even when irradiated underwater, producing twice the radical signal observed under ambient air. Among OSCs, UV filters with phenolic groups produced more PFRs, though bulky substituents suppress their formation. Under typical application, we estimate 10¹⁷ PFRs may form. These results raise concerns about potential environmental and health risks associated with MSC use that persist beyond exposure and may lead to prolonged oxidative stress in human skin and aquatic environments.

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.