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 (R > 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 ≲ 4). This miniaturized test lends itself to further automation and enables persistence assessment during chemical design, directly supporting SSbD principles.

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.

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 SiO, 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.

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 [TiO] 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 10 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.

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.

Exposure to organophosphate esters (OPEs), used as flame retardants and plasticizers, is highly variable in the general population, and limited data exist on exposures in young children. This study evaluated the use of silicone ankle bands to assess OPE exposure in infants under 18 months of age. Infants (n = 21) wore silicone ankle bands for three consecutive days, and spot urine samples were collected using either pediatric urine collection bags or toddler training toilets. Ankle bands were analyzed for 20 OPEs; seven were detected in >70% of samples. TDCIPP and TPHP were the most abundant compounds on bands (medians = 57.5 and 53.0 ng/g, respectively). All targeted urinary metabolites were detected in most samples, with BDCIPP being the most abundant biomarker (median = 3.7 ng/mL SG-corrected), 2.5 times higher than DPHP. Significant positive correlations were observed between urinary metabolites and parent compounds on the ankle bands (r = 0.40-0.73, p < 0.05), suggesting that silicone samplers reliably capture exposure trends. These findings support ankle bands as a practical, noninvasive tool for assessing OPE exposures in infants, offering an alternative to urine-based biomonitoring.

Accurate p values of per- and polyfluoroalkyl substances (PFAS) are urgently needed to improve predictions of their environmental fate, bioaccumulation, and removal, yet reliable experimental data remain scarce. Here, we determined the p values of 10 PFAS and three short-chain fluorinated acids (MFA: 2.58 ± 0.03; DFA: 1.22 ± 0.03, TFA: 0.03 ± 0.08) using F and H NMR-based chemical shift perturbation. Results were compared to prior experimental values, OPERA predictions (CompTox), and our COSMO-RS calculations. Measured p values include PFPrA (-0.18 to -0.54), PFOA (-0.27 ± 0.18), PFBS and PFOS (< -1.85), 6:2 FTS (<0.0), GenX (-0.20 ± 0.09), NFDHA (-0.32 ± 0.18), PFMPA (-0.26 ± 0.13), and 6:2 FTUCA (2.59 ± 0.11). Across C2, C3, and C8 homologues, PFCAs exhibit p values of approximately -0.2 to -0.3. Telomerization markedly reduces acidity: 5:3 FTCA (p = 4.05 ± 0.04) is >10-fold less acidic than PFOA, with COSMO-RS predicting similar effects from PFOS to 6:2 FTS. The dominant acidifying influence arises from CF groups at C1 and C2 near COOH or SOH. The unusually low p values for TFA, PFOA, and GenX reflect our low-MeOH, sorption-resistant NMR method. COSMO-RS consistently outperformed OPERA, underscoring the need for experimental benchmarks to improve predictive models for emerging PFAS.

Quantifying people's exposure to wildfires is essential for assessing related health risks. While hydroxyl metabolites of polycyclic aromatic hydrocarbons (PAHs) are commonly used exposure biomarkers of combustion-originated air pollutants, methylated PAHs are more abundant in woodsmoke than other sources. Thus, urinary PAH carboxylic acids, which are metabolites of methylated PAHs, may serve as more sensitive biomarkers of wildfire exposure. In this exploratory study, we developed an LC-MS/MS method to simultaneously quantify hydroxylated and carboxylic metabolites of PAHs and methyl-PAHs in urine. This method was then applied to 56 urine samples collected from 8 campers before, during, and after a 4-hour exposure to campfire. Campers also wore silicone wristbands to monitor ambient PAHs. We found that 1-pyrenecarboxylic acid (1-PYRCA) levels increased significantly at 4 h (96.9%, 95% CI: 2.60-101%), 6 h (96.8%, 95% CI: 5.85-107%), and 8 h (92.5%, 95% CI: 3.59-99.2%), and returned to baseline levels at 24 h. In contrast, the campfire exposure did not significantly increase other urinary PAH metabolites. Wristband PAHs also significantly increased during the 4-hour exposure. These results suggest the use of urinary 1-PYRCA as a sensitive exposure biomarker for woodsmoke and potentially for assessing exposure to wildfires.

Most known per- and polyfluoroalkyl substances (PFAS) bioaccumulate by binding to proteins or partitioning to phospholipids, leading to their prevalence in liver and blood. However, the recent discovery of high concentrations of unidentified extractable organofluorine (EOF) in the blubber of a killer whale () from Greenland suggests that some fluorinated substances preferentially bioaccumulate in storage lipids. To further investigate this, the present work examined blubber from 4 killer whales (3 from Greenland, 1 from Sweden) via gas chromatography-atmospheric pressure chemical ionization-ion mobility mass spectrometry. Using collision cross sections, we prioritized features suspected to be highly fluorinated and then selected 5 for manual annotation. Custom synthesized standards confirmed 10:2 and 12:2 fluorotelomer methylsulfone, 10:2 and 12:2 fluorotelomer chloromethylsulfone, and 6:2 bisfluorotelomer sulfone in all blubber samples from Greenland at concentrations ranging from <0.4 to 72.5 ng/g, explaining 34-75% of blubber EOF, but none in the Swedish sample. None of these substances were observable in liver, suggesting preferential accumulation in storage lipids. To the best of our knowledge, this is the first report of neutral fluorotelomer sulfones in wildlife and the first identification of lipophilic, highly fluorinated PFAS.

Urban air pollution remains a pressing challenge in rapidly developing economies, particularly in data-scarce regions. This study examined air quality in three major East African citiesKampala, Nairobi, and Dar es Salaamby integrating low-cost air sensors with satellite data to produce 1 km × 1 km resolution daily PM (particulate matter smaller than 2.5 μm) maps from 2019 to 2023. Average PM concentrations were 31.4 ± 6.6 μg/m around Kampala, 21.7 ± 2.8 μg/m around Nairobi, and 33.1 ± 7.4 μg/m around Dar es Salaam, indicating moderate to unhealthy levels of air quality. Unexpectedly, urban centers exhibited lower PM levels than surrounding suburban area. This discrepancy is likely due to combustion-related activities that occur in the suburbs. Such results suggest that air quality mitigation efforts must extend beyond urban centers to suburban areas, where seasonal vegetation loss and combustion processes may drive pollution spikes. Beyond presenting a scalable approach for monitoring air quality in data-scarce regions, this study highlights the importance of localized strategies for urban air quality management.

The virtual chemical space of substances, including emerging contaminants relevant to the environment and exposome, is rapidly expanding. Non-targeted analysis (NTA) by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is useful in measuring broad chemical space regions. Internal standards are typically used to optimize the selectivity and sensitivity of NTA LC-HRMS methods, assuming a linear relationship between structure and behavior across all analytes. However, this assumption fails for large, heterogeneous chemical spaces, narrowing measurable coverage to structurally similar compounds. We present a data-driven strategy for unbiased sampling of candidate structures for NTA LC-HRMS method development from extensive chemical spaces, such as the U.S. EPA's CompTox (>1 million chemicals). The workflow maximizes physicochemical/structural diversity using precomputed PubChem descriptors (e.g., molecular weight, XLogP) and grants LC-HRMS compatibility thanks to predicted mobility and ionization efficiency from molecular fingerprints. The resulting measurable compound lists (MCLs) provide broad, heterogeneous coverage for NTA method development, validation, and boundary assessment. Applied to the CompTox space, the approach yielded MCLs with greater chemical coverage and broader predicted LC-HRMS applicability than conventional "watch list" contaminants, offering a robust framework for enhancing NTA's measurable chemical space while preserving diversity.

() can sometimes establish in drinking water microbial communities and infect individuals inhaling contaminated aerosols. The premise plumbing portion of the drinking water distribution system is often especially vulnerable to growth. Innovative approaches to intentionally manipulate the microbial ecology to control have been proposed but remain elusive. Here, we retrospectively analyzed 16S rRNA gene amplicon sequences and droplet digital PCR data in samples derived from prior drinking water studies, wherein some inexplicable stochastic variations in the occurrence were observed in replicate microcosms. We discovered an apparent antagonistic relationship between and . This relationship was noted across three water sources (Flint, Detroit, and Blacksburg) and was at least partially mediated by the presence of copper, through either copper pipes or a dosed range of 0-2000 μg/L total copper. The observations of this study, which was conducted under realistic drinking water conditions harboring mixed microbial communities, are consistent with recent pure culture studies reporting that amoebic uptake may be inhibited when are established as amoebal endosymbionts. The findings may help explain the apparent stochastic behavior of in field and research settings and may open a door to new engineered ecological control strategies for .

Effluent-dominated streams are increasingly common in temperate regions and have potential for adverse ecological and human health effects. Nontarget analysis (NTA) using high resolution mass spectrometry (HRMS) is an emerging approach to examine complex chemical mixtures in the environment. Here, we leveraged archived samples previously analyzed for 154 target contaminants in a well-studied temperate region effluent-dominated stream and compared target results with suspected compounds from NTA. NTA enhanced the detectable chemical space by 20 times compared to target analysis alone. Target analysis was biased toward larger mass contaminants compared to the compounds detected with NTA, indicating that target analysis was not fully representative of the compound distribution for the effluent-impacted waters. Hierarchical cluster analysis exposed clusters of compounds significantly upregulated at the effluent/stream mixing zone, revealing evidence of a novel phenomenon wherein transformation product and/or metabolite formation appears to occur rapidly . Additionally, an exposure-driven NTA retrospective analysis uncovered upregulation of 7endocrine-disrupting compounds that may explain prior bioassay results. These findings have urgent implications for ecosystems and downstream communities experiencing de facto wastewater reuse conditions. NTA offers enhanced characterization of complex mixtures in effluent-dominated streams and can reveal novel mixture dynamics otherwise masked when employing target analysis alone.

Although the relationship between plastics and their embedded small molecules has been previously hypothesized, direct and systematic evidence remains limited. Herein, we introduced an innovative approach to validate this relationship by screening specific small molecules as markers to decode plastic information. Given the mature techniques available for polymer identification, enabling subsequent validation, this study focused on screening polymer-specific small molecule markers. Specifically, plastic samples of various polymer typesincluding raw plastic pellets and postprocessed plastic productswere collected, extracted, and analyzed with a nontargeted method. Distinct polymer-based features were observed in raw plastic pellets: 21 in polyethylene (PE), 69 in polypropylene (PP), 119 in poly-(ethylene terephthalate) (PET), and 14 in polystyrene (PS). Of these, 2, 28, 101, and 10 features were also detected in postprocessed plastic products of the same polymer, indicating these co-occurring features could serve as polymer-specific markers. Representative markers were identified, including Irganox 1010 transformation products in PP-based plastics, PET oligomers in PET-based plastics, and dibenzoylmethane in PS-based plastics. These markers were then used to identify the polymer type of two additional plastic bottles as PET, consistent with results obtained from pyrolysis-gas chromatography/mass spectrometry. This work provides a proof-of-concept for employing small molecule markers to decode plastic-related information.

Salt contamination of water supplies in tidal rivers is a global problem, but it has received little attention beyond site-specific studies. Drought, sea-level rise, navigation channel dredging, and watershed land-use change increase the risk of salinization and threaten drinking water supplies, agricultural irrigation, and infrastructure (via corrosion). The emerging issue of salt contamination of water supplies in tidal rivers and its diverse impacts highlight the critical need for interdisciplinary research that must integrate knowledge from oceanography, hydrology, and water resource management. Here we elucidate oceanic and hydrological processes regulating saltwater intrusion into estuaries and tidal rivers as well as watershed processes driving enhanced chemical weathering and export of watershed salts into rivers. By synthesizing studies around the world, we discuss how sea-level rise, prolonged drought, and increasingly extreme weather events in a changing climate are driving more frequent saltwater intrusion events that threaten water security globally. We propose a convergent research agenda toward the development of a decision support tool for salinity management. Specifically we recommend making ion-specific measurements and developing hydrological-hydrodynamic models to simulate the transport of major salt ions. These models can then be combined with artificial intelligence algorithms and enhanced monitoring to explore management strategies with stakeholders.

Hurricane Helene caused catastrophic flooding and infrastructure damage across the mountainous regions of western North Carolina. Responding agencies had to make real-time decisions about emergency response, infrastructure repair, and aid allocation. Here, we describe how our decade-long transdisciplinary research program supported data-driven recovery decisions in the days following a storm through the development of a novel emergency response decision support system (DSS). Integrating publicly available and geospatial data sets, we estimated that 4% of the total land area across the initial 25 disaster declared counties was flooded during Helene. While some areas did not experience a 100-year flood event, others had more severe flooding. We estimated that approximately 19 600 private wells, 34 300 businesses, and 500 fire stations were flooded. This type of real-time information was critical for supporting local health departments (LHDs) and state governments in their requests for emergency relief funding and their planning for emergency needs and assistance. Lessons learned through this effort highlight the importance of codeveloping knowledge and resources and providing actionable data and insights to enhance future disaster response efforts. Overall, our rapidly conceptualized and executed DSS demonstrated how providing actionable intelligence to responding LHDs and state governments can enable more effective distribution of real-time emergency resources.

Weakly absorbing reactive trace gases play important roles in the atmospheric environment and usually have short lifetimes ranging from seconds to days. HIRAS-II, the second hyperspectral infrared atmospheric sounder aboard the world's first civilian meteorological satellite in dawn-dusk orbit, FengYun-3E (FY-3E), can theoretically detect more than a dozen weakly absorbing reactive trace gases and make important contributions to global trace gas mapping by filling the gap for diurnal variation. This study uses state-of-the-art weak absorber thermal infrared spectral feature quantification and identification methods to detect weak absorbers from FY-3E/HIRAS-II and successfully capture 14 species from 35.4 million FY-3E/HIRAS-II clear-sky measurements in July 2023. We map the reliable global distribution of spectral features from nine routine reactive gases and find that these gases originate from scenes that are usually of special concern, including densely populated areas, vegetation, and biomass burning. This study confirms the capability of FY-3E/HIRAS-II in detecting weak absorbers and serves as a stepping stone for subsequent research in concentration retrieval. The case of the ammonia column over wildfires retrieved using neural network technology initially demonstrates that FY-3E/HIRAS-II can improve our understanding of the diurnal variation of trace gases by complementing measurements at dawn and dusk.

6PPD-quinone, a degradation product of the rubber antiozonant 6PPD that is frequently added to tires, has previously been identified as a causative agent of urban runoff mortality syndrome in salmonids. Previous high-throughput phenotypic profiling (HTPP) studies using the Cell Painting assay in the RTgill-W1 rainbow trout cell line has demonstrated that 6PPD-quinone toxicity occurs at much lower concentrations than the 6PPD parent molecule, which is consistent with available toxicity data in rainbow trout. Current research efforts include identifying alternative antiozonant compounds to potentially replace 6PPD in tire manufacturing. To fill bioactivity data gaps for potential 6PPD alternatives, 18 compounds including other substituted -phenylenediamines (PPD) and PPD-quinones were assayed using HTPP in RTgill-W1 cells. 7PPD-quinone and 77PD-quinone produced changes in cellular phenotype similar to 6PPD-quinone at comparable concentrations. IPPD-quinone produced changes in cellular phenotype at higher concentrations than 6PPD-quinone, with a phenotypic profile that was most similar to its parent molecule IPPD. These findings suggest that 7PPD-quinone and 77PD-quinone may exhibit similar effects in rainbow trout, and potentially other 6PPD-quinone sensitive salmonids. In contrast, IPPD may be less toxic to salmonids than 6PPD, given the relative lack of bioactivity of IPPD-quinone compared to 6PPD-quinone.

The efficacies of a thermal oxidizer and carbon adsorption beds used as air pollution control technologies at a fluoropolymer manufacturing facility were evaluated for nonpolar volatile fluorinated compounds (VFCs) using Other Test Method (OTM)-50. The target compounds for OTM-50 include industrial fluorocarbons, common products of incomplete combustion, reaction byproducts, and common refrigerants. The thermal oxidizer's emissions were found to contain tetrafluoromethane, CF. Emissions from the carbon adsorption beds used to scrub the fugitive air emissions for two vinyl ether synthesis facilities were sampled and the analyses showed that the compounds with boiling points below 100 °C were not effectively adsorbed. This research shows that the facility's thermal oxidizer is effective at destroying high concentration streams of perfluoroalkyl substances (PFAS) and that the carbon beds can reduce emissions for compounds with boiling points over 100 °C.

Residential wastewater, with no industrial inputs, is an underrecognized source of per- and polyfluoroalkyl substances (PFAS). This study provides the first direct comparison of PFAS in septage and pump stations, targeting 70 PFAS compounds and employing the total oxidizable precursor (TOP) assay. Septage exhibited markedly higher PFAS and precursors concentrations than pump stations, with median post-TOP levels of 687.5 ng/L vs 84.2 ng/L, respectively. FTCAs were fully oxidized, while diPAPs showed incomplete oxidation due to high organic loads. Septic systems function as PFAS reservoirs, increasing risks of groundwater contamination, particularly in areas with shallow aquifers. Pump stations contributed to episodic PFAS spikes, likely affecting downstream wastewater treatment. The detection of 27 PFAS compounds, including short-chain alternatives, highlights shifting contamination patterns. Findings emphasize the need for tailored analytical frameworks and pretreatment technologies to mitigate PFAS risks across decentralized and centralized wastewater systems. Integrating precursor analysis is critical for accurate risk assessment, as targeted PFAS measurements underestimate contamination. These results provide new insights into PFAS behavior in residential wastewater, guiding future mitigation efforts.

Arsenic methylation is the microbe-mediated transformation of inorganic As into methylated species, an important component of the biogeochemical arsenic cycle in rice paddies. Prior to methylation, arsenite is taken up into bacterial cells through GlpF, an aquaglyceroporin channel for uptake of glycerol and other low-molecular-weight organics. The uptake and subsequent biotransformation of arsenite are therefore linked to the bacterial utilization of organics. We hypothesized that increasing concentrations of carbon substrates will repress the uptake and methylation of arsenite through a carbon catabolite repression (CCR) mechanism. An arsenic biosensor assay demonstrated that arsenite uptake was repressed in the presence of glucose and environmental dissolved organic matter (DOM) isolates. RT-qPCR analysis of expression linked the decrease in arsenite uptake at higher carbon concentrations to the repression of glycerol-transporting GlpF channels. Methylation of arsenite by , a rice paddy isolate, was repressed by the upper glycolytic substrates glucose, xylose, and mannose, but was not affected by pyruvate and succinate. This result is consistent with current CCR theories. Our findings provide a new perspective on the impacts of organic carbon on microbial arsenic transformations, and suggest that arsenic biotransformation can be repressed in systems that are rich in upper glycolytic carbon substrates.