Bibai Du

Industrial recycling of spent lithium-ion batteries (LIBs) is expanding rapidly, yet its emissions of electrolyte-derived organic contaminants remain largely uncharacterized. Here, we provide the first field evidence that industrial LIB recycling is a significant source of diverse cyclic, linear, and fluorinated carbonates to the indoor environment. Using compound-specific GC-MS/MS, we screened 20 carbonates in 64 dust samples from a representative industrial-scale LIB recycling plant in China. Twelve carbonates were ubiquitously detected, including five cyclic carbonates, six linear carbonates, and one fluorinated carbonate, with total concentrations reaching up to 16,700 ng/g (mean: 3,870 ng/g). The contamination profile was dominated by cyclic carbonates (e.g., propylene carbonate and ethylene carbonate) and volatile linear carbonates, broadly reflecting commercial LIB electrolyte formulations. Notably, the frequent detection of 3,3,3-trifluoropropylene carbonate (TFPC) highlights the emission footprint of advanced fluorinated additives. Strong positive intercompound correlations indicate their corelease from residual electrolytes during LIB pretreatment. These findings significantly expand the chemical footprint of LIB recycling, identifying carbonate electrolytes as another abundant and critical class of new pollutants of emerging concern that necessitate urgent multimedia environmental monitoring and occupational exposure assessments.

Hindered amine light stabilizers (HALSs) have been detected in various environmental media, yet human biomonitoring evidence remains absent. Herein, we determined 11 HALSs in paired breast milk and urine samples from nursing mothers in South China. At least one HALS was detected in 98.7% of breast milk samples and 98.7% of urine samples, with ∑HALS concentration ranges of < MDL-19.9 ng/mL (median: 2.20 ng/mL) and < MDL-23.0 ng/mL (median: 1.29 ng/mL), respectively. HALS compositions differed between breast milk and urine samples and 4-hydroxy-1-(2-hydroxyethyl)-2,2,6,6-tetramethylpiperidine (HA 201) was the dominant compound. Most intercompound correlations were weak, suggesting compound-specific sources and toxicokinetic behaviors. In paired-sample regression analyses, breast milk concentrations of HA 201 and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (HS 508) showed weak but statistically significant positive associations with corresponding urinary concentrations. In exploratory analyses, recent home renovation, frequent plastic-packaged convenience food consumption, and greater personal care product use were associated with higher HALS levels. Under high exposure scenario, breastfeeding-mediated intakes of bis(1,2,2,6,6-pentamethyl-4-piperidyl) butyl(3,5-ditert-butyl-4-hydroxybenzyl) malonate (Tinuvin 144) in infants younger than 3 months exceeded the predicted reference dose, indicating a screening-level risk signal. This biomonitoring evidence of HALSs in human biological samples highlights the need for expanded exposure and toxicity studies.

Synthetic antioxidants (AOs) can accumulate in municipal sludge during wastewater treatment, yet current occurrence-based assessments remain largely focused on hindered phenolic antioxidants (HPAs), potentially overlooking other AO classes and transformation products (TPs) with distinct hazard characteristics. Here, we conducted a nationwide assessment of four major AO classes comprising 60 AOs and TPs in municipal sludge across China by integrating occurrence and hazard information. Forty-seven compounds were detected nationwide, including 17 compounds reported in sludge for the first time (e.g., AO 3052, PANA/PBNA, AO 168═O, and DLTP). HPAs overwhelmingly dominated AO occurrence, accounting for 94.0% of total AO concentrations nationwide, with BHT and DBP as the major contributors. In contrast, hazard-informed prioritization revealed that aromatic amine antioxidants (AAs) and their TPs, particularly 6PPD, DPA, and 6PPD-quinone, disproportionately dominated hazard profiles despite their substantially lower abundance. The high rankings of TPs further suggest an important role of environmental transformation in shaping AO-related hazards in sludge. These findings reveal a pronounced mismatch between abundance and hazard profiles across AO classes, suggesting that concentration-driven monitoring strategies may overlook lower-abundance but highly hazardous contaminants in municipal sludge.

Salinity fluctuations and chemical pollution co-occur frequently in estuarine environments, yet their combined effects on estuarine organisms and the underlying mechanisms remain largely unexplored. In this study, we investigated the physiological and transcriptomic responses of the estuarine diatom Chaetoceros muelleri to short-chain chlorinated paraffins (SCCPs) under three salinity conditions (5‰, 15‰, and 25‰). Reduced salinity (5‰) tended to decrease the diatom sensitivity to SCCPs, as evidenced by a lower EC₅₀ (150 ± 63 μg L^–1) compared to 15‰ salinity (194 ± 74 μg L^–1). Hormetic responses were observed at both 5‰ and 15‰, with maximum stimulation of 58.06% and 27.10%, respectively. In contrast, SCCPs at 25‰ salinity presented no hormetic effect but caused chlorophyll depletion and oxidative stress. Transcriptomic analysis indicated that a low concentration of SCCPs (nominal 10 μg L^–1) at 5‰ salinity down-regulated light-harvesting complexes and reallocated energy toward cell growth, which contributed to the observed hormesis under this condition. At 25‰ salinity, SCCPs induced no detectable transcriptional changes (0 differentially expressed genes), likely due to the reduced bioavailability under hyperosmotic conditions. These results demonstrated that salinity critically modulated SCCPs toxicity and highlighted the necessity of incorporating dynamic environmental factors into estuarine ecological risk assessments.

Vulcanization accelerators (VAs) are essential additives widely used in rubber production, especially for tire rubber. However, their environmental occurrence, migration, and risk in sediments on a large geographical scale remain poorly understood. In this study, we conducted the first large-scale geographical investigation of eight VA classes in sediments from multiple hydrologically connected water bodies spanning urban rivers, estuaries, coastal areas, the deep sea, and the open ocean. Five of the eight classes of VAs were detected across the studied areas, demonstrating the ubiquity of these anthropogenic chemicals. Thiazoles were the predominant class, followed by thioureas and guanidines. A total of 34 of the 43 traditional and emerging VAs were detected, with most nonthiazole VAs being reported in sediments for the first time. Total sedimentary VA concentrations declined along a gradient: urban river (median: 188 ng/g) > estuary (81.8 ng/g) > coast (53.5 ng/g) > deep sea (12.0 ng/g) > open ocean (7.49 ng/g). Riverine export fluxes indicate a significant input of these anthropogenic chemicals via particle-mediated transport from terrestrial sources into the coastal ocean. We developed a novel framework that combines multidimensional substance hazards and environmental occurrence indices to prioritize the identified chemicals and assess the risks of surface-deposited VAs in aquatic environments. Fourteen VAs posed medium to high risks in urban rivers and were identified as high-priority VAs of concern. These findings underscore the urgent need for regular monitoring and risk assessment of these ubiquitous but understudied rubber chemicals.

Fluorinated lithium (Li) salts are essential constituents of Li-ion battery (LIB) electrolytes, yet their environmental emissions during the rapidly expanding recycling of retired LIBs remain unexplored. Herein, we established a targeted screening list of 11 commonly used fluorinated Li salts and reported their first identification in dust and recycled black mass (BM; a powder-like primary form of crushed spent LIBs after pyrolysis) from a typical spent LIB recycling plant in China. Nine and seven fluorinated Li salts were detected in the dust and BM samples, respectively, with lithium hexafluorophosphate as the dominant compound, followed by lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide. Total concentrations of fluorinated Li salts (∑F-Li salts) exhibited high levels ranging from 581 to 47,500 ng/g (median: 12,100 ng/g) in ambient dust, with significantly higher levels in LIB dismantling areas than in nondismantling areas. By contrast, ∑F-Li salts in BM samples were much lower (<LOD-1800 ng/g; median: 17.8 ng/g), indicating that fugitive emissions to the environment or the transformation/decomposition of fluorinated Li salts occurred during high-temperature pyrolysis. Our findings demonstrate that spent LIB recycling contributes to substantial emissions of fluorinated Li salts into the surrounding environment, highlighting the need for further evaluation of their environmental impacts.

A robust analytical method based on Captiva EMR-Lipid solid-phase extraction and HPLC-MS/MS was developed and validated for the simultaneous determination of 19 aromatic amine antioxidants (AAs) and two p-phenylenediamine-derived quinones (PPD-Qs) in human plasma. The optimized protocol effectively removed phospholipid interferences from complex blood matrix, significantly mitigating ion suppression and improving the recovery of hydrophobic AAs compared to conventional liquid–liquid extraction. Method validation demonstrated good accuracy (spike recoveries: 73.0–96.8%), precision (RSD < 11%), and sensitivity with method detection limits ranging from 0.81 to 21 pg/mL. The method was successfully applied to plasma samples from 20 adults, in which 11 AAs were detected at total concentrations of 240–710 pg/mL. Diphenylamine derivatives, particularly bis(4-tert-butylphenyl)amine (DBDPA) and diphenylamine (DPA), were identified as the predominant compounds, contributing over 69% of the total AA burden. No PPDs or PPD-Qs were detected, which may be attributed to their biotransformation and urinary excretion, as well as the limited sample size. This study provides a comprehensive biomonitoring tool for assessing combined human exposure to multiple AAs and establishes a foundation for further investigation into their health implications.

Coral reefs are among the most biodiverse and ecologically valuable ecosystems on Earth. However, the increasing discharge of pollutants into marine environments from human activities, such as domestic sewage, industrial effluents, and agricultural runoff, has intensified stress on coral communities. These anthropogenic pollutants not only accelerate coral bleaching but also disrupt the ecological stability of reef-associated marine systems. In recent years, growing attention has been paid to the presence and impacts of emerging contaminants (ECs) in coral reef ecosystems. Major EC classes of concern include microplastics (MPs), antibiotics (ABs), organic UV absorbers (OUVAs), organophosphate esters (OPEs), and per- and polyfluoroalkyl substances (PFASs). This review systematically synthesizes current knowledge on the environmental occurrence, spatial distribution, and ecological risks of these five major EC classes in coral reef environments. Key knowledge gaps are highlighted, particularly with respect to mixture toxicity, chronic exposure, and interactions with climate-driven stressors. Finally, an integrated multi-stressor risk framework is proposed to support future monitoring, pollution management, and coral reef conservation under global environmental change.