Environmental Science & Technology Letters Environ.最新文献

Food loss and waste (FLW) is a defining inefficiency of the global food system, with far-reaching implications for food security, climate change, and resource and environmental sustainability. In this Perspective, we review evidence from global assessments to indicate that FLW levels have not declined meaningfully despite a decade of focus on Sustainable Development Goal 12.3 to halve per capita FLW by 2030. Experience from leading countries suggests that structural constraints limit achievable reductions through prevention alone. As near-term climate mitigation windows narrow, strategies beyond prevention are required. We argue that eliminating landfill and open-dump disposal of food waste represents an immediate and scalable mitigation opportunity, because systems-based evidence demonstrates that mature recycling pathways – including composting, anaerobic digestion, and repurposing food waste as animal feed – can deliver emissions reductions of approximately 900–1150 kg CO₂e per metric ton of food waste while recovering nutrients and sparing energy and land resources. We introduce a best-use framework that allocates FLW streams across recycling options based on emission mitigation potential, resource recovery, and implementation feasibility. Reframing food waste management from a prevention-dominated paradigm toward a landfill-avoidance and recycling-optimization paradigm provides a pragmatic path for near-term emissions abatement while advancing long-term sustainability objectives.

Chlorinated polyfluoroalkyl substances (Cl-PFAS) are widely used alternatives to legacy PFAS, but the molecular mechanism of their metabolic defluorination in mammals remains unknown. Here, we report the first atomic-level mechanistic study of P450-mediated reductive defluorination of Cl-PFAS in mammalian systems. Using halothane as a model, DFT calculations show under aerobic conditions, P450 Compound I catalyzes H-abstraction/OH-rebound followed by elimination and hydrolysis to form trifluoroacetic acid. Under hypoxic conditions (e.g., liver centrilobular regions), we elucidate the hepatotoxicity-associated reductive pathway by the Fe²⁺ form of P450: rate-determining concerted electron-transfer with C–Br cleavage generates •CF₃CHCl in a kinetic well between the first and second electron transfers; its prolonged lifetime initiates lipid peroxidation, while subsequent defluorination yields alkenes. The computed carbon kinetic isotope effect for the reductive pathway (1.076) is larger than for the oxidative pathway (1.020), providing an experimental signature for distinction. A QSAR model using vertical electron affinity and molar refractivity predicts the rate-determining electron-transfer barrier for diverse compounds, particularly long-chain Cl-PFAS (R² = 0.95), suggesting this reductive mode generalizes to other Cl-PFAS, consistent with their emerging hepatotoxicity. These findings reveal, for the first time, a molecular-level reductive defluorination pathway for Cl-PFAS in mammals, providing a mechanistic basis for bioactivation risk assessment.

The emission of nanoplastics through sea spray aerosol (SSA) from the ocean to the atmosphere has remained uncertain in different environments. The present study was intended to profile size-fractionated emission factors (EFs) of 100 nm polystyrene (PS) via SSA under different scenarios with surfactants and estimate the emission amounts of nano-PS from the North Atlantic. The EF of 100 nm PS in the synthetic seawater was 1700 ± 170. Fulvic acid reduced the emission of 100 nm PS, while Triton X-100 exhibited concentration-dependent effects on its release. The EFs in the synthetic seawater showed a unimodal peak at 1.0–1.8 μm. Fulvic acid and Triton X-100 shifted the peak size for EFs to 3.2–5.6 μm. The annual emission amount of nano-PS through SSA from the North Atlantic to the atmosphere was 135 000 t, accounting for 2% of the total budget in the mixed layer of the North Atlantic. The percentages would change to 0.8 and 2.8% with the presence of 0.1 mg L^–1 fulvic acid and 1 μg L^–1 Triton X-100, respectively. The present study documented the relative importance of emission of nanoplastics through SSA to their fate in the ocean and atmosphere.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous and water threshold limits are beginning to be enforced in various regions, particularly for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). An associated concern is PFAS contamination to soils, which impacts the potential transfer of PFAS to crops, grazing animals, and leaching to surface water and groundwater. Here we present the urgency to set international, normative soil limits for PFOS and PFOA.

The rapid expansion of lithium-ion battery (LIB) recycling is generating new environmental challenges, yet the off-site fate of electrolyte-derived fluorinated lithium (Li) salts remains largely unknown. This study provides the first field evidence of the widespread occurrence and dispersion of fluorinated Li salts in surface soils surrounding a typical recycling industrial park. Nine of 11 target fluorinated Li salts were frequently detected, with total concentrations ranging from 0.89 to 343 ng/g, demonstrating ubiquitous soil contamination. Lithium hexafluorophosphate (LiPF₆), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dominated the contamination burden, with mean concentrations of 10.8, 10.6, and 6.44 ng/g, respectively, reflecting a source-specific fingerprint of contemporary LIB electrolytes. Significant positive correlations among major salts indicated common recycling-related emissions. A clear distance-decay pattern was observed, with the highest concentrations occurring within 0.5 km of the park and decreasing sharply outward, while substantial variability in near-source soils indicated pronounced spatial heterogeneity in deposition-driven contamination. Given the persistence, mobility, and potential toxicity of these new pollutants, their accumulation in terrestrial sinks poses risks for groundwater leaching and food chain transfer. These findings reveal a distinctive chemical imprint of the LIB circular economy and highlight the urgent need for ecological risk assessment and source-control strategies.

Oil sands operations in Alberta, Canada, are a large source of secondary organic aerosol (SOA) with unknown health impacts. As a first step in closing this knowledge gap, the oxidative potential (OP), an established metric linking particle exposure to toxicological effects, of oil sands-derived SOA was investigated via OH-initiated oxidation. Experiments used a mixture of gas-phase precursors emitted from oil sands ore that is expected to be representative of mine-face emissions and three relevant single precursors (n-decane, m-xylene, and naphthalene) for comparison. The OP of the formed SOA in all cases was found to increase rapidly at short simulated photochemical ages (<1.5 days), followed by a decrease upon further oxidation (>2.5 days). This was driven by dynamic changes in SOA composition, particularly organic peroxides, quinones, and unsaturated carbonyls. The measured OP of oil sand ore SOA (OP_OS) ranged from 38.0 to 60.3 pmol min^–1 μg^–1 over photochemical ages of 0.4–4.6 days. This range of OP_OS is considerably higher than those reported for other types of aerosol particles typically present in the oil sands region, including the natural background (e.g., α-pinene and isoprene SOA). The results not only provide the first OP measurements of oil sands-derived SOA but also emphasize the importance of accounting for atmospheric aging when evaluating the oxidative potential of SOA.

Offshore gas flaring (GF) is a significant emission source of greenhouse gases and air pollutants. As China’s largest offshore oil-producing region, the Bohai Sea is a major GF hotspot, with potential impacts on climate change and air quality in the Beijing–Tianjin–Hebei region. Accurate quantification of offshore GF emissions is critical, yet remains challenging due to limited activity data, incomplete spatial information, and regionally unrepresentative emission factors. This study uses Sentinel-2 MSI observations to quantify offshore GF activities and associated emissions in the Bohai Sea during 2016–2024 through three steps: GF site detection based on the Thermal Anomaly index, radiance-based GF volumes estimation, and emission calculation using region-specific parameters. We identify 73 active sites, with the total volume increasing from 0.54 billion cubic meters (Bcm) in 2016 to 0.91 Bcm in 2024. GF activities display a highly heterogeneous and largely skewed spatial pattern, with approximately 17% of sites accounting for nearly 60% of the total spectral radiance contribution. Comparison with existing inventories suggests that these observation-constrained estimates can complement current representations of GF emissions. This study enhances the representation of regional atmospheric activities and provides policy-relevant evidence to support national and international initiatives on emission control and regulation.

Glyphosate is one of the most widely used herbicides, and its human health effects remain debated. Risk assessment requires robust human biomonitoring (HBM) data generated using validated analytical methods. However, recent population studies employing commercial enzyme-linked immunosorbent assays (ELISA) have reported urinary glyphosate concentrations higher than those measured by mass spectrometry (MS), raising concerns about potential overestimation and data comparability. This study compares two MS/MS-based methods, including a novel ion chromatography-MS/MS approach, with two ELISA methods across external quality assessment (EQA) urine samples (n = 13), spiked urine samples (n = 3, 0.1–0.3 ng/mL), and real-world human urine samples (n = 40). The evaluated ELISA methods overestimated urinary glyphosate concentrations below 1 ng/mL in EQA and spiked samples and exhibited poor repeatability (often >20%) relative to MS/MS-based methods. Analyses of real-world samples confirmed this trend, with ELISA yielding higher quantification frequencies (70–100% vs 45–63%), higher median concentrations (1.06–1.10 vs <LOQ–0.11 ng/mL), respectively, and lower repeatability (>30%) than MS/MS methods. These findings indicate that the evaluated ELISA methods lack sufficient reliability for quantifying urinary glyphosate at concentrations relevant to nonoccupational exposure, where matrix-related interferences may compromise analytical performance. These results support the preferential use of MS/MS-based methods for generating robust HBM data in research and regulatory contexts.

With the increasing release of tire wear particles, environmental exposure to tire additives and their transformation products (TATPs) has grown substantially; however, their risks remain poorly characterized and potentially underestimated. Dust samples from six driving training modules across 20 driving schools in Qingdao, China, were analyzed to investigate TATPs and their behavioral drivers. A total of 124 TATPs (median: 1.31 × 10⁴ ng/g) were detected, including 12 newly reported compounds. Antioxidants (median: 7.03 × 10³ ng/g) dominated, followed by plasticizers (median: 4.14 × 10³ ng/g) and vulcanization accelerators (median: 1.27 × 10³ ng/g). TATP concentrations varied significantly across training modules, with quarter turning modules showing the highest levels (median: 3.47 × 10⁴ ng/g) and straight driving modules the lowest (median: 4.69 × 10³ ng/g). Random forest and nonlinear models identified training module type as the key driver, with TATP enrichment increasing with driving intensity. These modules serve as proxies for urban traffic behavior, capturing fundamental tire–road interaction regimes. Integrating persistence, bioaccumulation, toxicity, and exposure, two high-priority and 20 medium-priority pollutants were identified. Overall, these results underscore the critical role of driving behavior in regulating TATP emissions and provide a basis for prioritizing high-risk pollutants in nonexhaust traffic pollution management.