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Ultrasound protocols used to detect vascular gas emboli in divers: a systematic review.

INTRODUCTION: Venous gas emboli (VGE) detected via ultrasound can be used as a surrogate marker for decompression stress. While Doppler ultrasound is the historical gold standard, two-dimensional (2D) ultrasonography offers advantages for on-site monitoring, including a wider field of view and reduced dependence on noise-free environments. This systematic review evaluates 2D ultrasonography protocols used in decompression research since the 2015 International Meeting on Ultrasound for Diving Research, identifying methodological similarities, differences, and adherence to consensus recommendations. METHODS: A search of PubMed and Scopus identified studies using 2D ultrasound to detect VGE in divers. Inclusion criteria were: (1) use of 2D ultrasound, (2) detection of VGE or monitoring of decompression stress, (3) inclusion of a diver cohort, and (4) publication after 2015. Data extraction focused on VGE scoring systems, ultrasound hardware, measurement protocols, and operator experience. Risk of bias was assessed using ROBINS-I-V2, and compliance with the 2015 consensus recommendations was evaluated. RESULTS: Twenty studies were included. The Eftedal-Brubakk scale was most commonly used (n = 15), with cardiac ultrasound as the primary imaging modality; one study assessed a peripheral vessel. Common shortcomings included post-dive measurements lasting less than two hours, underreporting of operator experience and hardware specifications, limited individual-level data, and inappropriate use of parametric statistics for ordinal bubble grade data. No study fully complied with all consensus recommendations. CONCLUSIONS: This review demonstrates that, although two-dimensional ultrasound is widely used for post-dive VGE assessment, methodological heterogeneity with multiple shortcomings remain. Furthermore, nearly all studies restricted imaging to the heart, thus leaving peripheral vessel assessment largely unexplored.

Embolism, Air

Surgical Outcomes after Preoperative Embolization of Primary and Secondary Pelvic Bone Tumors.

PURPOSE: To analyze the technical results and safety of preoperative embolization of pelvic bone tumors. MATERIALS & METHODS: Retrospective study analysis of a cohort of patients who underwent preoperative hypervascular, pelvic bone tumor embolization at the authors' institution between January 2008 and January 2025. Preinterventional data, including clinical, radiological, and laboratory findings, procedural angiographic and surgical data, and clinical follow-up data were collected from the patients' electronic medical records. Patient follow-ups were conducted until March 2025 or until the patient's death. RESULTS: Twenty-three patients (11 male patients; mean age of 42 years) underwent uneventful , preoperative embolization for primary (n=15) or metastatic (n=8) pelvic bone tumor resection. A mean of 2.3 tumor feeding arteries were preoperatively embolized with complete tumor blush disappearance in n=13 (56.5%) or near-complete tumor blush disappearance with less than 10% residual tumor blush visualized in n=10 patients (43.4%). Surgical intervention was performed with a mean of 1.7 days after embolization and was associated with a mean of 1.88 L perioperative blood loss. CONCLUSION: Preoperative pelvic tumor embolization is a safe procedure with a mean of more than two feeding arteries identified and embolized. KEY POINTS: · Preoperative embolization is a safe procedure for pelvic bone tumors.. · Angiography identified a mean of 2.3 tumor feeding arteries embolized.. · Complete preoperative angiographic tumoral devascularization was found in 56% of patients.. · Surgical intervention after preoperative tumor embolization was associated with a mean of 1.88L perioperative blood loss.. CITATION FORMAT: · Hubrechts M, Wafa H, Sinnaeve F et al. Surgical Outcomes after Preoperative Embolization of Primary and Secondary Pelvic Bone Tumors. Rofo 2026; DOI 10.1055/a-2942-7451.

Journal Article

Adjunctive middle meningeal artery embolization for chronic subdural hematoma: A systematic review and meta-analysis of eight randomized trials.

BACKGROUND: Randomized trials suggest that adjunctive middle meningeal artery embolization (MMAE) may reduce recurrence in chronic subdural hematoma (CSDH), but potential sources of variability in treatment effects across studies remain poorly understood. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of MMAE and to explore potential study-level sources of between-study heterogeneity. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials comparing MMAE plus surgery versus surgery alone, following PRISMA guidelines. Trial sequential analysis (TSA) was prespecified to assess the robustness of pooled findings. Exploratory mixed-effects meta-regression was performed to examine whether aggregate study-level mean age and anticoagulation use were associated with variability in recurrence outcomes. RESULTS: Eight trials including 1961 patients were analyzed. MMAE plus surgery was associated with a reduction in recurrence compared with surgery alone (RR 0.63, 95% CI 0.46-0.85; I² = 0%), and TSA supported this finding. Although conventional meta-analysis suggested a reduction in reoperation, the TSA findings were more sensitive to analytical assumptions and less robust. Exploratory study-level meta-regression analyses suggested possible associations between recurrence outcomes and mean age or anticoagulation use, although these findings should be interpreted as hypothesis-generating only. Safety outcomes were comparable between groups. CONCLUSIONS: Adjunctive MMAE was associated with reduced recurrence in CSDH. Exploratory analyses evaluating aggregate study-level characteristics were limited by the small number of included trials and the use of aggregate-level data, and should be considered hypothesis-generating only. Further prospective studies are needed to better understand variability in treatment effects.

Humans

Surgical management of jugular foramen meningiomas: a function-prioritized perioperative workflow.

OBJECTIVE: Jugular foramen meningiomas are challenging because of their deep, neurovascularly crowded location and multicompartment extension; hyperostosis and rigid dural attachment further narrow the corridor and increase the risk of lower cranial nerve morbidity, causing dysphagia and airway complications that may rarely require tracheostomy. This study aimed to describe a contemporary function-first workflow integrating compartment-based anatomy, venous sinus status, preoperative embolization, and continuous vagus nerve monitoring and its relation to clinically actionable recovery endpoints. METHODS: The authors retrospectively reviewed 26 consecutive patients who underwent primary surgery for jugular foramen meningiomas (2014-2025). Tumors were classified as intradural + intrajugular (IJ) or intradural + intrajugular + extracranial extension (IJE). Retrosigmoid, suprajugular, or transjugular approaches were selected by tumor extension and sigmoid-jugular venous status. Selective embolization and continuous vagus nerve monitoring were used when feasible. Outcomes included extubation timing, time to oral intake, 1-year swallowing/voice severity, extent of resection, and salvage stereotactic radiosurgery (SRS) for progression/regrowth. RESULTS: Twenty tumors were IJ and 6 were IJE. Selective embolization was performed in 16 patients (62%) without complications. Continuous vagus nerve monitoring was implemented in 16 patients (62%); lower preservation rates showed an exploratory association with worse 1-year swallowing. All patients were extubated immediately after surgery. Oral intake began by postoperative day ≤ 7 in 20 patients (77%); only 1 required > 14 days before resuming oral intake. At 1 year, swallowing and hoarseness remained worse in 54% and 46% of patients, respectively, but almost all cases were mild; the same patient had moderate dysphagia/hoarseness, and none required tracheostomy, gastrostomy, long-term tube feeding, or phonosurgery. Simpson grade IV comprised 69% of cases but predominantly reflected intrajugular/extracranial residual rather than persistent intradural disease. No patient without preoperative facial nerve palsy developed new palsy; serviceable hearing was preserved in 70%, and 38% with preoperative nonserviceable hearing improved to serviceable hearing. During a median 55.6-month follow-up, 3 patients (12%) underwent salvage SRS for regrowth; none required reoperation. CONCLUSIONS: A function-first workflow guided by anatomical compartment extension and intraoperative monitoring can support rapid recovery and durable functional independence in jugular foramen meningiomas. The IJE phenotype identifies a higher-risk subgroup for delayed oral intake and postoperative subjective dysphagia/hoarseness, while continuous vagus nerve monitoring may provide actionable insights to calibrate surgical aggressiveness and support function-prioritized acceptance of intrajugular/extracranial residual with close surveillance and salvage SRS when needed.

Humans

Evaluating the need for late angiography for complete obliteration of AVMs after endovascular treatment: collaborative AVM center experience and a systematic review.

Brain arteriovenous malformations (bAVMs) can be treated curatively by endovascular embolization. However, limited data exist on late recanalization rates. We investigated the rate of late bAVM recanalization following complete endovascular obliteration, confirmed by primary control angiography.We performed a single-center retrospective cohort study on late recurrences in adult patients with bAVMs after complete endovascular obliteration at a Radboud - Isala - MUMC+ (RIM) collaborative AVM center in the Netherlands between 2014 and 2022.Additionally, we conducted a systematic review to evaluate the rate of late recanalization following complete endovascular obliteration, confirmed on primary control angiography, in adults with bAVMs. The protocol for this review was registered in PROSPERO (CRD42024546875).Our retrospective study revealed 42 adult patients treated by endovascular means only; 90.5% (38 patients with mean age of 48.1 years) had confirmed complete obliteration. Both primary (6 months post-treatment) and secondary (more than 1 year post-treatment) angiographic control confirmed complete obliteration in 21 of 23 patients with complete follow-up. Mean follow-up was 47.8 months. Two late recurrences (9.5%) were detected at 5- and 6-years' follow-up imaging.Our systematic review included two studies encompassing a total of 19 patients with mean angiographical follow-up of 20.8 months. There were no late recurrences.Late bAVM recurrence after endovascular treatment with proven complete obliteration may be underestimated owing to limited long-term follow-up. Our findings suggest that after a 6-month angiographic confirmed obliteration, a 5-year angiographic imaging control is justified.

Humans

Pollution characteristics and health risks of PAHs and OPAHs in PM2.5 of an inland basin city in China under the influence of the clean air action plan.

Since the implementation of China's Clean Air Action, remarkable progress has been made in air pollution control, with continuous air quality improvement in Xi'an, a typical inland basin city in the Fenwei Plain. To clarify winter organic aerosol pollution variations and pinpoint targeted control needs under policy regulation, this study investigated PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) and oxygenated derivatives (OPAHs) in winter Xi'an, focusing on pollution levels, chemical compositions, source contributions, meteorological impacts, regional transport and health risks. Historical comparison showed generally lower wintertime PAH concentrations in Xi'an during the period of China's clean-air actions. PMF results indicated mixed source influences on PAHs and OPAHs, with biomass-burning-related mixed combustion showing the largest contribution. During haze episodes, absolute concentrations of both PAHs and OPAHs increased; the increase was statistically significant for OPAHs but not for parent PAHs, while 4-5 ring PAHs and BcdPQ dominated the PAH and OPAH profiles, respectively. Meteorological variability, particularly synoptic pressure patterns, was strongly associated with pollutant concentrations, and regional pollution was dominated by in-basin accumulation combined with short-range transport from northern Shaanxi industrial zones. Haze periods exhibited higher toxic-equivalent concentrations, with OPAHs, particularly BcdPQ, dominating the toxicity-equivalent burden. Screening-level ILCR estimates generally remained below 10⁻4 but increased during haze episodes, especially for adult and elderly groups. In conclusion, China's clean air actions have coincided with lower wintertime PAH pollution, but stronger control of residential biomass and other solid-fuel combustion, traffic emissions, and OPAH formation remains necessary in the Fenwei Plain.

China

An integrated multiscale air quality modelling framework for industrial park pollution: Linking local emissions to regional transport.

Capturing the spatiotemporal distribution of pollutants in industrial parks remains challenging for regional air quality models because of their coarse resolution (3 km), resulting in uncertainties in local emission quantification. To address this, we developed the Integrated Multiscale Air Quality Modelling System for Industry (IAQMS-Industry), coupling the regional Nested Air Quality Prediction Modelling System (NAQPMS) with a city-scale chemical transport model. This framework integrates point-source locations and Gaussian plume dispersion to simulate particulate matter with a diameter smaller than 2.5 micrometres (PM2.5) at 100 m resolution. Applied to the Beijing Yi Zhuang and Tangshan industrial parks and evaluated against observations. The coupled model achieved a normalized mean bias (NMB) ranging from 3.1 % to 6.2 %, improving upon NAQPMS (-16.9 % to -7.7 %). Spatial analysis revealed that coarse regional grids underestimated the PM2.5​ concentrations at industrial sites by smoothing gradients, whereas IAQMS-Industry successfully resolved spatial patterns. Industrial point emissions accounted for 22.9 %-26.4 % of PM2.5 in the coupled model, which was significantly greater than the regional model estimates of 1.6 %-13.7 %. These findings indicate that regional models overestimate pollutant dispersion processes in industrial parks while underestimating local industrial impacts. By explicitly resolving point-source dynamics and linking them to regional transport, IAQMS-Industry provides a robust tool for designing targeted emission controls in industrial cities and balancing local air quality improvements with minimized regional pollution outflow. This study underscores the necessity of multiscale modelling for accurate source apportionment and informed environmental governance in industrial zones.

Air Pollution

Marine air promotes structural compaction and coating growth of soot aerosols after long-range transport from East Asia.

Soot aerosol, a key global warming contributor, undergoes morphological and chemical transformations during atmospheric transport, particularly in humidified marine environments. This study investigates morphology, mixing state, and aging mechanisms of soot particles collected in the Bohai Sea and Yellow Sea. Transmission electron microscopy analyses reveal that coated soot particles dominate the marine atmosphere, accounting for over 98 % of soot-containing particles, with a mean mixing state index (χ) of 0.83. The fractal dimension (Df) of soot particles is 1.84 ± 0.05 in the Northern Yellow Sea, 1.90 ± 0.08 in the Bohai Sea, and 1.96 ± 0.07 in the Southern Yellow Sea, indicating structural compaction during long-range transport. Correspondingly, the average Dp/Dcore ratios (particle to core size ratio) are 5.3 in the Bohai Sea, 4.2 in the Northern Yellow Sea, and 3.9 in the Southern Yellow Sea. Notably, those ratios are higher in marine environments compared to those observed during continental regional transport from northern to southern China (3.54), suggesting enhanced coating growth in humid marine air. The results highlight the important role of marine atmospheres in accelerating soot aging, which in turn leads to significantly stronger light absorption compared to soot in continental air. Our results highlight the necessity of incorporating compact morphologies, uniform mixing states, and thick coatings into optical models for accurate radiative forcing simulations.

Aerosols

Clinical performance of a giomer-based pit and fissure sealant with and without air-abrasion pretreatment: a 12-month randomized clinical trial.

BACKGROUND: Pit and fissure sealants are widely used for caries prevention; however, their long-term success depends largely on retention. Giomer-based sealants containing surface pre-reacted glass ionomer fillers offer bioactive properties, yet concerns remain regarding their bonding durability when applied with mild self-etch primers. This randomized clinical trial evaluated the effect of bioactive glass air-abrasion pretreatment on the retention and caries preventive efficacy of a giomer-based sealant in young adults over 12 months. METHODS: This parallel-arm randomized clinical trial included 96 participants, each contributing one eligible sound permanent molar (n&#x2009;=&#x2009;48 per group). Participants were randomly allocated to either bioactive glass air-abrasion pretreatment followed by application of a giomer-based sealant (intervention group) or application of the same sealant without pretreatment (comparator group). Sealant retention and secondary caries incidence were evaluated at baseline, 6 months, and 12 months using Simonsen's criteria, and modified United States Public Health Service (USPHS) criteria, respectively. The primary outcome was sealant retention at 12 months, whereas secondary caries incidence was assessed as a secondary outcome. Intergroup comparisons were analyzed using the Chi-square test. Intragroup comparisons were analyzed using Cochran's Q test followed by multiple comparisons. Relative risk with 95% confidence intervals was calculated. Statistical significance was set at p&#x2009;&#x2264;&#x2009;0.05. RESULTS: At 6 months, complete sealant retention was observed in 91.7% of teeth in the intervention group and 75.0% in the comparator group, with no statistically significant difference between groups (p&#x2009;=&#x2009;0.068). At 12 months, complete sealant retention was significantly higher in the intervention group (87.5%) than in the comparator group (33.3%) (p&#x2009;<&#x2009;0.0001). Teeth in the intervention group exhibited an 81.25% lower risk of sealant retention failure compared with the comparator group (RR&#x2009;=&#x2009;0.1875; 95% CI: 0.0864-0.4069; p&#x2009;<&#x2009;0.0001). No differences in secondary caries incidence were detected between groups during the 12-month follow-up period (p&#x2009;=&#x2009;1.0000). CONCLUSIONS: Bioactive glass air-abrasion pretreatment significantly improved the retention of a giomer-based fissure sealant compared with sealant application without pretreatment. No differences in secondary caries incidence were detected between groups during the 12-month follow-up period. Incorporating mechanical surface conditioning prior to sealant placement may enhance sealant retention without compromising preventive efficacy. TRIAL REGISTRATION: https://clinicaltrials.gov/ , (NCT06003452), 15-08-2023.

Humans

Quantifying the combined effects of semi-closed terrain and monsoon on PM2.5 and O3 pollution aggregation in the North China Plain.

The North China Plain (NCP) and its surrounding regions represent one of the key priority areas for air pollution control. As anthropogenic emissions decline significantly, the effect of terrain and meteorology on air pollution pattern has become increasingly prominent, particularly given the NCP's unique semi-closed terrain and East Asian monsoon dynamics. However, quantitative characterization of terrain-dominated blocking effects remains unexplored. Here we quantitatively assess the blocking effects of mountains and terrain-coupled meteorological factors on air pollutant dispersion. We find the NCP on the eastern side of the Taihang Mountains showed high PM2.5 and O3 pollution levels, with winter PM2.5 and summer O3 high-value zones showing opposite north-south aggregation patterns. PM2.5 and O3 concentrations were highest in plains, followed by platforms, hills, and finally mountains. Within the 120-km buffer zones of the typical mountains in the NCP and its surrounding regions, PM2.5 and O3 concentrations increased initially with altitude but then decreased markedly above a threshold altitude. Above the threshold altitude, mountain blocking effects became dominant. The effective blocking altitudes of typical mountains in the NCP and its surrounding regions ranged between 22 and 929 m for winter PM2.5 pollution, and between 19 and 1060 m for summer O3 pollution. The Terrain-Wind Close Index indicates that the terrain-coupled East Asian monsoon showed stronger blocking effects on PM2.5 dispersion in southern NCP during winter and on O3 diffusion in northern NCP during summer, matching observed high-pollution zones. This study offers key insights for regional joint air pollution mitigation strategies, as well as regional pollution assessment.

Particulate Matter

Oxidative potential of fresh vs. O&#x2083;-aged PM2.5 across urban and rural sources in China.

Fine particulate matter (PM2.5) is a major health risk, yet its impacts are still largely assessed using mass concentration, which does not capture toxicity. Recently, oxidative potential (OP) has emerged as a more relevant metric, reflecting the ability of particles to generate reactive oxygen species. A current challenge, especially in China, is understanding how emission sources and ozone (O3) aging affect PM2.5 toxicity, given that O3 is an increasingly important pollutant there. A work by Ma and co-workers published in J. Environ. Sci. (doi.org/10.1016/j.jes.2024.04.023) addressed this by evaluating the OP of fresh and O3-aged PM2.5 from multiple sources in China using the dithiothreitol (DTT) assay. Biomass burning particles exhibited the highest OP, up to 35 times greater than suburban PM2.5, driven by water-soluble organics and transition metals. While O3 aging generally reduced OP, it also induced complex chemical transformations. These findings highlight that PM2.5 toxicity is dynamic and source-dependent, underscoring the need to move beyond mass-based air quality metrics.

Particulate Matter

Impact of climate change on pediatric health outcomes.

Climate change has become one of the most critical health issues globally in the twenty-first century with children bearing the disproportionate burden of the burden since they are more vulnerable than adults because of their physiological, behavioral, and developmental capacities. It is a systematic review that rates the evidence of the relationship between climatic exposures such as heat, air-pollution, and extreme weather events and pediatric health outcomes. The number of peer-reviewed studies involved was 23 published in 2000-2025, which represented different geographic areas and study designs and assessed acute and chronic health outcomes. The Newcastle-Ottawa Scale and the ROBINS-I tool were used to evaluate the methodological quality, and the majority of the studies had low to moderate risks of bias. The narrative synthesis shows that there are always links between air pollutants especially PM2.5, NO2 and O3 and respiratory morbidity, prevalence of asthma and hospitalization of children. Amplified temperatures as well as heat waves were associated with increased cases of heat illness, dehydration, and febrile state in infants and young children. There were elevated cases of diarrheal and vector-related infections, especially in low-resource settings, which were linked to extreme weather events especially floods. Although the overall results were similar, significant differences in the regions and methods were found, and low-income countries show little evidence. In addition, exposures as analyzed in most studies were usually considered individually, which may have underestimated the cumulative or compound climate risks.

Humans

Prenatal exposure to indoor PM2.5 and children's cognitive performance at 4 years of age: an observational analysis from the UGAAR randomized controlled trial.

Outdoor fine particulate matter (PM2.5) concentrations during pregnancy are linked to reduced cognitive performance in children. We previously reported that portable HEPA filter air cleaners use during pregnancy improved children's mean full-scale IQ (FSIQ), but no previous studies have evaluated the relationship between indoor PM2.5 during pregnancy and FSIQ in childhood. We conducted an observational analysis using data from the Ulaanbaatar Gestation and Air Pollution Research (UGAAR) randomized controlled trial. Using a previously developed model of weekly indoor PM2.5 concentrations, we estimated the average concentrations in participants' homes over the full pregnancy and in each trimester. When the children were four years old, we measured FSIQ using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV). We used multiple linear regression to assess the adjusted relationships between interquartile range (IQR) contrasts in indoor PM2.5 during pregnancy and FSIQ among 475 mother-child dyads. An 8.8&#xa0;&#x3bc;g/m3 increase in indoor PM2.5 concentration over the full pregnancy was associated with a reduction of 1.4 points (95% CI: -3.4, 0.6) in mean FSIQ. The strongest association between PM2.5 concentrations and FSIQ was in the first trimester, when a 19.1&#xa0;&#x3bc;g/m3 contrast was associated with a 2.8-point reduction (95% CI: -5.7, 0.2) in mean FSIQ. Indoor PM2.5, particularly during early pregnancy, may impair brain development, leading to lower mean FSIQ scores in four-year old children. These results, combined with our previous analysis of HEPA filter air cleaners, indicate that reducing PM2.5 exposure during pregnancy has beneficial effects on children's cognitive performance.

Humans

Exploring China's Clean Air Act and associated cardiovascular disease risk: a prospective, quasi-experimental, and causal inference modelling study.

BACKGROUND: Substantial improvements in air quality have been recorded following the implementation of China's Clean Air Act (CCAA) in 2013. However, the association between CCAA implementation and individual-level cardiovascular disease (CVD) risk remains unclear. We aimed to examine the long-term association between CCAA implementation and individual-level predicted CVD risk. METHODS: In this prospective, quasi-experimental study, we used data from the China Kadoorie Biobank, a prospective cohort study that recruited participants from five urban and five rural areas across China between 2004 and 2008, with three resurveys conducted after the baseline survey (in 2008, 2013-14, and 2020-21). We included 34&#x2009;862 individuals (mean age 51&#xb7;3 years) who participated in at least one resurvey and had no history of CVD at baseline. Participants were classified into intervention (n=25&#x2009;497) and control (n=9365) groups based on the local government's targets for particulate matter reduction. We estimated the 10-year risk of incident CVD morbidity or mortality using a validated risk prediction model. We used a difference-in-difference model to assess the long-term association between CCAA implementation and predicted risk, with adjustments made for regional confounders and individual-level characteristics, including demographics, lifestyle factors, medical history, and indoor air pollution exposure. The relationship between changes in long-term exposure to PM2&#xb7;5, PM10, and O3 and predicted risk after CCAA implementation was analysed using a linear model. The estimated risk differences associated with air pollutant changes were estimated based on the magnitude of changes and their corresponding effect sizes. FINDINGS: After the CCAA was implemented, PM2&#xb7;5 and PM10 concentrations declined in both groups, but O3 concentrations increased. The intervention group showed a 3&#xb7;95% (95% CI 3&#xb7;18-4&#xb7;72%) lower increase in predicted risk than the control group, with larger estimated differences under stricter enforcement. Between 2013 and 2021, each 10 &#x3bc;g/m3 change in PM2&#xb7;5 concentration was positively associated with a 1&#xb7;80 (1&#xb7;34-2&#xb7;27) percentage point change in predicted CVD risk, whereas each 10 &#x3bc;g/m3 change in PM10 concentration was associated with a 1&#xb7;24 (0&#xb7;84-1&#xb7;63) percentage point change and each 10 &#x3bc;g/m3 change in O3 concentration with a 0&#xb7;58 (0&#xb7;33-0&#xb7;83) percentage point change. Overall, the observed changes in air pollutants during the study period were associated with an average 6&#xb7;6 percentage point reduction in predicted CVD risk. INTERPRETATION: The CCAA and improved air quality were associated with a slower increase in predicted CVD risk, supporting the necessity for stricter, multipollutant air quality policies to maximise public health benefits. FUNDING: National Natural Science Foundation of China, Kadoorie Charitable Foundation, Noncommunicable Chronic Diseases-National Science and Technology Major Project, National Key R&D Program of China, Chinese Ministry of Science and Technology, and UK Wellcome Trust.

Journal Article

Three-dimensional source apportionment and quantitative characterization of horizontal and vertical transport fluxes of O3 and its precursors in the Beijing-Tianjin-Hebei region, China.

Persistent surface ozone (O3) pollution in the Beijing-Tianjin-Hebei (BTH) region is driven by coupled precursor emissions and multi-scale transport, yet its altitude-dependent transport and source contributions remain insufficiently quantified. Here we integrated the Weather Research and Forecasting and the Comprehensive Air Quality Model with Extensions with the Ozone Source Apportionment Technology and a quantitative transport-flux framework to characterize three-dimensional source apportionment and horizontal/vertical fluxes of O3, Volatile Organic Compounds&#x200c; (VOCs), and Nitrogen Oxides (NOx) across dynamic meteorological scenarios. Simulations showed that VOCs and NOx were dominated by local emissions near the surface (73.61 %-82.18 %), whereas surface O3 was primarily controlled by regional transport, with local contributions of only 11.01 %-13.75 %. Notably, the transport dominance further strengthened with altitude, exceeding 93 % at 1.8 km. Industrial and transportation emissions together contributed more than 75 % of precursor emissions and account for approximately 80 % of O3 formation, while favorable/unfavorable meteorological years modulated long-range transport efficiency and the vertical distribution of contributions. Horizontal flux analysis highlighted three major pathways (Northwest-Southeast, Southeast-Northwest, and Southwest-Northeast), with Shijiazhuang serving as a critical pollutant "sink" across altitude layers. Vertical fluxes revealed an altitude transition near 600 m: net downward transport dominated below 600 m, whereas enhanced summer convection promoted upward transport above 600 m. These results support altitude-dependent, scenario-specific strategies for coordinated regional O3 mitigation in the BTH region.

Ozone

Mechanisms of high-humidity hot air impingement blanching (HHAIB) on microbial counts, functional properties, phenolic profile transformation, and volatile compounds in celery stalks (Apium graveolens L.).

In this study, celery stalks were pretreated with different durations (0-150&#xa0;s) of high-humidity hot air impingement blanching (HHAIB), followed by far-infrared radiation assisted pulsed vacuum freeze-drying (FIR-PVFD) at 60, 65, and 70&#xa0;&#xb0;C. The effects of HHAIB on the physicochemical properties, composition and transformation of phenolic compounds, volatile components, and antioxidant capacity of FIR-PVFD-dried celery stalks were systematically investigated. The results showed that HHAIB not only effectively reduced the counts of total mesophilic aerobic bacteria (TMAB) and total yeast and mold (TYM), but also decreased the relative activities of polyphenol oxidase (PPO) and lipoxygenase (LOX) by more than 91% after 90&#xa0;s of treatment. HHAIB altered the cellular structure of celery stalks, shortened the drying time by 29.33-41.43%, and improved their hydration properties. HHAIB pretreatment promoted the conversion of bound phenolics to free phenolics in celery stalks, with significant increases in the contents of p-coumaric acid, apigenin, graveobioside A, and other components. The total free phenolic content increased by 56.99%, thus HHAIB enhanced the antioxidant activity. An electronic nose and sensory evaluation revealed that HHAIB-pretreated celery stalks better retained the characteristic herbal and pungent notes. GC-MS results indicated that HHAIB treatment optimized the aroma profile by regulating the contents and composition of terpenes, aldehydes, ketones, alcohols, and aromatic compounds.

Apium

Stable chloroform emissions in southeastern China: insights from recent observations.

Chloroform (CHCl3) is a short-lived ozone-depleting substance not currently regulated under the Montreal Protocol. Due to the unique meteorological conditions in East Asia, CHCl3 emitted in this region has a greater potential to reach the stratosphere and contribute to ozone depletion. As an essential component of national CHCl3 emissions, southeastern China has attracted increasing attention. However, long-term observational data in this region remain relatively scarce, with no updates since 2020. In this study, we continuously measured atmospheric CHCl3 concentrations at a remote monitoring station in southeastern China from 1 June 2023 to 31 May 2025. Frequent concentration enhancements were observed during the monitoring period, with mixing ratios ranging from 9.3 to 134.1 ppt and an average value of 36.8 &#xb1; 19.7 ppt. Back-trajectory analysis indicated that air masses associated with elevated CHCl3 levels primarily originated from coastal industrial provinces in eastern China. Using the Potential Source Contribution Function and Concentration Weighted Trajectory methods, we identified the Yangtze River Delta (Jiangsu, Anhui, and Zhejiang Provinces) and Jiangxi Province as dominant source regions. Emissions of CHCl3 in southeastern China were estimated using the Tracer Ratio Method to be approximately 30.1 &#xb1; 5.3 Gg/yr from 2023-06-01 to 2025-05-31, indicating overall stability relative to earlier estimates and no apparent upward trend. These findings provide updated insights into the current status of CHCl3 emissions in southeastern China and highlight the need for continued monitoring and emission assessment of CHCl3 in East Asia, given its unregulated status and implications for ozone layer recovery.

Air Pollutants

Prenatal exposure to particulate matter (PM) and autism spectrum disorder (ASD) among children: a systematic review and meta-analysis.

The global surge in Autism Spectrum Disorder (ASD) cases, coupled with evidence linking prenatal Particulate Matter (PM) exposure to developmental disruption, demands a comprehensive review to design targeted health interventions. This systematic review and meta-analysis aim to evaluate the strength and consistency of evidence linking prenatal PM exposure to ASD across studies, quantifying this relation to identify actionable environmental risk thresholds. This study employed PRISMA protocols to systematically extract and evaluate evidence from PubMed, Web of Science, Scopus, and ScienceDirect (2010-2024), and screened 4,013 articles to identify qualified case-control and cohort studies (n=29). Data synthesis employed random-effects modeling, accompanied by comprehensive assessment through I2 statistics, Q-tests, funnel plots, Duval and Tweedie's trim-and-fill analysis, and Egger's regression, to ensure validity. A meta-analysis of 16&#xa0;case-control studies revealed a 34&#x202f;% increased risk of ASD associated with prenatal PM exposure (pooled OR=1.34; 95&#x202f;% CI: 1.13-1.54), despite substantial between-study heterogeneity (I2=94.02&#x202f;%, p<0.001). Publication bias was not significant (Egger's test p value=0.114). Critical trimester-specific analysis uncovered that third-trimester exposure significantly increased ASD risk (OR=1.17; 95&#x202f;% CI: 1.01-1.34), while first-trimester (OR=1.02; 95&#x202f;% CI: 0.92-1.11; I2=49.18&#x202f;%, p<0.10) and second-trimester exposures (OR=1.13; 95&#x202f;% CI: 0.88-1.38; I2=92.59&#x202f;%, p<0.001) showed non-significant associations. This review identified prenatal and early life exposure to PM as a risk factor for ASD, indicating a trimester-specific vulnerability. It highlighted the necessity of focused air quality interventions and targeted guidance to reduce prenatal PM exposure to alleviate ASD risk during the critical-window.

Child