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Long-term PM2.5 exposure is associated with asthma prevalence and exhaled nitric oxide levels in children.

BACKGROUND: Exhaled nitric oxide concentration (FENO) is a marker of airway inflammation. This study aimed to evaluate the association of air pollution exposure with FENO levels and asthma prevalence with respiratory symptoms in school children. METHODS: We analyzed 4736 school children who reside in six townships near industrial areas in central Taiwan. We evaluated asthmatic symptoms, FENO, and conducted the environmental questionnaire. The personal exposure of PM2.5, NO, and SO2 was estimated using land-use regression models data on children's school and home addresses. RESULTS: Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma (OR&#x2009;=&#x2009;1.595), exercise-induced wheezing (OR&#x2009;=&#x2009;1.726), itchy eyes (OR&#x2009;=&#x2009;1.417), and current nasal problems (OR&#x2009;=&#x2009;1.334) (P&#x2009;<&#x2009;0.05). FENO levels in the absence of infection were positively correlated with age, previous wheezing, allergic rhinitis, atopic eczema, near the road, and for children with high exposure to PM2.5 (P&#x2009;<&#x2009;0.05). An increase of 1 &#x3bc;g/m3 PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels for children after adjusting for potential confounding variables, including exposures to NO and SO2. CONCLUSIONS: Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children. IMPACT: Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma and nasal problems and itchy eyes. Long-term exposures to PM2.5 were significantly associated with FENO levels after adjusting for potential confounding variables. This is first study to assess the association between FENO levels and long-term air pollution exposures in children near coal-based power plants. An increase of 1 &#x3bc;g/m3 annual PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels. Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children.

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

Differential DNA methylation in blood as potential mediator of the association between ambient PM2.5 and cerebrospinal fluid biomarkers of Alzheimer's disease among a cognitively normal population-based cohort.

Fine particulate matter (PM2.5) is a known risk factor for Alzheimer's disease (AD), with emerging evidence showing its effects detectable in the pre-clinical stage through cerebrospinal fluid (CSF) biomarkers of AD. While studies have linked PM2.5 exposure and AD to DNA methylation (DNAm) alterations, the role of DNAm as potential mediator in the association between PM2.5 and AD biomarkers in cognitively normal individuals remains largely unexplored, and formal mediation analyses addressing this question are scarce. Genome-wide DNAm profiles (Illumina EPIC BeadChips) in whole blood and CSF A&#x3b2;42 concentrations were assessed in 536 cognitively normal individuals from the Emory Healthy Brain Study (EHBS). Residential PM2.5 exposure for the year preceding participants' blood collection was estimated. A multi-stage analytical pipeline, incorporating single-mediator analysis, high-dimensional mediation analysis, and causal mediation analysis, was applied. Nine CpG sites were identified as noteworthy mediators of the relationship between PM2.5 and decreased CSF A&#x3b2;42 concentrations. Causal mediation analysis confirmed significant natural indirect effects (NIE) for eight CpGs, with effect estimates ranging from -0.015--0.029 per 1 ug/m3 increase in PM2.5 exposure. The proportion mediated ranging from 14-43%. Six CpGs are annotated to genes implicated in neuroinflammatory pathways. These findings suggest that differential DNAm, particularly in genes related to neuroinflammation, mediates the association between PM2.5 exposure and CSF A&#x3b2;42 concentrations, highlighting the utility of blood DNAm in detecting and studying biological pathways underlying PM2.5 toxicity in the pre-clinical stages of AD.

Humans

Breathing carcinogens: PM2.5 air pollution and lung cancer in never-smokers, a narrative review.

BACKGROUND AND OBJECTIVE: Lung cancer in never-smokers (LCINS) disproportionately affects women and younger individuals, and its incidence has increased over recent decades. Environmental respiratory hazards, such as particulate matter &#x2264;2.5 &#xb5;m (PM2.5), are associated with lung cancer incidence and mortality, but the mechanisms by which PM2.5 increases lung cancer susceptibility remain incompletely understood. This review summarizes the current evidence linking PM2.5 exposure to LCINS and identifies priorities for future research. METHODS: A narrative review was conducted using PubMed/MEDLINE to identify English-language studies published from 2000 through May 2026 using combinations of the terms "PM2.5", "fine particulate matter", "air pollution", "lung cancer", "never-smokers", "environmental respiratory hazards", "genomic alterations", and "tumor microenvironment". Additional relevant studies were identified through manual review of the reference lists of included articles. Studies were selected based on their relevance to the epidemiology, biological mechanisms, genomic and immune landscape, and clinical implications of PM2.5-associated LCINS, with emphasis on original investigations, high-quality reviews, and landmark publications. KEY CONTENT AND FINDINGS: PM2.5 exposure promotes inflammatory signaling, metabolic reprogramming, and tumor progression. Emerging evidence suggests that PM2.5 functions primarily as a tumor promoter rather than a direct mutagen and is associated with genomic and epigenetic alterations, more advanced disease, and worse survival following lung cancer diagnosis and surgical resection. LCINS also exhibits distinct molecular and immunologic characteristics with important implications for screening, molecular profiling, and targeted therapies. CONCLUSIONS: PM2.5 is an increasingly recognized contributor to lung carcinogenesis in never-smokers. Improved understanding of the biologic mechanisms linking environmental respiratory hazards to LCINS may inform future screening strategies, precision oncology approaches, and novel therapeutic targets for this growing and understudied patient population.

Fine particulate matter &#x2264;2.5 &#xb5;m in dia

The association between prenatal PM2.5 constituent exposure and gestational diabetes mellitus: Exploratory analysis of the potential modifying role of thyroid hormones.

The associations of PM2.5 constituents with blood glucose and GDM remain unclear, and the interplay between PM2.5 exposure and thyroid hormone levels in relation to GDM has not been well characterized. This retrospective cohort study included 1314 pregnant women with data collected through multiple methods. A generalized linear model analyzed PM2.5-glucose links, logistic regression assessed pollutant-GDM associations, and stratified analyses explored these relationships at different thyroid hormone levels. In the study population, first-trimester exposure to SO42- and BC correlated positively with FBG, as did PM2.5 and its components in the second trimester. First-trimester SO4&#xb2;&#x207b; exposure (OR=1.26, 95% CI: 1.06, 1.51) and second-trimester exposures to PM2.5 (OR=1.67, 95% CI: 1.19, 2.35), NO3&#x207b; (OR=1.34, 95% CI: 1.06, 1.68), and NH4&#x207a; (OR=1.33, 95% CI: 1.06, 1.65) were associated with increased GDM risk. Stratified analyses showed that second-trimester BC and OM were positively correlated with FBG in the high-TSH and low-FT4 strata, respectively. In addition, first-trimester exposure to SO42- (high TSH: OR = 1.42, 95% CI: 1.10, 1.84; low FT4: OR = 1.35, 95% CI: 1.05, 1.74) and to PM2.5 (high TSH: OR = 1.93, 95% CI: 1.14, 3.27; low FT4: OR = 1.82, 95% CI: 1.46, 2.25) in the second trimester were associated with higher odds of GDM. These findings show that PM2.5 exposure was associated with glucose dysregulation and GDM in pregnant women differently by trimester and component. Across the separate TSH- and FT4-stratified analyses, women in the high-TSH and low-FT4 strata, respectively, appeared to show greater susceptibility to air pollution-related GDM. These subgroup findings should therefore be interpreted as exploratory and require validation in future studies.

Effect modification

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

Metagenomic insights into biogeochemical functional potential and resistome dynamics of PM2.5 microbial communities.

Atmospheric particulate matter harbors diverse microorganisms, yet their functional potential in biogeochemical cycling and the associated risks of resistome remain poorly understood. Here, we performed metagenomic sequencing on PM2.5 samples collected across four months to unravel the microbial genetic repertoire involved in methane, nitrogen, phosphorus, and sulfur cycling, as well as the resistome, and pathogen composition. A broad range of functional genes was detected for each biogeochemical cycle, with more than 65% of gene subtypes shared across all months, indicating conserved functional signatures. In contrast, more than 80% of the resistome showed temporal variation in abundance, with the lowest richness observed in March. Temporal shifts were also observed in resistome composition, with several resistance determinants reaching higher abundances in April and May. Network analysis indicated frequent co-occurrence among several pathogenic and opportunistic taxa. Contig-based profiling identified 51 potential pathogenic taxa, including 32 human- or animal-associated taxa. In addition, both PM10 and PM2.5 concentrations were associated with pathogen abundance and functional gene richness (e.g., antibiotic resistance genes and virulence factors). Together, this metagenomic survey suggests contrasting temporal patterns between conserved biogeochemical functional potential and more variable resistome-related traits in PM2.5 microbial communities. While constrained by limited temporal coverage and sample size, this study provides preliminary insights into the ecological and potential public health relevance of airborne microbial communities in urban environments.

Particulate Matter

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&#x207b;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

Attribution of PM2.5-Induced Transcriptomic Perturbation to Toxic Components.

Ambient fine particulate matter (PM2.5) is a chemically complex mixture whose health impacts are not fully captured by particle mass. Here, we developed an interpretable chemotranscriptomic framework to attribute PM2.5-induced molecular perturbations to toxicity-relevant components. PM2.5 collected from urban roadside and coastal environments was separated into whole, extractable, and unextractable fractions, characterized by LC/GC &#xd7; GC-HRMS-based nontarget analysis and inductively coupled plasma mass spectrometry (ICP-MS), and evaluated using cytotoxicity testing and transcriptomic profiling in human bronchial epithelial cells. Urban PM2.5 exhibited greater cytotoxic potency per unit mass than coastal PM2.5, with extractable fractions accounting for most cytotoxic and pathway-level responses. Transcriptomics revealed distinct site-specific modes of action: urban PM2.5 preferentially induced oxidative stress, xenobiotic metabolism, and cell cycle suppression, consistent with acute, nonapoptotic injury, whereas coastal PM2.5 elicited weaker cytotoxicity but stronger interferon-mediated immune and apoptosis-related signaling. Integrating chemical abundance with pathway activity using random forest regression, SHAP interpretation, and mechanistic corroboration reduced 5,033 detected features to 444 pathway-linked candidate drivers. Fewer than 5% of features explained &#x223c;95% of cumulative model contribution. Standard-confirmed contributors included plasticizer-related compounds, aromatic and heteroaromatic combustion products, and copper for urban PM2.5 and secondary/aged organics and nickel for coastal PM2.5. These findings support mechanism-informed prioritization of hazardous PM2.5 components beyond mass-based assessment.

Particulate Matter

Multi-omics causal inference of childhood asthma triggered by ambient particulate matter.

BACKGROUND: The causal impact of fine particulate matter (PM2.5), an established environmental risk factor, on childhood asthma and its biological mechanisms remain to be elucidated. The objective of the present study was to evaluate the causal association between PM2.5 and childhood asthma and to dissect the mediating role of plasma proteins through a multi-omics integrated Mendelian randomisation (MR) framework. METHODS: Two-sample MR was performed on large-scale genome-wide association data to estimate the causal effect of PM2.5 on childhood asthma. Genes commonly associated with PM2.5 and childhood asthma were screened by transcriptome-wide association study (TWAS) and subjected to enrichment analyses and MR. Mediator proteins were identified by two-step MR. Potential adverse effects were scanned by phenome-wide MR (Phe-MR). RESULTS: MR revealed a significant positive causal effect of PM2.5 on childhood asthma (OR=1.897, 95% CI: 1.063-3.388, p=0.030). TWAS highlighted 70 genes co-expressed in PM2.5 and childhood asthma that were enriched in inflammatory pathways such as lysosome- and leukocyte-mediated immunity. MEAF6 was validated as a protective gene and RNF40 as a risk gene for childhood asthma. Two-step MR identified FUT10 as a positive mediator mediating 19.3% of the causal effect, and CD200 and MANBA as negative mediator proteins. Phe-MR indicated the association of these genes and proteins with multiple other diseases, implying possible adverse effects from therapeutic intervention. CONCLUSION: Long-term PM2.5 exposure is causally linked to childhood asthma with MEAF6, RNF40, CD200, MANBA and FUT10 identified as key molecules. The study provides new evidence for the biological mechanisms linking PM2.5 to childhood asthma.

Journal Article

Berberine shows potential in mitigating PM2.5-induced breast cancer progression by inducing DNA damage and inhibiting error-prone DNA repair pathways.

Breast cancer remains the most common cancer among women, with 2.3&#xa0;million new cases reported globally in 2022. Alongside established risk factors such as age, family history, genetics, obesity, smoking, and alcohol, exposure to fine particulate matter (PM2.5) has recently emerged as an environmental contributor. This risk is especially concerning for low- and middle-income countries (LMICs), where both PM2.5 exposure and cancer burden are disproportionately high; however, mechanistic studies from these regions remain limited. To address this gap and develop mitigation strategies, we investigated the oncogenic potential of water-soluble PM2.5 collected from ambient air on breast cancer and evaluated the potential role of nutraceuticals in mitigating these effects. PM2.5 exposure increased proliferation, migration, and ROS generation, while promoting the formation of multinucleated giant cells, leading to genomic instability. Berberine, a natural alkaloid, countered these effects by increasing DNA damage and exploiting tumor-specific genomic vulnerabilities through disruption of DNA damage response and repair networks, thereby promoting programmed cell death. Transcriptomic profiling of Delhi PM2.5-treated MCF7 cells revealed a Delhi PM2.5-associated carcinogenic gene signature enriched in MAPK signalling, reactive oxygen species, metabolic, lysosomal, and ribosomal pathways. We also found that several genes, including BIRC5, WSB1, and RCC1, within this PM2.5-induced gene signature were dysregulated in breast cancer patients and were inversely regulated by berberine treatment, suggesting that berberine counteracts the transcriptional effects of PM2.5. Our findings highlight ambient PM2.5 exposure as a driver of breast cancer progression and identify berberine as a promising candidate in mitigating PM2.5 effects; however, thorough preclinical and clinical validations are warranted.

Berberine

MASLD Exacerbates Chronic Low-dose PM2.5-induced Lung Injury, Inflammation, and Fibrosis.

BACKGROUND/AIM: Fine particulate matter (PM2.5) and metabolic dysfunction-associated steatotic liver disease (MASLD) are independent risk factors for respiratory disease. However, the combined impact of chronic, low-dose PM2.5 exposure and Western diet (WD)-induced metabolic dysfunction on pulmonary health remains poorly understood. We investigated whether this metabolic state exacerbates PM2.5-driven pathologies using an environmentally relevant PM2.5 dosage (~50 &#x3bc;g/m3). MATERIALS AND METHODS: C57BL/6J mice were fed a WD or normal diet (ND) for 28 weeks and concurrently received intratracheal instillations of PM2.5 (0.5 mg/kg diesel particulate matter) or vehicle three times per week. The MASLD phenotype was confirmed through metabolic and histological analyses. Pulmonary injury, fibrosis, and inflammation were assessed via histology (hematoxylin and eosin, and Masson's trichrome staining) and cytokine quantification in both bronchoalveolar lavage fluid using Luminex multiplex assay and lung tissue using enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. RESULTS: The WD successfully induced MASLD characterized by weight gain, hepatic steatosis, and dyslipidemia. While PM2.5 exposure did not significantly worsen the primary features of MASLD, its combination with a WD markedly exacerbated pulmonary injury and fibrosis compared to PM2.5 exposure alone. This exacerbation was driven by a surge in pro-inflammatory chemokines, including C-X-C motif chemokine ligands 1 and 2 (CXCL1 and CXCL2), and C-C motif chemokine ligand 5 (CCL5), confirmed by Luminex analysis of lavage fluid and mRNA/protein quantification in lung tissue. CONCLUSION: Diet-induced metabolic dysfunction primes the lung for a hyper-inflammatory response to chronic PM2.5 exposure. These findings identify individuals with MASLD as a population with heightened susceptibility to air pollution-related respiratory diseases and underscore the critical interplay between metabolic health and environmental toxicology.

Animals

A cross-sectional study of oxidative stress pathway genotypes and their interactions with environmental pollutant levels identifies associations with gene expression and lung function.

BACKGROUND: Asthma is a heterogeneous disease influenced by genetic and environmental factors. Fine particulate matter (PM2.5) exacerbates asthma, likely through oxidative stress pathways, but whether genetic variation modifies this effect remains unclear. METHODS: We analysed data on 948 adults with asthma from the Severe Asthma Research Program (SARP), linking ZIP-code-level PM2.5 exposure with whole-genome sequencing data. We tested 4337 single nucleotide polymorphisms (SNPs) in 120 oxidative stress pathway genes for gene-environment (GxE) interactions with PM2.5 on lung function (forced expiratory volume in 1 s [FEV1] % predicted) using weighted linear regression. Gene expression data from bronchial epithelial cells (n = 170) were used to assess cis-expression quantitative trait loci (eQTLs). FINDINGS: Higher PM2.5 exposure was associated with lower FEV1% predicted (&#x3b2; per &#x3bc;g/m3 = -0.7, p = 0.01). We identified 20 SNPs across seven genes (OXSR1, PXDN, TPO, LRRK2, APP, MSRA, MSRB2) with significant GxE interactions after multiple-testing correction. Five SNPs were also eQTLs, linking PM2.5-modified gene expression to lung function. Minor alleles in OXSR1 and PXDN were associated with reduced gene expression and worsened FEV1% under high PM2.5 exposure. Conversely, TPO variants were associated with higher baseline expression and lower lung function, but under increasing PM2.5 exposure, minor allele carriers showed suppressed TPO expression and improved FEV1%. INTERPRETATION: This study identified 20 SNPs in oxidative stress pathway genes that modify the effect of PM2.5 on lung function in asthma. These findings highlight the importance of integrating environmental context in genetic studies and suggest potential therapeutic targets for pollution-sensitive asthma phenotypes. FUNDING: Supported by NIH grants.

Cross-Sectional Studies

Endothelial function in relation to low-level chronic residential air pollution in a general population: a cohort study.

BACKGROUND: Given the recently updated clean-air targets, this population study assessed endothelial function at low exposure to particulate matter with an aerodynamic diameter of &#x2264;10&#xa0;&#xb5;m (PM10) and &#x2264;2.5&#x2009;&#xb5;m (PM2.5), nitrogen dioxide (NO2) and black carbon (BC). METHODS: In 453 Flemish participants (47.7% women; mean age, 52.8&#x2009;years), endothelial function was assessed by finger photoplethysmography after 5&#x2009;min of ischaemia. The outcome measures were the maximal ischaemic-to-control ratio (Rmax) and the maximal difference (Dmax) in pulse amplitude between the test and control fingers. The air pollutants were related to Rmax and Dmax using mixed models accounting for coresidence, to cardiovascular endpoints by proportional hazards regression, and to residential address by high-resolution spatiotemporal interpolation. RESULTS: From 2010 to 2015, PM10, PM2.5, NO2 and BC decreased (p&#x2009;<&#x2009;0.0001) with 6-year levels averaging 15.9, 12.8, 14.3 and 1.04&#xa0;&#xb5;g/m3. Irrespective of adjustment for risk factors, Dmax was inversely correlated with PM2.5, while associations of Rmax with PM2.5 and associations of both Dmax and Rmax with other pollutants were weaker (p values <0.10), but consistently inverse. Association sizes of Rmax and Dmax with PM10 and PM2.5 weakened over 6&#xa0;years, paralleling the decreasing air pollutants (p&#x2009;&#x2264;&#x2009;0.044). In adjusted analyses, the risk of a composite cardiovascular endpoint decreased (p&#x2009;&#x2264;&#x2009;0.043) with higher Rmax and Dmax with hazard ratios ranging from 0.31 to 0.49. Finally, in the geographical analysis, endothelial dysfunction followed the spatial gradients in PM2.5. CONCLUSIONS: Long-term low-level air pollution is associated with subclinical endothelial dysfunction, the initial and critical step leading to adverse cardiovascular outcomes.

Humans

Epigenome-Wide Analysis Identifies Pollution-Sensitive Loci in Fibrotic Interstitial Lung Disease.

Rationale: Particulate matter &#x2a7d;2.5 &#x3bc;m (PM2.5) adversely impacts patients with fibrotic interstitial lung disease (fILD). Objectives: We sought to determine whether PM2.5-associated epigenetic alterations contribute to the environmental pathogenesis of fILD. Methods: A retrospective two-cohort study applied satellite-derived PM2.5 and constituent exposure matching to the residential location of patients with fILD. Robust linear regressions were used to evaluate cohort-specific, epigenome-wide differential blood DNA methylation with increasing pollutant exposures (Illumina MethylationEPIC BeadChip). Cox and linear regressions were used to evaluate associations of cytosine-phosphate-guanine (CpG) loci with transplant-free survival and lung function. A Wilcoxon test was used to evaluate cartilage-associated protein (CRTAP) levels in fILD and control lungs. Measurements and Main Results: The University of Pittsburgh cohort (n&#x2009;=&#x2009;306) had 5-year median PM2.5 exposures of 12.1 &#x3bc;g/m3 compared with 5.1 &#x3bc;g/m3 in the University of British Columbia cohort (n&#x2009;=&#x2009;170). Higher pollutant exposures in the University of Pittsburgh cohort were associated with lower methylation at cg25354716, annotated to CRTAP, a critical extracellular matrix remodeling enzyme. Higher exposures in the University of British Columbia cohort were associated with higher methylation at cg01019301, annotated to TLN2 (talin-2), a cytoskeletal protein involved in fibroblast migration. A 10% increase in cg25354716 methylation was associated with a hazard ratio of 0.81 for death or lung transplantation in the meta-analyzed cohorts (95% confidence interval&#x2009;=&#x2009;0.69-0.96; P&#x2009;=&#x2009;0.01), whereas the same change in cg01019301 was associated with a hazard ratio of 1.36 (95% confidence interval&#x2009;= 1.07-1.74; P&#x2009;=&#x2009;0.01). CRTAP protein was more abundant in lungs from patients with fILD compared with those from donor controls (P&#x2009;<&#x2009;0.001). Conclusions: PM2.5 is associated with altered blood DNA methylation in fILD. This work identifies novel pollution-sensitive targets that hold potential for therapeutic modulation in fILD.

Humans

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&#x200b; 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

Pneumococcal population structure influences the effects of air pollution on invasive disease risk in South Africa.

Streptococcus pneumoniae is highly diverse, comprising over 100 serotypes and hundreds of genomic lineages amid widespread vaccination. While it can cause invasive pneumococcal disease (IPD) which exhibits pronounced seasonal spikes, the interplay between pneumococcal diversity and environmental drivers remains unexplored. Here we analysed 59,017 IPD cases over 19&#x2009;years from South Africa, incorporating 4,350 genome-sequenced isolates, using Bayesian spatiotemporal models to link environmental exposure and pneumococcal diversity. Cumulatively, across an 8-week period, moderate relative humidity (33-49%) and cold minimum temperatures (4-10&#x2009;&#xb0;C) increased IPD risk by 5% and 4%, respectively. Conversely, warm maximum temperatures (27-38&#x2009;&#xb0;C) were associated with up to a 10% increased risk within a week of exposure. There was a positive association between air pollution (PM2.5) and IPD, although it varied by age, disease presentation, and most notably serotype and lineage. Specifically, the lag time between PM2.5 exposure and disease onset varied by serotype, with only serotypes 4, 8 and 23F conferring an immediate IPD risk. High prevalence of GPSC21 lineage (serotype 19F) also modified the pollution response, shifting the lag structure to produce immediate risk of disease following high PM2.5 exposure. Our results demonstrate that pneumococcal population structure shapes air quality risk which in turn can shape the fitness landscape of microbial populations. Integration of these data may inform public health policy.

Journal Article