Cardiovascular effects of traffic-related air pollution: A multi-omics analysis from a randomized, crossover trial

Ambient low-level benzene, genetic factors, and heart failure incidence among urban adults

Ambient benzene, a representative volatile organic compound (VOC) primarily resulting from rapid industrialization and urbanization, is also of great concern as an urban air toxic. The global benzene market is experiencing steady growth, driven by its use in industrial manufacturing. Currently, population epidemiological evidence about the effects of ambient benzene on heart failure (HF) incidence is still inadequate, especially at low levels of long-term exposure. Leveraging data from 277,585 urban residents in the UK Biobank, the study utilized Cox regression models adjusted for potential confounders to evaluate the association between low-concentration benzene exposure and HF risk. The investigation also assessed potential interactions between genetic predisposition and ambient benzene by applying relative excess risk due to interaction (RERI) metrics and interaction significance testing. Furthermore, the effect of ambient benzene on cardiac functional parameters was estimated using multiple linear regression models. This study demonstrated that per interquartile range increment of ambient benzene was related to the elevated HF risk (hazard ratios = 1.22, 95 % confidence interval (CI): 1.07-1.39] from the time-dependent Cox model. An additive interaction between ambient benzene and genetic risk was observed (RERI = 0.18, 95 % CI: 0.01-0.36). Ambient benzene exposure demonstrated significant correlations with modifications in cardiac functional parameters, such as ventricular end-diastolic and end-systolic volumes. Prolonged exposure to low-concentration ambient benzene may elevate the likelihood of developing HF, which provides the necessary evidence for the systematic risk assessment of ambient benzene and promotes the formulation and updating of air quality guidelines worldwide.

Short-Term and Long-Term Effects of Inhaled Ultrafine Particles on Blood Markers of Cardiovascular Diseases: A Systematic Review and Meta-Analysis

Background/Objectives: Air pollution is the highest environmental risk factor of mortality and morbidity worldwide, leading to over 4 million deaths each year. Among different air pollutants, ultrafine particles (UFPs) constitute the highest risk factor of cardiovascular diseases (CVDs). Epidemiological studies have associated UFPs with the short- and long-term imbalance of numerous blood markers. Our objective was to systematically review the short-term and long-term impact of UFP exposure on blood markers of CVDs. Methods: We prepared the systematic review of CVD blood markers and meta-analyses of the short- and long-term effects of UFP exposure on high-sensitivity C-reactive protein (hsCRP) concentration. The eligibility criteria were established with the use of the Provider, Enrollment, Chain, and Ownership System (PECOS) model, and the literature search was conducted in Web of Science, PubMed, and Scopus databases from 1 January 2013 to 9 January 2025. The risk of bias (RoB) was prepared according to a World Health Organization (WHO) template. Results: The results showed an increase in hsCRP as a result of both short-term and long-term UFPs. Moreover, IL-6 and IL-1β together with other inflammatory markers increased after short-term UFP exposure. In addition, different nucleic acids, among which were miR-24-3p and let-7d-5p, were differentially expressed (DE) as a result of short-term UFP exposure. Chronic exposure to UFPs could lead to a persistent increase in hsCRP and other blood markers of CVDs. Conclusions: Our findings underline that UFPs may lead to the development and/or worsening of cardiovascular outcomes in fragile populations living in air-polluted areas.

The effects of oral gestational particulate matter 10 exposure: Insights into neurodevelopmental milestones, inhibitory control, adult sociability, and object recognition

Air pollutants have been associated with various neurodevelopmental disorders, with several studies specifically linking Particulate Matter (PM) exposure to attentional and social deficits. This link is even more pronounced when exposure occurs during the prenatal period, as it can disrupt normal brain development. However, while social deficits have been extensively studied during adolescence, their impact on adult social behaviors remains largely unexplored. To investigate these effects, pregnant Wistar rats were exposed throughout gestation (GD1-GD21) to PM10 at a dosage of 200 μg/Kg/day diluted in PBS that was freely drunk. After birth, the pups were evaluated on developmental milestones such as weight progression, ocular opening, and muscular strength. In adulthood, inhibitory control was assessed using the Five Choice Serial Reaction Time Task (5-CSRTT), social behavior using the Three-Chambered Crawley's Test (3-CT), and object recognition using the Novelty Object Recognition test (NOR). The results indicated that prenatal PM10 exposure is associated with higher birth weight and poorer performance in neuromuscular tests. However, no significant differences were observed in inhibitory control (5-CSRTT) or social behavior (3-CT). Interestingly, prenatally exposed rodents showed heightened novelty responses in the NOR test. In conclusion, gestational exposure to PM10 is related to differences in neurodevelopmental milestones, including weight and muscular strength. While it does not impact adult inhibitory control or social behavior, it influences novelty recognition in later life.

Effects of acute PM2.5 purification on cognitive function and underlying mechanisms: Evidence from integrating alternative splicing into multi-omics

The relationship between fine particulate matter (PM2.5) and cognition has been extensively investigated. However, the causal impact of acute PM2.5 purification on cognition improvement and the underlying biological mechanisms remain relatively opaque. Our double-blinded randomized controlled trial assessed the impact of acute PM2.5 purification on executive function, underpinned by multi-omics approaches including alternative splicing (AS) analysis. A total of 93 participants experienced a two-hour exposure to either reduced and normal PM2.5 levels. We measured the cognition of healthy young adults, collected peripheral blood before and after intervention, and performed multi-omics analysis including transcriptomics, metabolomics, and proteomics. Results indicated that reducing PM2.5 by 1 μg/m3 was associated with a 0.10 % (95 % CI: [0.18 %, 0.01 %]; p = 0.031) improvement in executive function. Notably, we identified 96 AS events without concurrent transcriptional amount alterations. Multi-layered omics analyses revealed disrupted pathways in hypoxia, mitochondrial function and energy metabolism, and immune responses, validated by ELISA and biochemical assay. These findings demonstrated short-term improvements of cognition following PM2.5 purification and provide mechanistic understandings of PM2.5-induced cognition alterations. This study underscores the significance of incorporating AS in the molecular framework of multi-omics research by exploring variable exon splicing, which could enrich multi-omics analysis methodologies and expose to broader audience.

Long-term effects of PM2.5 and its components on incident hypertension among the middle-aged and elderly: a national cohort study

BACKGROUND

The long-term health effects of fine particulate matter (PM2.5) on hypertension remain incomprehensive. We evaluated the relationship of PM2.5 and its components with hypertension incidence in middle-aged and elderly adults.

METHODS

We utilised data from the China Health and Retirement Longitudinal Study collected between 2011 and 2018. We obtained annual modelled data from the dataset of Tracking Air Pollution in China, including black carbon (BC), sulphate (SO42-), organic matter (OM), ammonium (NH4+), and nitrate (NO3-). Time-varying Cox models and quantile g-computation models were employed to explore the associations. Exposure-response curves were portrayed to investigate potential non-linear effects.

RESULTS

We enrolled 7,032 individuals with a mean age of 57.14 (range: 45-95) years. Over 36,997 person-years of follow-up (average time: 5.26 years), 3,119 individuals suffered from hypertension. With per interquartile range increment, the hazard ratios and 95% confidence intervals (CIs) of PM2.5 (3.82 [95% CI: 3.48-4.18]), BC (4.17 [95% CI: 3.54-4.92]), SO42- (4.24 [95% CI: 3.50-5.12]), OM (3.76 [95% CI: 3.14-4.50]), NH4+ (3.20 [95% CI: 2.91-3.52]), and NO3- (1.94 [95% CI: 1.77-2.13]) were discovered with lag 1 year. And the mixed effect was 18.0% [95% CI: 16.8%-19.2%], which was mainly driven by BC (66.0%) and SO42- (34.0%). Approximate J-shaped exposure-response relationships were revealed.

CONCLUSIONS

The positive associations of long-term exposure to PM2.5 and its components with hypertension incidence were discovered in adults aged ≥ 45 years. Controlling the emissions of PM2.5 components, especially BC and SO42-, could alleviate the burden of hypertension.

Oxidative gaseous air pollutant exposure interacts with PNPLA3-I148M genotype to influence liver fat fraction and multi-omics profiles in young adults

PNPLA3-I148M genotype is the strongest predictive single-nucleotide polymorphism for liver fat. We examine whether PNPLA3-I148M modifies associations between oxidative gaseous air pollutant exposure (Oxwt) with i) liver fat and ii) multi-omics profiles of miRNAs and metabolites linked to liver fat. Participants were 69 young adults (17-22 years) from the Meta-AIR cohort. Prior-month residential Oxwt exposure (redox-weighted oxidative capacity of nitrogen dioxide and ozone) was spatially interpolated from monitoring stations via inverse-distance-squared weighting. Liver fat fraction was assessed by MRI. Serum miRNAs and metabolites were assayed via NanoString nCounter and LC-HRMS, respectively. Multi-omics factor analysis (MOFA) was used to identify latent factors with shared variance across omics layers. Multivariable linear regression models adjusted for age, sex, body mass index, and genotype with liver fat or MOFA factors as an outcome and examined PNPLA3 (rs738409; CC/CG vs. GG) as a multiplicative interaction term. Overall, a standard deviation difference in Oxwt exposure was associated with 8.9% relative increase in liver fat (p = 0.04) and this relationship differed by PNPLA3 genotype (p-value for interaction term: pintx<0.001), whereby relative increases in liver fat for GG and CC/CG participants were 71.8% and 2.4%, respectively. There was no main effect of Oxwt on MOFA Factor 1 expression (p = 0.85), but there was an interaction with PNPLA3 genotype (pintx = 0.01), whereby marginal slopes were 0.211 and -0.017 for GG and CC/CG participants, respectively. MOFA Factor 1 in turn was associated with liver fat (p = 0.006). MOFA Factor 1 miRNAs targeted genes in Fatty Acid Biosynthesis and Metabolism and Lysine Degradation pathways. MOFA Factor 9 was also associated with liver fat and was comprised of branched-chain keto acid and amino acid metabolites. The effects of Oxwt exposure on liver fat is exacerbated in young adults with two PNPLA3 risk alleles, potentially through differential effects on miRNA and/or metabolite profiles.

Effects of Short-Term Traffic-Related Air Pollution Exposure on Nasal Microbiome in Young Healthy Adults: A Randomized Crossover Controlled Trial

Traffic-related air pollution (TRAP) remains a concern for public health. However, the exact mechanisms through which TRAP affects the respiratory system are still not fully understood. This study aimed to investigate the nasal microbiome change in healthy adults after short-term exposure to TRAP, contributing to the understanding of the adverse health effects associated with TRAP. A randomized crossover controlled trial was conducted from 9 March to 30 March 2024 among college students aged 19-24 years. Twenty healthy students were recruited through a baseline questionnaire survey and randomly assigned into two groups. One group followed a crowed-testing procedure: the park portion, a three-week washout period, and then the road portion, while the other group experienced the opposite procedure. Both groups were fully exposed to either a park environment or a road environment with high traffic volume. Nasal mucus samples were collected from the participants at the end of the trial, and then 16SrRNA sequencing was performed to analyze the differences in compositional structure and diversity of the nasal microbiome when volunteers were exposed to different levels of TRAP. The α-diversity indices, including the Chao1 index (p = 0.0097), observed species index (p = 0.0089), and Faith's PD index (p = 0.0255), demonstrated a significant increase in the nasal microbiome of healthy adults following short-term exposure to TRAP. Visualization through a two-dimensional NMDS plot (stress value < 0.2) indicated that nasal bacterial species distribution became richer after TRAP exposure. Furthermore, the relative abundance of nasal Firmicutes (Bacillota), Bacteroidota, and Actinobacteriota phyla, especially Firmicutes phylum, exhibited a richer distribution after conducting the trial in the road environment with high levels of TRAP, which was shown in the significance test of signature species. Collectively, our study indicates that short-term exposure to TRAP can affect the composition of the nasal microbiota in healthy adults. These findings offer a scientific basis for understanding how TRAP causes respiratory diseases.

Associations of Ozone Exposure with Serum Biomarkers in Acute Myocardial Infarction Patients in Taiyuan, China: The Mediating Role of Metabolites

Abundant epidemiological studies have conclusively demonstrated the effects of short-term ozone (O3) exposure on the incidence and mortality of cardiovascular diseases. However, the mechanism of its influence remains unverified. This study aimed to assess the impact of O3 on metabolomic-based biomarkers in acute myocardial infarction (AMI) patients. Accurate biomarkers for AMI were identified by combining serum biomarkers with metabolomics. A total of 137 volunteers were recruited, including 79 AMI patients and 58 healthy participants, from March to April 2023 in Taiyuan, China. Linear regression models were applied to analyze the associations of serum biomarkers and metabolites with O3. Mediation analyses were also conducted to assess the impact of metabolites, acting as mediators, on the associations between O3 and biomarkers. We found that O3 at lag2 captured the most remarkable effects. Metabolomic analysis revealed a substantial association between O3 (lag2) and 43 metabolites. Pathway analysis revealed that these metabolites primarily participate in the tricarboxylic acid cycle, arginine biosynthesis, and histidine metabolism. These findings suggest that O3 is an important factor in examining the metabolic mechanisms of cardiovascular disease, highlighting the importance of mitigating O3 to further protect AMI patients.

Space Prescription: Initiative to Improve Health and Well-being in Tokyo

This review introduces "space prescribing," an innovative healthcare approach that incorporates the physical environment's role in promoting health beyond traditional clinical settings. Recognizing that individuals spend a significant amount of time outside clinical environments, this approach explores the therapeutic potential of natural and built environments in improving well-being and managing diseases, particularly cardiovascular and mental health conditions.Traditional healthcare models focus on treatments in hospital and clinic settings. However, evidence suggests that environmental factors profoundly influence health outcomes. Space prescribing recommends specific environments that encourage healthier lifestyles and enhance wellbeing. This concept includes social prescribing, in which healthcare professionals direct patients to community-based, non-medical activities such as art classes and sports, acknowledging that well-being transcends biological factors.This review also highlights "Cultural Ecosystem Services" (CES) in health through stress reduction, social connections, and physical activity. For cardiovascular health, elements such as green spaces and urban design are vital for managing conditions, such as hypertension and heart disease. Similarly, the configuration of indoor and outdoor spaces plays a crucial role in mental health. Therapeutic landscapes, including community gardens and culturally enriched urban areas, support mental health recovery, foster community engagement and reduce isolation.In conclusion, space prescribing advocates an integrated approach that considers the physical and social environments as fundamental components of health promotion. This strategy aims to mitigate health disparities and enhance the quality of life, while making health-enhancing activities accessible in urban and rural settings. Through this holistic approach, space prescribing has the potential to transform public health by strategically utilizing environmental designs to support health outcomes.

Proteomic signatures of ambient air pollution and risk of non-alcoholic fatty liver disease: A prospective cohort study in the UK Biobank

Air pollution has been linked with non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms characterized by perturbations in the circulating proteome profile are largely unknown. Therefore, we included 51,357 participants from the UK Biobank with 2941 plasma proteins measured in blood samples collected between 2006 and 2010, measurements of annual fine particular matter <2.5 μm in diameter (PM2.5) and nitrogen dioxide (NO2), and follow-up data on NAFLD (743 incident cases occurred over a median follow-up of 13.6 years). Multiple linear regression was used to identify proteins associated with PM2.5 and NO2. Cox proportional hazards models were applied to assess associations of PM2.5 and NO2 and identified proteins with incident NAFLD. Mediation analyses were conducted to explore the mediation role of proteins in the associations between air pollution and incident NAFLD. After adjusting for selected covariates, PM2.5 (hazard ratio [HR] = 2.57, 95%CI:1.27, 5.21, per ln increase) and NO2 (HR = 1.43, 95%CI: 1.10, 1.84, per ln increase) were positively associated with incident NAFLD. We identified 138 proteins associated with PM2.5 (92 positively, 46 inversely, FDR <0.05) and 143 with NO2 (100 positively, 43 inversely). Of the proteins that were significantly associated with both PM2.5 and NO2, 93 (79 positively, 14 inversely) and 79 (69 positively, 10 inversely) were significantly associated with incident NAFLD. Furthermore, 84 PM2.5-associated proteins and 66 NO2-associated proteins significantly mediated the corresponding association between air pollutants and incident NAFLD, with the proportion of mediation effects ranging from 3.2 % to 27.3 % for PM2.5 and 2.6 % to 20.8 % for NO2, respectively. Of note, the majority of significant mediating proteins were enriched in pathways of cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptor. Our findings suggested that long-term exposure to PM2.5 and NO2 was associated with an increased risk of NAFLD partially by perturbating circulating proteins involved in pathways of inflammation and immunity responses.

Challenges and Potentials: Environmental Assessment of Particulate Matter in Spaces Under Highway Viaducts

Under-viaduct space (UVS) is becoming an important solution to urban mobility problems, and the construction and use of high-density city center highways and elevated bridges are increasing, which has a negative impact on the UVS. Air pollution is a problem in these spaces, but research on air pollution in UVSs is lacking. To further study air pollution in UVS, this study selected a case area of a UVS in central Shanghai and investigated the spatiotemporal distribution patterns of air pollution and the influencing factors. We found that air pollution in the UVS is significantly higher than the background levels, and the higher the background levels, the greater the difference between the pollution of the UVS and the background. In terms of the impact factor, air pollution is highly correlated with the built environment and traffic flow. The research provides evidence of the exposure to air pollution in under viaducts spaces in the microenvironment.

Short- and medium-term cumulative effects of traffic-related air pollution on resting heart rate in the elderly: A wearable device study

BACKGROUND

Epidemiological evidence regarding the association between air pollution and resting heart rate (RHR), a predictor of cardiovascular disease and mortality, is limited and inconsistent.

OBJECTIVES

We used wearable devices and time-series analysis to assess the exposure-response relationship over an extended lag period.

METHODS

Ninety-seven elderly individuals (>65 years) from the Taipei Basin participated from May to November 2020 and wore Garmin® smartwatches continuously until the end of 2021 for heart rate monitoring. RHR was defined as the daily average of the lowest 30-min heart rate. Air pollution exposure data, covering lag periods from 0 to 60 days, were obtained from nearby monitoring stations. We used distributed lag non-linear models and linear mixed-effect models to assess cumulative effects of air pollution. Principal component analysis was utilized to explore underlying patterns in air pollution exposure, and subgroup analyses with interaction terms were conducted to explore the modification effects of individual factors.

RESULTS

After adjusting for co-pollutants in the models, an interquartile range increase of 0.18 ppm in carbon monoxide (CO) was consistently associated with increased RHR across lag periods of 0-1 day (0.31, 95 % confidence interval [CI]: 0.24-0.38), 0-7 days (0.68, 95 % CI: 0.57-0.79), and 0-50 days (1.02, 95 % CI: 0.82-1.21). Principal component analysis identified two factors, one primarily influenced by CO and nitrogen dioxide (NO2), indicative of traffic sources. Increases in the varimax-rotated traffic-related score were correlated with higher RHR over 0-1 day (0.36, 95 % CI: 0.25-0.47), 0-7 days (0.62, 95 % CI: 0.46-0.77), and 0-50 days (1.27, 95 % CI: 0.87-1.67) lag periods. Over a 0-7 day lag, RHR responses to traffic pollution were intensified by higher temperatures (β = 0.80 vs. 0.29; interaction p-value [P_int] = 0.011). Males (β = 0.66 vs. 0.60; P_int < 0.0001), hypertensive individuals (β = 0.85 vs. 0.45; P_int = 0.028), diabetics (β = 0.96 vs. 0.52; P_int = 0.042), and those with lower physical activity (β = 0.70 vs. 0.54; P_int < 0.0001) also exhibited stronger responses. Over a 0-50 day lag, males (β = 0.99 vs. 0.96; P_int < 0.0001), diabetics (β = 1.66 vs. 0.69; P_int < 0.0001), individuals with lower physical activity (β = 1.49 vs. 0.47; P_int = 0.0006), and those with fewer steps on lag day 1 (β = 1.17 vs. 0.71; P_int = 0.029) showed amplified responses.

CONCLUSIONS

Prolonged exposure to traffic-related air pollution results in cumulative cardiovascular risks, persisting for up to 50 days. These effects are more pronounced on warmer days and in individuals with chronic conditions or inactive lifestyles.

Effects of socioeconomic status and regional inequality on the association between PM2.5 and its components and cardiometabolic multimorbidity: A multicenter population-based survey in eastern China

BACKGROUND

Despite evidence linking fine particulate matter (PM2.5) to cardiometabolic multimorbidity (CMM), the impact of its components remains unclear. Socioeconomic status (SES) and regional disparities may confound their association. We aim to evaluate the associations between PM2.5 components and CMM and explore how socioeconomic status and regional disparities affect these relationships.

METHODS

We recruited 108,941 participants aged 35-76 years from ten cities in eastern China. Individual exposure was assessed using Tracking Air Pollution in China (TAP) data, including PM2.5 and five components: ammonium (NH4+), black carbon (BC), nitrates (NO3-), organic matter (OM), and sulfates (SO42-). Generalized linear models and quantile g-computation models were employed to quantify the effects of PM2.5 components on CMM and to identify key components. Stratified analyses were performed to investigate the modifying effect of SES and regional disparities.

RESULTS

For each increase in interquartile range (IQR), BC (odds ratio [OR] 1.37, 95 % CI 1.29-1.47), OM (1.38, 1.29-1.48), NH4+ (1.31, 1.21-1.40), NO3- (1.34, 1.25-1.44), and SO42- (1.28, 1.20-1.38) were positively associated with CMM. Joint exposure to five components was significantly positively associated with CMM (OR: 1.27, 95 % CI: 1.21-1.33), with SO42- having the highest estimated weight, followed by NO3- and BC. These associations were stronger for participants from low socio-economic status and poor regions.

CONCLUSION

In summary, we found a stronger hazard effect of PM2.5 and its components on CMM, compared to those suffering from CMDs, particularly among participants with low socioeconomic status and in poor regions. SO42- may be a primary contributor to the association between PM2.5 components and CMM. These findings underscore the importance of prioritizing CMM and targeting SO42-related pollution sources in health policies, particularly amid China's aging population, reducing environmental health inequalities is critical.

Exploring the association between knee osteoarthritis outpatient visits and Asian dust storms: a time-series analysis

Osteoarthritis (OA) is one of the most prevalent musculoskeletal diseases in Taiwan, posing a significant public health challenge. In recent years, outdoor air pollution has become an increasingly critical global health issue. Asian Dust Storms (ADS) are known to exacerbate various health conditions due to elevated levels of particulate matter and other pollutants. However, the relationship between ADS and knee OA remains insufficiently explored. This study investigates the association between ADS occurrences and knee OA outpatient visits from January 2006 to December 2012, aiming to understand the potential health impacts of dust storms on OA patients. Using data from the National Health Insurance Research Database (NHIRD), the Taiwan Environmental Protection Agency (TEPA), and the Taiwan Central Weather Bureau, we conducted a time-series analysis employing the autoregressive moving average with exogenous variables (ARMAX) model. This approach accounted for daily outpatient visits related to knee OA, ADS events, and various environmental and meteorological factors. The results revealed a significant increase in knee OA outpatient visits on days immediately following ADS events, with peaks observed one to two days after the event. This increase was most pronounced among females, individuals aged 61 and above, and residents in the western regions. The study demonstrates an association between ADS and increased knee OA outpatient visits, highlighting the need for public health strategies to mitigate the health impacts of dust storms.

Association of ambient air pollution and Air Quality Index with risk of sudden sensorineural hearing loss: a cross-sectional study

OBJECTIVES

To explore the associations of air pollutants and Air Quality Index (AQI) with risk of sudden sensorineural hearing loss (SSNHL) DESIGN: Cross-sectional study SETTING: Medical record data and local population data collected between 2014 and 2022 in Changshu, China were retrospectively reviewed.

PARTICIPANTS

Adults aged 18 years and above who were diagnosed with SSNHL in Changshu No. 1 People's Hospital or Changshu No. 2 People's Hospital from the spring of 2014 to the fall of 2022 were included in the study.

OUTCOME MEASURE

SSNHL was diagnosed by clinicians using the Chinese diagnostic criteria for SSNHL.

RESULTS

Compared with those exposed to the lowest tertile of carbon monoxide (CO), the prevalence ratio for those exposed to middle and high tertiles of CO were 1.113 (95% CI 1.022 to 1.213) and 1.230 (95% CI 1.105 to 1.369), respectively. The risk of SSNHL was increased by 30.6% (95% CI 9.9% to 55.4%) per doubling increment of CO. No categorical association was found between ozone (O3) exposure and risk of SSNHL, however, an increased risk of 22.2% (0.8%-48.2%) was identified for each doubling of O3. No association was identified between other pollutants and AQI and risk of SSNHL.

CONCLUSIONS

In this study, CO and O3 were associated with an increased risk of SSNHL in Changshu, China. Further studies are warranted to confirm our findings.

Association between long-term exposure to fine particulate matter and its chemical constituents and premature death in individuals living with HIV/AIDS

Long-term exposure to fine particulate matter (PM2.5) is associated with an increased total mortality. However, the association of PM2.5 with mortality in people living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS, PLWHA) and the relationship between its constituents and adverse outcomes remain unknown. In this cohort study, 28,140 PLWHA were recruited from the HIV/AIDS Comprehensive Response Information Management System of the Hubei Provincial Centre for Disease Control and Prevention in China between 2001 and 2020. The annual PM2.5 chemical composition data, including sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), black carbon (BC), and organic matter (OM), was extracted from the Tracking Air Pollution (TAP) dataset in China. A Cox proportional hazard model with time-varying exposure and time-to-event quantile-based generalized (g) computation was used to assess the associations between PM2.5 chemical constituents, and mortality in PLWHA. A multivariate Cox proportional hazard model estimated an excess hazard ratio (eHR) of 0.32% [95% confidence interval (CI): (0.01%, 0.64%)] for AIDS-related death (ARD), associated with 1 μg/m3 rise in PM2.5 exposure. An increase of 1 μg/m3 in NH4+ was associated with 5.13% [95% CI: (2.89%, 7.43%)] and 2.97% [95% CI: (1.52%, 4.44%)] increase in the risk of ARD and all-cause deaths (ACD), respectively. When estimated using survival-based quantile g-computation, the eHR for ARD with a joint change in a decile increase in all five components was 6.10% [95% CI: 3.77%, 8.48%)]. Long-term exposure to PM2.5 chemical composition, particularly NH4+ increased the risk of death in PLWHA. This study provides epidemiological evidence that SO42- and NH4+ increased the risk of ARD and that NH4+ increased the risk of ACD in PLWHA. Multi-constituent analyses further suggested that NH4+ may be a key component in increasing the risk of premature death in patients with HIV/AIDS. Individuals aged ≥65 with HIV/AIDS are more vulnerable to SO42-, and consequent ACD.

Multiomic Signatures of Traffic-Related Air Pollution in London Reveal Potential Short-Term Perturbations in Gut Microbiome-Related Pathways

This randomized crossover study investigated the metabolic and mRNA alterations associated with exposure to high and low traffic-related air pollution (TRAP) in 50 participants who were either healthy or were diagnosed with chronic pulmonary obstructive disease (COPD) or ischemic heart disease (IHD). For the first time, this study combined transcriptomics and serum metabolomics measured in the same participants over multiple time points (2 h before, and 2 and 24 h after exposure) and over two contrasted exposure regimes to identify potential multiomic modifications linked to TRAP exposure. With a multivariate normal model, we identified 78 metabolic features and 53 mRNA features associated with at least one TRAP exposure. Nitrogen dioxide (NO2) emerged as the dominant pollutant, with 67 unique associated metabolomic features. Pathway analysis and annotation of metabolic features consistently indicated perturbations in the tryptophan metabolism associated with NO2 exposure, particularly in the gut-microbiome-associated indole pathway. Conditional multiomics networks revealed complex and intricate mechanisms associated with TRAP exposure, with some effects persisting 24 h after exposure. Our findings indicate that exposure to TRAP can alter important physiological mechanisms even after a short-term exposure of a 2 h walk. We describe for the first time a potential link between NO2 exposure and perturbation of the microbiome-related pathways.

Mechanistic insights into cardiovascular effects of ultrafine particle exposure: A longitudinal panel study

BACKGROUND

Ultrafine particle (UFP) has been linked with higher risks of cardiovascular diseases; however, the biological mechanisms remain to be fully elucidated.

OBJECTIVES

This study aims to investigate the cardiovascular responses to short-term UFP exposure and the biological pathways involved.

METHODS

A longitudinal panel study was conducted among 32 healthy, non-smoking young adults in Shanghai, China, who were engaged in five rounds of follow-ups between December 2020 and November 2021. Individual exposures were calculated based on the indoor and outdoor real-time measurements. Blood pressure, arterial stiffness, targeted biomarkers, and untargeted proteomics and metabolomics were examined during each follow-up. Linear mixed-effect models were applied to analyze the exposure and health data. The differential proteins and metabolites were used for pathway enrichment analyses.

RESULTS

Short-term UFP exposure was associated with significant increases in blood pressure and arterial stiffness. For example, systolic blood pressure increased by 2.10 % (95 % confidence interval: 0.63 %, 3.59 %) corresponding to each interquartile increase in UFP concentrations at lag 0-3 h, while pulse wave velocity increased by 2.26 % (95 % confidence interval: 0.52 %, 4.04 %) at lag 7-12 h. In addition, dozens of molecular biomarkers altered significantly. These effects were generally present within 24 h after UFP exposure, and were robust to the adjustment of co-pollutants. Molecular changes detected in proteomics and metabolomics analyses were mainly involved in systemic inflammation, oxidative stress, endothelial dysfunction, coagulation, and disturbance in lipid transport and metabolism.

DISCUSSION

This study provides novel and compelling evidence on the detrimental subclinical cardiovascular effects in response to short-term UFP exposure. The multi-omics profiling further offers holistic insights into the underlying biological pathways.

Traffic-related air pollution in marginalized neighborhoods: a community perspective

OBJECTIVES

Marginalized communities are exposed to higher levels of traffic-related air pollution (TRAP) than the general population. TRAP exposure is linked to pulmonary toxicity, neurotoxicity, and cardiovascular toxicity often through mechanisms of inflammation and oxidative stress. Early life exposure to TRAP is also implicated in higher rates of asthma in these same communities. There is a critical need for additional epidemiological, in vivo, and in vitro studies to define the health risks of TRAP exposure affecting the most vulnerable groups to set strict, protective air pollution standards in these communities.

MATERIALS AND METHODS

A literature review was conducted to summarize recent findings (2010-2024) concerning TRAP exposure and toxic mechanisms that are relevant to the most affected underserved communities.

CONCLUSIONS

Guided by the perspectives of NYC community scientists, this contemporary review of toxicological and epidemiological studies considers how the exposome could lead to disproportionate exposures and health effects in underserved populations.

Mapping multi-omics characteristics related to short-term PM2.5 trajectory and their impact on type 2 diabetes in middle-aged and elderly adults in Southern China

The relationship between PM2.5 and metabolic diseases, including type 2 diabetes (T2D), has become increasingly prominent, but the molecular mechanism needs to be further clarified. To help understand the mechanistic association between PM2.5 exposure and human health, we investigated short-term PM2.5 exposure trajectory-related multi-omics characteristics from stool metagenome and metabolome and serum proteome and metabolome in a cohort of 3267 participants (age: 64.4 ± 5.8 years) living in Southern China. And then integrate these features to examine their relationship with T2D. We observed significant differences in overall structure in each omics and 193 individual biomarkers between the high- and low-PM2.5 groups. PM2.5-related features included the disturbance of microbes (carbohydrate metabolism-associated Bacteroides thetaiotaomicron), gut metabolites of amino acids and carbohydrates, serum biomarkers related to lipid metabolism and reducing n-3 fatty acids. The patterns of overall network relationships among the biomarkers differed between T2D and normal participants. The subnetwork membership centered on the hub nodes (fecal rhamnose and glycylproline, serum hippuric acid, and protein TB182) related to high-PM2.5, which well predicted higher T2D prevalence and incidence and a higher level of fasting blood glucose, HbA1C, insulin, and HOMA-IR. Our findings underline crucial PM2.5-related multi-omics biomarkers linking PM2.5 exposure and T2D in humans.

Long-term exposure to ambient fine particulate matter constituents and mortality from total and site-specific gastrointestinal cancer

BACKGROUND

Ambient fine particulate matter (PM2.5) exposure has been associated with an increased risk of gastrointestinal cancer mortality, but the attributable constituents remain unclear.

OBJECTIVES

To investigate the association of long-term exposure to PM2.5 constituents with total and site-specific gastrointestinal cancer mortality using a difference-in-differences approach in Jiangsu province, China during 2015-2020.

METHODS

We split Jiangsu into 53 spatial units and computed their yearly death number of total gastrointestinal, esophagus, stomach, colorectum, liver, and pancreas cancer. Utilizing a high-quality grid dataset on PM2.5 constituents, we estimated 10-year population-weighted exposure to black carbon (BC), organic carbon (OC), sulfate, nitrate, ammonium, and chloride in each spatial unit. The effect of constituents on gastrointestinal cancer mortality was assessed by controlling time trends, spatial differences, gross domestic product (GDP), and seasonal temperatures.

RESULTS

Overall, 524,019 gastrointestinal cancer deaths were ascertained in 84.77 million population. Each interquartile range increment of BC (0.46 μg/m3), OC (4.56 μg/m3), and nitrate (1.41 μg/m3) was significantly associated with a 27%, 26%, and 34% increased risk of total gastrointestinal cancer mortality, respectively, and these associations remained significant in PM2.5-adjusted models and constituent-residual models. We also identified robust associations of BC, OC, and nitrate exposures with site-specific gastrointestinal cancer mortality. The mortality risk generally displayed increased trends across the total exposure range and rose steeper at higher levels. We did not identify robust associations for sulfate, ammonium, or chlorine exposure. Higher mortality risk ascribed to constituent exposures was identified in total gastrointestinal and liver cancer among women, stomach cancer among men, and total gastrointestinal and stomach cancer among low-GDP regions.

CONCLUSIONS

This study offers consistent evidence that long-term exposure to PM2.5-bound BC, OC, and nitrate is associated with total and site-specific gastrointestinal cancer mortality, indicating that these constituents need to be controlled to mitigate the adverse effect of PM2.5 on gastrointestinal cancer mortality.

Urban-rural disparities in the association of nitrogen dioxide exposure with cardiovascular disease risk in China: effect size and economic burden

BACKGROUND

Together with rapid urbanization, ambient nitrogen dioxide (NO2) exposure has become a growing health threat. However, little is known about the urban-rural disparities in the health implications of short-term NO2 exposure. This study aimed to compare the association between short-term NO2 exposure and hospitalization for cardiovascular disease (CVD) among urban and rural residents in Shandong Province, China. Then, this study further explored the urban-rural disparities in the economic burden attributed to NO2 and the explanation for the disparities.

METHODS

Daily hospitalization data were obtained from an electronic medical records dataset covering a population of 5 million. In total, 303,217 hospital admissions for CVD were analyzed. A three-stage time-series analytic approach was used to estimate the county-level association and the attributed economic burden.

RESULTS

For every 10-μg/m3 increase in NO2 concentrations, this study observed a significant percentage increase in hospital admissions on the day of exposure of 1.42% (95% CI 0.92 to 1.92%) for CVD. The effect size was slightly higher in urban areas, while the urban-rural difference was not significant. However, a more pronounced displacement phenomenon was found in rural areas, and the economic burden attributed to NO2 was significantly higher in urban areas. At an annual average NO2 concentration of 10 μg/m3, total hospital days and expenses in urban areas were reduced by 81,801 (44,831 to 118,191) days and 60,121 (33,002 to 86,729) thousand CNY, respectively, almost twice as much as in rural areas. Due to disadvantages in socioeconomic status and medical resources, despite similar air pollution levels in the urban and rural areas of our sample sites, the rural population tended to spend less on hospitalization services.

CONCLUSIONS

Short-term exposure to ambient NO2 could lead to considerable health impacts in either urban or rural areas of Shandong Province, China. Moreover, urban-rural differences in socioeconomic status and medical resources contributed to the urban-rural disparities in the economic burden attributed to NO2 exposure. The health implications of NO2 exposure are a social problem in addition to an environmental problem. Thus, this study suggests a coordinated intervention system that targets environmental and social inequality factors simultaneously.

Exposure to PM2.5, seminal plasma metabolome, and semen quality among Chinese adult men: Association and potential mediation analyses

Exposure to ambient fine particulate matter (PM2.5) has been linked to a decline in semen quality, but the underlying mechanisms for this association remain unclear. We aimed to examine whether specific metabolites act as mediators in the association between PM2.5 exposure and changes in semen quality. We conducted untargeted metabolomics analysis using LC-MS/MS platforms to identified seminal plasma metabolites associated with various semen quality parameters among 200 Chinese adult men. Additionally, we performed mediation analyses to examine the effects of the seminal plasma metabolites on the association between PM2.5 exposure and semen quality. We identified 140 differential metabolites between the normal and abnormal semen groups, involving two metabolic pathways: Alanine, aspartate and glutamate metabolism, and Aminoacyl-tRNA biosynthesis. We additionally identified 7 specific seminal plasma metabolites that were associated with discrepant metabolic networks related to semen quality. The mediation analysis revealed that D-Aspartate might play a mediating role in the adverse effects of ambient PM2.5 exposure on both total and progressive motility during spermatogenesis period (70-90 days before ejaculation), with a proportion of mediation up to 16% and 17%, respectively. Exposure to PM2.5 was associated with alterations in D-Aspartate levels, which might partially mediate the association between PM2.5 and reduced sperm motility.

Traffic Density Exposure, Oxidative Stress Biomarkers and Plasma Metabolomics in a Population-Based Sample: The Hortega Study

Exposure to traffic-related air pollution (TRAP) generates oxidative stress, with downstream effects at the metabolic level. Human studies of traffic density and metabolomic markers, however, are rare. The main objective of this study was to evaluate the cross-sectional association between traffic density in the street of residence with oxidative stress and metabolomic profiles measured in a population-based sample from Spain. We also explored in silico the potential biological implications of the findings. Secondarily, we assessed the contribution of oxidative stress to the association between exposure to traffic density and variation in plasma metabolite levels. Traffic density was defined as the average daily traffic volume over an entire year within a buffer of 50 m around the participants' residence. Plasma metabolomic profiles and urine oxidative stress biomarkers were measured in samples from 1181 Hortega Study participants by nuclear magnetic resonance spectroscopy and high-performance liquid chromatography, respectively. Traffic density was associated with 7 (out of 49) plasma metabolites, including amino acids, fatty acids, products of bacterial and energy metabolism and fluid balance metabolites. Regarding urine oxidative stress biomarkers, traffic associations were positive for GSSG/GSH% and negative for MDA. A total of 12 KEGG pathways were linked to traffic-related metabolites. In a protein network from genes included in over-represented pathways and 63 redox-related candidate genes, we observed relevant proteins from the glutathione cycle. GSSG/GSH% and MDA accounted for 14.6% and 12.2% of changes in isobutyrate and the CH2CH2CO fatty acid moiety, respectively, which is attributable to traffic exposure. At the population level, exposure to traffic density was associated with specific urine oxidative stress and plasma metabolites. Although our results support a role of oxidative stress as a biological intermediary of traffic-related metabolic alterations, with potential implications for the co-bacterial and lipid metabolism, additional mechanistic and prospective studies are needed to confirm our findings.

Methylomic, Proteomic, and Metabolomic Correlates of Traffic-Related Air Pollution in the Context of Cardiorespiratory Health: A Systematic Review, Pathway Analysis, and Network Analysis

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead to cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease and highlight contemporary challenges and opportunities associated with such efforts.

Association between ambient particulate matter levels and hypertension: results from the Korean Genome and Epidemiology Study

Background

Recently, there has been increasing worldwide concern about outdoor air pollution, especially particulate matter (PM), which has been extensively researched for its harmful effects on the respiratory system. However, sufficient research on its effects on cardiovascular diseases, such as hypertension, remains lacking. In this study, we examine the associations between PM levels and hypertension and hypothesize that higher PM concentrations are associated with elevated blood pressure.

Methods

A total of 133,935 adults aged ≥ 40 years who participated in the Korean Genome and Epidemiology Study were analyzed. Multiple linear regression analyses were conducted to investigate the short- (1-14 days), medium- (1 and 3 months), and long-term (1 and 2 years) impacts of PM on blood pressure. Logistic regression analyses were conducted to evaluate the medium- and long-term effects of PM on blood pressure elevation after adjusting for sex, age, body mass index, health-related lifestyle behaviors, and geographic areas.

Results

Using multiple linear regression analyses, both crude and adjusted models generated positive estimates, indicating an association with increased blood pressure, with all results being statistically significant, with the exception of PM levels over the long-term period (1 and 2 years) in non-hypertensive participants. In the logistic regression analyses on non-hypertensive participants, moderate PM10 (particulate matter with diameters < 10 μm) and PM2.5 (particulate matter with diameters < 2.5 μm) levels over the long-term period and all high PM10 and PM2.5 levels were statistically significant after adjusting for various covariates. Notably, high PM2.5 levels of the 1 year exhibited the highest odds ratio of 1.23 (95% confidence interval: 1.19-1.28) after adjustment.

Conclusions

These findings suggest that both short- and long-term exposure to PM is associated with blood pressure elevation.

Metabolomic alterations in healthy adults traveling to low-pollution areas: A natural experiment with ozone exposure

Numerous epidemiological studies have demonstrated links between short-term ozone exposure to various adverse health outcomes, but some ozone-induced pathological mechanisms remain unclear. To fill this knowledge gap, we enrolled 36 healthy young adults living in high-ozone areas and performed an untargeted metabolomic analysis in serum collected before, during, and after their travel to a low-ozone scenic area. Reviewing the literature, we found 16 metabolites significantly associated with ozone, pointing to neurological health, type 2 diabetes (T2D) risk, and cardiovascular health. Notably, we observed significant changes in these 16 metabolites from the ozone reduction when participants traveled from the campus to the scenic area (adjusted p-value < 0.05). However, when ozone increased after participants returned to campus from the scenic area, we observed that T2D risk and cardiovascular health-related metabolites returned to their original state (adjusted p-value < 0.05), but neurological health-related metabolites did not change significantly with ozone exposure. Our study showed that ozone exposure was linked to prompt alterations in serum metabolites related to cardiovascular health and T2D risk but less sensitive changes in neurological health-related metabolites. Among many lipids, free fatty acids and acylcarnitines were the most sensitive compounds positively associated with changes in ozone exposure.

Achieving better indoor air quality with IoT systems for future buildings: Opportunities and challenges

With the development of IoT technology and low-cost indoor air quality (IAQ) sensors, the IoT-based IAQ monitoring platform has garnered significant research interest and demonstrated its potential in enhancing IAQ management. This study presents a comprehensive review of previous research on the development and application of IoT-based IAQ platforms in different built environments. It offers detailed insights into the design and implementation of recent IoT-based IAQ platforms. The findings indicate that the IoT-based IAQ platforms are able to provide reliable information for IAQ monitoring. To ensure quality control of the IoT-based IAQ platform, it is suggested to replace the sensors every 4-6 months for reliable monitoring. In another aspect, integrating data-driven technology into the platform is crucial for IAQ prediction and efficient control of ventilation systems, leveraging the wealth of data available from the IoT platform. According to recent studies that applied data-driven algorithms for IAQ management, it can be confirmed that the data-driven algorithms are able to prompt IAQ by providing either more information or a control strategy. However, it should be noted that only 9.1 % of the developed platforms integrated data-driven models for IAQ management. Based on our findings, current challenges and further opportunities are discussed. Future studies should focus on integrating data-driven algorithms into IoT-based IAQ platforms and developing digital twins that can be used for real building IAQ management. However, there is obvious tension between controlling ventilation for energy efficiency versus better air quality. It is important to make a balance between energy efficiency and better air quality according to the current situations of specific built environments. Also, the next generation of IoT-based IAQ platforms should include occupants in the loop to create a more occupant-centric IAQ management approach.

Methylomic, proteomic, and metabolomic correlates of traffic-related air pollution: A systematic review, pathway analysis, and network analysis relating traffic-related air pollution to subclinical and clinical cardiorespiratory outcomes

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease, and highlight contemporary challenges and opportunities associated with such efforts.

Hazard, Distribution and Exposure of Particulate Pollution from Indoor and Outdoor Environments

Air is an essential natural resource for life [...].

Multi-omics analysis revealed NMBA induced esophageal carcinoma tumorigenesis via regulating PPARα signaling pathway

As widespread environmental carcinogens causing esophageal carcinoma (EC), the effects of N-nitrosamines on human health hazards and accurate toxicity mechanisms have not been well-elucidated. In this study, we explored the tumorigenic mechanism of N-nitrosomethylbenzylamine (NMBA) exposure using both cell and rat models. It was found that NMBA (2 μM) exposure for 26 weeks induced malignant transformation of normal esophageal epithelial (Het-1A) cells. After then proteomics analysis showed that lipid metabolism disorder predominantly participated in the process of NMBA-induced cell malignant transformation. Further the integrated proteomics and lipidomics analysis revealed that the enhancement of fatty acid metabolism promoted the EC tumorigenesis induced by NMBA through facilitating the fatty acid-associated PPARα signaling pathway. The animal studies also revealed that accelerated fatty acid decomposition in the progression of NMBA-induced EC models of rats was accompanied by the activation of the PPARα pathway. Overall, our findings depicted the key dynamic molecular alteration triggered by N-nitrosamines, and provided comprehensive biological perspectives into the carcinogenic risk assessment of N-nitrosamines.

Short-term effects of ultrafine particles on heart rate variability: A systematic review and meta-analysis

An increasing number of epidemiological studies have examined the association between ultrafine particles (UFP) and imbalanced autonomic control of the heart, a potential mechanism linking particulate matter air pollution to cardiovascular disease. This study systematically reviews and meta-analyzes studies on short-term effects of UFP on autonomic function, as assessed by heart rate variability (HRV). We searched PubMed and Web of Science for articles published until June 30, 2022. We extracted quantitative measures of UFP effects on HRV with a maximum lag of 15 days from single-pollutant models. We assessed the risk of bias in the included studies regarding confounding, selection bias, exposure assessment, outcome measurement, missing data, and selective reporting. Random-effects models were applied to synthesize effect estimates on HRV of various time courses. Twelve studies with altogether 1,337 subjects were included in the meta-analysis. For an increase of 10,000 particles/cm³ in UFP assessed by central outdoor measurements, our meta-analysis showed immediate decreases in the standard deviation of the normal-to-normal intervals (SDNN) by 4.0% [95% confidence interval (CI): 7.1%, -0.9%] and root mean square of successive R-R interval differences (RMSSD) by 4.7% (95% CI: 9.1%, 0.0%) within 6 h after exposure. The immediate decreases in SDNN and RMSSD associated with UFP assessed by personal measurements were smaller and borderline significant. Elevated UFP were also associated with decreases in SDNN, low-frequency power, and the ratio of low-frequency to high-frequency power when pooling estimates of lags across hours to days. We did not find associations between HRV and concurrent-day UFP exposure (daily average of at least 18 h) or exposure at lags ≥ one day. Our study indicates that short-term exposure to ambient UFP is associated with decreased HRV, predominantly as an immediate response within hours. This finding highlights that UFP may contribute to the onset of cardiovascular events through autonomic dysregulation.

Overview of particulate air pollution and human health in China: Evidence, challenges, and opportunities

Ambient particulate matter (PM) pollution in China continues to be a major public health challenge. With the release of the new WHO air quality guidelines in 2021, there is an urgent need for China to contemplate a revision of air quality standards (AQS). In the recent decade, there has been an increase in epidemiological studies on PM in China. A comprehensive evaluation of such epidemiological evidence among the Chinese population is central for revision of the AQS in China and in other developing countries with similar air pollution problems. We thus conducted a systematic review on the epidemiological literature of PM published in the recent decade. In summary, we identified the following: (1) short-term and long-term PM exposure increase mortality and morbidity risk without a discernible threshold, suggesting the necessity for continuous improvement in air quality; (2) the magnitude of long-term associations with mortality observed in China are comparable with those in developed countries, whereas the magnitude of short-term associations are appreciably smaller; (3) governmental clean air policies and personalized mitigation measures are potentially effective in protecting public and individual health, but need to be validated using mortality or morbidity outcomes; (4) particles of smaller size range and those originating from fossil fuel combustion appear to show larger relative health risks; and (5) molecular epidemiological studies provide evidence for the biological plausibility and mechanisms underlying the hazardous effects of PM. This updated review may serve as an epidemiological basis for China’s AQS revision and proposes several perspectives in designing future health studies.

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Acute effects of PM are smaller in China compared with developed countries

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Health effects caused by PM depend on particle composition, source, and size

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There are no thresholds for the health effects of PM

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Mechanistic studies support the biological plausibility of PM’s health effects

Characterization of plasma-derived exosomal miRNA changes following traffic-related air pollution exposure: A randomized, crossover trial based on small RNA sequencing

BACKGROUND

The underlying mechanisms for health effects of traffic-related air pollution (TRAP) are still unclear. Small RNA sequencing (RNA-seq) in exosomes represents as a powerful approach to elucidate biological pathways in response to environmental exposure. We therefore aimed to explore impact of TRAP exposure on exosomal miRNAs.

METHODS

We performed a randomized, crossover study among 35 healthy college students in Shanghai, China. Participants were randomly assigned to 4-hour exposure in a traffic-polluted Road and in a traffic-free Park, respectively, intermitted by a washout period (at least 2 weeks). RNA-seq was conducted to identify plasma-derived exosomal miRNAs and the differential miRNAs were explored using linear mixed-effect models. Pathway enrichment was conducted using ingenuity pathway analysis. Further, we validated several selected miRNAs by droplet digital PCR (ddPCR).

RESULTS

The average concentrations of air pollutants including ultrafine particles, black carbon, nitrogen dioxide, and carbon dioxide were 2-3 times higher in the Road compared to those in the Park. We identified 271 exosomal miRNAs (212 up-regulated and 59 down-regulated) that were significantly associated with TRAP. We found 5 miRNAs with 242 experimentally validated mRNA targets that were involved in cardiovascular pathway, cytokine signaling, and immune response. The ddPCR analysis suggested that miR-3612, miR-21-5p, and miR-195-5p were significantly changed following TRAP exposure.

CONCLUSIONS

For the first time this trial characterized the genome-wide changes of exosomal miRNA associated with TRAP exposure. The molecular profiling of exosomal miRNAs and "novel" associations of some miRNAs were useful for understanding on biological mechanisms for the adverse effects of TRAP.