Air pollution and cardiovascular disease: car sick

In Situ and Rapid Toxicity Assessment of Air Pollution by Self-Assembly Passive Colonization Hydrogel

Air pollution is a leading environmental health risk factor, and in situ toxicity assessment is urgently needed. Bacteria-based bioassays offer cost-effective and rapid toxicity assessments. However, the application of these bioassays for air toxicity assessment has been challenging, due to the instability of bacterial survival and functionality when directly exposed to air pollutants. Here, we developed an approach employing self-assembly passive colonization hydrogel (SAPCH) for in situ air toxicity assessment. The SAPCH features a core-shell structure, enabling the quantitatively immobilization of bacteria on its shell while continuously provides nutrients from its core. An antimicrobial polyelectrolyte layer between the core and shell confines bacteria to the air-liquid interface, synchronizing bacterial survival with exposure to air pollutants. The SAPCH immobilized a battery of natural and recombinant luminescent bacteria, enabling simultaneous detection of various toxicological endpoints (cytotoxicity, genotoxicity and oxidative stress) of air pollutants within 2 h. Its sensitivity was 3-5 orders of magnitude greater than that of traditional liquid-phase toxicity testing, and successfully evaluating the toxicity of volatile organic compounds and combustion smoke. This study presents a method for in situ, rapid, and economical toxicity assessment of air pollution, making a significant contribution to future air quality monitoring and control.

Environmental regulation effect on health poverty in China

How does government spending on environmental protection benefit people's health? The current paper analyzed 2010 and 2018 data from the China Family Panel Studies (CFPS) database to measure the impact of province-level environmental regulations on the health of local population. The study also applied the Alkire Foster method to develop the multidimensional health poverty (MHP) score, a new index intended to measure the health status of individuals in a holistic manner. Our results indicated that more fiscal spending on environmental regulation could improve health of the local population, especially among low-income population living in the rural areas. Further, the size of health benefit differs by the type of environmental regulation. More specifically, regulations focusing on preventing environmental pollution can achieve more sizable health benefits than remedial ones. Finally, fine inhalable particle (PM2.5) has the largest mediating effect on the relationship between environmental regulation and public health. These results provide several policy implications, which highlight the importance of: scaling up fiscal environmental expenditure and optimizing the structure of environmental expenditure with more emphasis on rural areas where more low-income population are located; shifting from ex-post accountability to ex-ante prevention; and strengthening regional cooperation in environmental protection among local governments, and establishing a cross-regional coordination mechanism.

Palliative effects of carnosol on lung-deposited pollutant particles-induced thrombogenicity and vascular injury in mice

The toxicity of inhaled particulate air pollution perseveres even at lower concentrations than those of the existing air quality limit. Therefore, the identification of safe and effective measures against pollutant particles-induced vascular toxicity is warranted. Carnosol is a bioactive phenolic diterpene found in rosemary herb, with anti-inflammatory and antioxidant actions. However, its possible protective effect on the thrombotic and vascular injury induced by diesel exhaust particles (DEP) has not been studied before. We assessed here the potential alleviating effect of carnosol (20 mg/kg) administered intraperitoneally 1 h before intratracheal (i.t.) instillation of DEP (20 μg/mouse). Twenty-four hours after the administration of DEP, various parameters were assessed. Carnosol administration prevented the increase in the plasma concentrations of C-reactive protein, fibrinogen, and tissue factor induced by DEP exposure. Carnosol inhibited DEP-induced prothrombotic effects in pial microvessels in vivo and platelet aggregation in vitro. The shortening of activated partial thromboplastin time and prothrombin time induced by DEP was abated by carnosol administration. Carnosol inhibited the increase in pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor α) and adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and P-selectin) in aortic tissue. Moreover, it averted the effects of DEP-induced increase of thiobarbituric acid reactive substances, depletion of antioxidants and DNA damage in the aortic tissue. Likewise, carnosol prevented the decrease in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) caused by DEP. We conclude that carnosol alleviates DEP-induced thrombogenicity and vascular inflammation, oxidative damage, and DNA injury through Nrf2 and HO-1 activation.

The stress-responsive cytotoxic effect of diesel exhaust particles on lymphatic endothelial cells

Diesel exhaust particles (DEPs) are very small (typically < 0.2 μm) fragments that have become major air pollutants. DEPs are comprised of a carbonaceous core surrounded by organic compounds such as polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs. Inhaled DEPs reach the deepest sites in the respiratory system where they could induce respiratory/cardiovascular dysfunction. Additionally, a previous study has revealed that a portion of inhaled DEPs often activate immune cells and subsequently induce somatic inflammation. Moreover, DEPs are known to localize in lymph nodes. Therefore, in this study we explored the effect of DEPs on the lymphatic endothelial cells (LECs) that are a constituent of the walls of lymph nodes. DEP exposure induced cell death in a reactive oxygen species (ROS)-dependent manner. Following exposure to DEPs, next-generation sequence (NGS) analysis identified an upregulation of the integrated stress response (ISR) pathway and cell death cascades. Both the soluble and insoluble components of DEPs generated intracellular ROS. Three-dimensional Raman imaging revealed that DEPs are taken up by LECs, which suggests internalized DEP cores produce ROS, as well as soluble DEP components. However, significant cell death pathways such as apoptosis, necroptosis, ferroptosis, pyroptosis, and parthanatos seem unlikely to be involved in DEP-induced cell death in LECs. This study clarifies how DEPs invading the body might affect the lymphatic system through the induction of cell death in LECs.

Interaction of physical activity and low-level air pollution on cardiovascular disease: a prospective cohort study in UK Biobank

To investigate the associations of physical activity (PA), low-level air pollution, and interaction on cardiovascular diseases (CVD) incidence based on the UK Biobank. PA was measured by the International Physical Activity Questionnaire and five air pollutants were estimated using Land Use Regression. All association estimates were based on Cox regression. Dose-response relationship was explored by restricted cubic spline, while multiplicative and additive interaction were examined by Pinteraction and relative excess risk due to interaction (RERI). As deviating proportional hazards assumption, we analyzed data as follow-up < 4 years and ≥ 4 years, separately. PA with 1000-4000 Metabolic Equivalent Task (MET) min/week showed the strongest protective impact on CVD incidence, while only low-level nitrogen dioxides (NO2) showed negative impact among five air pollutants and was considered for further analysis. Multiplicative interaction between PA and NO2 was observed during ≥ 4 years follow-up (Pinteraction = 0.049) while not during < 4 years (Pinteraction = 0.290). Positive additive interactions were found for high PA and low NO2 (< 20 μg/m3) group (RERI: 0.07, 95% confidence intervals: 0.02-0.11) during < 4 years, and for moderate PA with NO2 at 40- μg/m3 (0.07, 0.02-0.13) and < 20 μg/m3 (0.07, 0.02-0.12), while high PA showed similar results with NO2 at 40-, 20- and < 20 μg/m3 during ≥ 4 years. PA about 1000-4000 METs min/week showed the lowest CVD risk. Possibility of interaction with PA and NO2 is more likely to present with the increase in follow-up duration. We call for the optimal thresholds of PA, and exploring interaction thoroughly by considering types of PA.

Associations of urinary volatile organic compounds with cardiovascular disease among the general adult population

This study was to estimate the associations of volatile organic compounds (VOCs) exposure with the prevalence of total and specific cardiovascular disease (CVD) among the general adult population. This cross-sectional study analyzed 15 urinary VOC metabolites in the general population using the 2011-2016 National Health and Nutrition Examination Survey (n = 5,213). The weighted study population with 47.0 years median age, was primarily female (51.2%). The prevalence of total CVD in the overall population was 7.9%. The single-exposure analyzes of AAMA, ATCA, CEMA, CYMA, DHBMA, 3HPMA, and 3MHA +4MHA were significantly associated with increased prevalence of total CVD. Qgcomp regression consistently showed that urinary VOCs-mixed exposure was positively correlated with the prevalence of total and specific CVDs (chronic heart failure, angina, and stroke), and highlighted each VOCs metabolite weights and direction. The similar results were observed for the WQS regression using mixed analysis methods. In conclusion, exposure to VOCs increases CVD prevalence and advances the identification of risk factors for CVD for environmental study.

Research on the cascading mechanism of "urban built environment-air pollution-respiratory diseases": a case of Wuhan city

Background

Most existing studies have only investigated the direct effects of the built environment on respiratory diseases. However, there is mounting evidence that the built environment of cities has an indirect influence on public health via influencing air pollution. Exploring the "urban built environment-air pollution-respiratory diseases" cascade mechanism is important for creating a healthy respiratory environment, which is the aim of this study.

Methods

The study gathered clinical data from 2015 to 2017 on patients with respiratory diseases from Tongji Hospital in Wuhan. Additionally, daily air pollution levels (sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter (PM2.5, PM10), and ozone (O3)), meteorological data (average temperature and relative humidity), and data on urban built environment were gathered. We used Spearman correlation to investigate the connection between air pollution and meteorological variables; distributed lag non-linear model (DLNM) was used to investigate the short-term relationships between respiratory diseases, air pollutants, and meteorological factors; the impacts of spatial heterogeneity in the built environment on air pollution were examined using the multiscale geographically weighted regression model (MGWR).

Results

During the study period, the mean level of respiratory diseases (average age 54) was 15.97 persons per day, of which 9.519 for males (average age 57) and 6.451 for females (average age 48); the 24 h mean levels of PM10, PM2.5, NO2, SO2 and O3 were 78.056 μg/m3, 71.962 μg/m3, 54.468 μg/m3, 12.898 μg/m3, and 46.904 μg/m3, respectively; highest association was investigated between PM10 and SO2 (r = 0.762, p < 0.01), followed by NO2 and PM2.5 (r = 0.73, p < 0.01), and PM10 and PM2.5 (r = 0.704, p < 0.01). We observed a significant lag effect of NO2 on respiratory diseases, for lag 0 day and lag 1 day, a 10 μg/m3 increase in NO2 concentration corresponded to 1.009% (95% CI: 1.001, 1.017%) and 1.005% (95% CI: 1.001, 1.011%) increase of respiratory diseases. The spatial distribution of NO2 was significantly influenced by high-density urban development (population density, building density, number of shopping service facilities, and construction land, the bandwidth of these four factors are 43), while green space and parks can effectively reduce air pollution (R2 = 0.649).

Conclusion

Previous studies have focused on the effects of air pollution on respiratory diseases and the effects of built environment on air pollution, while this study combines these three aspects and explores the relationship between them. Furthermore, the theory of the "built environment-air pollution-respiratory diseases" cascading mechanism is practically investigated and broken down into specific experimental steps, which has not been found in previous studies. Additionally, we observed a lag effect of NO2 on respiratory diseases and spatial heterogeneity of built environment in the distribution of NO2.

Lifetime losses due to cardiovascular and respiratory diseases attributable to air pollution in polluted and unpolluted areas

The article assesses differences in lifetime losses caused by premature deaths from cardiopulmonary disease in populations living in areas with different environmental burdens. The results provide different perspectives on data on total years lost and lifetime losses attributable to air pollution. Such lifetime losses in the industrial area related to cardiovascular causes of death are 7.6 or 5.1 years per male or female deceased, representing an average lifetime loss of 0.01907 years (i.e. 7 days) per 1 male or 0.01273 years (i.e. 4.6 days) per 1 female in the entire population. Losses related to cerebrovascular or respiratory causes of death are about 5.4 or 5.9 years per 1 deceased male or 3.9 or 5 years per 1 deceased female, respectively, which represents a loss of 0.00481 (1.8 days), or 0.00148 years (0.5 days) per 1 male or 0.00466 (1.7 days), or 0.00058 years (0.2 days) per 1 female.

Spatiotemporal distribution characteristics and influencing factors of the rate of cardiovascular hospitalization in Ganzhou city of China

Aims

The objective of this study was to analyze hospitalization rates for cardiovascular diseases (CVD) in Ganzhou City, Jiangxi Province of China from 2015 to 2020 and to uncover the spatiotemporal distribution characteristics and influencing factors, and thus to provide reference for the prevention and control of CVD and public health resources planning.

Methods

The hospitalization data for CVDs from 2016 to 2020 was obtained from the First Affiliated Hospital of Gannan Medical University, and ArcGIS 10.8, SaTScan 9.5, and Matlab 20.0 were used to analyze the spatial autocorrelation, spatiotemporal scan statistics, and potential affecting factors of the hospitalization rates.

Results

The hospitalization rate for CVDs in Ganzhou City showed a slightly increasing trend from 2016 to 2020, with higher rates in winter and summer than that in spring and autumn, and the individuals aged 61 and above constitute a higher proportion compared to other age groups. Additionally, there was a positive correlation between hospitalization rates for CVDs and the counties and districts in Ganzhou City, with high-high aggregation areas mainly distributed in Nankang District, the western urban area of Ganzhou City. The spatial scan analysis identified three different types of significant aggregation areas: high-risk, low-risk, and middle-risk areas. The high-risk area was mainly centered around Zhanggong District or Shangyu County in the central and western regions, with a disease hospitalization rate 2-3 times higher than the rest areas. The study also found that environmental meteorological factors such as the annual average concentration of NO2, O3, average annual temperature, and annual maximum temperature diurnal range had a significant positive effect on hospitalization rates for CVDs in Ganzhou City, with O3 concentration and average annual temperature having significant positive indirect spatial spillover effects.

Conclusion

Winter and summer are the seasons with high hospitalization rate of cardiovascular diseases. County residents aged 61 and above are the higher-risk population that needs to pay more attention on for prevention and control of CVD in Ganzhou City, which exhibits significant spatiotemporal clustering. The urban areas of Zhanggong and Nankang in Ganzhou City are the key areas for prevention and control of CVD. The hospitalization rate of CVD in Ganzhou City is influenced by the aforementioned four environmental meteorological factors, with the annual maximum temperature diurnal range showing the most significant positive direct effect.

Global Air Pollutant Phenanthrene and Arrhythmic Outcomes in a Mouse Model

BACKGROUND

The three-ringed polycyclic aromatic hydrocarbon (PAH) phenanthrene (Phe) has been implicated in the cardiotoxicity of petroleum-based pollution in aquatic systems, where it disrupts the contractile and electrical function of the fish heart. Phe is also found adsorbed to particulate matter and in the gas phase of air pollution, but to date, no studies have investigated the impact of Phe on mammalian cardiac function.

OBJECTIVES

Our objectives were to determine the arrhythmogenic potential of acute Phe exposure on mammalian cardiac function and define the underlying mechanisms to provide insight into the toxicity risk to humans.

METHODS

Ex vivo Langendorff-perfused mouse hearts were used to test the arrhythmogenic potential of Phe on myocardial function, and voltage- and current-clamp recordings were used to define underlying cellular mechanisms in isolated cardiomyocytes.

RESULTS

Mouse hearts exposed to ∼ 8 μ M Phe for 15-min exhibited a significantly slower heart rate (p = 0.0006 , N = 10 hearts), a prolonged PR interval (p = 0.036 , N = 8 hearts), and a slower conduction velocity (p = 0.0143 , N = 7 hearts). Whole-cell recordings from isolated cardiomyocytes revealed action potential (AP) duration prolongation (at 80% repolarization; p = 0.0408 , n = 9 cells) and inhibition of key murine repolarizing currents-transient outward potassium current (I to ) and ultrarapid potassium current (I Kur )-following Phe exposure. A significant reduction in AP upstroke velocity (p = 0.0445 , n = 9 cells) and inhibition of the fast sodium current (I Na ; p = 0.001 , n = 8 cells) and calcium current (I Ca ; p = 0.0001 ) were also observed, explaining the slowed conduction velocity in intact hearts. Finally, acute exposure to ∼ 8 μ M Phe significantly increased susceptibility to arrhythmias (p = 0.0455 , N = 9 hearts).

DISCUSSION

To the best of our knowledge, this is the first evidence of direct inhibitory effects of Phe on mammalian cardiac electrical activity at both the whole-heart and cell levels. This electrical dysfunction manifested as an increase in arrhythmia susceptibility due to impairment of both conduction and repolarization. Similar effects in humans could have serious health consequences, warranting greater regulatory attention and toxicological investigation into this ubiquitous PAH pollutant generated from fossil-fuel combustion. https://doi.org/10.1289/EHP12775.

Air Pollution and Cardiac Diseases: A Review of Experimental Studies

Air pollution is associated with around 6.5 million premature deaths annually, which are directly related to cardiovascular diseases, and the most dangerous atmospheric pollutants to health are as follows: NO2, SO2, CO, and PM. The mechanisms underlying the observed effects have not yet been clearly defined. This work aims to conduct a narrative review of experimental studies to provide a more comprehensive and multiperspective assessment of how the effect of atmospheric pollutants on cardiac activity can result in the development of cardiac diseases. For this purpose, a review was carried out in databases of experimental studies, excluding clinical trials, and epidemiological and simulation studies. After analyzing the available information, the existence of pathophysiological effects of the different pollutants on cardiac activity from exposure during both short-term and long-term is evident. This narrative review based on experimental studies is a basis for the development of recommendations for public health.

The impact of the synergistic effect of SO2 and PM2.5/PM10 on obstructive lung disease in subtropical Taiwan

Background

Chronic Obstructive lung diseases (COPD) are complex conditions influenced by various environmental, lifestyle, and genetic factors. Ambient air pollution has been identified as a potential risk factor, causing 4.2 million deaths worldwide in 2016, accounting for 25% of all COPD-related deaths and 26% of all respiratory infection-related deaths. This study aims to evaluate the associations among chronic lung diseases, air pollution, and meteorological factors.

Methods

This cross-sectional study obtained data from the Taiwan Biobank and Taiwan Air Quality Monitoring Database. We defined obstructive lung disease as patients with FEV1/FVC < 70%. Descriptive analysis between spirometry groups was performed using one-way ANOVA and the chi-square or Fisher's exact test. A generalized additive model (GAM) was used to evaluate the relationship between SO2 and PM2.5/PM10 through equations and splines fitting.

Results

A total of 2,635 participants were enrolled. Regarding environmental factors, higher temperature, higher relative humidity, and lower rainfall were risk factors for obstructive lung disease. SO2 was positively correlated with PM10 and PM2.5, with correlation coefficients of 0.53 (p < 0.0001) and 0.52 (p < 0.0001), respectively. Additionally, SO2 modified the relative risk of obstructive impairment for both PM10 [β coefficient (β) = 0.01, p = 0.0052] and PM2.5 (β = 0.01, p = 0.0155). Further analysis per standard deviation (per SD) increase revealed that SO2 also modified the relationship for both PM10 (β = 0.11, p = 0.0052) and PM2.5 (β = 0.09, p = 0.0155). Our GAM analysis showed a quadratic pattern for SO2 (per SD) and PM10 (per SD) in model 1, and a quadratic pattern for SO2 (per SD) in model 2. Moreover, our findings confirmed synergistic effects among temperature, SO2 and PM2.5/PM10, as demonstrated by the significant associations of bivariate (SO2 vs. PM10, SO2 vs. PM2.5) thin-plate smoothing splines in models 1 and 2 with obstructive impairment (p < 0.0001).

Conclusion

Our study showed high temperature, humidity, and low rainfall increased the risk of obstructive lung disease. Synergistic effects were observed among temperature, SO2, and PM2.5/PM10. The impact of air pollutants on obstructive lung disease should consider these interactions.

Research trends on the relationship between air pollution and cardiovascular diseases in 2013-2022 - A scientometric analysis

Exposure to air pollution is linked with an elevated risk of cardiovascular diseases (CVDs) and CVDs-related mortality. However, there is a shortage of scientometric analysis on this topic. Therefore, we propose a scientometric study to explore research hotspots and directions in this topical field over the past decade. We used the core collection of Web of Science (WoS) to obtain relevant publications and analyzed them using Excel, the Bibliometix R-package, CiteSpace, and VOSviewer. The study covered various aspects such as annual publications, highly cited papers, co-cited references, journals, authors, countries, organizations, and keywords. Research on air pollution and CVDs has remarkable increase over the past decade, with notable researchers including Kan H, Brook RD, Peters A, and Schwartz J. The 3144 articles were published by 4448 institutions in 131 countries/regions. The leading countries were the USA and China, and the most published journal was Environmental Research. Mortality, hospital admissions, oxidative stress, inflammation, long-term exposure, fine particulate matter, and PM2.5 are the top areas that merit further investigation and hold significant potential for advancing our understanding of the complex relationship between air pollution and CVDs.

Assessing the relationship between energy-related methane emissions and the burden of cardiovascular diseases: a cross-sectional study of 73 countries

The energy industry significantly contributes to anthropogenic methane emissions, which add to global warming and have been linked to an increased risk of cardiovascular diseases (CVD). This study aims to evaluate the relationship between energy-related methane emissions and the burden of CVD, measured in disability-adjusted life years (DALYs), in 2019. We conducted a cross-sectional analysis of datasets from 73 countries across all continents. The analyzed datasets included information from 2019 on environmental energy-related methane emissions, burden of DALYs due to CVD. The age-standardized prevalence of obesity in adults and life expectancy at birth were retrieved. The relationship between the variables of interest was evaluated using multiple linear regression models. In the multiple model, we observed a positive linear association between methane emissions and the log-transformed count of DALYs related to CVD. Specifically, for each unit increase in energy-related methane emissions, the burden of CVD increased by 0.06% (95% CI 0.03-0.09%, p < 0.001). The study suggests that reducing methane emissions from the energy industry could improve public health for those at risk of CVD. Policymakers can use these findings to develop strategies to reduce methane emissions and protect public health.

Particulate Matter Pollution Remains a Threat for Cardiovascular Health: Findings From the Global Burden of Disease 2019

Background Particulate matter (PM) pollution is a significant risk factor for cardiovascular diseases, causing substantial disease burden and deaths worldwide. This study aimed to investigate the global burden of cardiovascular diseases attributed to PM from 1990 to 2019. Methods and Results We used the GBD (Global Burden of Disease) study 2019 to investigate disability-adjusted life-years (DALYs), years of life lost (YLLs), years lived with disability (YLDs), and deaths attributed to PM as well as its subgroups. It was shown that all burden measures' age-standardized rates for PM were in the same decreasing trend, with the highest decline recorded for deaths (-36.7%). However, the all-age DALYs increased by 31%, reaching 8.9 million in 2019, to which YLLs contributed the most (8.2 million [95% uncertainty interval, 7.3 million-9.2 million]). Men had higher deaths, DALYs, and YLLs despite lower years lived with disability in 2019 compared with women. There was an 8.1% increase in the age-standardized rate of DALYs for ambient PM; however, household air pollution from solid fuels decreased by 65.4% in the assessed period. Although higher in men, the low and high sociodemographic index regions had the highest and lowest attributed YLLs/YLDs ratio for PM pollution in 2019, respectively. Conclusions Although the total age-standardized rate of DALYs for PM-attributed cardiovascular diseases diminished from 1990 to 2019, the global burden of PM on cardiovascular diseases has increased. The differences between men and women and between regions have clinical and policy implications in global health planning toward more exact funding and resource allocation, in addition to addressing inequity in health care access.

Breathing Fresh Air in the City: Implementing Avenue Trees as a Sustainable Solution to Reduce Particulate Pollution in Urban Agglomerations

The issue of air pollution from particulate matter (PM) is getting worse as more and more people move into urban areas around the globe. Due to the complexity and diversity of pollution sources, it has long been hard to rely on source control techniques to manage this issue. Due to the fact that urban trees may provide a variety of ecosystem services, there is an urgent need to investigate alternative strategies for dramatically improving air quality. PM has always been a significant concern due to its adverse effects on humans and the entire ecosystem. The severity of this issue has risen in the current global environmental context. Numerous studies on respiratory and other human disorders have revealed a statistical relationship between human exposure to outdoor levels of particles or dust and harmful health effects. These risks are undeniably close to industrial areas where these airborne, inhalable particles are produced. The combined and individual effects of the particle and gaseous contaminants on plants' general physiology can be detrimental. According to research, plant leaves, the primary receptors of PM pollution, can function as biological filters to remove significant amounts of particles from the atmosphere of urban areas. This study showed that vegetation could provide a promising green infrastructure (GI) for better air quality through the canopy and leaf-level processes, going beyond its traditional role as a passive target and sink for air pollutants. Opportunities exist for urban GI as a natural remedy for urban pollution caused by PMs.

Ellagic Acid Prevents Particulate Matter-Induced Pulmonary Inflammation and Hyperactivity in Mice: A Pilot Study

The inhalation of fine particulate matter (PM) is a significant health-related environmental issue. Previously, we demonstrated that repeated PM exposure causes hyperlocomotive activity in mice, as well as inflammatory and hypoxic responses in their lungs. In this study, we evaluated the potential efficacy of ellagic acid (EA), a natural polyphenolic compound, against PM-induced pulmonary and behavioral abnormalities in mice. Four treatment groups were assigned in this study (n = 8): control (CON), particulate-matter-instilled (PMI), low-dose EA with PMI (EL + PMI), and high-dose EA with PMI (EH + PMI). EA (20 and 100 mg/kg body weight for low dose and high dose, respectively) was orally administered for 14 days in C57BL/6 mice, and after the eighth day, PM (5 mg/kg) was intratracheally instilled for 7 consecutive days. PM exposure induced inflammatory cell infiltration in the lungs following EA pretreatment. Moreover, PM exposure induced inflammatory protein expression in the bronchoalveolar lavage fluid and the expression of inflammatory (tumor necrosis factor alpha (Tnfα), interleukin (Il)-1b, and Il-6) and hypoxic (vascular endothelial growth factor alpha (Vegfα), ankyrin repeat domain 37 (Ankrd37)) response genes. However, EA pretreatment markedly prevented the induction of expression of inflammatory and hypoxic response genes in the lungs. Furthermore, PM exposure significantly triggered hyperactivity by increasing the total moving distance with an increase in moving speed in the open field test. On the contrary, EA pretreatment significantly prevented PM-induced hyperactivity. In conclusion, dietary intervention with EA may be a potential strategy to prevent PM-induced pathology and activity.

Short-Term Ambient Air Ozone Exposure and Components of Metabolic Syndrome in a Cohort of Mexican Obese Adolescents

Ambient air pollution is a major global public health concern; little evidence exists about the effects of short-term exposure to ozone on components of metabolic syndrome in young obese adolescents. The inhalation of air pollutants, such as ozone, can participate in the development of oxidative stress, systemic inflammation, insulin resistance, endothelium dysfunction, and epigenetic modification. Metabolic alterations in blood in components of metabolic syndrome (MS) and short-term ambient air ozone exposure were determined and evaluated longitudinally in a cohort of 372 adolescents aged between 9 to 19 years old. We used longitudinal mixed-effects models to evaluate the association between ozone exposure and the risk of components of metabolic syndrome and its parameters separately, adjusted using important variables. We observed statistically significant associations between exposure to ozone in tertiles in different lag days and the parameters associated with MS, especially for triglycerides (20.20 mg/dL, 95% CI: 9.5, 30.9), HDL cholesterol (-2.56 mg/dL (95% CI: -5.06, -0.05), and systolic blood pressure (1.10 mmHg, 95% CI: 0.08, 2.2). This study supports the hypothesis that short-term ambient air exposure to ozone may increase the risk of some components of MS such as triglycerides, cholesterol, and blood pressure in the obese adolescent population.

Genome-Wide Profiling of Exosomal Long Noncoding RNAs Following Air Pollution Exposure: A Randomized, Crossover Trial

Changes in human genome-wide long noncoding RNAs (lncRNAs) associated with air pollution are unknown. This study aimed to investigate the effect of air pollution on human exosomal lncRNAs. A randomized, crossover trial was conducted among 35 healthy adults. Participants were allocated to 4 h exposure in road (high air pollution) and park (low air pollution) sessions in random order with a 2 week washout period. RNA sequencing was performed to measure lncRNAs. Differential lncRNAs were identified using a linear mixed-effect model. Mean concentrations of air pollutants such as ultrafine particles (UFP), black carbon (BC), carbon monoxide (CO), and nitrogen dioxide (NO₂) were 2-3 times higher in the road than those in the park. Fifty-five lncRNAs [false discovery rate (FDR) < 0.05] including lncRNA NORAD, MALAT1, and H19 were changed in response to air pollution exposure. We found that 54 lncRNAs were associated with CO, 49 lncRNAs with UFP, 49 lncRNAs with BC, 48 lncRNAs with NO₂, and 4 lncRNAs with PM_2.5 (FDR < 0.05). These differential lncRNAs participated in dozens of pathways including cardiovascular signaling, epithelial cell proliferation, inflammation, and transforming growth factor. This trial for the first time profiled changes of human exosomal lncRNAs following air pollution. Our findings revealed multiple biological processes moderated by lncRNAs and provided epigenetic insights into cardiovascular effects of air pollution.

CARD9 deficiency improves the recovery of limb ischemia in mice with ambient fine particulate matter exposure

Background

Exposure to fine particulate matter (PM) is a significant risk for cardiovascular diseases largely due to increased reactive oxygen species (ROS) production and inflammation. Caspase recruitment domain (CARD)9 is critically involved in innate immunity and inflammation. The present study was designed to test the hypothesis that CARD9 signaling is critically involved in PM exposure-induced oxidative stress and impaired recovery of limb ischemia.

Methods and results

Critical limb ischemia (CLI) was created in male wildtype C57BL/6 and age matched CARD9 deficient mice with or without PM (average diameter 2.8 μm) exposure. Mice received intranasal PM exposure for 1 month prior to creation of CLI and continued for the duration of the experiment. Blood flow and mechanical function were evaluated in vivo at baseline and days 3, 7, 14, and 21 post CLI. PM exposure significantly increased ROS production, macrophage infiltration, and CARD9 protein expression in ischemic limbs of C57BL/6 mice in association with decreased recovery of blood flow and mechanical function. CARD9 deficiency effectively prevented PM exposure-induced ROS production and macrophage infiltration and preserved the recovery of ischemic limb with increased capillary density. CARD9 deficiency also significantly attenuated PM exposure-induced increase of circulating CD11b⁺/F4/80⁺ macrophages.

Conclusion

The data indicate that CARD9 signaling plays an important role in PM exposure-induced ROS production and impaired limb recovery following ischemia in mice.

Risk of De Novo Hypertensive Disorders of Pregnancy After Exposure to PM1 and PM2.5 During the Period From Preconception to Delivery: Birth Cohort Study

BACKGROUND

Particulate matter (PM) is detrimental to the respiratory and circulatory systems. However, no study has evaluated the lag effects of weekly exposure to fine PM during the period from preconception to delivery on the risk of hypertensive disorders of pregnancy (HDPs).

OBJECTIVE

We set out to investigate the lag effect windows of PM on the risk of HDPs on a weekly scale.

METHODS

Data from women with de novo HDPs and normotensive pregnant women who were part of the Peking University Retrospective Birth Cohort, based on the hospital information system of Tongzhou district, were obtained for this study. Meteorological data and data on exposure to fine PM were predicted by satellite remote sensing data based on maternal residential address. The de novo HDP group consisted of pregnant women who were diagnosed with gestational hypertension or preeclampsia. Fine PM was defined as PM2.5 and PM1. The gestational stage of participants was from preconception (starting 12 weeks before gestation) to delivery (before the 42nd gestational week). A distributed-lag nonlinear model (DLNM) was nested in a Cox regression model to evaluate the lag effects of weekly PM exposure on de novo HDP hazard by controlling the nonlinear relationship of exposure-reaction. Stratified analyses by employment status (employed or unemployed), education level (higher or lower), and parity (primiparity or multiparity) were performed.

RESULTS

A total of 22,570 pregnant women (mean age 29.1 years) for whom data were available between 2013 and 2017 were included in this study. The prevalence of de novo HDPs was 6.7% (1520/22,570). Our findings showed that PM1 and PM2.5 were significantly associated with an elevated hazard of HDPs. Exposure to PM1 during the 5th week before gestation to the 6th gestational week increased the hazard of HDPs. A significant lag effect of PM2.5 was observed from the 1st week before gestation to the 6th gestational week. The strongest lag effects of PM1 and PM2.5 on de novo HDPs were observed at week 2 and week 6 (hazard ratio [HR] 1.024, 95% CI 1.007-1.042; HR 1.007, 95% CI 1.000-1.015, respectively, per 10 μg/m3 increase). The stratified analyses indicated that pregnant women who were employed, had low education, and were primiparous were more vulnerable to PM exposure for de novo HDPs.

CONCLUSIONS

Exposure to PM1 and PM2.5 was associated with the risk of de novo HDPs. There were significant lag windows between the preconception period and the first trimester. Women who were employed, had low education, and were primiparous were more vulnerable to the effects of PM exposure; more attention should be paid to these groups for early prevention of de novo HDPs.

A Time Series Study for Effects of PM10 on Coronary Heart Disease in Ganzhou, China

Objective: To investigate the effect of PM10 exposure in low concentration areas on the daily hospitalized patients with coronary heart disease. Methods: Daily air quality monitoring data, meteorological monitoring data and daily hospitalization data of coronary heart disease during 2019−2021 in Ganzhou, China were collected. Generalized additive model and distributed lag nonlinear model were used to evaluate the association between environmental PM10 and daily hospital visits for coronary heart disease. Stratified by sex and age to see their potential impact on this association. Results: PM10 exposure was correlated with an increased risk of hospitalization in coronary heart disease patients. Single-pollutant model analysis shows that at the day of lag1, for every 10 µg/m3 increase in PM10, the risk of coronary heart disease hospitalization increased by 1.69% (95%CI 0.39~3.00%); Subgroup analysis showed that females and older adults (>65 years) were more sensitive to PM10 exposure. In addition, in the dual-pollutant model, by adjusting other pollutants (including SO2, CO and O3), it was found that the relationship between PM10 exposure and coronary heart disease hospitalization was robust. And with changing the model’s degree of freedom was still robust. Conclusion: Short-term exposure to low concentrations of PM10 is associated with hospitalization for coronary heart disease. These results are important for local environmental public health policy development, so as to protect vulnerable populations.

Indoor Particle's Pollution in Bucharest, Romania

Air pollution risk factor on human health was surpassed only by high blood pressure, tobacco use and poor diet. Total number of deaths due to air pollution worldwide was estimated to 6.67 million people in 2019. In the European Union, 97% of the urban population is exposed to levels of fine particulate matter above the latest guideline levels set by the World Health Organization. Air pollution accounts for 20% of newborn deaths worldwide, most related to complications of low birth weight and preterm birth. Low birth weight and preterm birth are responsible for 1.8 million deaths worldwide. Bucharest is the capital city of Romania and one of the most polluted cities in Europe, ranking in the 9th position out of 96 of the top cities from Europe and in the 4th position out of 32 of the top cities in Eastern Europe, data from June 2022. The aim of this study was to measure the real time level of indoor particulate pollution levels in different indoor environments from Bucharest, during the pandemic period. The PM_2.5/PM₁₀ ratio and its rate of change were also determined for the measured data. The PM_2.5/PM₁₀ ratio and its rate of change were also calculated based on the measurement data. The PM_2.5/PM₁₀ ratio showed an upward trend on weekends compared to weekdays, suggesting a relationship with outdoor PM where leisure activities and traffic infiltrated the indoors. The fluctuation range of the PM_2.5/PM₁₀ ratio was 0.44~0.95, and low measured values were detected on weekdays. Of the seasons, the proportion of particulate in autumn and its rate of change tended to be higher than in summer. It was suggested that outdoor air may have permeated the room. In addition, the relationship was considered, such as it is a holiday period, there are few rainy days, the concentration of coarse particles is high, and the number of residents in the city decreases. When it comes to indoor air quality, the higher this ratio, the more serious the air pollution. PM₁₀ concentrations decreased by 29.1% in the absence of human activity and increased by 35.1% in the presence of humans. PM_2.5 concentration decreased by 30.3% without human activity and increased by 3.1% with the presence of humans. Certain trends were suggested for the resumption of human activity and an increase in PM_2.5 concentrations. The average relative difference between October 2021, a pandemic period, and October 2022, a post pandemic period, was 64% for PM₁₀ and 47% for PM_2.5. The pandemic period brought a significantly better indoor air quality from the particulate pollution point of view.

Long-term exposure to air pollution, coronary artery calcification, and carotid artery plaques in the population-based Swedish SCAPIS Gothenburg cohort

Long-term exposure to air pollution is associated with cardiovascular events. A main suggested mechanism is that air pollution accelerates the progression of atherosclerosis, yet current evidence is inconsistent regarding the association between air pollution and coronary artery and carotid artery atherosclerosis, which are well-established causes of myocardial infarction and stroke. We studied associations between low levels of long-term air pollution, coronary artery calcium (CAC) score, and the prevalence and area of carotid artery plaques, in a middle-aged population-based cohort. The Swedish CArdioPulmonary bioImage Study (SCAPIS) Gothenburg cohort was recruited during 2013-2017 and thoroughly examined for cardiovascular risk factors, including computed tomography of the heart and ultrasonography of the carotid arteries. In 5070 participants (age 50-64 years), yearly residential exposures to air pollution (PM_2.5, PM₁₀, PM_coarse, NO_x, and exhaust-specific PM_2.5 1990-2015) were estimated using high-resolution dispersion models. We used Poisson regression to examine associations between long-term (26 years' mean) exposure to air pollutants and CAC score, and prevalence of carotid artery plaques, adjusted for potential confounders. Among participants with carotid artery plaques, we also examined the association with plaque area using linear regression. Mean exposure to PM_2.5 was low by international standards (8.5 μg/m³). There were no consistent associations between long-term total PM_2.5 exposure and CAC score or presence of carotid artery plaques, but an association between total PM_2.5 and larger plaque area in participants with carotid plaques. Associations with traffic-related air pollutants were consistently positive for both a high CAC score and bilateral carotid artery plaques. These associations were independent of road traffic noise. We found stronger associations among men and participants with cardiovascular risk factors. The results lend some support to atherosclerosis as a main modifiable pathway between low levels of traffic-related ambient air pollution and cardiovascular disease, especially in vulnerable individuals.

Global research trends in atherosclerosis: A bibliometric and visualized study

Background

Increasing evidence has spurred a considerable evolution of concepts related to atherosclerosis, prompting the need to provide a comprehensive view of the growing literature. By retrieving publications in the Web of Science Core Collection (WoSCC) of Clarivate Analytics, we conducted a bibliometric analysis of the scientific literature on atherosclerosis to describe the research landscape.

Methods

A search was conducted of the WoSCC for articles and reviews serving exclusively as a source of information on atherosclerosis published between 2012 and 2022. Microsoft Excel 2019 was used to chart the annual productivity of research relevant to atherosclerosis. Through CiteSpace and VOSviewer, the most prolific countries or regions, authors, journals, and resource-, intellectual-, and knowledge-sharing in atherosclerosis research, as well as co-citation analysis of references and keywords, were analyzed.

Results

A total of 20,014 publications were retrieved. In terms of publications, the United States remains the most productive country (6,390, 31,93%). The most publications have been contributed by Johns Hopkins Univ (730, 3.65%). ALVARO ALONSO produced the most published works (171, 0.85%). With a betweenness centrality of 0.17, ERIN D MICHOS was the most influential author. The most prolific journal was identified as Atherosclerosis (893, 4.46%). Circulation received the most co-citations (14,939, 2.79%). Keywords with the ongoing strong citation bursts were “nucleotide-binding oligomerization (NOD), Leucine-rich repeat (LRR)-containing protein (NLRP3) inflammasome,” “short-chain fatty acids (SCFAs),” “exosome,” and “homeostasis,” etc.

Conclusion

The research on atherosclerosis is driven mostly by North America and Europe. Intensive research has focused on the link between inflammation and atherosclerosis, as well as its complications. Specifically, the NLRP3 inflammasome, interleukin-1β, gut microbiota and SCFAs, exosome, long non-coding RNAs, autophagy, and cellular senescence were described to be hot issues in the field.

Urban air quality changes resulting from the lockdown period due to the COVID-19 pandemic

This work aims to quantify potential pollution level changes in an urban environment (Madrid city, Spain) located in South Europe due to the lockdown measures for preventing the SARS-CoV-2 transmission. Polluting 11 species commonly monitored in urban zones were attended. Except for O3, a prompt target pollutant levels abatement was reached, intensely when implanted stricter measures and moderately along those measures' relaxing period. In the case of TH and CH4, it is evidenced a progressive diminution over the lockdown period. While the highest decreasing average changes relapsed on NOx (NO2: - 40.0% and NO: - 33.3%) and VOCs (C7H8: - 36.3% and C6H6: - 32.8%), followed by SO2 (- 27.0%), PM10 (- 19.7%), CO (- 16.6%), CH4 (- 14.7%), TH (- 11.6%) and PM2.5 (- 10.1%), the O3 level slightly raised 0.4%. These changes were consistently dependent on the measurement station location, emphasizing urban background zones for SO2, CO, C6H6, C7H8, TH and CH4, suburban zones for PM2.5 and O3, urban traffic sites for NO and PM10, and keeping variations reasonably similar at all the stations in the case of NO2. Those pollution changes were not translated in variations on geospatial pattern, except for NO, O3 and SO2. Although the researched urban atmosphere improvement was not attributable to meteorological conditions' variations, it was in line with the decline in traffic intensity. The evidenced outcomes might offer valuable clues to air quality managers in urban environments regarding decision-making in favor of applying punctual severe measures for quickly and considerably relieving polluting high load occurred in urban environments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13762-022-04464-6.

Protecting playgrounds: local-scale reduction of airborne particulate matter concentrations through particulate deposition on roadside ‘tredges’ (green infrastructure)

Exposure to traffic-related particulate air pollution has been linked with excess risks for a range of cardiovascular, respiratory and neurological health outcomes; risks likely to be exacerbated in young children attending schools adjacent to highly-trafficked roads. One immediate way of reducing airborne PM concentrations at the local (i.e., near-road community) scale is installation of roadside vegetation as a means of passive pollution abatement. Roadside vegetation can decrease airborne PM concentrations, through PM deposition on leaves, but can also increase them, by impeding airflow and PM dispersion. Critical to optimizing PM removal is selection of species with high particle deposition velocity (Vd) values, currently under-parameterised in most modelling studies. Here, the measured amounts of leaf-deposited magnetic PM after roadside greening (‘tredge’) installation, and measured reductions in playground PM, particle number and black carbon concentrations demonstrate that air quality improvements by deposition can be achieved at the local, near-road, community/playground scale. PM deposition on the western red cedar tredge removed ~ 49% of BC, and ~ 46% and 26% of the traffic-sourced PM_2.5 and PM₁, respectively. These findings demonstrate that roadside vegetation can be designed, installed and maintained to achieve rapid, significant, cost-effective improvement of air quality by optimising PM deposition on plant leaves.

Effect of Short- to Long-Term Exposure to Ambient Particulate Matter on Cognitive Function in a Cohort of Middle-Aged and Older Adults: KoGES

Exposure to ambient air pollution and its threat to human health is a global concern, especially in the elderly population. Therefore, more in-depth studies are required to understand the extent of the harmful effects of particulate matter (PM) based on duration and levels of exposure. An investigation was conducted to determine the association between short- (1-14 days), medium- (1, 3, and 6 months), and long-term (1, 2, and 3 years) exposure to air pollutants (PM_2.5 and PM₁₀) and cognitive function among Koreans (4175 participants, mean age 67.8 years, 55.2% women) aged over 50 years. Higher levels of PM_2.5 exposure for short to long term and PM₁₀ exposure for medium to long term were found to be associated with decreased cognitive function, as indicated by lower scores of the Mini-Mental State Examination adopted in Korean (K-MMSE). There were significant effect modifications by sex, age group, alcohol consumption, physical activity, and smoking status in the association between long-term PM_2.5 and PM₁₀ exposure and cognitive function. These findings, which underscore the importance of the efforts to reduce the exposure levels and durations of air pollutants, especially in the vulnerable elderly population, provide evidence for establishing more stringent policies for air pollution regulations.

The Impact of Fine Particulate Matter 2.5 on the Cardiovascular System: A Review of the Invisible Killer

Air pollution exerts several deleterious effects on the cardiovascular system, with cardiovascular disease (CVD) accounting for 80% of all premature deaths caused by air pollution. Short-term exposure to particulate matter 2.5 (PM_2.5) leads to acute CVD-associated deaths and nonfatal events, whereas long-term exposure increases CVD-associated risk of death and reduces longevity. Here, we summarize published data illustrating how PM_2.5 may impact the cardiovascular system to provide information on the mechanisms by which it may contribute to CVDs. We provide an overview of PM_2.5, its associated health risks, global statistics, mechanistic underpinnings related to mitochondria, and hazardous biological effects. We elaborate on the association between PM_2.5 exposure and CVD development and examine preventive PM_2.5 exposure measures and future strategies for combating PM_2.5-related adverse health effects. The insights gained can provide critical guidelines for preventing pollution-related CVDs through governmental, societal, and personal measures, thereby benefitting humanity and slowing climate change.

PM2.5-Induced Programmed Myocardial Cell Death via mPTP Opening Results in Deteriorated Cardiac Function in HFpEF Mice

PM2.5 exposure can induce or exacerbate heart failure and is associated with an increased risk of heart failure hospitalization and mortality; however, the underlying mechanisms remain unclear. This study focuses on the potential mechanisms underlying PM2.5 induction of cardiomyocyte programmed necrosis as well as its promotion of cardiac function impairment in a mouse model of heart failure with preserved ejection fraction (HFpEF). HFpEF mice were exposed to concentrated ambient PM2.5 (CAP) (CAP group) or filtered air (FA) (FA group) for 6 weeks. Changes in myocardial pathology and cardiac function were documented for comparisons between the two groups. In vitro experiments were performed to measure oxidative stress and mitochondrial permeability transition pore (mPTP) dynamics in H9C2 cells following 24 h exposure to PM2.5. Additionally, co-immunoprecipitation was conducted to detect p53 and cyclophilin D (CypD) interactions. The results showed exposure to CAP promoted cardiac function impairment in HFpEF mice. Myocardial pathology analysis and in vitro experiments demonstrated that PM2.5 led to mitochondrial damage in cardiomyocytes and, eventually, their necrosis. Moreover, our experiments also suggested that PM2.5 increases mitochondrial reactive oxygen species (ROS), induces DNA oxidative damage, and decreases the inner mitochondrial membrane potential (ΔΨm). This indicates the presence of mPTP opening. Co-immunoprecipitation results showed a p53/CypD interaction in the myocardial tissue of HFpEF mice in the CAP group. Inhibition of CypD by cyclosporin A was found to reverse PM2.5-induced mPTP opening and H9C2 cell death. In conclusion, PM2.5 induces mPTP opening to stimulate mitochondria-mediated programmed necrosis of cardiomyocytes, and it might exacerbate cardiac function impairment in HFpEF mice.

Air Pollution’s Impact on Cardiac Remodeling in an Experimental Model of Chagas Cardiomyopathy

Background

Chagas disease is characterized by intense myocardial fibrosis stimulated by the exacerbated production of inflammatory cytokines, oxidative stress, and apoptosis. Air pollution is a serious public health problem and also follows this same path. Therefore, air pollution might amplify the inflammatory response of Chagas disease and increase myocardial fibrosis.

Methods

We studied groups of Trypanosoma cruzi infected Sirius hamsters (Chagas=CH and Chagas exposed to pollution=CH+P) and 2 control groups (control healthy animals=CT and control exposed to pollution=CT+P). We evaluated acute phase (60 days post infection) and chronic phase (10 months). Echocardiograms were performed to assess left ventricular systolic and diastolic diameter, in addition to ejection fraction. Interstitial collagen was measured by morphometry in picrosirius red staining tissue. The evaluation of inflammation was performed by gene and protein expression of cytokines IL10, IFN-γ, and TNF; oxidative stress was quantified by gene expression of NOX1, MnSOD, and iNOS and by analysis of reactive oxygen species; and apoptosis was performed by gene expression of BCL2 and Capsase3, in addition to TUNEL analysis.

Results

Chagas groups had increased collagen deposition mainly in the acute phase, but air pollution did not increase this deposition. Also, Chagas groups had lower ejection fraction in the acute phase (p = 0.002) and again air pollution did not worsen ventricular function or dilation. The analysis of the inflammation and oxidative stress pathways were also not amplified by air pollution. Apoptosis analysis showed increased expression of BCL2 and Caspase3 genes in chagasic groups in the acute phase, with a marginal p of 0.054 in BCL2 expression among infected groups, and TUNEL technique showed amplified of apoptotic cells by pollution among infected groups.

Conclusions

A possible modulation of the apoptotic pathway was observed, inferring interference from air pollution in this pathway. However, it was not enough to promote a greater collagen deposition, or worsening ventricular function or dilation caused by air pollution in this model of Chagas cardiomyopathy.

Air Pollution Exposure Induces Vascular Injury and Hampers Endothelial Repair by Altering Progenitor and Stem Cells Functionality

Extensive evidence indicates an association of air pollution exposure with an increased risk of cardiovascular disease (CVD) development. Fine particulate matter (PM) represents one of the main components of urban pollution, but the mechanisms by which it exerts adverse effects on cardiovascular system remain partially unknown and under investigation. The alteration of endothelial functions and inflammation are among the earliest pathophysiological impacts of environmental exposure on the cardiovascular system and represent critical mediators of PM-induced injury. In this context, endothelial stem/progenitor cells (EPCs) play an important role in vascular homeostasis, endothelial reparative capacity, and vasomotor functionality modulation. Several studies indicate the impairment of EPCs' vascular reparative capacity due to PM exposure. Since a central source of EPCs is bone marrow (BM), their number and function could be related to the population and functional status of stem cells (SCs) of this district. In this review, we provide an overview of the potential mechanisms by which PM exposure hinders vascular repair by the alteration of progenitor and stem cells' functionality.

A Review of Road Traffic-Derived Non-Exhaust Particles: Emissions, Physicochemical Characteristics, Health Risks, and Mitigation Measures

Implementation of regulatory standards has reduced exhaust emissions of particulate matter from road traffic substantially in the developed world. However, nonexhaust particle emissions arising from the wear of brakes, tires, and the road surface, together with the resuspension of road dust, are unregulated and exceed exhaust emissions in many jurisdictions. While knowledge of the sources of nonexhaust particles is fairly good, source-specific measurements of airborne concentrations are few, and studies of the toxicology and epidemiology do not give a clear picture of the health risk posed. This paper reviews the current state of knowledge, with a strong focus on health-related research, highlighting areas where further research is an essential prerequisite for developing focused policy responses to nonexhaust particles.

miRNAs-mediated overexpression of Periostin is correlated with poor prognosis and immune infiltration in lung squamous cell carcinoma

Lung cancer is one of the most common malignancies with a high mortality rate worldwide. POSTN has been shown to be strongly correlated with the poor prognosis of lung cancer patients. However, the function and mechanism of action of POSTN in lung cancer remain unclear. Here, we carried out a pan-cancer analysis to assess the clinical prognostic value of POSTN based on the TCGA, TIMER, Oncomine, Kaplan-Meier, and UALCAN databases. We found that upregulated POSTN can be a promising biomarker to predict the prognosis of patients with lung cancer. High levels of POSTN correlated with immune cell infiltration in lung cancer, especially lung squamous cell carcinoma (LUSC), which was further confirmed based on the results from the TISIDB database. Moreover, the expression analysis, correlation analysis, and survival analysis revealed that POSTN-targeted miRNAs, downregulation of has-miR-144-3p and has-miR-30e-3p, were significantly linked to poor prognosis in patients with LUSC. Taken together, we identified that POSTN can act as a novel biomarker for determining the prognosis related to immune infiltration in patients with LUSC and deserves further research.

Potential of NRF2 Pathway in Preventing Developmental and Reproductive Toxicity of Fine Particles

Air pollution is associated with significant adverse health effects. Recent studies support the idea that inhalation of fine particles can instigate extrapulmonary effects on the cardiovascular system through several pathways. The systemic transfer of ultrafine particles (UFPs) or soluble particle components (organic compounds and metals) is of particular concern. An integral role of reactive oxygen species (ROS)-dependent pathways has been suggested in systemic inflammatory responses and vascular dysfunction at the molecular level. Accumulating lines of evidence suggest that fine particles affect fetal development, giving rise to low birth weight and a reduction in fetal growth, and also affect the immune, cardiovascular, and central nervous systems. Oxidative stress plays an important role in fine particles toxicity; pre-treatment with antioxidants partially suppresses the developmental toxicity of fine particles. On the other hand, Nuclear factor erythroid-derived 2-like 2 (Nfe2l2), also known as NRF2, is a transcription factor essential for inducible and/or constitutive expression of phase II and antioxidant enzymes. Studies using Nrf2-knockout mice revealed that NRF2 dysfunction is intimately involved in the pathogenesis of various human diseases. Multiple single nucleotide polymorphisms (SNPs) have been detected in human NRF2 locus. An NRF2 gene SNP (−617C > A; rs6721961), located in the upstream promoter region, affects the transcriptional level of NRF2 and thereby the protein level and downstream gene expression. It has been reported that the SNP-617 is associated with various diseases. The onset and exacerbation of the diseases are regulated by genetic predisposition and environmental factors; some people live in the air-polluted environment but are not affected and remain healthy, suggesting the presence of individual differences in the susceptibility to air pollutants. NRF2 polymorphisms may also be associated with the fetal effects of fine particles exposure. Screening high-risk pregnant women genetically susceptible to oxidative stress and prevention by antioxidant interventions to protect fetal development in air-polluted areas should be considered. This article reviews the recent advances in our understanding of the fetal health effects of fine particles and describes potential chemoprevention via the NRF2 pathway to prevent the developmental and reproductive toxicity of fine particles.

Tempol Preserves Endothelial Progenitor Cells in Male Mice with Ambient Fine Particulate Matter Exposure

Ambient fine particulate matter (PM) exposure associates with an increased risk of cardiovascular diseases (CVDs). Major sex differences between males and females exist in epidemiology, pathophysiology, and outcome of CVDs. Endothelial progenitor cells (EPCs) play a vital role in the development and progression of CVDs. PM exposure-induced reduction of EPCs is observed in male, not female, mice with increased reactive oxygen species (ROS) production and oxidative stress. The lung is considered an important source of ROS in mice with PM exposure. The aim of the present study was to investigate the sex differences in pulmonary superoxide dismutase (SOD) expression and ROS production, and to test the effect of SOD mimic Tempol on the populations of EPCs in mice with PM exposure. Both male and female C57BL/6 mice (8–10 weeks) were exposed to intranasal PM or vehicle for 6 weeks. Flow cytometry analysis demonstrated that PM exposure significantly decreased the levels of EPCs (CD34⁺/CD133⁺) in both blood and bone marrow with increased ROS production in males, but not in females. ELISA analysis showed higher levels of serum IL-6 and IL-1βin males than in females. Pulmonary expression of the antioxidant enzyme SOD1 was significantly decreased in males after PM exposure, but not in females. Administration of the SOD mimic Tempol in male mice with PM exposure attenuated the production of ROS and inflammatory cytokines, and preserved EPC levels. These data indicated that PM exposure-induced reduction of EPC population in male mice may be due to decreased expression of pulmonary SOD1 in male mice.

The Salutary Effects of Catalpol on Diesel Exhaust Particles-Induced Thrombogenic Changes and Cardiac Oxidative Stress, Inflammation and Apoptosis

Inhaled particulate air pollution exerts pulmonary inflammation and cardiovascular toxicity through secondary systemic effects due to oxidative stress and inflammation. Catalpol, an iridiod glucoside, extracted from the roots of Rehmannia glutinosa Libosch, has been reported to possess anti-inflammatory and antioxidant properties. Yet, the potential ameliorative effects of catalpol on particulate air pollution-induced cardiovascular toxicity, has not been studied so far. Hence, we evaluated the possible mitigating mechanism of catalpol (5 mg/kg) which was administered to mice by intraperitoneal injection one hour before the intratracheal (i.t.) administration of a relevant type of pollutant particle, viz. diesel exhaust particles (DEPs, 30 µg/mouse). Twenty-four hours after the lung deposition of DEPs, several cardiovascular endpoints were evaluated. DEPs caused a significant shortening of the thrombotic occlusion time in pial microvessels in vivo, induced platelet aggregation in vitro, and reduced the prothrombin time and the activated partial thromboplastin time. All these actions were effectively mitigated by catalpol pretreatment. Likewise, catalpol inhibited the increase of the plasma concentration of C-reactive proteins, fibrinogen, plasminogen activator inhibitor-1 and P- and E-selectins, induced by DEPs. Moreover, in heart tissue, catalpol inhibited the increase of markers of oxidative (lipid peroxidation and superoxide dismutase) and nitrosative (nitric oxide) stress, and inflammation (tumor necrosis factor α, interleukin (IL)-6 and IL-1β) triggered by lung exposure to DEPs. Exposure to DEPs also caused heart DNA damage and increased the levels of cytochrome C and cleaved caspase, and these effects were significantly diminished by the catalpol pretreatment. Moreover, catalpol significantly reduced the DEPs-induced increase of the nuclear factor κB (NFκB) in the heart. In conclusion, catalpol significantly ameliorated DEPs-induced procoagulant events and heart oxidative and nitrosative stress, inflammation, DNA damage and apoptosis, at least partly, through the inhibition of NFκB activation.

Links between chronic exposure to outdoor air pollution and cardiovascular diseases: a review

Acute exposure to air pollution is associated with an increasing risk of death and cardiovascular disorders. Nonetheless, the impact of chronic exposure to air pollution on the circulatory system is still debated. Here, we review the links of chronic exposure to outdoor air pollution with mortality and most common cardiovascular diseases, in particular during the coronavirus disease 2019 event (COVID-19). We found that recent studies provide robust evidence for a causal effect of chronic exposure to air pollution and cardiovascular mortality. In terms of mortality, the strongest relationship was noted for fine particulate matter, nitrogen dioxide, and ozone. There is also increasing evidence showing that exposure to air pollution, mainly fine particulate matter and nitrogen dioxide, is associated with the development of atherosclerosis, hypertension, stroke, and heart failure. However, available scientific evidence is not strong enough to support associations with cardiac arrhythmias and coagulation disturbances. Noteworthy, for some pollutants, the risk of negative health effects is high for concentrations lower than the limit values recommended by the European Union and Word Health Organization. Efforts to diminish exposure to air pollution and to design optimal methods of air pollution reduction should be urgently intensified and supported by effective legislation and interdisciplinary cooperation.

Relationship Between Exposure to Sulphur Dioxide Air Pollution, White Cell Inflammatory Biomarkers and Enzymatic Infarct Size in Patients With ST-segment Elevation Acute Coronary Syndromes

Aims: To analyse the relationship among air pollutants, markers of inflammation and infarct size in patients with acute coronary syndrome (ACS). Methods: This was a prospective analysis of consecutive patients admitted to hospital because of ACS. Cardiac biomarkers were drawn. The daily mean values of the air pollutants from the day before until 7 days before admission were analysed. The study population was stratified according to infarct size, based on median peak troponin value. Results: Patients were divided into two groups of 108 subjects each, according to median peak troponin value. Patients with extensive MIs had a higher neutrophil:lymphocyte ratio and leukocyte and neutrophil counts than patients with smaller MIs. In addition, they were exposed to higher concentrations of sulphur dioxide (9.7 ± 4.1 versus 8.4 ± 3.1 μg/m³; p=0.009) and lower concentrations of ozone (33.8 ± 13.7 versus 38.6 ± 14.5 μg/m³; p=0.014). Multivariate analysis showed that sulphur dioxide levels (OR 1.12; 95% CI [1.031–1.21]; p=0.007) and neutrophil/lymphocyte ratio (OR 1.08; 95% CI [1.011–1.17]; p=0.024) were independent predictors of infarct size. Conclusion: Patients with extensive MIs had higher white cell inflammatory levels and had been exposed to higher sulphur dioxide concentrations in the ambient air.

Mitochondria and traffic-related air pollution linked coronary artery calcification: exploring the missing link

The continuing increase in the exposure to Traffic-related air pollution (TRAP) in the general population is predicted to result in a higher incidence of non-communicable diseases like cardiovascular disease. The chronic exposure of air particulate matter from TRAP upon the vascular system leads to the enhancement of deposition of calcium in the vasculature leading to coronary artery calcification (CAC), triggered by inflammatory reactions and endothelial dysfunction. This calcification forms within the intimal and medial layers of vasculature and the underlying mechanism that connects the trigger from TRAP is not well explored. Several local and systemic factors participate in this active process including inflammatory response, hyperlipidemia, presence of self-programmed death bodies and high calcium-phosphate concentrations. These factors along with the loss of molecules that inhibit calcification and circulating nucleation complexes influence the development of calcification in the vasculature. The loss of defense to prevent osteogenic transition linked to micro organelle dysfunction that includes deteriorated mitochondria, elevated mitochondrial oxidative stress, and defective mitophagy. In this review, we examine the contributory role of mitochondria involved in the mechanism of TRAP linked CAC development. Further we examine whether TRAP is an inducer or trigger for the enhanced progression of CAC.

Nuclear Receptors in Myocardial and Cerebral Ischemia-Mechanisms of Action and Therapeutic Strategies

Nearly 18 million people died from cardiovascular diseases in 2019, of these 85% were due to heart attack and stroke. The available therapies although efficacious, have narrow therapeutic window and long list of contraindications. Therefore, there is still an urgent need to find novel molecular targets that could protect the brain and heart against ischemia without evoking major side effects. Nuclear receptors are one of the promising targets for anti-ischemic drugs. Modulation of estrogen receptors (ERs) and peroxisome proliferator-activated receptors (PPARs) by their ligands is known to exert neuro-, and cardioprotective effects through anti-apoptotic, anti-inflammatory or anti-oxidant action. Recently, it has been shown that the expression of aryl hydrocarbon receptor (AhR) is strongly increased after brain or heart ischemia and evokes an activation of apoptosis or inflammation in injury site. We hypothesize that activation of ERs and PPARs and inhibition of AhR signaling pathways could be a promising strategy to protect the heart and the brain against ischemia. In this Review, we will discuss currently available knowledge on the mechanisms of action of ERs, PPARs and AhR in experimental models of stroke and myocardial infarction and future perspectives to use them as novel targets in cardiovascular diseases.

Association Between the Ambient Fine Particulate Pollution and the Daily Internal Medicine Outpatient Visits in Zhoushan, China: A Time-Series Study

Background: There has been a recent worsening of air pollution in China, which poses a huge threat to public health by inducing and promoting circulatory and respiratory diseases. This study aimed to explore the association between the concentration of air pollution and daily internal medicine outpatient visits registered for the treatment of circulatory and respiratory symptoms in Zhoushan, China using a time-series method.

Methods: We validated and acquired the daily internal medicine outpatient visits records between January 1, 2014, and December 31, 2019, from the Zhoushan Center for Disease Control and Prevention in Zhejiang, China. Further, we collected the daily average records of the ambient air pollutants from the Zhoushan Environmental Monitoring Centre within the same duration. A generalized additive model with the natural splines was constructed to explore the association between the ambient air pollutants and daily internal medicine outpatient visits. Further, we conducted a lag analysis by using the distributed lag non-linear model to estimate the time-delayed effects of the air pollutants on the daily internal medicine outpatient visits.

Results: A total of 2,190,258 daily internal medicine outpatient visits with a mean of 202.4 visits per day were recorded. The non-linear relationships were found among particulate matter_2.5 (PM_2.5), sulfur dioxide (SO₂), and the daily internal medicine outpatient visits. Overall, PM_2.5 was positively correlated with the daily internal medicine outpatient visits. Both ozone (O₃) and SO₂ had significant delayed effects on the daily internal medical outpatient numbers; however, PM_2.5 only showed a short-term risk.

Conclusion: Short-term exposure to PM_2.5 was associated with an increase in the daily internal medicine outpatient visits for circulatory and respiratory diseases/symptoms in Zhoushan, China. SO₂ and O₃ were shown to induce significant effects after a concentration-dependent time lag.

Air pollution and cardiovascular disease: Can the Australian bushfires and global COVID-19 pandemic of 2020 convince us to change our ways?

Air pollution is a major global challenge for a multitude of reasons. As a specific concern, there is now compelling evidence demonstrating a causal relationship between exposure to airborne pollutants and the onset of cardiovascular disease (CVD). As such, reducing air pollution as a means to decrease cardiovascular morbidity and mortality should be a global health priority. This review provides an overview of the cardiovascular effects of air pollution and uses two major events of 2020-the Australian bushfires and COVID-19 pandemic lockdown-to illustrate the relationship between air pollution and CVD. The bushfires highlight the substantial human and economic costs associated with elevations in air pollution. Conversely, the COVID-19-related lockdowns demonstrated that stringent measures are effective at reducing airborne pollutants, which in turn resulted in a potential reduction in cardiovascular events. Perhaps one positive to come out of 2020 will be the recognition that tough measures are effective at reducing air pollution and that these measures have the potential to stop thousands of deaths from CVD.

State of birth and cardiovascular disease mortality: Multilevel analyses of the National Longitudinal Mortality Study

Cardiovascular disease (CVD) is the leading contributor to mortality in the United States. Previous studies have linked early life individual and family factors, along with various contemporaneous place-based exposures to differential individual CVD mortality risk. However, the impacts of early life place exposures and how they compare to the effects of an individual's current place of residence on CVD mortality risk is not well understood. Using the National Longitudinal Mortality Study, this research examined the effects of both state of birth and state of residence on individual's risk of CVD mortality. We estimated individual mortality risk by estimating multi-level logistic regression models. We found that during a follow-up period of 11 years, 18,292 (4.2%) out of 433,345 participants died from CVD. The impact of state of birth on subsequent CVD mortality risk are greater than state of residence, even after adjusting for socio-demographic factors. Individuals who were born in certain states such as Tennessee, Kentucky, and Pennsylvania on average had higher CVD mortality risk. Conversely, those born in California, North Dakota, and Montana were found to have lower risk, no matter where they presently live. This study implies that early life state-level environments may be more prominent to individual's CVD mortality risk, compared to the state in which one lives. Future research should address specific mechanisms through which state of birth may affect people's risk of CVD mortality.

•

State of birth is a stronger predictor of CVD mortality than state of residence.

•

Models including state of birth random effects better predict individual CVD mortality risk.

•

Those born in Tennessee and Kentucky had the highest average CVD mortality risk while those born in California and North Dakota had the lowest risk.

•

Tennessee, Kentucky, Virginia, West Virginia, and Pennsylvania are a cluster of high state of birth effects.

Implications of Nonstationary Effect on Geographically Weighted Total Least Squares Regression for PM2.5 Estimation

Land use regression (LUR) models are used for high-resolution air pollution assessment. These models use independent parameters based on an assumption that these parameters are accurate and invariable; however, they are observational parameters derived from measurements or modeling. Therefore, the parameters are commonly inaccurate, with nonstationary effects and variable characteristics. In this study, we propose a geographically weighted total least squares regression (GWTLSR) to model air pollution under various traffic, land use, and meteorological parameters. To improve performance, the proposed model considers the dependent and independent variables as observational parameters. The GWTLSR applies weighted total least squares in order to take into account the variable characteristics and inaccuracies of observational parameters. Moreover, the proposed model considers the nonstationary effects of parameters through geographically weighted regression (GWR). We examine the proposed model’s capabilities for predicting daily PM_2.5 concentration in Isfahan, Iran. Isfahan is a city with severe air pollution that suffers from insufficient data for modeling air pollution with conventional LUR techniques. The advantages of the model features, including consideration of the variable characteristics and inaccuracies of predictors, are precisely evaluated by comparing the GWTLSR model with ordinary least squares (OLS) and GWR models. The R2 values estimated by the GWTLSR model during the spring and autumn are 0.84 and 0.91, respectively. The corresponding average R2 values estimated by the OLS model during the spring and autumn are 0.74 and 0.69, respectively, and the R2 values estimated by the GWR model are 0.76 and 0.70, respectively. The results demonstrate that the proposed functional model efficiently described the physical nature of the relationships among air pollutants and independent variables.

Environmental Fe, Ti, Al, Cu, Hg, Bi, and Si Nanoparticles in the Atrioventricular Conduction Axis and the Associated Ultrastructural Damage in Young Urbanites: Cardiac Arrhythmias Caused by Anthropogenic, Industrial, E-Waste, and Indoor Nanoparticles

Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.

Heart Failure and PAHs, OHPAHs, and Trace Elements Levels in Human Serum: Results from a Preliminary Pilot Study in Greek Population and the Possible Impact of Air Pollution

Cardiovascular diseases (CVDs) have been associated with environmental pollutants. The scope of this study is to assess any potential relation of polycyclic aromatic hydrocarbons (PAHs), their hydroxylated derivatives, and trace elements with heart failure via their direct determination in human serum of Greek citizens residing in different areas. Therefore, we analyzed 131 samples including cases (heart failure patients) and controls (healthy donors), and the respective demographic data were collected. Significantly higher concentrations (p < 0.05) were observed in cases' serum regarding most of the examined PAHs and their derivatives with phenanthrene, fluorene, and fluoranthene being the most abundant (median of >50 μg L-1). Among the examined trace elements, As, Cd, Cu, Hg, Ni, and Pb were measured at statistically higher concentrations (p < 0.05) in cases' samples, with only Cr being significantly higher in controls. The potential impact of environmental factors such as smoking and area of residence has been evaluated. Specific PAHs and trace elements could be possibly related with heart failure development. Atmospheric degradation and smoking habit appeared to have a significant impact on the analytes' serum concentrations. PCA-logistic regression analysis could possibly reveal common mechanisms among the analytes enhancing the hypothesis that they may pose a significant risk for CVD development.

A Review on Ionic Liquids-Based Membranes for Middle and High Temperature Polymer Electrolyte Membrane Fuel Cells (PEM FCs)

Today, the use of polymer electrolyte membranes (PEMs) possessing ionic liquids (ILs) in middle and high temperature polymer electrolyte membrane fuel cells (MT-PEMFCs and HT-PEMFCs) have been increased. ILs are the organic salts, and they are typically liquid at the temperature lower than 100 °C with high conductivity and thermal stability. The membranes containing ILs can conduct protons through the PEMs at elevated temperatures (more than 80 °C), unlike the Nafion-based membranes. A wide range of ILs have been identified, including chiral ILs, bio-ILs, basic ILs, energetic ILs, metallic ILs, and neutral ILs, that, from among them, functionalized ionic liquids (FILs) include a lot of ion exchange groups in their structure that improve and accelerate proton conduction through the polymeric membrane. In spite of positive features of using ILs, the leaching of ILs from the membranes during the operation of fuel cell is the main downside of these organic salts, which leads to reducing the performance of the membranes; however, there are some ways to diminish leaching from the membranes. The aim of this review is to provide an overview of these issues by evaluating key studies that have been undertaken in the last years in order to present objective and comprehensive updated information that presents the progress that has been made in this field. Significant information regarding the utilization of ILs in MT-PEMFCs and HT-PEMFCs, ILs structure, properties, and synthesis is given. Moreover, leaching of ILs as a challenging demerit and the possible methods to tackle this problem are approached in this paper. The present review will be of interest to chemists, electrochemists, environmentalists, and any other researchers working on sustainable energy production field.

MiR-939-5p suppresses PM2.5-induced endothelial injury via targeting HIF-1α in HAECs

Ambient air pollution is a leading cause of non-communicable disease in the world. PM_2.5 has the potential to change the miRNAs profiles, which in turn causes cardiovascular effects. Hypoxia-inducible factor (HIF)-1 plays a critical role in the development of atherosclerosis. Yet, the possible role of miR-939-5p/HIF-1α in PM_2.5-induced endothelial injury remains elusive. Therefore, the study aims to investigate the effects of miR-939-5p and HIF-1α on PM_2.5-triggered endothelial injury. The results from immunofluorescence, qRT-PCR, LSCM, and western blot assays demonstrated that PM_2.5 increased the levels of HIF-1α, inflammation and apoptosis in human aortic endothelial cells (HAECs). Yet, the inflammatory response and mitochondrial-mediated apoptosis pathway were effectively inhibited in HIF-1α knockdown HAECs lines. The expression of miR-939-5p was significantly down-regulated in HAECs after exposed to PM_2.5. The luciferase reporter, qRT-PCR and western blot results demonstrated that miR-939-5p could directly targeted HIF-1α. And the miR-939-5p overexpression restricted PM_2.5-triggered decreases in cell viability and increases in lactic dehydrogenase (LDH) activity, reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and inflammation. In addition, miR-939-5p overexpression remarkably suppressed PM_2.5-triggered BcL-2/Bax ratio reduction and Cytochrome C, Cleaved Caspase-9 and Cleaved Caspase-3 expression increase, revealed that miR-939-5p hampered PM_2.5-induced endothelial apoptosis through mitochondrial-mediated apoptosis pathway. Our results demonstrated that PM_2.5 increased the expression of HIF-1α followed by a pro-inflammatory and apoptotic response in HAECs. The protective effect of miR-939-5p on PM_2.5-triggered endothelial cell injury by negatively regulating HIF-1α. miR-939-5p might present a new therapeutic target for PM_2.5 induced endothelial injury.