Long-Term Exposure to Outdoor Air Pollution and Incidence of Cardiovascular Diseases

Rural-urban difference in the association between particulate matters and stroke incidence: The evidence from a multi-city perspective cohort study

Available evidence suggests that air pollutants can cause stroke, but little research has investigated the confounding effects of urban-rural differences. Here, we investigated the urban-rural difference in the correlation between particulate matter (PM2.5 and PM10) exposure and stroke. This cohort study was based on a prospective multi-city community-based cohort (Guizhou Population Health Cohort Study (GPHCS)) in Guizhou Province, China. A total of 7988 eligible individuals (≥18 years) were enrolled with baseline assessments from November 2010 to December 2012, and follow-up was completed by June 2020. Two major particulate matters (PMs, including PM2.5 and PM10) were assessed monthly from 2000 by using satellite-based spatiotemporal models. The risk of stroke was estimated using a Cox proportional hazard regression model. The association between particulate matters' exposure and stroke in different areas (total, urban, and rural) and the potential modification effect of comorbidities (hypertension, diabetes, and dyslipidemia) and age (≤65/>65 years) were examined using stratified analyses. The risk of stroke increased for every 10 μg/m3 increase in mean PMs' concentrations during the previous 1 year at the residential address (HR: 1.26, 95%CI: 1.24, 1.29 (PM2.5); HR: 1.13, 95%CI: 1.11, 1.15 (PM10)). The presence of diabetes and dyslipidemia increased the risk of PM10-induced stroke in whole, urban, and rural areas. Specifically, people living in rural areas were more likely to experience the effects of PMs in causing a stroke. The risk of stroke due to PMs was statistically increased in the young and older populations living in rural areas. In conclusion, long-term exposure to PMs increased the risk of stroke and such association was more pronounced in people living in rural areas with lower income levels. Diabetes and dyslipidemia seemed to strengthen the association between PMs and stroke.

Long-term PM2.5 exposure associated with severity of angina pectoris and related health status in patients admitted with acute coronary syndrome: Modification effect of genetic susceptibility and disease history

Long-term particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5) exposure has been associated with the occurrence of acute coronary syndrome (ACS). However, the impact of PM2.5 exposure and its components on the severity of angina pectoris and disease-related health status in patients hospitalized for ACS is understudied. To assess the association between long-term exposure to PM2.5 components and the angina pectoris severity in ACS patients, as well as the modification effects of genetic factors and disease history in north China. During 2017-2019, 6729 ACS patients were collected in Shandong Province and Beijing, with their angina pectoris severity evaluated using Seattle Angina Questionnaire (SAQ). The 0-3 years' average concentrations of PM2.5 and its five major components were assigned to each patient's residential address. Linear mixed-effects model, weighted quantile regression, and quantile g-computation were used to estimate the effects of both single and joint associations between PM2.5 components and SAQ scores. The interactive effect was estimated by polygenic risk scores and disease history. For each interquartile range increase in PM2.5, the overall SAQ score changed by -3.71% (95%CI: -4.54% to -2.88%), with score of angina stability more affected than angina frequency and other dimensions of angina pectoris severity. Sulfate and ammonium were major contributors to the effect of PM2.5 exposure. Significant modification effect was only observed for disease history, especially for the dimension of physical limitation. Among a series of pre-existing diseases, patients with a family history of coronary artery disease, previous percutaneous coronary intervention or coronary artery bypass grafting, and stroke were more susceptible to PM2.5 exposure than others. Greater exposure to PM2.5 is associated with more serious angina pectoris and worse disease-related health status in ACS patients. Public health and clinical priority should be given to cutting down key effective components and protecting highly vulnerable individuals.

Long-term exposure to ambient ozone and cardiovascular diseases: Evidence from two national cohort studies in China

INTRODUCTION

The health effects of ambient ozone have been investigated in many previous studies. However, the effects of long-term exposure to ambient ozone on the incidence of cardiovascular disease (CVD) remain inconclusive.

OBJECTIVES

To estimate the associations of long-term exposure to maximum daily 8-hours average ozone (MDA8 O3) with the incidence of total CVD, heart disease, hypertension, and stroke.

METHODS

This was a prospective cohort study, and the data was obtained from the China Health and Retirement Longitudinal Survey (CHARLS) implemented during 2011-2018 and the China Family Panel Studies (CFPS) implemented during 2010-2018. We applied a Cox proportional hazards regression model to evaluate the associations of MDA8 O3 with total CVD, heart disease, hypertension, and stroke risks, and the corresponding population-attributable fractions (PAF) attributable to MDA8 O3 were also calculated. All analyses were conducted by R software.

RESULTS

The mean MDA8 O3 concertation of all included participants in the CHARLS and CFPS were 51.03 part per billion (ppb) and 51.15 ppb, respectively. In the CHARLS including 18,177 participants, each 10 ppb increment in MDA8 O3 concentration was associated with a 31% increase [hazard ratio (HR) = 1.31, 95% confidence interval (CI): 1.22-1.42] in the risk of incident heart disease, and the corresponding population-attributable fractions (PAF) was 13.79% [10.12%-17.32%]. In the CFPS including 30,226 participants, each 10 ppb increment in MDA8 O3 concentration was associated with an increase in the risk of incident total CVD (1.07 [1.02-1.13]), and hypertension (1.10 [1.03-1.18]). The PAFs of total CVD, and hypertension attributable to MDA8 O3 were 3.53% [0.82%-6.16%], and 5.11% [1.73%-8.38%], respectively. Stratified analyses showed greater associations in males, urban areas, and Southern China.

CONCLUSIONS

Long-term exposure to MDA8 O3 may increase the incidence of CVD. Therefore, the policies that control O3 and related precursors are persistently needed.

The key characteristics of cardiotoxicity for the pervasive pollutant phenanthrene

The key characteristic (KCs) framework has been used previously to assess the carcinogenicity and cardiotoxicity of various chemical and pharmacological agents. Here, the 12 KCs of cardiotoxicity are used to evaluate the previously reported cardiotoxicity of phenanthrene (Phe), a tricyclic polycyclic aromatic hydrocarbon (PAH), and major component of fossil fuel-derived air pollution. Phe is a semi-volatile pollutant existing in both the gas phase and particle phase through adsorption onto or into particulate matter (PM). Phe can translocate across the airways and gastrointestinal tract into the systemic circulation, enabling body-wide effects. Our evaluation based on a comprehensive literature review, indicates Phe exhibits 11 of the 12 KCs for cardiotoxicity. These include adverse effects on cardiac electromechanical performance, the vasculature and endothelium, immunomodulation and oxidative stress, and neuronal and endocrine control. Environmental agents that have similarly damaging effects on the cardiovascular system are heavily regulated and monitored, yet globally there is no air quality regulation specific for PAHs like Phe. Environmental monitoring of Phe is not the international standard with benzo[a]pyrene being frequently used as a proxy despite the two PAH species exhibiting significant differences in sources, concentration variations and toxic effects. The evidence summarised in this evaluation highlights the need to move away from proxied PAH measurements and develop a monitoring network capable of measuring Phe concentration. It also stresses the need to raise awareness amongst the medical community of the potential cardiovascular impact of PAH exposure. This will allow the production of mitigation strategies and possibly the development of new policies for the protection of the societal groups most vulnerable to cardiovascular disease.

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.

Association between PM10 exposure and risk of myocardial infarction in adults: A systematic review and meta-analysis

BACKGROUND

Air pollution has several negative health effects. Particulate matter (PM) is a pollutant that is often linked to health adversities. PM2.5 (PM with an aerodynamic diameter of ≤2.5μm) exposure has been associated with negative cardiovascular (CV) outcomes. However, the impact of PM10 (PM with an aerodynamic diameter of ≤10μm) exposure is often overlooked due to its limited ability to pass the alveolar barrier. This study aims to assess the association between PM10 exposure and risk of myocardial infarction (MI) amongst adults (≥18 years of age) as this has been poorly studied.

METHODS

The study protocol was published on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023409796) on March 31, 2023. Literature searches were conducted on 4 databases (Ovid Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Web of Science) on January 17, 2023, for studies looking at associations between PM and MI. English studies from all time periods were assessed. Studies selected for review were time-series, case-crossover, and cohort studies which investigated the risk of MI as an outcome upon PM10 exposure. The quality of evidence was assessed using Cochrane's Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Data for different risk outcomes (risk ratio (RR), odds ratio (OR), hazard ratio (HR)) and 3 lags was meta-analyzed using an inverse variance statistical analysis using a random effects model. The pooled effect sizes and the 95% confidence intervals (CIs) were reported in forest plots.

RESULTS

Among the 1,099 studies identified, 41 were included for review and 23 were deemed eligible for meta-analysis. Our analysis revealed that there is an increased risk (OR = 1.01; 95% CI:1.00-1.02) of MI with a 10 μg/m3 increase in PM10 after a lag 0 and lag 1 delay.

CONCLUSIONS

Our findings indicate that PM10 exposure is associated with an increased risk of MI. This can aid in informing environmental policy-making, personal-level preventative measures, and global public health action.

The impact of air quality on cardiovascular health: A state of the art review

Air pollution is a global health challenge, increasing the risk of cardiovascular diseases such as heart disease, stroke, and arrhythmias. Particulate matter (PM), particularly PM2.5 and ultrafine particles (UFP), is a key contributor to the adverse effects of air pollution on cardiovascular health. PM exposure can lead to oxidative stress, inflammation, atherosclerosis, vascular dysfunction, cardiac arrhythmias, and myocardial injury. Reactive oxygen species (ROS) play a key role in mediating these effects. PM exposure can also lead to hypertension, a significant risk factor for cardiovascular disease. The COVID-19 pandemic resulted in a significant reduction of air pollutants, leading to a decline in the incidence of heart attacks and premature deaths caused by cardiovascular diseases. This review highlights the relationship between environmental air quality and cardiovascular health, elucidating the pathways through which air pollutants affect the cardiovascular system. It also emphasizes the need for increased awareness, collective efforts to mitigate the adverse effects of air pollution, and strategic policies for long-term air quality improvement to prevent the devastating effects of air pollution on global cardiovascular health.

Association of air pollution exposure and increased coronary artery disease risk: the modifying effect of genetic susceptibility

BACKGROUND

Both genetic factors and air pollution are risk factors for coronary artery disease (CAD), but their combined effects on CAD are uncertain. The study aimed to comprehensively investigate their separate, combined and interaction effects on the onset of CAD.

METHODS

We utilized data from the UK Biobank with a recruitment of 487,507 participants who were free of CAD at baseline from 2006 to 2010. We explored the separate, combined effect or interaction association among genetic factors, air pollution and CAD with the polygenic risk score (PRS) and Cox proportional hazard models.

RESULTS

The hazard ratios (HRs) [95% confidence interval (CI)] of CAD for 10-µg/m3 increases in PM2.5, NO2 and NOx concentrations were 1.25 (1.09, 1.44), 1.03 (1.01, 1.05) and 1.01 (1.00, 1.02), respectively. Participants with high PRS and air pollution exposure had a higher risk of CAD than those with the low genetic risk and low air pollution exposure, and the HRs (95% CI) of CAD in the PM2.5, PM10, NO2 and NOx high joint exposure groups were 1.56 (1.48, 1.64), 1.55(1.48, 1.63), 1.57 (1.49, 1.65), and 1.57 (1.49, 1.65), respectively. Air pollution and genetic factors exerted significant additive effects on the development of CAD (relative excess risk due to the interaction [RERI]: 0.12 (0.05, 0.19) for PM2.5, 0.17 (0.10, 0.24) for PM10, 0.14 (0.07, 0.21) for NO2, and 0.17 (0.10, 0.24) for NOx; attributable proportion due to the interaction [AP]: 0.09 (0.04, 0.14) for PM2.5, 0.12 (0.07, 0.18) for PM10, 0.11 (0.06, 0.16) for NO2, and 0.13 (0.08, 0.18) for NOx).

CONCLUSION

Exposure to air pollution was significantly related to an increased CAD risk, which could be further strengthened by CAD gene susceptibility. Additionally, there were positive additive interactions between genetic factors and air pollution on the onset of CAD. This can provide a more comprehensive, precise and individualized scientific basis for the risk assessment, prevention and control of CAD.

Long-Term Exposure to Air Pollution Below Regulatory Standards and Cardiovascular Diseases Among US Medicare Beneficiaries: A Double Negative Control Approach

Growing evidence suggests that long-term air pollution exposure is a risk factor for cardiovascular mortality and morbidity. However, few studies have investigated air pollution below current regulatory limits, and causal evidence is limited. We used a double negative control approach to examine the association between long-term exposure to air pollution at low concentrations and three major cardiovascular events among Medicare beneficiaries aged ≥ 65 years across the contiguous United States between 2000 and 2016. We derived ZIP code-level estimates of ambient fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and warm-season ozone (O 3 ) from high-resolution spatiotemporal models. The outcomes of interest were hospitalizations for stroke, heart failure (HF), and atrial fibrillation and flutter (AF). The analyses were restricted to areas with consistently low pollutant levels on an annual basis (PM 2.5 <10 µg/m³, NO 2  < 45 or 40 ppb, warm-season O 3  < 45 or 40 ppb). For each 1 µg/m 3 increase in PM 2.5 , the hospitalization rates increased by 2.25% (95% confidence interval (CI): 1.96%, 2.54%) for stroke and 3.14% (95% CI: 2.80%, 3.94%) for HF. Each ppb increase in NO 2 increased hospitalization rates for stroke, HF, and AF by 0.28% (95% CI: 0.25%, 0.31%), 0.56% (95% CI: 0.52%, 0.60%), and 0.45% (95% CI: 0.41%, 0.49%), respectively. For each ppb increase in warm-season O 3 , there was a 0.32% (95% CI: 0.21%, 0.44%) increase in hospitalization rate for stroke. The associations for NO 2 and warm-season O 3 became stronger under a more restrictive upper threshold. Using an approach robust to omitted confounders, we concluded that long-term exposure to low-level PM 2.5 , NO 2 , and warm-season O 3 was associated with increased risks of cardiovascular diseases in the US elderly. Stricter national air quality standards should be considered.

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.

Middle-term nitrogen dioxide exposure and electrocardiogram abnormalities: A nationwide longitudinal study

BACKGROUND

Recently, professionals, such as those from the World Health Organization, have recommended a rigorous standard for nitrogen dioxide (NO2), a typical urban air pollutant affected by regular traffic emissions, based on its short-term and long-term cardiorespiratory effects. However, the association between middle-term NO2 exposure and cardiovascular disorders remains unknown.

OBJECTIVES

This study was conducted to examine the relationship between NO2 exposure and its middle-term cardiovascular risks indicated by electrocardiogram (ECG) abnormalities.

METHOD

We included 61,094 subjects (132,249 visits) with repeated ECG observations based on longitudinal data from the China National Stroke Screening Survey (CNSSS). The NO2 exposure concentration was derived from a predictive model, measured as the monthly average concentration in the 6 months of preceding the ECG measurement. We used the generalized estimation equation to assess the association between NO2 exposure and ECG abnormalities.

RESULT

For each 10 µg/m3 increase in monthly average NO2 concentration, the odds ratio of ECG abnormalities was 1.10 (95% confidence interval [CI] 1.09-1.12) after multiple adjustments. Stratified regression analyses of urban and rural residents showed associations between middle-term NO2 exposure and ECG abnormalities in urban (OR 1.09 [95% CI 1.08-1.11]) and rural residents (OR 1.14 [95% CI 1.10-1.19]). The association was robust within different subpopulations. Associations generally remained statistically significant (OR 1.03 [95% CI 1.02-1.05]) after extra adjustment for PM2.5. Exposure-response relationship analysis revealed a nearly linear relationship between NO2 exposure and the risk for ECG abnormalities.

CONCLUSION

Using the variation in ECG signals as a potentially reversible indicator for subclinical risk in cardiovascular systems, our study provides additional evidence on the increased risk posed by middle-term NO2 exposure. Our study showed that policies controlling for NO2 concentrations are beneficial to prevent cardiovascular diseases among Chinese adults.

Long-term exposure to ambient ozone at workplace is positively and non-linearly associated with incident hypertension and blood pressure: longitudinal evidence from the Beijing-Tianjin-Hebei medical examination cohort

BACKGROUND

There is limited longitudinal evidence on the hypertensive effects of long-term exposure to ambient O3. We investigated the association between long-term O3 exposure at workplace and incident hypertension, diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), and mean arterial pressure (MAP) in general working adults.

METHODS

We conducted a cohort study by recruiting over 30,000 medical examination attendees through multistage stratified cluster sampling. Participants completed a standard questionnaire and comprehensive medical examination. Three-year ambient O3 concentrations at each employed participant's workplace were estimated using a two-stage machine learning model. Mixed-effects Cox proportional hazards models and linear mixed-effects models were used to examine the effect of O3 concentrations on incident hypertension and blood pressure parameters, respectively. Generalized additive mixed models were used to explore non-linear concentration-response relationships.

RESULTS

A total of 16,630 hypertension-free working participants at baseline finished the follow-up. The mean (SD) O3 exposure was 45.26 (2.70) ppb. The cumulative incidence of hypertension was 7.11 (95% CI: 6.76, 7.47) per 100 person-years. Long-term O3 exposure was independently, positively and non-linearly associated with incident hypertension (Hazard ratios (95% CI) for Q2, Q3, and Q4 were 1.77 (1.34, 2.36), 2.06 (1.42, 3.00) and 3.43 (2.46, 4.79), respectively, as compared with the first quartile (Q1)), DBP (β (95% CI) was 0.65 (0.01, 1.30) for Q2, as compared to Q1), SBP (β (95% CI) was 2.88 (2.00, 3.77), 2.49 (1.36, 3.61) and 2.61 (1.64, 3.58) for Q2, Q3, and Q4, respectively), PP (β (95% CI) was 2.12 (1.36, 2.87), 2.03 (1.18, 2.87) and 2.14 (1.38, 2.90) for Q2, Q3, and Q4, respectively), and MAP (β (95% CI) was 1.39 (0.76, 2.02), 1.04 (0.24, 1.84) and 1.12 (0.43, 1.82) for Q2, Q3, and Q4, respectively). The associations were robust across sex, age, BMI, and when considering PM2.5 and NO2.

CONCLUSIONS

To our knowledge, this is the first cohort study in the general population that demonstrates the non-linear hypertensive effects of long-term O3 exposure. The findings are particularly relevant for policymakers and researchers involved in ambient pollution and public health, supporting the integration of reduction of ambient O3 into public health interventions.

A Narrative Review on the Impact of Air Pollution on Heart Failure Risk and Exacerbation

Air pollution is a risk factor for many cardiovascular diseases, including heart failure (HF). Although the links between air pollution and HF have been explored, the results are scattered and difficult to piece together into a cohesive story. Therefore, we undertook a narrative review of all aspects of the relationship between HF and air pollution exposure, including risks of developing HF when exposed to air pollution, the exacerbation of HF symptoms by air pollution exposure, and the increased susceptibility that individuals with HF have for air pollution-related health risks. We also examined the literature on environmental justice as well as air pollution interventions for HF. We found substantial evidence linking air pollution exposure to HF incidence. There were a limited number of studies that examined air pollution exposure in clearly defined populations with HF to explore exacerbation of HF or the susceptibility of individuals with HF to air pollution health risks. However, there is substantial evidence that HF-related hospitalisations are increased under air pollution exposure and that the air pollution associated increase in HF-related hospitalisations is greater than hospitalisations for other chronic diseases, supporting links between air pollution and both exacerbation of HF and susceptibility of individuals with HF. There is emerging evidence for interventions that can decrease air pollution health risks for individuals with HF, and more studies are needed, particularly randomised controlled trials. Thus, although the air pollution-related health risks for HF incidence and hospitalisations are clear, further studies specifically targeted at identified data gaps will greatly improve our knowledge of the susceptibility of individuals with HF and interventions to reduce risks.

Connections Between Air Pollution, Climate Change, and Cardiovascular Health

Globally, more people die from cardiovascular disease than any other cause. Climate change, through amplified environmental exposures, will promote and contribute to many noncommunicable diseases, including cardiovascular disease. Air pollution, too, is responsible for millions of deaths from cardiovascular disease each year. Although they may appear to be independent, interchangeable relationships and bidirectional cause-and-effect arrows between climate change and air pollution can eventually lead to poor cardiovascular health. In this topical review, we show that climate change and air pollution worsen each other, leading to several ecosystem-mediated effects. We highlight how increases in hot climates as a result of climate change have increased the risk of major air pollution events such as severe wildfires and dust storms. In addition, we show how altered atmospheric chemistry and changing patterns of weather conditions can promote the formation and accumulation of air pollutants: a phenomenon known as the climate penalty. We demonstrate these amplified environmental exposures and their associations to adverse cardiovascular health outcomes. The community of health professionals-and cardiologists, in particular-cannot afford to overlook the risks that climate change and air pollution bring to the public's health.

Environmental pollutants and their effects on human health

Numerous environmental contaminants significantly contribute to human disease, affecting climate change and public and individual health, resulting in increased mortality and morbidity. Because of the scarcity of information regarding pollution exposure from less developed nations with inadequate waste management, higher levels of poverty, and limited adoption of new technology, the relationship between pollutants and health effects needs to be investigated more. A similar situation is present in many developed countries, where solutions are only discovered after the harm has already been done and the necessity for safeguards has subsided. The connection between environmental toxins and health needs to be better understood due to difficulties in quantifying exposure levels and a lack of systematic monitoring. Different pollutants are to blame for both chronic and acute disorders. Additionally, research becomes challenging when disease problems are seen after prolonged exposure. This review aims to discuss the present understanding of the association between environmental toxins and human health in bridging this knowledge gap. The genesis of cancer and the impact of various environmental pollutants on the human body's cardiovascular, respiratory, reproductive, prenatal, and neural health are discussed in this overview.

Evidence of the adverse effects of air pollution on the population's health in Spain: analysis of the economic costs of premature deaths

Exposure to ambient air pollution increases mortality and morbidity, leading disabilities, and premature deaths. Air pollution has been identified as a leading cause of global disease burden, especially in low- and middle-income countries in 2015 (Global Burden of Diseases, Injuries and Risk Factors Study, 2015). This study explores the relation between mortality rates and particulate matter (PM) concentrations in the 50 Spanish regions for the period 2002-2017. Moreover, we estimated the premature deaths due to PM in Spain according to welfare and production losses in 2017. Random-effects models were developed to evaluate the relation between mortality rates and PM concentrations. The economic cost of premature deaths was assessed using the Willingness to Pay approach to quantify welfare losses and the Human Capital method to estimate production losses. PM10 concentrations are positively related to mortality due to respiratory diseases and stroke. Based on 10,342 premature deaths in 2017, losses in welfare amount to EUR 36,227 million (3.1% of Spanish GDP). The economic value of current and future production losses reached EUR 229 million (0.02% of GDP). From a social perspective, air pollution is a public health concern that greatly impacts health and quality of life. Results highlight the need to implement or strengthen regulatory, fiscal, and health public policies to substantially benefit the population's health by reducing their exposure to air pollution.

Perspective on Particulate Matter: From Biomass Burning to the Health Crisis in Mainland Southeast Asia

Air pollution, notably particulate matter pollution, has become a serious concern in Southeast Asia in recent decades. The combustion of biomass has been recognized to considerably increase air pollution problems from particulate matter in this region. Consequently, its effect on people in this area is significant. This article presents a synthesis of several datasets obtained from satellites, global emissions, global reanalysis, and the global burden of disease (GBD) to highlight the air quality issue and emphasize the health crisis in mainland Southeast Asia. We found that the death rates of people have increased significantly along with the rise of hotspots in mainland Southeast Asia over the last two decades (2000-2019). In comparison, most countries saw a considerable increase in the predicted fatality rates associated with chronic respiratory illnesses during those two decades. Several reports highlight the continued prevalence of chronic respiratory diseases likely related to poor air quality in Southeast Asia.

Rural-Urban Disparities in Multimorbidity Associated With Climate Change and Air Pollution: A Longitudinal Analysis Among Chinese Adults Aged 45

Background and Objectives

Chronic conditions and multimorbidity are increasing worldwide. Yet, understanding the relationship between climate change, air pollution, and longitudinal changes in multimorbidity is limited. Here, we examined the effects of sociodemographic and environmental risk factors in multimorbidity among adults aged 45+ and compared the rural-urban disparities in multimorbidity.

Research Design and Methods

Data on the number of chronic conditions (up to 14), sociodemographic, and environmental factors were collected in 4 waves of the China Health and Retirement Longitudinal Study (2011-2018), linked with the full-coverage particulate matter 2.5 (PM2.5) concentration data set (2000-2018) and temperature records (2000-2018). Air pollution was assessed by the moving average of PM2.5 concentrations in 1, 2, 3, 4, and 5 years; temperature was measured by 1-, 2-, 3-, 4-, and 5-year moving average and their corresponding coefficients of variation. We used the growth curve modeling approach to examine the relationship between climate change, air pollution, and multimorbidity, and conducted a set of stratified analyses to study the rural-urban disparities in multimorbidity related to temperature and PM2.5 exposure.

Results

We found the higher PM2.5 concentrations and rising temperature were associated with higher multimorbidity, especially in the longer period. Stratified analyses further show the rural-urban disparity in multimorbidity: Rural respondents have a higher prevalence of multimorbidity related to rising temperature, whereas PM2.5-related multimorbidity is more severe among urban ones. We also found temperature is more harmful to multimorbidity than PM2.5 exposure, but PM2.5 exposure or temperature is not associated with the rate of multimorbidity increase with age.

Discussion and Implications

Our findings indicate that there is a significant relationship between climate change, air pollution, and multimorbidity, but this relationship is not equally distributed in the rural-urban settings in China. The findings highlight the importance of planning interventions and policies to deal with rising temperature and air pollution, especially for rural individuals.

Air pollution exposure and heart failure: A systematic review and meta-analysis

While the literature strongly supports a positive association between particulate matter with diameter ≤ 2.5 μm (PM_2.5) exposure and heart failure (HF), there is uncertainty regarding the other pollutants and the dose and duration of exposure that triggers an adverse response. To comprehensively assess and quantify the association of air pollution exposure with HF incidence and mortality, we performed separate meta-analyses according to pollutant types [PM_2.5, PM₁₀, sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃)], and exposure duration (short- and long-term). We systematically searched PubMed, EMBASE, and Web of Science for relevant articles with publication dates up to July 12, 2022, identifying 35 eligible studies. Random-effects models were used to summarize the pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs). For long-term exposure, the growing risk of HF was significantly associated with each 10 μg/m³ increase in PM_2.5 (OR = 1.196, 95 % CI: 1.079-1.326; I² = 76.8 %), PM₁₀ (1.190, 1.045-1.356; I² = 76.2 %), and NO₂ (1.072, 1.028-1.118; I² = 78.3 %). For short-term exposure, PM_2.5, PM₁₀, NO₂, and O₃ (per 10 μg/m³ increment) increased the risk of HF, with estimated ORs of 1.019 (1.008-1.030; I² = 39.9 %), 1.012 (1.007-1.017; I² = 28.3 %), 1.016 (1.005-1.026; I² = 53.7 %), and 1.006 (1.002-1.010; I² = 0.0 %), respectively. No significant effects of SO₂ and CO exposure on the risk of HF were observed. In summary, our study powerfully highlights the deleterious impact of PM_2.5, PM₁₀, and NO₂ exposure (either short- or long-term) on HF risk. Serious efforts should be made to improve air quality through legislation and interdisciplinary cooperation.

Source-Specific Air Pollution Including Ultrafine Particles and Risk of Myocardial Infarction: A Nationwide Cohort Study from Denmark

BACKGROUND

Air pollution is negatively associated with cardiovascular health. Impediments to efficient regulation include lack of knowledge about which sources of air pollution contributes most to health burden and few studies on effects of the potentially more potent ultrafine particles (UFP).

OBJECTIVE

The authors aimed to investigate myocardial infarction (MI) morbidity and specific types and sources of air pollution.

METHODS

We identified all persons living in Denmark in the period 2005-2017, age >50 y and never diagnosed with MI. We quantified 5-y running time-weighted mean concentrations of air pollution at residencies, both total and apportioned to traffic and nontraffic sources. We evaluated particulate matter (PM) with aerodynamic diameter ≤2.5μm (PM2.5), <0.1μm (UFP), elemental carbon (EC), and nitrogen dioxide (NO2). We used Cox proportional hazards models, with adjustment for time-varying exposures, and personal and area-level demographic and socioeconomic covariates from high-quality administrative registers.

RESULTS

In this nationwide cohort of 1,964,702 persons (with 18 million person-years of follow-up and 71,285 cases of MI), UFP and PM2.5 were associated with increased risk of MI with hazard ratios (HRs) per interquartile range (IQR) of 1.040 [95% confidence interval (CI): 1.025, 1.055] and 1.053 (95% CI: 1.035, 1.071), respectively. HRs per IQR of UFP and PM2.5 from nontraffic sources were similar to the total (1.034 and 1.051), whereas HRs for UFP and PM2.5 from traffic sources were smaller (1.011 and 1.011). The HR for EC from traffic sources was 1.013 (95% CI: 1.003, 1.023). NO2 from nontraffic sources was associated with MI (HR=1.048; 95% CI: 1.034, 1.062) but not from traffic sources. In general, nontraffic sources contributed more to total air pollution levels than national traffic sources.

CONCLUSIONS

PM2.5 and UFP from traffic and nontraffic sources were associated with increased risk of MI, with nontraffic sources being the dominant source of exposure and morbidity. https://doi.org/10.1289/EHP10556.

Air pollution and myocardial infarction; effect modification by sociodemographic and environmental factors. A cohort study from Denmark

Air pollution is associated with increased risk of myocardial infarction (MI), but it is unresolved to what extent the association is modified by factors such as socioeconomic status, comorbidities, financial stress, residential green space, or road traffic noise. We formed a cohort of all (n = 1,964,702) Danes, aged 50-85 years, with 65,311 cases of MI during the followed-up period 2005-2017. For all participants we established residential five-year running average exposure to particulate matter <2.5  μm (PM_2.5), ultrafine particles (UFP, <0.1  μm), elemental carbon (EC) and nitrogen dioxide (NO₂). We evaluated risk in population strata, using Aalen additive hazards models to estimate absolute risk and Cox proportional hazards models to estimate relative risk of MI with 95% confidence intervals (CI). PM_2.5 and the other pollutant were associated with MI. Lower education and lower income were associated with higher absolute risks of MI from air pollution, whereas no clear effect modification was apparent for relative risk estimates. For example, 5 μg/m³ higher PM_2.5 was associated with HR for MI of 1.16 (95% CI: 1.10-1.22) among those with only mandatory education and 1.13 (95% CI: 1.03-1.24) among those with long education. The corresponding rate differences per 100,000 person years were 243 (95% CI: 216-271) and 358 (95% CI: 338-379), respectively. Higher level of comorbidity was consistently across all four pollutants associated with both higher absolute and relative risk of MI. In conclusion, people with comorbid conditions or of lower SES appeared more vulnerable to long-term exposure to air pollution and more cases of MI may be prevented by focused interventions in these groups.

Airborne levels of cadmium are correlated with urinary cadmium concentrations among young children living in the New York state city of Syracuse, USA

Air pollution is a serious public health issue with early childhood exposure being of high concern because of the greater risk that children might experience negative health outcomes. Industrial sources in and near communities are one potential path of exposure that children might face with greater levels of air pollution correlating with higher levels of toxicants detected in children. We compare estimated ambient air concentrations of Cadmium (Cd) to a cohort (n = 281) of 9 to 11-year old children during their early childhood years (0-5 years of age) in a mid-size city in Upstate New York. Levels of Cd air pollution are compared to children's urine-Cd levels. Urine has been shown to be a superior biomarker to blood for Cd exposure particularly for longer-term exposures. We find that participants who reside in households that faced greater Cd air pollution during the child's early years have higher urine-Cd levels. This association is stable and stronger than previously presented associations for blood-Cd. Findings support expanded use of air modelling data for risk screening to reduce the potential health burden that industrial pollution can have.

Long-term ambient air pollution exposure and cardio-respiratory disease in China: findings from a prospective cohort study

BACKGROUND

Existing evidence on long-term ambient air pollution (AAP) exposure and risk of cardio-respiratory diseases in China is mainly on mortality, and based on area average concentrations from fixed-site monitors for individual exposures. Substantial uncertainty persists, therefore, about the shape and strength of the relationship when assessed using more personalised individual exposure data. We aimed to examine the relationships between AAP exposure and risk of cardio-respiratory diseases using predicted local levels of AAP.

METHODS

A prospective study included 50,407 participants aged 30-79 years from Suzhou, China, with concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), fine (PM2.5), and inhalable (PM10) particulate matter, ozone (O3) and carbon monoxide (CO) and incident cases of cardiovascular disease (CVD) (n = 2,563) and respiratory disease (n = 1,764) recorded during 2013-2015. Cox regression models with time-dependent covariates were used to estimate adjusted hazard ratios (HRs) for diseases associated with local-level concentrations of AAP exposure, estimated using Bayesian spatio-temporal modelling.

RESULTS

The study period of 2013-2015 included a total of 135,199 person-years of follow-up for CVD. There was a positive association of AAP, particularly SO2 and O3, with risk of major cardiovascular and respiratory diseases. Each 10 µg/m3 increase in SO2 was associated with adjusted hazard ratios (HRs) of 1.07 (95% CI: 1.02, 1.12) for CVD, 1.25 (1.08, 1.44) for COPD and 1.12 (1.02, 1.23) for pneumonia. Similarly, each 10 µg/m3 increase in O3 was associated with adjusted HR of 1.02 (1.01, 1.03) for CVD, 1.03 (1.02, 1.05) for all stroke, and 1.04 (1.02, 1.06) for pneumonia.

CONCLUSIONS

Among adults in urban China, long-term exposure to ambient air pollution is associated with a higher risk of cardio-respiratory disease.

A Review of the GSTM1 Null Genotype Modifies the Association between Air Pollutant Exposure and Health Problems

Air pollution is one of the significant environmental risks known as the cause of premature deaths. It has deleterious effects on human health, including deteriorating respiratory, cardiovascular, nervous, and endocrine functions. Exposure to air pollution stimulates reactive oxygen species (ROS) production in the body, which can further cause oxidative stress. Antioxidant enzymes, such as glutathione S-transferase mu 1 (GSTM1), are essential to prevent oxidative stress development by neutralizing excess oxidants. When the antioxidant enzyme function is lacking, ROS can accumulate and, thus, cause oxidative stress. Genetic variation studies from different countries show that GSTM1 null genotype dominates the GSTM1 genotype in the population. However, the impact of the GSTM1 null genotype in modifying the association between air pollution and health problem is not yet clear. This study will elaborate on GSTM1's null genotype role in modifying the relationship between air pollution and health problems.

Association of Long-term Exposure to Particulate Air Pollution With Cardiovascular Events in California

Importance

Long-term exposure to fine particulate air pollution (PM2.5) is a known risk factor for cardiovascular events, but controversy remains as to whether the current National Ambient Air Quality Standard (12 μg/m3 for 1-year mean PM2.5) is sufficiently protective.

Objective

To evaluate the associations between long-term fine particulate air pollution and cardiovascular events using electronic health record and geocoded address data.

Design, Setting, and Participants

This retrospective cohort study included adults in the Kaiser Permanente Northern California integrated health care system during 2007 to 2016 and followed for up to 10 years. Study participants had no prior stroke or acute myocardial infarction (AMI), and lived in Northern California for at least 1 year. Analyses were conducted January 2020 to December 2022.

Exposure

Long-term exposure to PM2.5. Individual-level time-varying 1-year mean PM2.5 exposures for every study participant were updated monthly from baseline through the end of follow-up, accounting for address changes.

Main Outcomes and Measures

Incident AMI, ischemic heart disease (IHD) mortality, and cardiovascular disease (CVD) mortality. Cox proportional hazards models were fit with age as time scale, adjusted for sex, race and ethnicity, socioeconomic status, smoking, body mass index, baseline comorbidities, and baseline medication use. Associations below the current regulation limit were also examined.

Results

The study cohort included 3.7 million adults (mean [SD] age: 41.1 [17.2] years; 1 992 058 [52.5%] female, 20 205 [0.5%] American Indian or Alaskan Native, 714 043 [18.8%] Asian, 287 980 [7.6%] Black, 696 796 [18.4%] Hispanic, 174 261 [4.6%] multiracial, 1 904 793 [50.2%] White). There was a 12% (95% CI, 7%-18%) increased risk of incident AMI, a 21% (95% CI, 13%-30%) increased risk of IHD mortality, and an 8% (95% CI, 3%-13%) increased risk of CVD mortality associated with a 10 μg/m3 increase in 1-year mean PM2.5. PM2.5 exposure at moderate concentrations (10.0 to 11.9 μg/m3) was associated with increased risks of incident AMI (6% [95% CI, 3%-10%]) and IHD mortality (7% [95% CI, 2%-12%]) compared with low concentrations (less than 8 μg/m3).

Conclusions and Relevance

In this study, long-term PM2.5 exposure at moderate concentrations was associated with increased risks of incident AMI, IHD mortality, and CVD mortality. This study's findings add to the evidence that the current regulatory standard is not sufficiently protective.

Cell-free circulating mitochondrial DNA: An emerging biomarker for airborne particulate matter associated with cardiovascular diseases

The association of airborne particulate matter exposure with the deteriorating function of the cardiovascular system is fundamentally driven by the impairment of mitochondrial-nuclear crosstalk orchestrated by aberrant redox signaling. The loss of delicate balance in retrograde communication from mitochondria to the nucleus often culminates in the methylation of the newly synthesized strand of mitochondrial DNA (mtDNA) through DNA methyl transferases. In highly metabolic active tissues such as the heart, mtDNA's methylation state alteration impacts mitochondrial bioenergetics. It affects transcriptional regulatory processes involved in biogenesis, fission, and fusion, often accompanied by the integrated stress response. Previous studies have demonstrated a paradoxical role of mtDNA methylation in cardiovascular pathologies linked to air pollution. A pronounced alteration in mtDNA methylation contributes to systemic inflammation, an etiological determinant for several co-morbidities, including vascular endothelial dysfunction and myocardial injury. In the current article, we evaluate the state of evidence and examine the considerable promise of using cell-free circulating methylated mtDNA as a predictive biomarker to reduce the more significant burden of ambient air pollution on cardiovascular diseases.

Association between air pollution exposure and coronary heart disease hospitalization in a humid sub-tropical region of China: A time-series study

Objective

Emerging evidence has highlighted the possible links of environmental pollution with several cardiovascular diseases (CVDs). The current study aimed to explore the impact of short-term air pollution exposure on CHD hospitalization in Hefei.

Methods

Data about the daily number of CHD admissions (from 2014 to 2021) were retrieved from the First Affiliated Hospital of Anhui Medical University. Air pollutants and meteorological data were obtained from the China Environmental Monitoring Station and the China Meteorological Data Service Center, respectively. The correlation between air pollution and CHD hospitalization was assessed using distributed lag non-linear model (DLNM) and Poisson generalized linear regression.

Results

In the single-pollutant model, NO₂, O₃, and CO strongly correlated with CHD hospitalization rate. Specifically, exposure to NO₂ (lag0, relative risk [RR]: 1.013, 95%CI: 1.002-1.024, per 10 μg/m³ increase) and CO (lag13, RR: 1.035, 95%CI: 1.001-1.071, per 1 μg/m³ increase) revealed a positive correlation with an increased rate of CHD hospitalization. Interestingly, O₃ had a protective association with hospitalization of CHD (lag0, RR: 0.993, 95%CI: 0.988-0.999, per 10 μg/m³ increase). Similar results, to those of the single-pollutant model, were revealed following verification using two-pollutant models. Subgroup analyses indicated that young people, women, and people in hot seasons were more susceptible to NO₂ exposure, while the elderly, women, and people in cold seasons were more susceptible to O₃. Furthermore, the elderly were more susceptible to CO exposure.

Conclusion

Overall, exposure to NO₂ and CO increases the rate of CHD hospitalization, but exposure to O₃ shows a protective association with the rate of CHD hospitalization. Therefore, early preventive measures against air pollutants should be applied to protect vulnerable patients with CHD.

Fine particulate matter and cardiorespiratory health in China: A systematic review and meta-analysis of epidemiological studies

This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_2.5 published during the 13^th Five-Year Plan period (2016-2020) in China. Original articles published between January 1, 2016 and June 30, 2021 were searched in PubMed, Web of Science, the China National Knowledge Internet Database and Wanfang Database. Random- or fixed-effects models were used to pool effect estimates where appropriate. Of 8558 records identified, 145 met the full eligibility criteria. A 10 µg/m³ increase in short-term PM_2.5 exposure was significantly associated with increases of 0.70%, 0.86%, 0.38% and 0.96% in cardiovascular mortality, respiratory mortality, cardiovascular morbidity, and respiratory morbidity, respectively. The specific diseases with significant associations included stroke, ischemic heart disease, heart failure, arrhythmia, chronic obstructive pulmonary disease, pneumonia and allergic rhinitis. The pooled estimates per 10 µg/m³ increase in long-term PM_2.5 exposure were 15.1%, 11.9% and 21.0% increases in cardiovascular, stroke and lung cancer mortality, and 17.4%, 11.0% and 4.88% increases in cardiovascular, hypertension and lung cancer incidence respectively. Adverse changes in blood pressure, heart rate variability, systemic inflammation, blood lipids, lung function and airway inflammation were observed for either short-term or long-term PM_2.5 exposure, or both. Collectively, we summarized representative exposure-response relationships between short- and long-term PM_2.5 exposure and a wide range of cardiorespiratory outcomes applicable to China. The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries. Our findings are helpful for future standard revisions and policy formulation. There are still some notable gaps that merit further investigation in China.

Long-term exposure to traffic-related air pollution and stroke: A systematic review and meta-analysis

BACKGROUND

Stroke remains the second cause of death worldwide. The mechanisms underlying the adverse association of exposure to traffic-related air pollution (TRAP) with overall cardiovascular disease may also apply to stroke. Our objective was to systematically evaluate the epidemiological evidence regarding the associations of long-term exposure to TRAP with stroke.

METHODS

PubMed and LUDOK electronic databases were searched systematically for observational epidemiological studies from 1980 through 2019 on long-term exposure to TRAP and stroke with an update in January 2022. TRAP was defined according to a comprehensive protocol based on pollutant and exposure assessment methods or proximity metrics. Study selection, data extraction, risk of bias (RoB) and confidence assessments were conducted according to standardized protocols. We performed meta-analyses using random effects models; sensitivity analyses were assessed by geographic area, RoB, fatality, traffic specificity and new studies.

RESULTS

Nineteen studies were included. The meta-analytic relative risks (and 95% confidence intervals) were: 1.03 (0.98-1.09) per 1 μg/m³ EC, 1.09 (0.96-1.23) per 10 μg/m³ PM₁₀, 1.08 (0.89-1.32) per 5 μg/m³ PM_2.5, 0.98 (0.92; 1.05) per 10 μg/m³ NO₂ and 0.99 (0.94; 1.04) per 20 μg/m³ NO_x with little to moderate heterogeneity based on 6, 5, 4, 7 and 8 studies, respectively. The confidence assessments regarding the quality of the body of evidence and separately regarding the presence of an association of TRAP with stroke considering all available evidence were rated low and moderate, respectively.

CONCLUSION

The available literature provides low to moderate evidence for an association of TRAP with stroke.

Particulate matter 2.5, metropolitan status, and heart failure outcomes in US counties: A nationwide ecologic analysis

The relationship between particulate matter with a diameter of 2.5 micrometers or less (PM2.5) and heart failure (HF) hospitalizations and mortality in the US is unclear. Prior studies are limited to studying the effects of daily PM2.5 exposure on HF hospitalizations in specific geographic regions. Because PM2.5 can vary by geography, this study examines the effects of annual ambient PM2.5 exposure on HF hospitalizations and mortality at a county-level across the US. A cross-sectional analysis of county-level ambient PM2.5 concentration, HF hospitalizations, and HF mortality across 3135 US counties nationwide was performed, adjusting for county-level demographics, socioeconomic factors, comorbidities, and healthcare-associated behaviors. There was a moderate correlation between county PM2.5 and HF hospitalization among Medicare beneficiaries (r = 0.41) and a weak correlation between county PM2.5 and HF mortality (r = 0.08) (p-values < 0.01). After adjustment for various county level covariates, every 1 ug/m3 increase in annual PM2.5 concentration was associated with an increase of 0.51 HF Hospitalizations/1,000 Medicare Beneficiaries and 0.74 HF deaths/100,000 residents (p-values < 0.05). In addition, the relationship between PM2.5 and HF hospitalizations was similar when factoring in metropolitan status of the counties. In conclusion, increased ambient PM2.5 concentration level was associated with increased incidence of HF hospitalizations and mortality at the county level across the US. This calls for future studies exploring policies that reduce ambient particulate matter pollution and their downstream effects on potentially improving HF outcomes.

Annual exposure to PM10 is related to cerebral small vessel disease in general adult population

Ambient air pollution is one of the most important global health issues. Although several studies have been reported the associations between air pollution and brain function or structure, impact of the air pollution on cerebral small vessel disease (cSVD) have rarely been explored in Asian adult population. We evaluated the association between exposure to air pollutants and cSVD in Korean asymptomatic adults. This cross-sectional study included 3257 participants of a health screening program from January 2006 to December 2013. All participants performed brain magnetic resonance imaging. To assess the cSVD, we considered three features such as white matter hyperintensities (WMH), silent lacunar infarction (SLI), and cerebral microbleeds (CMBs). The annual average exposure to air pollutants [particulate matter ≤ 10 μm in aerodynamic diameter (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO)] was generated. The mean [standard deviation (SD)] age of the total 3257 participants was 56.5 (9.5) years, and 54.0% of them were male. Among all the included participants, 273 (8.4%) had SLI and 135 (4.1%) had CMBs. The mean volume (± SD) of WMH was 2.72 ± 6.57 mL. In result of linear regression analysis, the volume of WMH was associated with various potential factors including age, height, weight, smoking and alcohol consumption status, blood pressure (BP), hypertension, and diabetes mellitus. SLI-positive group, compared to the SLI-negative group, was older, shorter, and had higher BP as well as higher frequency of hypertension and diabetes mellitus. After adjusting for covariates, the annual average concentration of PM₁₀ was significantly associated with the volume of WMH [β (95% CI) for Model 1 = 0.082 (0.038- 0.125), p < 0.001; β (95% CI) for Model 2 = 0.060 (0.013, 0.107), p = 0.013]. CMBs were not associated with the annual average concentration of PM₁₀. No significant associations of NO₂, SO₂, and CO with cSVD were observed. In conclusion, PM₁₀ exposure is associated with significant increases in brain WMH' volume and silent lacunar infarcts in asymptomatic adults.

Primary Prevention of Ischemic Stroke

Ischemic stroke is by far the most common type of cerebrovascular event and remains a major cause of death and disability globally. Despite advancements in acute stroke care, primary prevention is still the most cost-effective approach in reducing the burden of ischemic stroke. The two main strategies for primary stroke prevention include population-wide versus high-risk group interventions. Interventions such as increasing access to primary care, regulation of salt and sugar contents in processed foods, public education, and campaigns to control cerebrovascular risk factors are examples of population-wide interventions. High-risk group interventions, on the other hand, focus on recognition of individuals at risk and aim to modify risk factors in a timely and multifaceted manner. This article provides an overview on conventional modifiable risk factors for ischemic stroke and highlights the emerging risk factors and approaches for high-risk group identification and treatment.

Association between Long-Term Air Pollution, Chronic Traffic Noise, and Resting-State Functional Connectivity in the 1000BRAINS Study

BACKGROUND

Older adults show a high variability in cognitive performance that cannot be explained by aging alone. Although research has linked air pollution and noise to cognitive impairment and structural brain alterations, the potential impact of air pollution and noise on functional brain organization is unknown.

OBJECTIVE

This study examined the associations between long-term air pollution and traffic noise with measures of functional brain organization in older adults. We hypothesize that exposures to high air pollution and noise levels are associated with age-like changes in functional brain organization, shown by less segregated brain networks.

METHODS

Data from 574 participants (44.1% female, 56-85 years of age) in the German 1000BRAINS study (2011-2015) were analyzed. Exposure to particulate matter (PM10, PM2.5, and PM2.5 absorbance), accumulation mode particle number (PNAM), and nitrogen dioxide (NO2) was estimated applying land-use regression and chemistry transport models. Noise exposures were assessed as weighted 24-h (Lden) and nighttime (Lnight) means. Functional brain organization of seven established brain networks (visual, sensorimotor, dorsal and ventral attention, limbic, frontoparietal and default network) was assessed using resting-state functional brain imaging data. To assess functional brain organization, we determined the degree of segregation between networks by comparing the strength of functional connections within and between networks. We estimated associations between air pollution and noise exposure with network segregation, applying multiple linear regression models adjusted for age, sex, socioeconomic status, and lifestyle variables.

RESULTS

Overall, small associations of high exposures with lesser segregated networks were visible. For the sensorimotor networks, we observed small associations between high air pollution and noise and lower network segregation, which had a similar effect size as a 1-y increase in age [e.g., in sensorimotor network, -0.006 (95% CI: -0.021, 0.009) per 0.3 ×10-5/m increase in PM2.5 absorbance and -0.004 (95% CI: -0.006, -0.002) per 1-y age increase].

CONCLUSION

High exposure to air pollution and noise was associated with less segregated functional brain networks. https://doi.org/10.1289/EHP9737.

Air pollution and cardiovascular disease: the Paul Wood Lecture, British Cardiovascular Society 2021

Air pollution is associated with up to 8.8 million excess deaths worldwide each year and is a major contributor to the global burden of disease. Cardiovascular conditions are the predominant cause for air pollution-related deaths and there is an urgent need to address the silent pandemic of air pollution on cardiovascular health. Air pollution exposure is associated with acute events like acute coronary syndrome and stroke, and with chronic conditions, such as atherosclerosis and heart failure. Several potential mechanisms have been proposed that link particle inhalation to cardiovascular disease including oxidative stress and inflammation, changes in autonomic balance and neuroendocrine regulation and the particle translocation into the circulation itself. This, in turn, can cause endothelial, vasomotor and fibrinolytic dysfunction and increased thrombogenicity and blood pressure which are implicated in the mediation of adverse cardiovascular events. Certain interventions can help mitigate these adverse effects. At an individual level, this includes the use of a facemask and indoor air purification systems. At an environmental level, interventions reducing the generation or release of combustion-derived pollutants are key and include public health policies to facilitate active transport, cleaner sources of energy and reductions in vehicular and fossil fuel emissions. In this review, we summarise the key pathways and mechanisms that draw together how air pollution can lead to adverse cardiovascular effects, as well as explore potential interventions to reduce the burden of air pollution-induced cardiovascular morbidity and mortality.

Recent Insights into Particulate Matter (PM2.5)-Mediated Toxicity in Humans: An Overview

Several epidemiologic and toxicological studies have commonly viewed ambient fine particulate matter (PM_2.5), defined as particles having an aerodynamic diameter of less than 2.5 µm, as a significant potential danger to human health. PM_2.5 is mostly absorbed through the respiratory system, where it can infiltrate the lung alveoli and reach the bloodstream. In the respiratory system, reactive oxygen or nitrogen species (ROS, RNS) and oxidative stress stimulate the generation of mediators of pulmonary inflammation and begin or promote numerous illnesses. According to the most recent data, fine particulate matter, or PM_2.5, is responsible for nearly 4 million deaths globally from cardiopulmonary illnesses such as heart disease, respiratory infections, chronic lung disease, cancers, preterm births, and other illnesses. There has been increased worry in recent years about the negative impacts of this worldwide danger. The causal associations between PM_2.5 and human health, the toxic effects and potential mechanisms of PM_2.5, and molecular pathways have been described in this review.

Environmental inequality: Air pollution and asthma in children

INTRODUCTION

Whether you benefit from high-quality urban environments, such as those rich in green and blue spaces, that may offer benefits to allergic and respiratory health depends on where you live and work. Environmental inequality, therefore, results from the unequal distribution of the risks and benefits that stem from interactions with our environment.

METHODS

Within this perspective, this article reviews the evidence for an association between air pollution caused by industrial activities, traffic, disinfection-by-products, and tobacco/e-cigarettes, and asthma in children. We also discuss the proposed mechanisms by which air pollution increases asthma risk, including environmental epigenetic regulations, oxidative stress, and damage, disrupted barrier integrity, inflammatory pathways, and enhancement of respiratory sensitization to aeroallergens.

RESULTS AND CONCLUSIONS

Environmental air pollution is a major determinant of childhood asthma, but the magnitude of effect is not shared equally across the population, regions, and settings where people live, work, and spend their time. Improvement of the exposure assessment, a better understanding of critical exposure time windows, underlying mechanisms, and drivers of heterogeneity may improve the risk estimates. Urban conditions and air quality are not only important features for national and local authorities to shape healthy cities and protect their citizens from environmental and health risks, but they also provide opportunities to mitigate inequalities in the most deprived areas where the environmental burden is highest. Actions to avoid exposure to indoor and outdoor air pollutants should be complementary at different levels-individual, local, and national levels-to take effective measures to protect children who have little or no control over the air they breathe.

The long-term effect of exposure to respirable particulate matter on the incidence of myocardial infarction: a systematic review and meta-analysis study

Although several studies have investigated the long-term association of respirable particulate matter (PM ≤ 10 µm) with the incidence of myocardial infarction (MI), this association is inconclusive or even contradictory. This systematic review and meta-analysis study aimed to quantify the long-term effect of exposure to respirable PM on the incidence of MI. To find relevant publications, online databases, including Scopus, PubMed, and Web of Science, were searched on October 10, 2021. A random-effect model was used to calculate the pooled hazard ratio (HR) and 95% confidence interval (95% CI) of MI across studies. Heterogeneity was presented with reporting I² index. Of 4591 records found in the primary searching, the number of 24 prospective cohort studies with more than 70 million participants was included. The pooled HR (95% CI) of MI per 1 µg/m³ increment of respirable PM was estimated as 1.01 (1.00, 1.01). Subgroup analyses according to aerodynamic diameter of PM showed an only significant stronger risk of MI per 1 µg/m³ increase in PM with aerodynamic diameter < 2.5 µm (HR = 1.01, 95% CI = 1.00, 1.01). No sex difference was found in the association of respirable PM with MI incidence. There was only a significant association among studies defined MI as ICD-10: I21 code (HR = 1.01, 95% CI = 1.00, 1.01) and studies defined MI as ICD-10: I21-22 (HR = 1.02, 95% CI = 1.00, 1.04). No significant publication bias was observed across studies. In conclusion, this study confirms a significant association between long-term exposure to respirable PM air pollution and development of MI.

Exposure to Elevated Nitrogen Dioxide Concentrations and Cardiac Remodeling in Patients With Dilated Cardiomyopathy

BACKGROUND

Empirical evidence suggests a strong link between exposure to air pollution and heart failure incidence, hospitalizations, and mortality, but the biological basis of this remains unclear. We sought to determine the relationship between differential air pollution levels and changes in cardiac structure and function in patients with dilated cardiomyopathy.

METHODS AND RESULTS

We undertook a prospective longitudinal observational cohort study of patients in England with dilated cardiomyopathy (enrollment 2009-2015, n = 716, 66% male, 85% Caucasian) and conducted cross sectional analysis at the time of study enrollment. Annual average air pollution exposure estimates for nitrogen dioxide (NO2) and particulate matter with diameter of 2.5 µm or less (PM2.5) at enrolment were assigned to each residential postcode (on average 12 households). The relationship between air pollution and cardiac morphology was assessed using linear regression modelling. Greater ambient exposure to NO2 was associated with higher indexed left ventricular (LV) mass (4.3 g/m2 increase per interquartile range increase in NO2, 95% confidence interval 1.9-7.0 g/m2) and lower LV ejection fraction (-1.5% decrease per interquartile range increase in NO2, 95% confidence interval -2.7% to -0.2%), independent of age, sex, socioeconomic status, and clinical covariates. The associations were robust to adjustment for smoking status and geographical clustering by postcode area. The effect of air pollution on LV mass was greatest in women. These effects were specific to NO2 exposure.

CONCLUSIONS

Exposure to air pollution is associated with raised LV mass and lower LV ejection fraction, with the strongest effect in women. Although epidemiological associations between air pollution and heart failure have been established and supported by preclinical studies, our findings provide novel empirical evidence of cardiac remodeling and exposure to air pollution with important clinical and public health implications.

Incident cardiovascular disease and long-term exposure to source-specific air pollutants in a Swedish cohort

BACKGROUND

Air pollution is associated with cardiovascular morbidity and mortality, but its role in the development of congestive heart failure (CHF) and the role of different pollution sources in cardiovascular disease remain uncertain.

METHODS

Participants were enrolled in the Malmö Diet and Cancer cohort in 1991-1996 with information on lifestyle and clinical indicators of cardiovascular disease. The cohort participants were followed through registers until 2016. Annual total and local source-specific concentrations of particulate matter less than 10 μm and 2.5 μm (PM₁₀ and PM_2.5), black carbon (BC), and nitrogen oxides (NO_x) from traffic, residential heating, and industry were assigned to each participant's address throughout the study period. Cox proportional hazards models adjusted for possible confounders was used to estimate associations between air pollution 1-5 years prior to outcomes of incident CHF, fatal myocardial infarction (MI), major adverse coronary events (MACE), and ischemic stroke.

RESULTS

Air pollution exposure levels (mean annual exposures to PM_2.5 of 11 μg/m³ and NO_x of 26 μg/m³) within the cohort were moderate in terms of environmental standards. After adjusting for confounders, we observed statistically significant associations between NO_x and CHF (hazard ratio [HR] 1.11, 95% confidence interval [CI] 1.01-1.22) and NO_x and fatal MI (HR 1.10, 95%CI 1.01-1.20) per interquartile range (IQR) of 9.6 μg/m³. In fully adjusted models, the estimates were similar, but the precision worse. In stratified analyses, the associations were stronger in males, ever-smokers, older participants, and those with baseline carotid artery plaques. Locally emitted and traffic-related air pollutants generally showed positive associations with CHF and fatal MI. There were no associations between air pollution and MACE or stroke.

DISCUSSION/CONCLUSION

In an area with low to moderate air pollution exposure, we observed significant associations of long-term residential NO_x with increased risk of incident CHF and fatal MI, but not with coronary events and stroke.

Short-Term Effects of Low-Level Ambient Air NO2 on the Risk of Incident Stroke in Enshi City, China

Previous studies found that exposure to ambient nitrogen dioxide (NO₂) was associated with an increased risk of incident stroke, but few studies have been conducted for relatively low NO₂ pollution areas. In this study, the short-term effects of NO₂ on the risk of incident stroke in a relatively low-pollution area, Enshi city of Hubei Province, China, were investigated through time-series analysis. Daily air-pollution data, meteorological data, and stroke incidence data of residents in Enshi city from 1 January 2015 to 31 December 2018 were collected. A time-series analysis using a generalised additive model (GAM) based on Poisson distribution was applied to explore the short-term effects of low-level NO₂ exposure on the risk of incident stroke and stroke subtypes, as well as possible age, sex, and seasonal differences behind the effects. In the GAM model, potential confounding factors, such as public holidays, day of the week, long-term trends, and meteorological factors (temperature and relative humidity), were controlled. A total of 9122 stroke incident cases were included during the study period. We found that NO₂ had statistically significant effects on the incidence of stroke and ischemic stroke, estimated by excess risk (ER) of 0.37% (95% CI: 0.04–0.70%) and 0.58% (95% CI: 0.18–0.98%), respectively. For the cumulative lag effects, the NO₂ still had a statistically significant effect on incident ischemic stroke, estimated by ER of 0.61% (95% CI: 0.01–1.21%). The two-pollutant model showed that the effects of NO₂ on incident total stroke were still statistically significant after adjusting for other air pollutants (PM_2.5, PM₁₀, SO₂, CO, and O₃). In addition, the effects of NO₂ exposure on incident stroke were statistically significant in elderly (ER = 0.75%; 95% CI: 0.11–1.40%), males (ER = 0.47%; 95% CI: 0.05–0.89%) and cold season (ER = 0.83%; 95% CI: 0.15–1.51%) subgroups. Our study showed that, as commonly observed in high-pollution areas, short-term exposure to low-level NO₂ was associated with an increased risk of incident stroke, including ischemic stroke. Males and elderly people were more vulnerable to the effects of NO₂, and the adverse effects might be promoted in the cold season.

Exposure to Air Pollutants Increases the Risk of Chronic Rhinosinusitis in Taiwan Residents

Air pollution triggers a tissue-specific inflammatory response. However, studies on the association between exposure to air pollutants and chronic rhinosinusitis (CRS) risk remain limited. Thus, we conducted this nationwide study to define the association between air pollution and CRS. We used the Longitudinal Health Insurance Database (LHID) and Taiwan Air Quality-Monitoring Database (TAQMD) to conduct a population-based cohort study. Study participants were recruited from the LHID, a data subset of the National Health Insurance Research Database that randomly sampled one million individuals. TAQMD has been an air pollutant database since 1998. In univariate and multivariate Cox proportional hazards regression models, adjusted hazard ratios (aHRs) and 95% CIs of CRS in five air pollutants were accounted. We adjusted for age, sex, urbanization level, insurance fee, comorbidities, and pollutant levels in the multivariate model. The total number of participants enrolled in this study was 160,504. The average age was 40.46 ± 14.62 years; males constituted 43.8% of the total participants. The percentages of alcoholism, tobacco dependence, and COPD were 1.5%, 2.8%, and 28.3%, respectively. After adjustment for age, sex, urbanization level, insurance fee, and comorbidities, the highest levels of air pollutants, including PM_2.5 (aHR = 1.14, 95% CI = 1.06–1.22), NO₂ (aHR = 1.07, 95% CI = 1.00–1.15), and PM₁₀ (aHR = 1.13, 95% CI = 1.05–1.21) had a significantly greater CRS risk; we selected the lower concentration as the reference but did not correlate with CO. We found a significantly increased risk of CRS in residents with air pollutant exposure.

Joint associations between neighborhood walkability, greenness, and particulate air pollution on cardiovascular mortality among adults with a history of stroke or acute myocardial infarction

Fine particulate matter (PM_2.5) is a known risk factor for cardiovascular disease (CVD). Neighborhood walkability and greenness may also be associated with CVD, but there is limited evidence on their joint or interacting effects with PM_2.5.

Ambient air pollution and the risk of acute myocardial infarction and stroke: A national cohort study

We used a large national cohort in Canada to assess the incidence of acute myocardial infarction (AMI) and stroke hospitalizations in association with long-term exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃). The study population comprised 2.7 million respondents from the 2006 Canadian Census Health and Environment Cohort (CanCHEC), followed for incident hospitalizations of AMI or stroke between 2006 and 2016. We estimated 10-year moving average estimates of PM_2.5, NO₂, and O₃, annually. We used Cox proportional hazards models to examine the associations adjusting for various covariates. For AMI, each interquartile range (IQR) increase in exposure was found to be associated with a hazard ratio of 1.026 (95% CI: 1.007-1.046) for PM_2.5, 1.025 (95% CI: 1.001-1.050) for NO₂, and 1.062 (95% CI: 1.041-1.084) for O₃, respectively. Similarly, for stroke, an IQR increase in exposure was associated with a hazard ratio of 1.078 (95% CI: 1.052-1.105) for PM_2.5, 0.995 (95% CI: 0.965-1.030) for NO₂, and 1.055 (95% CI: 1.028-1.082) for O₃, respectively. We found consistent evidence of positive associations between long-term exposures to PM_2.5, and O₃, and to a lesser degree NO₂, with incident AMI and stroke hospitalizations.

Air pollution and surrounding greenness in relation to ischemic stroke: A population-based cohort study

BACKGROUND

Evidence for the association between environmental exposures and ischemic stroke (IS) is limited and inconsistent. We aimed to assess the relationship between exposure to air pollutants, residential surrounding greenness, and incident IS, and to identify population subgroups particularly sensitive to these exposures.

METHODS

We used data from administrative health registries of the public healthcare system in Catalonia, Spain to construct a cohort of individuals aged 18 years and older without a previous stroke diagnosis at 1st January 2016 (n = 3 521 274). We collected data on sociodemographic characteristics and cerebrovascular risk factors, and derived exposure at the participant's residence to ambient levels of fine particulate matter (PM_2.5), black carbon (BC), nitrogen dioxide (NO₂), and Normalized Difference Vegetation Index (NDVI) in a 300 m buffer as an indicator of greenness. The primary outcome was IS diagnosis at any point during the follow-up. We used Cox proportional hazards models to estimate associations between environmental exposures and incident IS and stratified analyses to investigate effect modification.

RESULTS

Between 1st January 2016 and 31st December 2017, 10 865 individuals were admitted to public hospitals with an IS diagnosis. Median exposure levels were: 17 µg/m³ PM_2.5, 35 µg/m³ NO₂, 2.28 µg/m³ BC and 0.27 NDVI. Individuals with higher residential exposure to air pollution were at greater risk of IS: HR 1·04 (95% CI:0·99-1·10) per 5 µg/m³ of PM_2.5; HR 1.05 (95% CI:1·00-1·10) per 1 µg/m³ of BC; HR 1·04 (95% CI:1·03-1·06) per 10 µg/m³ of NO₂. Conversely, individuals with higher residential surrounding green space, had lower risk of IS (HR 0·84; CI 95%:0·7-1.0). There was no evidence of effect modification by individual characteristics.

CONCLUSIONS

Higher incidence of IS was observed in relation to long-term exposures to air pollution, particularly NO₂, in a region that meets European health-based air quality standards. Residential surrounding greenness was associated with lower incidence of IS.

Higher ambient nitrogen dioxide is associated with an elevated risk of hospital-acquired acute kidney injury

BACKGROUND

Previous studies have suggested that long-term exposure to air pollution increases the risk of chronic kidney disease and its progression. However, the effect of air pollution on the risk of acute kidney injury (AKI) has not been studied. We aim to evaluate the transient effect of air pollution on the risk of hospital-acquired AKI (HA-AKI).

METHODS

We selected from the Epidemiology of AKI in Chinese Hospitalized patients cohort AKI cases in which the onset date could be unambiguously determined. We obtained city-specific daily averages of the ambient level of particulate matter (2.5 μm and 10 μm), carbon monoxide, nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and ozone (O₃) from the Ministry of Environmental Protection of China. We used the time-stratified case-crossover approach to examine the association between the ambient level of air pollutants and the risk of HA-AKI in the selected cases.

RESULTS

A total of 11 293 AKI cases that met the inclusion and exclusion criteria were selected. In univariable analysis, the ambient levels of NO₂ and SO₂ were significantly associated with the risk of HA-AKI. In the multivariable analysis that incorporated all six pollutants in the same model, NO₂ was the sole pollutant whose level remained associated with the risk of AKI (P < 0.001). The relationship between the level of NO₂ and the risk of HA-AKI appeared to be linear, with an estimated odds ratio of 1.063 (95% confidence interval 1.026-1.101) for each increment of 1 median absolute deviation in the exposure. The association was consistent across the subgroups stratified by age, gender, baseline estimated glomerular filtration rate, AKI severity, need for intensive care and season.

CONCLUSIONS

Higher ambient levels of NO₂ are associated with an increased risk of HA-AKI in hospitalized adults in China.

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.

Particulate Matter-Induced Acute Coronary Syndrome: MicroRNAs as Microregulators for Inflammatory Factors

The most prevalent cause of mortality and morbidity worldwide is acute coronary syndrome (ACS) and its consequences. Exposure to particulate matter (PM) from air pollution has been shown to impair both. Various plausible pathogenic mechanisms have been identified, including microRNAs (miRNAs), an epigenetic regulator for gene expression. Endogenous miRNAs, average 22-nucleotide RNAs (ribonucleic acid), regulate gene expression through mRNA cleavage or translation repression and can influence proinflammatory gene expression posttranscriptionally. However, little is known about miRNA responses to fine PM (PM_2.5, PM₁₀, ultrafine particles, black carbon, and polycyclic aromatic hydrocarbon) from air pollution and their potential contribution to cardiovascular consequences, including systemic inflammation regulation. For the past decades, microRNAs (miRNAs) have emerged as novel, prospective diagnostic and prognostic biomarkers in various illnesses, including ACS. We wanted to outline some of the most important studies in the field and address the possible utility of miRNAs in regulating particulate matter-induced ACS (PMIA) on inflammatory factors in this review.

Air pollution and cardiovascular disease hospitalization - Are associations modified by greenness, temperature and humidity?

BACKGROUND

Studies have observed associations between long-term air pollution and cardiovascular disease hospitalization. Little is known, however, about effect modification of these associations by greenness, temperature and humidity.

METHODS

We constructed an open cohort consisting of all fee-for-service Medicare beneficiaries, aged ≥ 65, living in the contiguous US from 2000 through 2016 (~63 million individuals). We assigned annual average PM2.5, NO2 and ozone zip code concentrations. Cox-equivalent Poisson models were used to estimate associations with first cardiovascular disease (CVD), coronary heart disease (CHD) and cerebrovascular disease (CBV) hospitalization.

RESULTS

PM2.5 and NO2 were both positively associated with CVD, CHD and CBV hospitalization, after adjustment for potential confounders. Associations were substantially stronger at the lower end of the exposure distributions. For CVD hospitalization, the hazard ratio (HR) of PM2.5 was 1.041 (1.038, 1.045) per IQR increase (4.0 µg/m3) in the full study population and 1.327 (1.305, 1.350) per IQR increase for a subgroup with annual exposures always below 10 µg/m3 PM2.5. Ozone was only positively associated with CVD, CHD and CBV hospitalization for the low-exposure subgroup (<40 ppb). Associations of PM2.5 were stronger in areas with higher greenness, lower ozone and Ox, lower summer and winter temperature and lower summer and winter specific humidity.

CONCLUSION

PM2.5 and NO2 were positively associated with CVD, CHD and CBV hospitalization. Associations were more pronounced at low exposure levels. Associations of PM2.5 were stronger with higher greenness, lower ozone and Ox, lower temperature and lower specific humidity.

Long-Term Exposure to Air Pollution, Road Traffic Noise, and Heart Failure Incidence: The Danish Nurse Cohort

Background We examined the association of long-term exposure to air pollution and road traffic noise with incident heart failure (HF). Methods And Results Using data on female nurses from the Danish Nurse Cohort (aged >44 years), we investigated associations between 3-year mean exposures to air pollution and road traffic noise and incident HF using Cox regression models, adjusting for relevant confounders. Incidence of HF was defined as the first hospital contact (inpatient, outpatient, or emergency) between cohort baseline (1993 or 1999) and December 31, 2014, based on the Danish National Patient Register. Annual mean levels of particulate matter with a diameter <2.5 µm since 1990 and NO2 and road traffic noise since 1970 were estimated at participants' residences. Of the 22 189 nurses, 484 developed HF. We detected associations with all 3 pollutants, with hazard ratios (HRs) of 1.17 (95% CI, 1.01-1.36), 1.10 (95% CI, 0.99-1.22), and 1.12 (95% CI, 0.99-1.26) per increase of 5.1 µg/m3 in particulate matter with a diameter <2.5 µm, 8.6 µg/m3 in NO2, and 9.3 dB in road traffic noise, respectively. We observed an enhanced risk of HF incidence for those exposed to high levels of the 3 pollutants; however, the effect modification of coexposure was not statistically significant. Former smokers and nurses with hypertension showed the strongest associations with particulate matter with a diameter <2.5 µm (Peffect modification<0.05). Conclusions We found that long-term exposures to air pollution and road traffic noise were independently associated with HF.

Environmental risk factors and cardiovascular diseases: a comprehensive review

Noncommunicable diseases (NCDs) are fatal for more than 38 million people each year and are thus the main contributors to the global burden of disease accounting for 70% of mortality. The majority of these deaths are caused by cardiovascular disease. The risk of NCDs is strongly associated with exposure to environmental stressors such as pollutants in the air, noise exposure, artificial light at night and climate change, including heat extremes, desert storms and wildfires. In addition to the traditional risk factors for cardiovascular disease such as diabetes, arterial hypertension, smoking, hypercholesterolemia and genetic predisposition, there is a growing body of evidence showing that physicochemical factors in the environment contribute significantly to the high NCD numbers. Furthermore, urbanization is associated with accumulation and intensification of these stressors. This comprehensive expert review will summarize the epidemiology and pathophysiology of environmental stressors with a focus on cardiovascular NCDs. We will also discuss solutions and mitigation measures to lower the impact of environmental risk factors with focus on cardiovascular disease.