Noise and Air Pollution as Risk Factors for Hypertension: Part II-Pathophysiologic Insight

2024 Latin American Society of Hypertension guidelines on the management of arterial hypertension and related comorbidities in Latin America

Hypertension is responsible for more than two million deaths due to cardiovascular disease annually in Latin America (LATAM), of which one million occurs before 70 years of age. Hypertension is the main risk factor for cardiovascular morbidity and mortality, affecting between 20 and 40% of LATAM adults. Since the publication of the 2017 LASH hypertension guidelines, reports from different LATAM countries have confirmed the burden of hypertension on cardiovascular disease events and mortality in the region. Many studies in the region have reported and emphasized the dramatically insufficient blood pressure control. The extremely low rates of awareness, treatment, and control of hypertension, particularly in patients with metabolic disorders, is a recognized severe problem in LATAM. Earlier implementation of antihypertensive interventions and management of all cardiovascular risk factors is the recognized best strategy to improve the natural history of cardiovascular disease in LATAM. The 2024 LASH guidelines have been developed by a large group of experts from internal medicine, cardiology, nephrology, endocrinology, general medicine, geriatrics, pharmacology, and epidemiology of different countries of LATAM and Europe. A careful search for novel studies on hypertension and related diseases in LATAM, together with the new evidence that emerged since the 2017 LASH guidelines, support all statements and recommendations. This update aims to provide clear, concise, accessible, and useful recommendations for health professionals to improve awareness, treatment, and control of hypertension and associated cardiovascular risk factors in the region.

Childhood exposure to air pollution, noise, and surrounding greenness and incident hypertension in early adulthood in a US nationwide cohort-the Growing Up Today Study (GUTS)

Exposure to increased air pollution, noise, and reduced surrounding greenness have been suggested as potential environmental risk factors for hypertension in adults, but limited evidence exists regarding early-life exposure, particularly from prospective studies. We investigated independent and joint associations of childhood exposure to these factors with incident hypertension in early adulthood in a US nationwide cohort. Study participants were from the Growing Up Today Study (GUTS) established in 1996 (GUTSI) and 2004 (GUTSII), who were ages 9-14 (GUTSI) or 10-17 (GUTSII) at enrollment. Incident hypertension was identified by self-report on questionnaires from 2010 to 2021. We estimated residential exposures to air pollution (from spatiotemporal models), noise, and surrounding greenness throughout childhood (10-18y). We applied Cox proportional hazards models adjusted for potential confounders to assess hazard ratios (HRs) and 95% confidence intervals (CIs) associated with each interquartile range (IQR) change in exposure. We performed a quantile g-computation to assess the joint association of simultaneous exposure to the mixture. We considered potential effect modification by sex, maternal history of hypertension, overweight/obese status at age 18, urbanicity, and neighborhood socioeconomic status. Among 17,762 participants, 1530 hypertensive cases occurred during an average follow-up of 12.8 years. HRs for all exposures were small with CIs including unity. A joint HR of 1.03 (95% CI: 0.95, 1.11) was associated with a one-quartile increase across simultaneous exposure to the environmental mixture. The joint associations were stronger among non-obese participants or participants living in less advantaged neighborhoods: HRs of 1.07 (95% CI: 0.97, 1.18) and 1.08 (95% CI: 0.98, 1.18), respectively. In conclusion, we did not identify an independent or joint association between childhood exposure to air pollution, noise, and surrounding greenness and early adulthood hypertension. However, a positive joint association was suggested among non-obese participants or those living in less advantaged neighborhoods.

The effects of air and transportation noise pollution-related altered blood gene expression, DNA methylation, and protein abundance levels on gastrointestinal diseases risk

INTRODUCTION

Air pollution and transportation noise pollution has been linked to gastrointestinal (GI) diseases, but their relationship remains unclear.

METHODS

We extracted the significantly modulated genes and CpG sites related to air pollution (PM2.5, PM10, and NOx) and transportation noise pollution (aircraft, railway, and traffic road noise) from previous published studies. Genome-wide methylation analysis and colocalization analysis with these CpG sites and GWAS data of GI diseases were performed to disentangle the relationship between pollution-related blood DNA methylation (DNAm) alterations and GI diseases risk. Summary-based Mendelian randomization (SMR) analysis assessed the impact of pollution-related genes on GI diseases risk across methylation, gene expression, and protein levels. Enrichment analysis investigated the implicated biological pathways and immune cell types.

RESULTS

DNAm at cg00227781 [CD300A] (modulated by NOx exposure) and cg19215199 [ZMIZ1] (modulated by PM2.5 exposure) was significantly linked to increased noninfective enteritis and colitis risk, while cg08500171 [BAT2] (modulated by NOx exposure) is significantly associated with an increased gastroesophageal reflux disease (GERD) risk. Colocalization analysis provides strong evidence supporting a shared causal variant between these associations. Multi-omics levels SMR analysis revealed that pollution-modulated lower DNAm at 5 specific CpG sites were associated with increased expression of 4 genes (IL21R, EVPL, SYNGR1, and WDR46), subsequently increasing the risk of GERD, ulcerative colitis, and gastric ulcer. 7 circulating proteins coded by pollution-modulated genes were observed to be associated with 6 GI diseases risk. Enrichment analysis implicates immune and inflammatory responses, MAPK signaling, and telomere maintenance in these pollution-induced effects.

CONCLUSION

We identified potential links between air and transportation noise pollution-related gene methylation, expression, and protein abundance with GI diseases risk, possibly revealing new therapeutic targets.

[Arterial hypertension-Current recommendations for action]

Arterial hypertension (aHT) currently affects nearly 1 in every 3 persons in Germany and the number of those affected is steadily increasing. Only half of the patients treated show a controlled blood pressure in the follow-up. A suboptimal treatment involves the danger of cardiovascular and renal events that under certain circumstances can have a fatal course. The publication of the first national treatment guidelines (NVL) on hypertension and the new guidelines of the European Society of Hypertension (ESH) 2023 simultaneously represent two updates. Both emphasize the necessity to avoid hypertension-mediated organ damage (HMOD) and the identification of high blood pressure. The focussing on preventive measures and lifestyle recommendations as well as the simplification of target blood pressure values play important roles in the routine practice. This article provides a practical summary of the current recommendations of both guidelines on the diagnostics and treatment of aNT, discusses relevant differences and provides routinely applicable advice.

Challenges posed by climate hazards to cardiovascular health and cardiac intensive care: implications for mitigation and adaptation

Global warming, driven by increased greenhouse gas emissions, has led to unprecedented extreme weather events, contributing to higher morbidity and mortality rates from a variety of health conditions, including cardiovascular disease (CVD). The disruption of multiple planetary boundaries has increased the probability of connected, cascading, and catastrophic disasters with magnified health impacts on vulnerable populations. While the impact of climate change can be manifold, non-optimal air temperatures (NOTs) pose significant health risks from cardiovascular events. Vulnerable populations, especially those with pre-existing CVD, face increased risks of acute cardiovascular events during NOT. Factors such as age, socio-economic status, minority populations, and environmental conditions (especially air pollution) amplify these risks. With rising global surface temperatures, the frequency and intensity of heatwaves and cold spells are expected to increase, emphasizing the need to address their health impacts. The World Health Organization recommends implementing heat-health action plans, which include early warning systems, public education on recognizing heat-related symptoms, and guidelines for adjusting medications during heatwaves. Additionally, intensive care units must be prepared to handle increased patient loads and the specific challenges posed by extreme heat. Comprehensive and proactive adaptation and mitigation strategies with health as a primary consideration and measures to enhance resilience are essential to protect vulnerable populations and reduce the health burden associated with NOTs. The current educational review will explore the impact on cardiovascular events, future health projections, pathophysiology, drug interactions, and intensive care challenges and recommend actions for effective patient care.

Soil and water pollution and cardiovascular disease

Healthy, uncontaminated soils and clean water support all life on Earth and are essential for human health. Chemical pollution of soil, water, air and food is a major environmental threat, leading to an estimated 9 million premature deaths worldwide. The Global Burden of Disease study estimated that pollution was responsible for 5.5 million deaths related to cardiovascular disease (CVD) in 2019. Robust evidence has linked multiple pollutants, including heavy metals, pesticides, dioxins and toxic synthetic chemicals, with increased risk of CVD, and some reports suggest an association between microplastic and nanoplastic particles and CVD. Pollutants in soil diminish its capacity to produce food, leading to crop impurities, malnutrition and disease, and they can seep into rivers, worsening water pollution. Deforestation, wildfires and climate change exacerbate pollution by triggering soil erosion and releasing sequestered pollutants into the air and water. Despite their varied chemical makeup, pollutants induce CVD through common pathophysiological mechanisms involving oxidative stress and inflammation. In this Review, we provide an overview of the relationship between soil and water pollution and human health and pathology, and discuss the prevalence of soil and water pollutants and how they contribute to adverse health effects, focusing on CVD.

Burden of disease in Germany attributed to ambient particulate matter pollution : Findings from the Global Burden of Disease Study 2019

INTRODUCTION

Ambient fine particulate matter pollution with a diameter less than 2.5 micrometers (PM2.5) is a significant risk factor for chronic noncommunicable diseases (NCDs), leading to a substantial disease burden, decreased quality of life, and deaths globally. This study aimed to investigate the disease and mortality burdens attributed to PM2.5 in Germany in 2019.

METHODS

Data from the Global Burden of Disease (GBD) Study 2019 were used to investigate disability-adjusted life-years (DALYs), years of life lost (YLLs), years lived with disability (YLDs), and deaths attributed to ambient PM2.5 pollution in Germany.

RESULTS

In 2019, ambient PM2.5 pollution in Germany was associated with significant health impacts, contributing to 27,040 deaths (2.82% of total deaths), 568,784 DALYs (2.09% of total DALYs), 135,725 YLDs (1.09% of total YLDs), and 433,058 YLLs (2.92% of total YLLs). The analysis further revealed that cardiometabolic and respiratory conditions, such as ischemic heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and diabetes mellitus, were the leading causes of mortality and disease burden associated with ambient PM2.5 pollution in Germany from 1990-2019. Comparative assessments between 1990 and 2019 underscored ambient PM2.5 as a consistent prominent risk factor, ranking closely with traditional factors like smoking, arterial hypertension, and alcohol use contributing to deaths, DALYs, YLDs, and YLLs.

CONCLUSION

Ambient PM2.5 pollution is one of the major health risk factors contributing significantly to the burden of disease and mortality in Germany, emphasizing the urgent need for targeted interventions to address its substantial contribution to chronic NCDs.

Multiple Environmental Exposures and the Development of Hypertension in a Prospective US-Based Cohort of Female Nurses: A Mixture Analysis

We investigated the independent and joint associations between multiple environmental exposures and incident hypertension in a US nationwide prospective cohort of women: the Nurses' Health Study II. We followed 107,532 nonhypertensive participants from 1989 to diagnosis of hypertension, loss to follow-up, death, or end of follow-up in June 2019. We applied Cox proportional hazards models to assess associations of incident hypertension with time-varying residential exposure to air pollution, noise, surrounding greenness, temperature, and neighborhood socioeconomic status (nSES), adjusting for potential confounders and coexposures. We evaluated the joint association of simultaneous exposure using quantile g-computation. We observed 38,175 hypertension cases over 2,062,109 person-years. Increased hypertension incidence was consistently associated with lower nSES and higher levels of fine particles (PM2.5) and nighttime noise exposures: hazard ratio (HRs) and 95% confidence intervals (CIs) of 1.06 (1.04, 1.08), 1.04 (1.01, 1.07), and 1.01 (1.00, 1.03), respectively, per interquartile range change. Joint HR for a one-quartile change in simultaneous exposure to the mixture was 1.05 (95% CI: 1.02, 1.09), assuming additivity, or 1.13 (95% CI: 1.06, 1.20), considering potential interactions within the mixture. Hypertension prevention should focus on enhancing nSES and reducing PM2.5 and noise levels, recognizing that reducing the overall exposures may yield additional benefits.

Causal Associations of Environmental Pollution and Cardiovascular Disease: A Two-Sample Mendelian Randomization Study

Background

There is growing evidence that concentrations of environmental pollutants are previously associated with cardiovascular disease; however, it is unclear whether this association reflects a causal relationship.

Methods

We utilized a two-sample Mendelian randomization (MR) approach to investigate how environmental pollution affects the likelihood of developing cardiovascular disease. We primarily employed the inverse variance weighted (IVW) method. Additionally, to ensure the robustness of our findings, we conducted several sensitivity analyses using alternative methodologies. These included maximum likelihood, MR-Egger regression, weighted median method and weighted model methods.

Results

Inverse variance weighted estimates suggested that an SD increase in PM2.5 exposure increased the risk of heart failure (OR = 1.40, 95% CI 1.02-1.93, p = 0.0386). We found that an SD increase in PM10 exposure increased the risk of hypertension (OR = 1.45, 95% CI 1.02-2.05, p = 0.03598) and atrial fibrillation (OR = 1.41, 95% CI 1.03-1.94, p = 0.03461). Exposure to chemical or other fumes in a workplace was found to increase the risk of hypertension (OR = 3.08, 95% CI 1.40-6.78, p = 0.005218), coronary artery disease (OR = 1.81, 95% CI 1.00-3.26, p = 0.04861), coronary heart disease (OR = 3.15, 95% CI 1.21-8.16, p = 0.0183) and myocardial infarction (OR = 3.03, 95% CI 1.13-8.17, p = 0.02802).

Conclusion

This study reveals the causal relationship between air pollutants and cardiovascular diseases, providing new insights into the protection of cardiovascular diseases.

Increased Risk of Gestational Hypertension by Periconceptional Exposure to Ambient Air Pollution and Effect Modification by Prenatal Depression

BACKGROUND

Air pollution has been associated with gestational hypertension (GH) and preeclampsia, but susceptible windows of exposure and potential vulnerability by comorbidities, such as prenatal depression, remain unclear.

METHODS

We ascertained GH and preeclampsia cases in a prospective pregnancy cohort in Los Angeles, CA. Daily levels of ambient particulate matters (with a diameter of ≤10 μm [PM10] or ≤2.5 μm [PM2.5]), nitrogen dioxide, and ozone were averaged for each week from 12 weeks preconception to 20 gestational weeks. We used distributed lag models to identify susceptible exposure windows, adjusting for potential confounders. Analyses were additionally stratified by probable prenatal depression to explore population vulnerability.

RESULTS

Among 619 participants, 60 developed preeclampsia and 42 developed GH. We identified a susceptible window for exposure to PM2.5 from 1 week preconception to 11 weeks postconception: higher exposure (5 µg/m3) within this window was associated with an average of 8% (95% CI, 1%-15%) higher risk of GH. Among participants with probable prenatal depression (n=179; 32%), overlapping sensitive windows were observed for all pollutants from 8 weeks before to 10 weeks postconception with increased risk of GH (PM2.5, 16% [95% CI, 3%-31%]; PM10, 39% [95% CI, 13%-72%]; nitrogen dioxide, 65% [95% CI, 17%-134%]; and ozone, 45% [95% CI, 9%-93%]), while the associations were close to null among those without prenatal depression. Air pollutants were not associated with preeclampsia in any analyses.

CONCLUSIONS

We identified periconception through early pregnancy as a susceptible window of air pollution exposure with an increased risk of GH. Prenatal depression increases vulnerability to air pollution exposure and GH.

Updates in the management of hypertension

Hypertension is the leading cause of cardiovascular diseases and nephropathies. Its treatment and management require long-term follow-up which can be facilitated by the emergence of device-based therapies. Novel recommendations have been well described in the latest ESH guidelines as well as new risk factors have been identified. The authors summarized the published evidence on hypertension management. The authors also cited in this review novel treatment approaches in different settings and the intervention of medication adherence in treatment success. Such non-communicable disease requires long-term follow-up and monitoring, which is quite facilitated in the era of digitalization by cuff-less devices based on prediction tools.

Understanding the Cardiovascular and Metabolic Health Effects of Air Pollution in the Context of Cumulative Exposomic Impacts

Poor air quality accounts for more than 9 million deaths a year globally according to recent estimates. A large portion of these deaths are attributable to cardiovascular causes, with evidence indicating that air pollution may also play an important role in the genesis of key cardiometabolic risk factors. Air pollution is not experienced in isolation but is part of a complex system, influenced by a host of other external environmental exposures, and interacting with intrinsic biologic factors and susceptibility to ultimately determine cardiovascular and metabolic outcomes. Given that the same fossil fuel emission sources that cause climate change also result in air pollution, there is a need for robust approaches that can not only limit climate change but also eliminate air pollution health effects, with an emphasis of protecting the most susceptible but also targeting interventions at the most vulnerable populations. In this review, we summarize the current state of epidemiologic and mechanistic evidence underpinning the association of air pollution with cardiometabolic disease and how complex interactions with other exposures and individual characteristics may modify these associations. We identify gaps in the current literature and suggest emerging approaches for policy makers to holistically approach cardiometabolic health risk and impact assessment.

Environmental Exposome and Atrial Fibrillation: Emerging Evidence and Future Directions

There has been increased awareness of the linkage between environmental exposures and cardiovascular health and disease. Atrial fibrillation is the most common sustained cardiac arrhythmia, affecting millions of people worldwide and contributing to substantial morbidity and mortality. Although numerous studies have explored the role of genetic and lifestyle factors in the development and progression of atrial fibrillation, the potential impact of environmental determinants on this prevalent condition has received comparatively less attention. This review aims to provide a comprehensive overview of the current evidence on environmental determinants of atrial fibrillation, encompassing factors such as air pollution, temperature, humidity, and other meteorologic conditions, noise pollution, greenspace, and the social environment. We discuss the existing evidence from epidemiological and mechanistic studies, critically evaluating the strengths and limitations of these investigations and the potential underlying biological mechanisms through which environmental exposures may affect atrial fibrillation risk. Furthermore, we address the potential implications of these findings for public health and clinical practice and identify knowledge gaps and future research directions in this emerging field.

Noise annoyance and cardiovascular disease risk: results from a 10-year follow-up study

The relationship between noise annoyance and risk of cardiovascular disease (CVD) still needs to be fully elucidated. Thus, we examined the relationship between noise annoyance and CVD risk in a large population-based cohort study. Cross-sectional (N = 15,010, aged 35-74 years, baseline investigation period 2007-2012) and prospective data (5- and 10-year follow-up from 2012 to 2022) from the Gutenberg Health Study were used to examine the relationship between noise annoyance due to different sources and risk of prevalent and incident CVD comprising atrial fibrillation, coronary artery disease, myocardial infarction, stroke, chronic heart failure, peripheral artery disease, and venous thromboembolism. In cross-sectional analyses, noise annoyance was an independent risk factor for prevalent CVD, with the strongest associations seen for noise annoyance during sleep (e.g., neighborhood noise annoyance: odds ratio 1.20, 95% confidence interval 1.13-1.27, p < 0.0001). While in the 10-year follow-up, mostly positive associations (although not significant) between noise annoyance and incident CVD were observed, no indication of increased CVD risk was observed after 5 years of follow-up. Noise annoyance due to different sources was associated with prevalent CVD, whereas only weak associations with incident CVD were found. Further large-scale studies are needed to establish the relationship between noise annoyance and risk of CVD.

Air pollution exposure and cardiometabolic risk

The Global Burden of Disease assessment estimates that 20% of global type 2 diabetes cases are related to chronic exposure to particulate matter (PM) with a diameter of 2·5 μm or less (PM2·5). With 99% of the global population residing in areas where air pollution levels are above current WHO air quality guidelines, and increasing concern in regard to the common drivers of air pollution and climate change, there is a compelling need to understand the connection between air pollution and cardiometabolic disease, and pathways to address this preventable risk factor. This Review provides an up to date summary of the epidemiological evidence and mechanistic underpinnings linking air pollution with cardiometabolic risk. We also outline approaches to improve awareness, and discuss personal-level, community, governmental, and policy interventions to help mitigate the growing global public health risk of air pollution exposure.

[Air pollution, noise and hypertension : Partners in crime]

Air pollution and traffic noise are two important environmental risk factors that endanger health in urban societies and often act together as "partners in crime". Although air pollution and noise often co-occur in urban environments, they have typically been studied separately, with numerous studies documenting consistent effects of individual exposure on blood pressure. In the following review article, we examine the epidemiology of air pollution and noise, especially regarding the cardiovascular risk factor arterial hypertension and the underlying pathophysiology. Both environmental stressors have been shown to lead to endothelial dysfunction, oxidative stress, pronounced vascular inflammation, disruption of circadian rhythms and activation of the autonomic nervous system, all of which promote the development of hypertension and cardiovascular diseases. From a societal and political perspective, there is an urgent need to point out the potential dangers of air pollution and traffic noise in the American Heart Association (AHA)/American College of Cardiology (ACC) prevention guidelines and the European Society of Cardiology (ESC) guidelines on prevention. Therefore, an essential goal for the future is to raise awareness of environmental risk factors as important and, in particular, preventable risk factors for cardiovascular diseases.

Health position paper and redox perspectives - Disease burden by transportation noise

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Short-term effects of PM2.5 and its components exposure on endothelial function in Chinese elders

Particulate matter (PM2.5) and its components have been studied widely around the world and are associated with many adverse health events (e.g. cardiovascular diseases and death). Flow-mediated dilation (FMD) is a non-invasive assessment that is able to detect endothelial damage at an early stage, therefore, improving the prognosis of atherosclerotic cardiovascular disease. The current study used data from Shanghai to explore the relationship between PM2.5 and its components and FMD using multiple statistical models. The results of the analysis of 812 patients' data (age ≥ 65) suggested that as PM2.5 level rises, endothelial function reduces. Among the five PM2.5 components included in this study, black carbon was shown by both models to be the dominating factor three days post-exposure (lag3). However, results from lag4 and lag5 were inconclusive in the two models with some evidence proposing the significance of sulphate, organic matter, and ammonium. Our results are in concordance with previous literature and further prove the significance of black carbon as an individual pollutant in the atmosphere. More research is needed to confirm the role of sulphate, organic matter, and ammonium as independent pollutants in relation to health.

Systemic health effects of noise exposure

Noise, any unwanted sound, is pervasive and impacts large populations worldwide. Investigators suggested that noise exposure not only induces auditory damage but also produces various organ system dysfunctions. Although previous reviews primarily focused on noise-induced cardiovascular and cerebral dysfunctions, this narrow focus has unintentionally led the research community to disregard the importance of other vital organs. Indeed, limited studies revealed that noise exposure impacts other organs including the liver, kidneys, pancreas, lung, and gastrointestinal tract. Therefore, the aim of this review was to examine the effects of noise on both the extensively studied organs, the brain and heart, but also determine noise impact on other vital organs. The goal was to illustrate a comprehensive understanding of the systemic effects of noise. These systemic effects may guide future clinical research and epidemiological endpoints, emphasizing the importance of considering noise exposure history in diagnosing various systemic diseases.

Influence of Air Pollution Exposures on Cardiometabolic Risk Factors: a Review

PURPOSE OF REVIEW

The increasing prevalence of cardiometabolic risk factors (CRFs) contributes to the rise in cardiovascular disease. Previous research has established a connection between air pollution and both the development and severity of CRFs. Given the ongoing impact of air pollution on human health, this review aims to summarize the latest research findings and provide an overview of the relationship between different types of air pollutants and CRFs.

RECENT FINDINGS

CRFs include health conditions like diabetes, obesity, hypertension etc. Air pollution poses significant health risks and encompasses a wide range of pollutant types, air pollutants, such as particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O2). More and more population epidemiological studies have shown a positive correlation between air pollution and CRFs. Although various pollutants have diverse effects on specific cellular molecular pathways, their main influence is on oxidative stress, inflammation response, and impairment of endothelial function. More and more studies have proved that air pollution can promote the occurrence and development of cardiovascular and metabolic risk factors, and the research on the relationship between air pollution and CRFs has grown intensively. An increasing number of studies are using new biological monitoring indicators to assess the occurrence and development of CRFs resulting from exposure to air pollution. Abnormalities in some important biomarkers in the population (such as homocysteine, uric acid, and C-reactive protein) caused by air pollution deserve more attention. Further research is warranted to more fully understand the link between air pollution and novel CRF biomarkers and to investigate potential prevention and interventions that leverage the mechanistic link between air pollution and CRFs.