Cardiovascular pathophysiology of environmental pollutants

Fludioxonil induces cardiotoxicity via mitochondrial dysfunction and oxidative stress in two cardiomyocyte models

Fludioxonil (Flu) is a phenylpyrrole fungicide and is currently used in over 900 agricultural products globally. Flu possesses endocrine-disrupting chemical-like properties and has been shown to mediate various physiological and pathological changes, such as apoptosis and differentiation, in diverse cell lines. However, the effects of Flu on cardiomyocytes have not been studied so far. The present study investigated the effects of Flu on mitochondria in AC16 human cardiomyocytes and H9c2 rat cardiomyoblasts. Flu decreased cell viability in a water-soluble tetrazolium assay and mediated morphological changes suggestive of apoptosis in AC16 and H9c2 cells. We confirmed that annexin V positive cells were increased by Flu through annexin V/propidium iodide staining. This suggests that the decrease in cell viability due to Flu may be associated with increased apoptotic changes. Flu consistently increased the expression of pro-apoptotic markers such as Bcl-2-associated X protein (Bax) and cleaved-caspase 3. Further, Flu reduced the oxygen consumption rate (OCR) in AC16 and H9c2 cells, which is associated with decreased mitochondrial membrane potential (MMP) as observed through JC-1 staining. In addition, Flu augmented the production of mitochondrial reactive oxygen species, which can trigger oxidative stress in cardiomyocytes. Taken together, these results indicate that Flu induces mitochondrial dysregulation in cardiomyocytes via the downregulation of the OCR and MMP and upregulation of the oxidative stress, consequently resulting in the apoptosis of cardiomyocytes. This study provides evidence of the risk of Flu toxicity on cardiomyocytes leading to the development of cardiovascular diseases and suggests that the use of Flu in agriculture should be done with caution and awareness of the probable health consequences of exposure to Flu.

Development of an Automated Morphometric Approach to Assess Vascular Outcomes following Exposure to Environmental Chemicals in Zebrafish

BACKGROUND

Disruptions in vascular formation attributable to chemical insults is a pivotal risk factor or potential etiology of developmental defects and various disease settings. Among the thousands of chemicals threatening human health, the highly concerning groups prevalent in the environment and detected in biological monitoring in the general population ought to be prioritized because of their high exposure risks. However, the impacts of a large number of environmental chemicals on vasculature are far from understood. The angioarchitecture complexity and technical limitations make it challenging to analyze the entire vasculature efficiently and identify subtle changes through a high-throughput in vivo assay.

OBJECTIVES

We aimed to develop an automated morphometric approach for the vascular profile and assess the vascular morphology of health-concerning environmental chemicals.

METHODS

High-resolution images of the entire vasculature in Tg(fli1a:eGFP) zebrafish were collected using a high-content imaging platform. We established a deep learning-based quantitative framework, ECA-ResXUnet, combined with MATLAB to segment the vascular networks and extract features. Vessel scores based on the rates of morphological changes were calculated to rank vascular toxicity. Potential biomarkers were identified by vessel-endothelium-gene-disease integrative analysis.

RESULTS

Whole-trunk blood vessels and the cerebral vasculature in larvae exposed to 150 representative chemicals were automatically segmented as comparable to human-level accuracy, with sensitivity and specificity of 95.56% and 95.81%, respectively. Chemical treatments led to heterogeneous vascular patterns manifested by 31 architecture indexes, and the common cardinal vein (CCV) was the most affected vessel. The antipsychotic medicine haloperidol, flame retardant 2,2-bis(chloromethyl)trimethylenebis[bis(2-chloroethyl) phosphate], and tert-butylphenyl diphenyl phosphate ranked as the top three in vessel scores. Pesticides accounted for the largest group, with a vessel score of ≥ 1 , characterized by a remarkable inhibition of subintestinal venous plexus and delayed development of CCV. Multiple-concentration evaluation of nine per- and polyfluoroalkyl substances (PFAS) indicated a low-concentration effect on vascular impairment and a positive association between carbon chain length and benchmark concentration. Target vessel-directed single-cell RNA sequencing of f l i 1 a + cells from larvae treated with λ -cyhalothrin , perfluorohexanesulfonic acid, or benzylbutyl phthalate, along with vessel-endothelium-gene-disease integrative analysis, uncovered potential associations with vascular disorders and identified biomarker candidates.

DISCUSSION

This study provides a novel paradigm for phenotype-driven screenings of vascular-disrupting chemicals by converging morphological and transcriptomic profiles at a high-resolution level, serving as a powerful tool for large-scale toxicity tests. Our approach and the high-quality morphometric data facilitate the precise evaluation of vascular effects caused by environmental chemicals. https://doi.org/10.1289/EHP13214.

Greenspaces And Cardiovascular Health

Accumulating evidence suggests that living in areas of high surrounding greenness or even brief exposures to areas of high greenery is conducive to cardiovascular health, which may be related to the environmental, social, psychological, and physiological benefits of greenspaces. Recent data from multiple cross-sectional, longitudinal, and cohort studies suggest that living in areas of high surrounding greenness is associated with a lower risk of all-cause and cardiovascular mortality. High levels of neighborhood greenery have been linked also to a decrease in the burden of cardiovascular disease risk factors as reflected by lower rates of hypertension, dyslipidemia, and diabetes. Those who live in greener environments report better mental health and more frequent social interactions, which can benefit cardiovascular health as well. In this narrative review, we discuss evidence linking greenspaces to cardiovascular health as well as the potential mechanisms underlying the beneficial effects of greenspaces, including the impact of vegetation on air, noise and light pollution, ambient temperature, physical activity, mental health, and biodiversity. We review literature on the beneficial effects of acute and chronic exposure to nature on cardiovascular disease risk factors, inflammation and immune function, and we highlight the potential cardiovascular effects of biogenic volatile organic compounds that are emitted by trees and shrubs. We identify current knowledge gaps in this area and underscore the need for additional population studies to understand more clearly and precisely the link between greenness and health. Such understanding is urgently needed to fully redeem the promise of greenspaces in preventing adverse environmental exposures, mitigating the effects of climate change, and creating healthier living environments.

Hair-Derived Exposome Exploration of Cardiometabolic Health: Piloting a Bayesian Multitrait Variable Selection Approach

Cardiometabolic health is complex and characterized by an ensemble of correlated and/or co-occurring conditions including obesity, dyslipidemia, hypertension, and diabetes mellitus. It is affected by social, lifestyle, and environmental factors, which in-turn exhibit complex correlation patterns. To account for the complexity of (i) exposure profiles and (ii) health outcomes, we propose to use a multitrait Bayesian variable selection approach and identify a sparse set of exposures jointly explanatory of the complex cardiometabolic health status. Using data from a subset (N = 941 participants) of the nutrition, environment, and cardiovascular health (NESCAV) study, we evaluated the link between measurements of the cumulative exposure to (N = 33) pollutants derived from hair and cardiometabolic health as proxied by up to nine measured traits. Our multitrait analysis showed increased statistical power, compared to single-trait analyses, to detect subtle contributions of exposures to a set of clinical phenotypes, while providing parsimonious results with improved interpretability. We identified six exposures that were jointly explanatory of cardiometabolic health as modeled by six complementary traits, of which, we identified strong associations between hexachlorobenzene and trifluralin exposure and adverse cardiometabolic health, including traits of obesity, dyslipidemia, and hypertension. This supports the use of this type of approach for the joint modeling, in an exposome context, of correlated exposures in relation to complex and multifaceted outcomes.

Relationships of Liver X Receptor Antagonists and Atherosclerosis in Drinking Water from Six Chinese Major Cities

While environmental factors have been considered contributors to atherosclerosis, it remains unclear whether drinking water promotes foam cell formation, the initial event of atherosclerosis. This study revealed that drinking water from six major cities in China, namely, Harbin, Jinan, Shanghai, Wuhan, Chongqing, and Zhuhai, significantly promoted foam cell formation in an in vitro macrophage model at a minimum concentration fold of 2. Moreover, cholesterol efflux was significantly impeded by all samples at 2-16-fold, while cholesterol influx was induced only by samples from Jinan and Chongqing at 16-fold, suggesting the dominant role of efflux in foam cell formation. Interestingly, except for the sample from Jinan, the samples exhibited complete inhibition of liver X receptor α (LXRα) activities at 160-fold, indicating the potential role of chemicals in drinking water in promoting foam cell formation by antagonizing LXRα. Through LXRα protein affinity selection-mass spectrometry, we identified ten LXRα-binding compounds, with efavirenz being revealed for the first time as a significant inducer of foam cell formation through LXRα antagonism. Overall, this study clarifies the atherosclerotic risks posed by drinking water and demonstrates the efavirenz-related atherosclerotic effects.

Reduced Transcriptome Analysis of Zebrafish Embryos Prioritizes Environmental Compounds with Adverse Cardiovascular Activities

Cardiovascular diseases are the leading cause of premature death in humans and remain a global public health challenge. While age, sex, family history, and false nutrition make a contribution, our understanding of compounds acting as cardiovascular disruptors is far from complete. Here, we aim to identify cardiovascular disruptors via a reduced transcriptome atlas (RTA) approach, which integrates large-scale transcriptome data sets of zebrafish and compiles a specific gene panel related to cardiovascular diseases. Among 767 gene expression profiles covering 81 environmental compounds, 11 priority compounds are identified with the greatest effects on the cardiovascular system at the transcriptional level. Among them, metals (AgNO₃, Ag nanoparticles, arsenic) and pesticides/biocides (linuron, methylparaben, triclosan, and trimethylchlorotin) are identified with the most significant effects. Distinct transcriptional signatures are further identified by the percentage values, indicating that different physiological endpoints exist among prioritized compounds. In addition, cardiovascular dysregulations are experimentally confirmed for the prioritized compounds via alterations of cardiovascular physiology and lipid profiles of zebrafish. The accuracy rate of experimental verification reaches up to 62.9%. The web-based RTA analysis tool, Cardionet, for rapid cardiovascular disruptor discovery was further provided at http://www.envh.sjtu.edu.cn/cardionet.jsp. Our integrative approach yields an efficient platform to discover novel cardiovascular-disrupting chemicals in the environment.

Benzotriazole ultraviolet stabilizer UV-234 promotes foam cell formation in RAW264.7 macrophages

Benzotriazole ultraviolet stabilizers (BUVSs) have been reported to induce inflammatory responses which may promote cholesterol accumulation and to downregulate the expression of genes involved in cholesterol biosynthesis; hence, we speculated whether BUVSs promote foam cell formation, which plays a key role in all stages of atherosclerosis. Herein, we used high-content imaging to screen all available BUVSs; of all the 17 candidates, 6 of them could promote foam cell formation at 10 μM. Further analyses showed that one BUVS UV-234 markedly increased the foam cell staining intensity by 15.0%-55.9% in the 0.5-10 μM exposure groups in a dose-dependent manner. Cholesterol influx was markedly enhanced by 21.0%-24.5% in the 5-10 μM exposure groups and cholesterol efflux was downregulated by 21.2%-59.3% in the 0.5-10 μM exposure groups, indicating that cholesterol efflux may play a major role in foam formation considering cholesterol efflux was downregulated at a relatively low concentration. Gene expression of ABCA1 and ABCG1 which regulate the cholesterol efflux were also decreased at 0.5-10 μM. The degradation of hypoxia-inducible factor 1α (HIF1α) via the ubiquitin-proteasome system was observed at 0.5-10 μM, probably contributing to the downregulated expression of the genes encoding liver X receptors (LXR) α/β and their targets, ABCA1 and ABCG1. Thus, our study revealed that BUVSs frequently detected in the environment can promote foam cell formation in macrophages, contributing to the risk of atherosclerosis in humans.

Environmental Stressors and the PINE Network: Can Physical Environmental Stressors Drive Long-Term Physical and Mental Health Risks?

Both psychosocial and physical environmental stressors have been linked to chronic mental health and chronic medical conditions. The psycho-immune-neuroendocrine (PINE) network details metabolomic pathways which are responsive to varied stressors and link chronic medical conditions with mental disorders, such as major depressive disorder via a network of pathophysiological pathways. The primary objective of this review is to explore evidence of relationships between airborne particulate matter (PM, as a concrete example of a physical environmental stressor), the PINE network and chronic non-communicable diseases (NCDs), including mental health sequelae, with a view to supporting the assertion that physical environmental stressors (not only psychosocial stressors) disrupt the PINE network, leading to NCDs. Biological links have been established between PM exposure, key sub-networks of the PINE model and mental health sequelae, suggesting that in theory, long-term mental health impacts of PM exposure may exist, driven by the disruption of these biological networks. This disruption could trans-generationally influence health; however, long-term studies and information on chronic outcomes following acute exposure event are still lacking, limiting what is currently known beyond the acute exposure and all-cause mortality. More empirical evidence is needed, especially to link long-term mental health sequelae to PM exposure, arising from PINE pathophysiology. Relationships between physical and psychosocial stressors, and especially the concept of such stressors acting together to impact on PINE network function, leading to linked NCDs, evokes the concept of syndemics, and these are discussed in the context of the PINE network.

Immunological Insights into Cigarette Smoking-Induced Cardiovascular Disease Risk

Smoking is one of the most prominent addictions of the modern world, and one of the leading preventable causes of death worldwide. Although the number of tobacco smokers is believed to be at a historic low, electronic cigarette use has been on a dramatic rise over the past decades. Used as a replacement for cigarette smoking, electronic cigarettes were thought to reduce the negative effects of burning tobacco. Nonetheless, the delivery of nicotine by electronic cigarettes, the most prominent component of cigarette smoke (CS) is still delivering the same negative outcomes, albeit to a lesser extent than CS. Smoking has been shown to affect both the structural and functional aspects of major organs, including the lungs and vasculature. Although the deleterious effects of smoking on these organs individually is well-known, it is likely that the adverse effects of smoking on these organs will have long-lasting effects on the cardiovascular system. In addition, smoking has been shown to play an independent role in the homeostasis of the immune system, leading to major sequela. Both the adaptive and the innate immune system have been explored regarding CS and have been demonstrated to be altered in a way that promotes inflammatory signals, leading to an increase in autoimmune diseases, inflammatory diseases, and cancer. Although the mechanism of action of CS has not been fully understood, disease pathways have been explored in both branches of the immune system. The pathophysiologically altered immune system during smoking and its correlation with cardiovascular diseases is not fully understood. Here we highlight some of the important pathological mechanisms that involve cigarette smoking and its many components on cardiovascular disease and the immune systems in order to have a better understanding of the mechanisms at play.

Association between urinary thallium exposure and cardiovascular disease in U.S. adult population

Exposure to environmental metals, especially heavy metals, can damage human health. However, the association between metals and the prevalence of cardiovascular disease (CVD) remains controversial. The objective of this study was to determine the relationship of urinary metals to CVD in a general population of U.S. adults. We analyzed the cross-sectional data from 6867 adult (age ≥20 years) participants with 12 urinary metals in the National Health and Nutrition Examination Survey (NHANES) (2011-2016). Multivariate logistic regression and restricted cubic spline (RCS) regression were conducted to explore the association between urinary metals and CVD outcomes. Sensitivity analyses were performed to test the robustness of the results. Compared to the lowest quartile, the odds ratios with 95% confidence intervals for CVD across the quartiles were 0.73 (0.38, 1.42), 0.58 (0.42, 0.81), and 0.71 (0.59, 0.84) for urinary thallium (U-Tl) (P for trend <0.001). RCS plot showed the nonlinear association between log₂-transformed U-Tl levels and CVD (P for nonlinearity = 0.001). Sensitivity analyses confirmed the robustness. Higher concentrations of urinary cobalt, manganese and tungsten were associated with an increased risk of CVD. In summary, the large sample data suggests U-Tl is nonlinearly and negatively associated with the prevalence of CVD in the U.S. general adults with low exposure levels. Considering the shortcomings of cross-sectional study design, further studies are warranted to verify our results and to clarify the potential mechanisms.

Propensity score analysis of the association between maternal exposure to second-hand tobacco smoke and birth defects in Northwestern China

Previous studies have suggested that maternal active smoking can increase the risk of birth defects, but evidence on second-hand tobacco smoke (SHS) is limited. We aimed to assess the association between maternal exposure to SHS and birth defects in a Chinese population. The data were based on a large-scale cross-sectional survey conducted in Shaanxi Province, China. Considering the characteristics of survey design and the potential impact of confounding factors, we adopted propensity score matching (PSM) to match the SHS exposure group and the non-exposure group to attain a balance of the confounders between the two groups. Subsequently, conditional logistic regression was employed to estimate the effect of SHS exposure on birth defects. Furthermore, sensitivity analyses were conducted to verify the key findings. After nearest neighbor matching of PSM with a ratio of 2 and a caliper width of 0.03, there were 6,205 and 12,410 participants in the exposure and control group, respectively. Pregnant women exposed to SHS were estimated to be 58% more likely to have infants with overall birth defects (OR = 1.58, 95% CI: 1.30-1.91) and 75% more likely to have infants with circulatory system defects (OR = 1.75, 95% CI: 1.26-2.44). We also observed that the risk effect of overall birth defects had an increasing trend as the frequency of exposure increased. Additionally, sensitivity analyses suggested that our results had good robustness. These results indicate that maternal exposure to SHS likely increases the risk of overall birth defects, especially circulatory system defects, in Chinese offspring.

Preparation of LDL , Oxidation , Methods of Detection, and Applications in Atherosclerosis Research

The concept of lipid peroxidation has been known for a long time. It is now well established that LDL plays a major role in atherosclerosis. Oxidized low-density lipoprotein (Ox-LDL) has been studied for over 35 years. Numerous pro- and anti-atherogenic properties have been attributed to Ox-LDL. Component composition of Ox-LDL is complex due to the influence of various factors, including the source, method of preparation, storage and use. Hence, it is very difficult to clearly define and characterize Ox-LDL. It contains unoxidized and oxidized fatty acid derivatives both in the ester and free forms, their decomposition products, cholesterol and its oxidized products, proteins with oxidized amino acids and cross-links, polypeptides with varying extents of covalent modification with lipid oxidation products and many others. The measurement of lipid oxidation has been a great boon, not only to the understanding of the process but also in providing numerous serendipitous discoveries and methodologies. In this chapter, we outline the methodologies for the preparation and testing of various lipoproteins for oxidation studies.

Inverse association between blood ethylene oxide levels and obesity in the general population: NHANES 2013-2016

BACKGROUND

Ethylene oxide (EO) has been shown to associate with increased cardiovascular risk. This study aimed to explore the relationship and its meditating factors between EO exposure and the major cardiovascular risk factor of obesity among the general adult population.

METHODS

Cross-sectional data of 3,220 participants from National Health and Nutritional Examination Survey (NHANES) 2013-2016 were enrolled. Obesity was defined as body mass index (BMI) ≥30 kg/m², and abdominal obesity was defined as waist circumference (WC) ≥102 cm in men and ≥88 cm in women. The association among hemoglobin adduct of EO (HbEO), inflammatory biomarkers, and obesity was evaluated using restricted cubic splines and the multivariable linear regression model. Mediation analysis was used to further assess their association.

RESULTS

The increased quartiles of HbEO were inversely associated with BMI and WC [Q1 vs. Q4, BMI: β = -2.98 (-3.74, -2.22), WC: β = -6.50 (-8.60, -4.39); all p for trend < 0.05], and were inversely associated with obesity after full adjustment [obesity: OR = 0.43 (0.31, 0.58), abdominal obesity: OR = 0.42 (0.27, 0.65); all p for trend < 0.05]. The levels of alkaline phosphatase, white blood cells, lymphocytes, and neutrophils were also positively associated with BMI and WC (all p < 0.05). Mediation analysis showed that exposure of EO not only had a negative direct effect on BMI and WC, but also generated an inverse indirect effect.

CONCLUSIONS

Current findings showed an inverse association between HbEO and obesity, and suggested that systemic inflammation may not be their only mediator. Additional research is required to explore the underlying link of EO and system metabolism.

Association between blood ethylene oxide levels and the risk of cardiovascular diseases in the general population

Ethylene oxide (EtO) is a highly reactive organic compound that is mainly used as a sterilizing agent. However, to date, the effects of EtO on the cardiovascular system are not clear. We aimed to explore the association between blood EtO levels and the risk of cardiovascular disease (CVD) in the general US population. We obtained information on blood levels of EtO and CVD outcomes in 3,410 participants from the National Health and Nutritional Examination Survey (NHANES) 2013-2014 and 2015-2016. Logistic regression models were applied to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association between EtO and risk of all CVD as well as subtypes of CVD. Linear regression analyses were used to estimate the associations of EtO with potential mechanistic parameters of CVD, including blood pressure, blood lipid levels and inflammatory parameters. Higher blood levels of EtO were associated with an increased risk of all CVD (p for trend = 0.003), with an adjusted OR (95% CI) in the highest quartile of 1.94 (1.24, 3.02) compared with the lowest quartile as a reference. Higher concentrations of EtO were positively associated with the risk of angina (p for trend = 0.04) and heart attack (p for trend = 0.011). In addition, the concentration of EtO was positively associated with the levels of triglycerides, white blood cells, lymphocytes, monocytes, neutrophils and eosinophils (p = 0.003 for eosinophils and p < 0.001 for the others) and negatively associated with the level of high-density lipoprotein cholesterol (p < 0.001). We found that exposure to EtO was associated with angina, heart attack and all CVD in a large representative US population. Furthermore, EtO may induce CVD through the inflammatory response and abnormal fatty acid metabolism.

Cardiovascular Effects of Particulate Air Pollution

Inhalation of fine particulate matter (PM_2.5), produced by the combustion of fossil fuels, is an important risk factor for cardiovascular disease. Exposure to PM_2.5 has been linked to increases in blood pressure, thrombosis, and insulin resistance. It also induces vascular injury and accelerates atherogenesis. Results from animal models corroborate epidemiological evidence and suggest that the cardiovascular effects of PM_2.5 may be attributable, in part, to oxidative stress, inflammation, and the activation of the autonomic nervous system. Although the underlying mechanisms remain unclear, there is robust evidence that long-term exposure to PM_2.5 is associated with premature mortality due to heart failure, stoke, and ischemic heart disease. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Cardiotoxicity of some pesticides and their amelioration

Pesticides are used to control pests that harm plants, animals, and humans. Their application results in the contamination of the food and water systems. Pesticides may cause harm to the human body via occupational exposure or the ingestion of contaminated food and water. Once a pesticide enters the human body, it may create health consequences such as cardiotoxicity. There is not enough information about pesticides that cause cardiotoxicity in the literature. Currently, there are few reports that summarized the cardiotoxicity due to some pesticide groups. This necessitates reviewing the current literature regarding pesticides and cardiotoxicity and to summarize them in a concrete review. The objectives of this review article were to summarize the advances in research related to pesticides and cardiotoxicity, to classify pesticides into certain groups according to cardiotoxicity, to discuss the possible mechanisms of cardiotoxicity, and to present the agents that ameliorate cardiotoxicity. Approximately 60 pesticides were involved in cardiotoxicity: 30, 13, and 17 were insecticides, herbicides, and fungicides, respectively. The interesting outcome of this study is that 30 and 13 pesticides from toxicity classes II and III, respectively, are involved in cardiotoxicity. The use of standard antidotes for pesticide poisoning shows health consequences among users. Alternative safe medical management is the use of cardiotoxicity-ameliorating agents. This review identifies 24 ameliorating agents that were successfully used to manage 60 cases. The most effective agents were vitamin C, curcumin, vitamin E, quercetin, selenium, chrysin, and garlic extract. Vitamin C showed ameliorating effects in a wide range of toxicities. The exposure mode to pesticide residues, where 1, 2, 3, and 4 are aerial exposure to pesticide drift, home and/or office exposure, exposure due to drinking contaminated water, and consumption of contaminated food, respectively. General cardiotoxicity is represented by 5, whereas 6, 7, 8 and 9 are electrocardiogram (ECG) of hypotension due to exposure to OP residues, ECG of myocardial infraction due to exposure to OPs, ECG of hypertension due to exposure to OC and/or PY, and normal ECG respectively.

Association between Atrial Fibrillation Incidence and Temperatures, Wind Scale and Air Quality: An Exploratory Study for Shanghai and Kunming

As a common cardiovascular disease, atrial fibrillation has the characteristics of high morbidity, high disability, and high fatality rates, seriously endangering human health and sustainability. Some research has confirmed that environmental factors are related to the risk of illness and death from cardiovascular diseases (including atrial fibrillation), while there is still little comparison on the situation of the two cities in China. This research uses medical data in Shanghai and Kunming establishing, through two-step research, logistic models to compare the impacts on atrial fibrillation incidence to figure out the association between environmental factors (including air pollution, weather, temperature, and wind scales) and atrial fibrillation. Finally, this research shows that environmental impacts on atrial fibrillation prevalence have generality, regionality, and lagging characteristics. The result is significant for atrial fibrillation patients and provides a reliable medical theory basis for nursing measures. Besides, this research provides a prospective method of offering early warning for potential atrial fibrillation patients, helping to maintain human beings’ sustainable development.

Exposure to volatile organic compounds - acrolein, 1,3-butadiene, and crotonaldehyde - is associated with vascular dysfunction

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Exposure to air pollution, specifically particulate matter of diameter ≤2.5 μm (PM2.5), is a well-established risk factor for CVD. However, the contribution of gaseous pollutant exposure to CVD risk is less clear.

OBJECTIVE

To examine the vascular effects of exposure to individual volatile organic compounds (VOCs) and mixtures of VOCs.

METHODS

We measured urinary metabolites of acrolein (CEMA and 3HPMA), 1,3-butadiene (DHBMA and MHBMA3), and crotonaldehyde (HPMMA) in 346 nonsmokers with varying levels of CVD risk. On the day of enrollment, we measured blood pressure (BP), reactive hyperemia index (RHI - a measure of endothelial function), and urinary levels of catecholamines and their metabolites. We used generalized linear models for evaluating the association between individual VOC metabolites and BP, RHI, and catecholamines, and we used Bayesian Kernel Machine Regression (BKMR) to assess exposure to VOC metabolite mixtures and BP.

RESULTS

We found that the levels of 3HPMA were positively associated with systolic BP (0.98 mmHg per interquartile range (IQR) of 3HPMA; CI: 0.06, 1.91; P = 0.04). Stratified analysis revealed an increased association with systolic BP in Black participants despite lower levels of urinary 3HPMA. This association was independent of PM2.5 exposure and BP medications. BKMR analysis confirmed that 3HPMA was the major metabolite associated with higher BP in the presence of other metabolites. We also found that 3HPMA and DHBMA were associated with decreased endothelial function. For each IQR of 3HPMA or DHBMA, there was a -4.4% (CI: -7.2, -0.0; P = 0.03) and a -3.9% (CI: -9.4, -0.0; P = 0.04) difference in RHI, respectively. Although in the entire cohort the levels of several urinary VOC metabolites were weakly associated with urinary catecholamines and their metabolites, in Black participants, DHBMA levels showed strong associations with urinary norepinephrine and normetanephrine levels.

DISCUSSION

Exposure to acrolein and 1,3-butadiene is associated with endothelial dysfunction and may contribute to elevated risk of hypertension in participants with increased sympathetic tone, particularly in Black individuals.

Cardiorespiratory and Immunologic Effects of Electronic Cigarettes

PURPOSE OF REVIEW

Although e-cigarettes have become popular, especially among youth, the health effects associated with e-cigarette use remain unclear. This review discusses current evidence relating to the cardiovascular, pulmonary, and immunological effects of e-cigarettes.

RECENT FINDINGS

The use of e-cigarettes by healthy adults has been shown to increase blood pressure, heart rate, and arterial stiffness, as well as resistance to air flow in lungs. Inhalation of e-cigarette aerosol has been shown to elicit immune responses and increase the production of immunomodulatory cytokines in young tobacco-naïve individuals. In animal models, long-term exposure to e-cigarettes leads to marked changes in lung architecture, dysregulation of immune genes, and low-grade inflammation. Exposure to e-cigarette aerosols in mice has been shown to induce DNA damage, inhibit DNA repair, and promote carcinogenesis. Chronic exposure to e-cigarettes has also been reported to result in the accumulation of lipid-laden macrophages in the lung and dysregulation of lipid metabolism and transport in mice. Although, the genotoxic and inflammatory effects of e-cigarettes are milder than those of combustible cigarettes, some of the cardiorespiratory effects of the two insults are comparable. The toxicity of e-cigarettes has been variably linked to nicotine, as well as other e-cigarette constituents, operating conditions, and use patterns.

SUMMARY

The use of e-cigarettes in humans is associated with significant adverse cardiorespiratory and immunological changes. Data from animal models and in vitro studies support the notion that long-term use of e-cigarettes may pose significant health risks.

Personal Exposure to PM2.5 Oxidative Potential in Association with Pulmonary Pathophysiologic Outcomes in Children with Asthma

Fine particulate matter (PM_2.5) with a higher oxidative potential has been thought to be more detrimental to pulmonary health. We aim to investigate the associations between personal exposure to PM_2.5 oxidative potential and pulmonary outcomes in asthmatic children. We measured each of the 43 asthmatic children 4 times for airway mechanics, lung function, airway inflammation, and asthma symptom scores. Coupling measured indoor and outdoor concentrations of PM_2.5 mass, constituents, and oxidative potential with individual time-activity data, we calculated 24 h average personal exposures 0-3 days prior to a health outcome measurement. We found that increases in daily personal exposure to PM_2.5 oxidative potential were significantly associated with increased small, large, and total airway resistance, increased airway impedance, decreased lung function, and worsened scores of individual asthma symptoms and the total symptom score. Among the PM_2.5 constituents, organic matters largely of indoor origin contributed the greatest to PM_2.5 oxidative potential. Given that the variability in PM_2.5 oxidative potential was a stronger driver than PM_2.5 mass for the variability in the respiratory health outcomes, it is suggested to reduce PM_2.5 oxidative potential, particularly by reducing the organic matter constituent of indoor PM_2.5, as a targeted source control strategy in asthma management.

Residential proximity to greenness mitigates the hemodynamic effects of ambient air pollution

Residential proximity to greenness is associated with a lower risk of cardiovascular disease (CVD) and all-cause mortality. However, it is unclear whether the beneficial effects of greenness are linked to a reduction in the effects of ambient air pollutants. We measured arterial stiffness in 73 participants with moderate to high CVD risk. Average levels of ambient PM2.5 and ozone were calculated from local monitoring stations. Residential greenness was estimated using satellite-derived normalized difference vegetation index (NDVI) for a 200-m and 1-km radius around each participant's home. Participants were 51% female, average age of 52 yr, and 79% had diagnosed hypertension. In multiple linear regression models, residential NDVI was negatively associated with augmentation index (-3.8% per 0.1 NDVI). Ambient levels of PM2.5 [per interquartile range (IQR) of 6.9 μg/m3] were positively associated with augmentation pressure (3.1 mmHg), pulse pressure (5.9 mmHg), and aortic systolic pressure (8.1 mmHg). Ozone (per IQR of 0.03 ppm) was positively associated with augmentation index (5.5%), augmentation pressure (3.1 mmHg), and aortic systolic pressure (10 mmHg). In areas of low greenness, both PM2.5 and ozone were positively associated with pulse pressure. Additionally, ozone was positively associated with augmentation pressure and systolic blood pressure. However, in areas of high greenness, there was no significant association between indices of arterial stiffness with either PM2.5 or ozone. Residential proximity to greenness is associated with lower values of arterial stiffness. Residential greenness may mitigate the adverse effects of PM2.5 and ozone on arterial stiffness.NEW & NOTEWORTHY Previous studies have linked proximity to green spaces with lower cardiovascular disease risk. However, the mechanisms underlying the salutary effects of green areas are not known. In our study of participants at risk of cardiovascular disease, we found that arterial stiffness was positively associated with short-term exposure to PM2.5, PM10, and ozone and inversely associated with greenness. The association between pollution and arterial stiffness was attenuated in areas of high greenness, suggesting that living green neighborhoods can lessen the adverse cardiovascular effects of air pollution.

E-Cigarettes and Cardiopulmonary Health

E-cigarettes have surged in popularity over the last few years, particularly among youth and young adults. These battery-powered devices aerosolize e-liquids, comprised of propylene glycol and vegetable glycerin, typically with nicotine, flavors, and stabilizers/humectants. Although the use of combustible cigarettes is associated with several adverse health effects including multiple pulmonary and cardiovascular diseases, the effects of e-cigarettes on both short- and long-term health have only begun to be investigated. Given the recent increase in the popularity of e-cigarettes, there is an urgent need for studies to address their potential adverse health effects, particularly as many researchers have suggested that e-cigarettes may pose less of a health risk than traditional combustible cigarettes and should be used as nicotine replacements. This report is prepared for clinicians, researchers, and other health care providers to provide the current state of knowledge on how e-cigarette use might affect cardiopulmonary health, along with research gaps to be addressed in future studies.

Urinary Levels of the Acrolein Conjugates of Carnosine Are Associated with Cardiovascular Disease Risk

Carnosine is a naturally occurring dipeptide (β-alanine-L-histidine) which supports physiological homeostasis by buffering intracellular pH, chelating metals, and conjugating with and neutralizing toxic aldehydes such as acrolein. However, it is not clear if carnosine can support cardiovascular function or modify cardiovascular disease (CVD) risk. To examine this, we measured urinary levels of nonconjugated carnosine and its acrolein conjugates (carnosine-propanal and carnosine-propanol) in participants of the Louisville Healthy Heart Study and examined associations with indices of CVD risk. We found that nonconjugated carnosine was significantly associated with hypertension (p = 0.011), heart failure (p = 0.015), those categorized with high CVD risk (p < 0.001), body mass index (BMI; p = 0.007), high sensitivity C-reactive protein (hsCRP; p = 0.026), high-density lipoprotein (HDL; p = 0.007) and certain medication uses. Levels of carnosine-propanal and carnosine-propanol demonstrated significant associations with BMI, blood glucose, HDL and diagnosis of diabetes. Carnosine-propanal was also associated with heart failure (p = 0.045) and hyperlipidemia (p = 0.002), but no associations with myocardial infarction or stroke were identified. We found that the positive associations of carnosine conjugates with diabetes and HDL remain statistically significant (p < 0.05) in an adjusted, linear regression model. These findings suggest that urinary levels of nonconjugated carnosine, carnosine-propanal and carnosine-propanol may be informative biomarkers for the assessment of CVD risk—and particularly reflective of skeletal muscle injury and carnosine depletion in diabetes.

Protocol to assess the efficacy of carnosine supplementation in mitigating the adverse cardiovascular responses to particulate matter (PM) exposure: the Nucleophilic Defense Against PM Toxicity (NEAT) trial

INTRODUCTION

Exposure to airborne particulate matter (PM) is associated with cardiovascular disease. These outcomes are believed to originate from pulmonary oxidative stress and the systemic delivery of oxidised biomolecules (eg, aldehydes) generated in the lungs. Carnosine is an endogenous di-peptide (β-alanine-L-histidine) which promotes physiological homeostasis in part by conjugating to and neutralising toxic aldehydes. We hypothesise that an increase of endogenous carnosine by dietary supplementation would mitigate the adverse cardiovascular outcomes associated with PM exposure in humans.

METHODS AND ANALYSIS

To test this, we designed the Nucleophilic Defense Against PM Toxicity trial. This trial will enroll 240 participants over 2 years and determine if carnosine supplementation mitigates the adverse effects of PM inhalation. The participants will have low levels of endogenous carnosine to facilitate identification of supplementation-specific outcomes. At enrollment, we will measure several indices of inflammation, preclinical cardiovascular disease and physical function. Participants will be randomly allocated to carnosine or placebo groups and instructed to take their oral supplement for 12 weeks with two return clinical visits and repeated assessments during times of peak PM exposure (June-September) in Louisville, Kentucky, USA. Statistical modelling approaches will be used to assess the efficacy of carnosine supplementation in mitigating adverse outcomes.

ETHICS AND DISSEMINATION

This study protocol has been approved by the Institutional Review Board at the University of Louisville. Results from this study will be disseminated at scientific conferences and in peer-reviewed publications.Trial registration: NCT03314987; Pre-results.

Toxic effect of alpha cypermethrin, an environmental pollutant, on myocardial tissue in male wistar rats

α-Cypermethrin (CYP) is a pyrethroid insecticide-like environmental pollutant, widely found in the environment. New research links exposure to high levels of CYP to health damage; however, little is known about the effect of CYP on cardiovascular disease. The purpose of the present study was to evaluate, for the first time, biochemical and cardiovascular changes in male rats resulting from subchronic CYP exposure. The animals were divided into three groups: group 1 served as the control, group 2 (CYP1) received 4 mg/kg of CYP by gavage, and group 3 (CYP2) received 8 mg/kg of CYP by gavage, for 8 weeks each. Results showed that both CYP1 and CYP2 markedly increased plasma concentrations of cardiac markers (LDH, CK-MB, and troponin-T). Moreover, compared to the control group, CYP treatment elevated cardiac oxidative stress, as shown by increased MDA level and decreased activity of SOD, CAT, and GSH-Px. In addition, CYP2 caused a significant increase of 42% the concentration of total cholesterol and more than 75% in triglycerides compared to the control group. Furthermore, DNA fragmentation and collagen deposition were both amplified owing to CYP toxicity. This harmful effect was confirmed by a histological study using H-E and Sirius Red staining. Overall, our results clearly proved the cardiotoxicity caused by α-cypermethrin.

Screening of House Dust from Chinese Homes for Chemicals with Liver X Receptors Binding Activities and Characterization of Atherosclerotic Activity Using an in Vitro Macrophage Cell Line and ApoE-/- Mice

BACKGROUND

Atherosclerotic cardiovascular disease has become the leading cause of death worldwide, and environmental pollutants are increasingly recognized as risk factors for atherosclerosis. Liver X receptors (LXRs) play a central role in atherosclerosis; however, LXR activity of organic pollutants and associated potential risk of atherosclerosis have not yet been characterized.

OBJECTIVES

This study aimed to explore whether LXR-antagonistic chemicals are present in indoor house dust and, if so, to characterize this activity in relation to changes in macrophages in vitro and cardiovascular disease indicators in vivo in an atherosclerosis ApoE-/- mouse model.

METHODS

We used a His-LXRα-pull-down assay and a nontarget high-resolution mass spectrometry method to screen house dust collected from Chinese homes for LXRα- and LXRβ-antagonist activity. A chemical identified in this manner was assessed for its ability to induce cholesterol efflux and foam cell formation in RAW264.7 macrophages, to down-regulate the expression of two LXR-dependent genes, ABCA1 and ABCG1, and finally to induce atherosclerotic lesions in vivo using an ApoE-/- mouse model.

RESULTS

We identified the flame retardants triphenyl phosphate (TPHP) and 2-ethylhexyl diphenyl phosphate (EHDPP) in house dust samples and demonstrated their ability to antagonize LXRs. The potency of TPHP was similar to that of the LXR-antagonist SR9238. TPHP could also inhibit cholesterol efflux and promote foam cell formation in RAW264.7 macrophages and mouse peritoneal macrophages and significantly promoted atherosclerotic lesion formation in the ApoE-/- mouse model.

CONCLUSIONS

We found LXR-antagonist chemicals in environmental samples of indoor dust from Chinese homes. One of the chemicals, TPHP, was able to promote the development of atherosclerotic lesions in the ApoE-/- mouse model. These results highlight the need to assess the LXR-antagonist activities of pollutants in future environmental management programs. https://doi.org/10.1289/EHP5039.

Comparative effects of parent and heated cinnamaldehyde on the function of human iPSC-derived cardiac myocytes

Many e-cigarette products contain cinnamaldehyde as a primary constituent of cinnamon flavorings. When used as a food additive, cinnamaldehyde is generally regarded as safe for ingestion. However, little is known about the effects of cinnamaldehyde or its degradation products, generated after heating and inhalation, which may lead to elevated circulatory exposure to the heart. Hence, in this study, we tested the in vitro cardiac toxicity of cinnamaldehyde and its thermal degradation products generated by heating at low (200 ± 50 °C) and high temperatures (700 ± 50 °C) on the contractility, rhythmicity and electrical signaling properties of human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs). Cellular impedance measurements on spontaneously beating hiPSC-CMs revealed that cinnamaldehyde significantly alters contraction-dependent signal amplitude, beating rate, and cell morphology. These effects were attenuated after cinnamaldehyde was subjected to heating at low or high temperatures. Current clamp analysis of hiPSC-CM action potentials (APs) showed only modest effects of acute application of 1-100 μM cinnamaldehyde on resting membrane potential, while prolonged (~20 min) application of 100 μM cinnamaldehyde resulted in progressive depolarization and loss of rhythmic AP spiking activity. Collectively, these results suggest that micromolar levels of cinnamaldehyde could alter cardiac excitability, in part by impairing the processes that regulate membrane potential and depolarization. Our results further suggest that heating cinnamaldehyde by itself does not directly lead to the formation of products with greater cardiotoxicity in vitro.

Toxic trans-crotonaldehyde in mitochondria intercepted by oxyresveratrol contributing to anticancer

The aim of this study was to explore how the toxic trans-crotonaldehyde (TCA) in mitochondria or aldehyde dehydrogenase (ALDH) at different pHs was intercepted by oxyresveratrol (Oxy-Res) contributing to anticancer. Ultraviolet-visible (UV-vis) spectroscopy and Raman spectroscopy were employed. UV-vis spectra showed that the Oxy-Res red shifted the peak of the toxic TCA from 316 nm to 325 nm, while the peaks of the Oxy-Res shifted from 329 nm with 290 nm and 300 nm to 325 nm with 303 nm. In the mitochondria, the Oxy-Res blue shifted the peaks of the toxic TCA from 325 nm with 303 nm to 321 nm with 301 nm. Raman spectra revealed that the Oxy-Res caused shifting of the CHO of the toxic TCA from 1,689 cm^-1 to 1,671 cm^-1 with band decline. The CC of the toxic TCA at 1641 cm^-1 was split into 1,639 cm^-1 and 1,642 cm^-1 with band decline. The bands of the Oxy-Res at 1634 cm^-1 , 1,617 cm^-1 , and 1,595 cm^-1 disappeared. In the mitochondria, the CC of the toxic TCA at 1641 cm^-1 splitting disappeared. In ALDH, with the decrease of pH from 7.8 to 6.5, the CHO of the toxic TCA did not red shift from 1,689 cm^-1 to 1,674 cm^-1 up to pH 6.5. There was no change in the CC of the toxic TCA at 1640 cm^-1 in ALDH at different pHs. The conclusion of the study was that the CHO of the toxic TCA was intercepted by the Oxy-Res under the action of ALDH in the mitochondria, particularly at pH 7.8. © 2019 IUBMB Life, 2019.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

Ambient PM2.5 Human Health Effects—Findings in China and Research Directions

Exposure to fine particulate matter (PM) results in adverse health outcomes. Although this is a global concern, residents of China may be particularly vulnerable due to frequent severe air pollution episodes associated with economic growth, industrialization, and urbanization. Until 2012, PM2.5 was not regulated and monitored in China and annual average concentrations far exceeded the World Health Organizations guidelines of 10 μg/m3. Since the establishment of PM2.5 Ambient Air Quality Criteria in 2012, concentrations have decreased, but still pose significant health risks. A review of ambient PM2.5 health effect studies is warranted to evaluate the current state of knowledge and to prioritize future research efforts. Our review found that recent literature has confirmed associations between PM2.5 exposure and total mortality, cardiovascular mortality, respiratory mortality, hypertension, lung cancer, influenza and other adverse health outcomes. Future studies should take a long-term approach to verify associations between exposure to PM2.5 and health effects. In order to obtain adequate exposure assessment at finer spatial resolutions, high density sampling, satellite remote sensing, or models should be employed. Personal monitoring should also be conducted to validate the use of outdoor concentrations as proxies for exposure. More research efforts should be devoted to seasonal patterns, sub-population susceptibility, and the mechanism by which exposure causes health effects. Submicron and ultrafine PM should also be monitored and regulated.

Exposure to acrylamide and the risk of cardiovascular diseases in the National Health and Nutrition Examination Survey 2003-2006

BACKGROUND

Long-term exposure to acrylamide (AA) from diet sources may induce oxidative stress and chronic inflammation. However, the association between AA exposure and the prevalence of cardiovascular diseases (CVD) remains unclear.

OBJECTIVES

We aimed to examine the association between blood exposure levels of AA biomarkers and the prevalence of main types of CVD in a general population of US adults.

METHODS

We analyzed the associations between AA hemoglobin biomarkers [hemoglobin adducts of acrylamide (HbAA) and glycidamide (HbGA), sum of HbAA and HbGA (HbAA+HbGA), and ratio of HbGA to HbAA (HbGA:HbAA)] and self-reported diagnosis of CVD in 8290 adults (≥20 years of age) from the National Health and Nutrition Examination Survey (NHANES) 2003-2006. Multivariable logistic regression models were employed for estimating the associations in three groups classified by the combination of smoking status and serum cotinine levels.

RESULTS

In people exposed to environmental tobacco smoke (n = 4670), HbGA, HbAA+HbGA, and HbGA:HbAA were significantly and inversely associated with the prevalence of total CVD (p < 0.0001, p = 0.0155, and p = 0.0014 for trend, respectively) after adjusting for various covariates. The odd ratios (ORs) for total CVD in the highest quartiles of HbGA, HbAA+HbGA, and HbGA:HbAA were 0.311 [95% confidence interval (CI): 0.193-0.500], 0.664 (95% CI: 0.485-0.911), and 0.495 (95% CI: 0.326-0.752) when compared with the individual lowest quartiles. In active smokers (n = 2432), HbAA was positively associated with CVD risk (p = 0.0088 for trend), while HbGA:HbAA was inversely related to total CVD (p = 0.0137 for trend). However, no significant associations of any AA hemoglobin biomarker with total and individual CVD prevalence were observed in the nonsmoking group (n = 1188).

CONCLUSIONS

AA hemoglobin biomarkers are significantly associated with CVD in the active smoking group and the group exposed to environmental tobacco smoke but not in the nonsmoking group. Further prospective studies should clarify the causal relationship between HbAA and HbGA and the prevalence of CVD.

Defining the Human Envirome: An Omics Approach for Assessing the Environmental Risk of Cardiovascular Disease

Both genetic and environmental factors contribute to the development of cardiovascular disease, but in comparison with genetics, environmental factors have received less attention. Evaluation of environmental determinants of cardiovascular disease is limited by the lack of comprehensive omics approaches for integrating multiple environmental exposures. Hence, to understand the effects of the environment as a whole (envirome), it is important to delineate specific domains of the environment and to assess how, individually and collectively; these domains affect cardiovascular health. In this review, we present a hierarchical model of the envirome; defined by 3 consecutively nested domains, consisting of natural, social, and personal environments. Extensive evidence suggests that features of the natural environment such as sunlight, altitude, diurnal rhythms, vegetation, and biodiversity affect cardiovascular health. However, the effects of the natural environment are moderated by the social environment comprised of built environments, agricultural and industrial activities, pollutants and contaminants, as well as culture, economic activities, and social networks that affect health by influencing access to healthcare, social cohesion, and socioeconomic status. From resources available within society, individuals create personal environments, characterized by private income, wealth and education, and populated by behavioral and lifestyle choices relating to nutrition, physical activity, sleep, the use of recreational drugs, and smoking. An understanding of the interactions between different domains of the envirome and their integrated effects on cardiovascular health could lead to the development of new prevention strategies and deeper insights into etiologic processes that contribute to cardiovascular disease risk and susceptibility.

Role of oxidative stress in cardiovascular disease outcomes following exposure to ambient air pollution

Exposure to ambient air pollution is associated with adverse cardiovascular outcomes. These are manifested through several, likely overlapping, pathways including at the functional level, endothelial dysfunction, atherosclerosis, pro-coagulation and alterations in autonomic nervous system balance and blood pressure. At numerous points within each of these pathways, there is potential for cellular oxidative imbalances to occur. The current review examines epidemiological, occupational and controlled exposure studies and research employing healthy and diseased animal models, isolated organs and cell cultures in assessing the importance of the pro-oxidant potential of air pollution in the development of cardiovascular disease outcomes. The collective body of data provides evidence that oxidative stress (OS) is not only central to eliciting specific cardiac endpoints, but is also implicated in modulating the risk of succumbing to cardiovascular disease, sensitivity to ischemia/reperfusion injury and the onset and progression of metabolic disease following ambient pollution exposure. To add to this large research effort conducted to date, further work is required to provide greater insight into areas such as (a) whether an oxidative imbalance triggers and/or worsens the effect and/or is representative of the consequence of disease progression, (b) OS pathways and cardiac outcomes caused by individual pollutants within air pollution mixtures, or as a consequence of inter-pollutant interactions and (c) potential protection provided by nutritional supplements and/or pharmacological agents with antioxidant properties, in susceptible populations residing in polluted urban cities.

Environmental Determinants of Cardiovascular Disease

Many features of the environment have been found to exert an important influence on cardiovascular disease (CVD) risk, progression, and severity. Changes in the environment because of migration to different geographic locations, modifications in lifestyle choices, and shifts in social policies and cultural practices alter CVD risk, even in the absence of genetic changes. Nevertheless, the cumulative impact of the environment on CVD risk has been difficult to assess and the mechanisms by which some environment factors influence CVD remain obscure. Human environments are complex, and their natural, social, and personal domains are highly variable because of diversity in human ecosystems, evolutionary histories, social structures, and individual choices. Accumulating evidence supports the notion that ecological features such as the diurnal cycles of light and day, sunlight exposure, seasons, and geographic characteristics of the natural environment such as altitude, latitude, and greenspaces are important determinants of cardiovascular health and CVD risk. In highly developed societies, the influence of the natural environment is moderated by the physical characteristics of the social environments such as the built environment and pollution, as well as by socioeconomic status and social networks. These attributes of the social environment shape lifestyle choices that significantly modify CVD risk. An understanding of how different domains of the environment, individually and collectively, affect CVD risk could lead to a better appraisal of CVD and aid in the development of new preventive and therapeutic strategies to limit the increasingly high global burden of heart disease and stroke.

Aldehyde Detection in Electronic Cigarette Aerosols

Acetaldehyde, acrolein, and formaldehyde are the principal toxic aldehydes present in cigarette smoke and contribute to the risk of cardiovascular disease and noncancerous pulmonary disease. The rapid growth of the use of electronic cigarettes (e-cigarettes) has raised concerns over emissions of these harmful aldehydes. This work determines emissions of these aldehydes in both free and bound (aldehyde-hemiacetal) forms and other carbonyls from the use of e-cigarettes. A novel silicon microreactor with a coating phase of 4-(2-aminooxyethyl)-morpholin-4-ium chloride (AMAH) was used to trap carbonyl compounds in the aerosols of e-cigarettes via oximation reactions. AMAH-aldehyde adducts were measured using gas chromatography-mass spectrometry. ¹H nuclear magnetic resonance spectroscopy was used to analyze hemiacetals in the aerosols. These aldehydes were detected in the aerosols of all e-cigarettes. Newer-generation e-cigarette devices generated more aldehydes than the first-generation e-cigarettes because of higher battery power output. Formaldehyde-hemiacetal was detected in the aerosols generated from some e-liquids using the newer e-cigarette devices at a battery power output of 11.7 W and above. The emission of these aldehydes from all e-cigarettes, especially higher levels of aldehydes from the newer-generation e-cigarette devices, indicates the risk of using e-cigarettes.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Effect of Occupational Exposure on Blood Cell Counts, Electrocardiogram and Blood Pressure in Rice Mill Workers

INTRODUCTION

Under normal conditions, parasympathetic and sympathetic nervous systems interact to regulate the heart rate of about 70 beats per minute. Activation of sympathetic nervous system by emotional or physical stress increases heart rate and the force of heart beat. There are many factors which alter the heart rate. The chemical and mechanical stimulation of receptors can also cause change in blood pressure through autonomic nervous system. Exposure to dust also causes alteration in blood cell counts. This can be due to allergic reactions and inflammation which in turn evoked by dust entering the lungs.

OBJECTIVES

Aim of the study was to evaluate the effect of occupational exposure on haematological and cardiovascular parameters of rice mill workers by analysing Blood Cell Counts, ECG and Blood Pressure.

MATERIALS AND METHODS

This cross-sectional study was carried on 134 rice mill workers and an equal number of age and sex matched healthy individual. The blood cell counts were determined by automated cell counter machine, ECG was recorded by using ECG machine and Blood Pressure was measured by using mercurial sphygmomanometer.

RESULTS

Neurtrophil, Eosinophil and Lymphocyte count among haematological parameters were significantly increased in exposed individuals. Marked variation was seen in ECG and Blood pressure among cardiovascular parameters of exposed individuals compared with control group.

CONCLUSION

The findings of our study clearly indicate that the rice mill workers are under high level of dust exposure which has deleterious effects on their blood and tissues. It is due to high oxidative stress. There are abnormalities seen in cardiovascular system.

Environmental factors in cardiovascular disease

Environmental exposure is an important but underappreciated risk factor contributing to the development and severity of cardiovascular disease (CVD). The heart and vascular system are highly vulnerable to a number of environmental agents--ambient air pollution and the metals arsenic, cadmium, and lead are widespread and the most-extensively studied. Like traditional risk factors, such as smoking and diabetes mellitus, these exposures advance disease and mortality via augmentation or initiation of pathophysiological processes associated with CVD, including blood-pressure control, carbohydrate and lipid metabolism, vascular function, and atherogenesis. Although residence in highly polluted areas is associated with high levels of cardiovascular risk, adverse effects on cardiovascular health also occur at exposure levels below current regulatory standards. Considering the widespread prevalence of exposure, even modest contributions to CVD risk can have a substantial effect on population health. Evidence-based clinical and public-health strategies aimed at reducing environmental exposures from current levels could substantially lower the burden of CVD-related death and disability worldwide.

Residential Proximity to Major Roadways Is Associated With Increased Levels of AC133+ Circulating Angiogenic Cells

OBJECTIVES

Previous studies have shown that residential proximity to a roadway is associated with increased cardiovascular disease risk. Yet, the nature of this association remains unclear, and its effect on individual cardiovascular disease risk factors has not been assessed. The objective of this study was to determine whether residential proximity to roadways influences systemic inflammation and the levels of circulating angiogenic cells.

APPROACH AND RESULTS

In a cross-sectional study, cardiovascular disease risk factors, blood levels of C-reactive protein, and 15 antigenically defined circulating angiogenic cell populations were measured in participants (n=316) with moderate-to-high cardiovascular disease risk. Attributes of roadways surrounding residential locations were assessed using geographic information systems. Associations between road proximity and cardiovascular indices were analyzed using generalized linear models. Close proximity (<50 m) to a major roadway was associated with lower income and higher rates of smoking but not C-reactive protein levels. After adjustment for potential confounders, the levels of circulating angiogenic cells in peripheral blood were significantly elevated in people living in close proximity to a major roadway (CD31(+)/AC133(+), AC133(+), CD34(+)/AC133(+), and CD34(+)/45(dim)/AC133(+) cells) and positively associated with road segment distance (CD31(+)/AC133(+), AC133(+), and CD34(+)/AC133(+) cells), traffic intensity (CD31(+)/AC133(+) and AC133(+) cells), and distance-weighted traffic intensity (CD31(+)/34(+)/45(+)/AC133(+) cells).

CONCLUSIONS

Living close to a major roadway is associated with elevated levels of circulating cells positive for the early stem marker AC133(+). This may reflect an increased need for vascular repair. Levels of these cells in peripheral blood may be a sensitive index of cardiovascular injury because of residential proximity to roadways.

Acrolein decreases endothelial cell migration and insulin sensitivity through induction of let-7a

Acrolein is a major reactive component of vehicle exhaust, and cigarette and wood smoke. It is also present in several food substances and is generated endogenously during inflammation and lipid peroxidation. Although previous studies have shown that dietary or inhalation exposure to acrolein results in endothelial activation, platelet activation, and accelerated atherogenesis, the basis for these effects is unknown. Moreover, the effects of acrolein on microRNA (miRNA) have not been studied. Using AGILENT miRNA microarray high-throughput technology, we found that treatment of cultured human umbilical vein endothelial cells with acrolein led to a significant (>1.5-fold) upregulation of 12, and downregulation of 15, miRNAs. Among the miRNAs upregulated were members of the let-7 family and this upregulation was associated with decreased expression of their protein targets, β3 integrin, Cdc34, and K-Ras. Exposure to acrolein attenuated β3 integrin-dependent migration and reduced Akt phosphorylation in response to insulin. These effects of acrolein on endothelial cell migration and insulin signaling were reversed by expression of a let-7a inhibitor. Also, inhalation exposure of mice to acrolein (1 ppm x 6 h/day x 4 days) upregulated let-7a and led to a decrease in insulin-stimulated Akt phosphorylation in the aorta. These results suggest that acrolein exposure has broad effects on endothelial miRNA repertoire and that attenuation of endothelial cell migration and insulin signaling by acrolein is mediated in part by the upregulation of let-7a. This mechanism may be a significant feature of vascular injury caused by inflammation, oxidized lipids, and exposure to environmental pollutants.

Early life permethrin treatment leads to long-term cardiotoxicity

Environmental, nutritional or hormonal influences in early life may have long-term effects changing homeostatic processes and physiological parameters in adulthood. NF-kB and Nrf2, two of the main transcription factors regulating genes involved in pro-inflammatory and antioxidant responses respectively, can be modified by various stimuli. NF-kB controls immediate early genes and is required for cardiomyocyte hypertrophic growth, while Nrf2 protects the heart from oxidative stress-induced cardiovascular complications. The aim of this study was to investigate the impact of early life permethrin treatment (1/50 of LD50, from 6th to 21st day of life) on the development of cardiotoxicity in 500-day-old rats. Nrf2 and NF-kB gene expression, calcium level and heart surface area were chosen as biomarkers of toxicity. Six candidate reference genes were first examined and GAPDH resulted the most stable one for RT-qPCR. The comparative expression analysis of the target genes showed 1.62-fold increase in Nrf2 mRNA level, while the NF-kB mRNA in treated rats was not significantly changed compared to control ones. A significant decrease in heart surface area was observed in treated rats (296.59 ± 8.09, mm(2)) with respect to the control group (320.86 ± 4.93, mm(2)). Finally, the intracellular calcium influx in heart of early life treated rats increased 4.33-fold compared to the control one. In conclusion, early life pesticide exposure to low doses of permethrin insecticide, has long-term consequences leading to cardiac hypotrophy, increased calcium and Nrf2 gene expression levels in old age.

Comparison of nicotine and carcinogen exposure with water pipe and cigarette smoking

BACKGROUND

Smoking tobacco preparations in a water pipe (hookah) is widespread in many places of the world and is perceived by many as relatively safe. We investigated biomarkers of toxicant exposure with water pipe compared with cigarette smoking.

METHODS

We conducted a crossover study to assess daily nicotine and carcinogen exposure with water pipe and cigarette smoking in 13 people who were experienced in using both products.

RESULTS

When smoking an average of 3 water pipe sessions compared with smoking 11 cigarettes per day (cpd), water pipe use was associated with a significantly lower intake of nicotine, greater exposure to carbon monoxide (CO), and a different pattern of carcinogen exposure compared with cigarette smoking, with greater exposure to benzene, and high molecular weight polycyclic aromatic hydrocarbon (PAH), but less exposure to tobacco-specific nitrosamines, 1,3-butadiene, acrolein, acrylonitrile, propylene oxide, ethylene oxide, and low molecular weight PAHs.

CONCLUSIONS

A different pattern of carcinogen exposure might result in a different cancer risk profile between cigarette and water pipe smoking. Of particular concern is the risk of leukemia related to high levels of benzene exposure with water pipe use.

IMPACT

Smoking tobacco in water pipes has gained popularity in the United States and around the world. Many believe that water pipe smoking is not addictive and less harmful than cigarette smoking. We provide data on toxicant exposure that will help guide regulation and public education regarding water pipe health risk.

Small reactive carbonyl compounds as tissue lipid oxidation products; and the mechanisms of their formation thereby

Small reactive carbonyl compounds (RCCs) such as formaldehyde, acetaldehyde, acrolein, crotonaldehyde, glyoxal, methylglyoxal, glycolaldehyde, glycidaldehyde, and 2-butene-1,4-dial are involved in carbonyl and oxidative stress-related physiological disorders. While some evidence indicates that lipid oxidation could be an important source of these compounds in vivo, this has sometimes been doubted because the mechanisms of their formation thereby are poorly understood. Here, representative literature supporting the significant formation of these compounds during lipid oxidation under physiologically relevant conditions are highlighted, and the strengths and weaknesses of previously proposed mechanisms of their formation thereby are considered. In addition, based on the current understanding of lipid oxidation chemistry, some new pathways of their formation are suggested. The suggested pathways also generate 4-hydroxy-2-butenal, a precursor of the carcinogen furan, whose endogenous formation in tissues has hitherto not been seriously considered.

Glutathione peroxidase inhibitory assay for electrophilic pollutants in diesel exhaust and tobacco smoke

We developed a rapid kinetic bioassay demonstrating the inhibition of glutathione peroxidase 1 (GPx-1) by organic electrophilic pollutants, such as acrolein, crotonaldehyde, and p-benzoquinone, that are frequently found as components of tobacco smoke, diesel exhaust, and other combustion sources. In a complementary approach, we applied a high-resolution proton-transfer reaction time-of-flight mass spectrometer to monitor in real-time the generation of electrophilic volatile carbonyls in cigarette smoke. The new bioassay uses the important antioxidant selenoenzyme GPx-1, immobilized to 96-well microtiter plates, as a probe. The selenocysteine bearing subunits of the enzyme's catalytic site are viewed as cysteine analogues and are vulnerable to electrophilic attack by compounds with conjugated carbonyl systems. The immobilization of GPx-1 to microtiter plate wells enabled facile removal of excess reactive inhibitory compounds after incubation with electrophilic chemicals or aqueous extracts of air samples derived from different sources. The inhibitory response of cigarette smoke and diesel exhaust particle extracts were compared with chemical standards of a group of electrophilic carbonyls and the arylating p-benzoquinone. GPx-1 activity was directly inactivated by millimolar concentrations of highly reactive electrophilic chemicals (including acrolein, glyoxal, methylglyoxal, and p-benzoquinone) and extracts of diesel and cigarette smoke. We conclude that the potential of air pollutant components to generate oxidative stress may be, in part, a result of electrophile-derived covalent modifications of enzymes involved in the cytosolic antioxidant defense.