Air pollution and cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis

Fine particulate matter-sudden death association modified by ventricular hypertrophy and inflammation: a case-crossover study

Background

Sudden death accounts for approximately 10% of deaths among working-age adults and is associated with poor air quality. Objectives: To identify high-risk groups and potential modifiers and mediators of risk, we explored previously established associations between fine particulate matter (PM2.5) and sudden death stratified by potential risk factors.

Methods

Sudden death victims in Wake County, NC, from 1 March 2013 to 28 February 2015 were identified by screening Emergency Medical Systems reports and adjudicated (n = 399). Daily PM2.5 concentrations for Wake County from the Air Quality Data Mart were linked to event and control periods. Potential modifiers included greenspace metrics, clinical conditions, left ventricular hypertrophy (LVH), and neutrophil-to-lymphocyte ratio (NLR). Using a case-crossover design, conditional logistic regression estimated the OR (95%CI) for sudden death for a 5 μg/m3 increase in PM2.5 with a 1-day lag, adjusted for temperature and humidity, across risk factor strata.

Results

Individuals having LVH or an NLR above 2.5 had PM2.5 associations of greater magnitude than those without [with LVH OR: 1.90 (1.04, 3.50); NLR > 2.5: 1.25 (0.89, 1.76)]. PM2.5 was generally less impactful for individuals living in areas with higher levels of greenspace.

Conclusion

LVH and inflammation may be the final step in the causal pathway whereby poor air quality and traditional risk factors trigger arrhythmia or myocardial ischemia and sudden death. The combination of statistical evidence with clinical knowledge can inform medical providers of underlying risks for their patients generally, while our findings here may help guide interventions to mitigate the incidence of sudden death.

MXene-Decorated Nylon Mesh Filters for Improvement of Indoor Air Quality by PM2.5 Filtration

Air pollution is a problem that is increasing day by day and poses a threat on a global scale. Particulate matter (PM) is one of the air pollutants that is the biggest concern regarding air quality. In order to control PM pollution, highly effective air filters are required. This is especially necessary for PM with a diameter of less than 2.5 micrometers (PM_2.5), which poses a health risk to humans. In this study, we demonstrate for the first time the use of a two-dimensional titanium carbide (Ti₃C₂) MXene nanosheets-decorated nylon mesh (MDNM) as a low cost and highly efficient PM_2.5 filter. This study develops a proof-of-concept method to capture PM_2.5. Thanks to their high specific surface area and active surface-terminating groups, conductive MXene nanosheets have made nylon mesh filters promising candidates for air filtration. The developed filters used electrostatic force to capture PM_2.5 and showed high removal efficiency (90.05%) when an ionizer was used and under an applied voltage of 10 V, while a commercial high-efficiency particulate air (HEPA) filter had a removal efficiency of 91.03% measured under identical conditions. The proposed filters, which stand out with their low energy consumption, low pressure drop (∼14 Pa), and cost-effectiveness, have the potential to be a strong competitor to conventional PM filter systems used in many fields.

Long-term air pollution exposure and markers of cardiometabolic health in the National Longitudinal Study of Adolescent to Adult Health (Add Health)

BACKGROUND

Air pollution exposure is associated with cardiovascular morbidity and mortality. Although exposure to air pollution early in life may represent a critical window for development of cardiovascular disease risk factors, few studies have examined associations of long-term air pollution exposure with markers of cardiovascular and metabolic health in young adults.

OBJECTIVES

By combining health data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) with air pollution data from the Fused Air Quality Surface using Downscaling (FAQSD) archive, we: (1) calculated multi-year estimates of exposure to ozone (O3) and particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5) for Add Health participants; and (2) estimated associations between air pollution exposures and multiple markers of cardiometabolic health.

METHODS

Add Health is a nationally representative longitudinal cohort study of over 20,000 adolescents aged 12-19 in the United States (US) in 1994-95 (Wave I). Participants have been followed through adolescence and into adulthood with five in-home interviews. Estimated daily concentrations of O3 and PM2.5 at census tracts were obtained from the FAQSD archive and used to generate tract-level annual averages of O3 and PM2.5 concentrations. We estimated associations between average O3 and PM2.5 exposures from 2002 to 2007 and markers of cardiometabolic health measured at Wave IV (2008-09), including hypertension, hyperlipidemia, body mass index (BMI), diabetes, C-reactive protein, and metabolic syndrome.

RESULTS

The final sample size was 11,259 individual participants. The average age of participants at Wave IV was 28.4 years (range: 24-34 years). In models adjusting for age, race/ethnicity, and sex, long-term O3 exposure (2002-07) was associated with elevated odds of hypertension, with an odds ratio (OR) of 1.015 (95% confidence interval [CI]: 1.011, 1.029); obesity (1.022 [1.004, 1.040]); diabetes (1.032 [1.009,1.054]); and metabolic syndrome (1.028 [1.014, 1.041]); PM2.5 exposure (2002-07) was associated with elevated odds of hypertension (1.022 [1.001, 1.045]).

CONCLUSION

Findings suggest that long-term ambient air pollution exposure, particularly O3 exposure, is associated with cardiometabolic health in early adulthood.

Perinatal diesel exhaust exposure causes persistent changes in the brains of aged mice: An assessment of behavioral and biochemical endpoints related to neurodegenerative disease

Epidemiological studies support an association between air pollution exposure, specifically particulate matter (PM), and neurodegenerative disease. Diesel exhaust (DE) is a principal component of ambient air pollution and a major contributor of PM. Our study aimed to examine whether early-life perinatal DE exposure is sufficient to affect behavioral and biochemical endpoints related to Alzheimer's disease later in life. To achieve this, mice were perinatally exposed (embryonic day 0-postnatal day 21) to DE (250-300 μg/m3 ) or filtered air (FA), and allowed to reach aged status (>18 months). Mice underwent behavioral assessment at 6 and 20 months of age, with tissue collected at 22 months for biochemical endpoints. At 6 months, minimal changes were noted in home-cage behavior of DE treated animals. At 20 months, an alternation deficit was noted with the T-maze, although no difference was seen in the object location task or any home-cage metrics. DE exposure did not alter the expression of Aβ42, phosphorylated tau S199, or total tau. However, IBA-1 protein, a microglial activation marker, was significantly higher in DE exposed animals. Further, lipid peroxidation levels were significantly higher in the DE exposed animals compared to FA controls. Cytokine levels were largely unchanged with DE exposure, suggesting a lack of inflammation despite persistent lipid peroxidation. Taken together, the findings of this study support that perinatal exposure alone is sufficient to cause lasting changes in the brain, although the effects appear to be less striking than those previously reported in younger animals, suggesting some effects do not persist over time. These findings are encouraging from a public health standpoint and support the aggressive reduction of DE emissions to reduce lifetime exposure and potentially reduce disease outcome.

Cognitive impairment, depressive-like behaviors and hippocampal microglia activation following exposure to air pollution nanoparticles

Air pollution particulate matter (PM) is a world risk factor that the effects of long-term exposure to these factors in terms of damage to cardiovascular and pulmonary function are well known, but little is known comparatively about the effects of PM on emotional and cognitive processes. Exposure to PM can adversely affect the central nervous system (CNS) by inflammatory pathways and activation of reactive oxygen species (ROS) associated with urban air pollution PM. Therefore, we investigated whether prolonged exposure to diesel exhaust particles (DEPs) affects hippocampal inflammatory cytokines and emotional and cognition responses. Male mice were exposed to DEPs for 6 and 12 weeks. DEP-exposed mice indicated more disorders in depressive-like responses and spatial memory and learning than in control groups. Pro-inflammatory cytokine expression in tge hippocampus was increased among mice exposed to DEPs. The number of activated microglia increased in the dentate gyrus (DG) and CA1 regions of the hippocampus in DEP-exposed mice. These results show that chronic exposure to DEPs can alter neurobehavioral and impair cognition. Generally, these findings reaffirm the importance of protecting from exposure to ambient PM2.5 and also advance our understanding of the toxic actions of air pollution nanoparticles.

Exposure to urban air pollution particulate matter: neurobehavioral alteration and hippocampal inflammation

Air pollution is associated with many neurodevelopmental and neurological disorders in human populations. Rodent models show similar neurotoxic effects of urban air pollution ultrafine particulate matter (UFPs < 100 nm (PM0.1)), collected by different methods or from various sources. Exposure to ultrafine particulate matter (UFPs < 100 nm (PM0.1)) can be adversely impacting the central nervous system (CNS) by the activation of proinflammatory pathways and reactive oxygen species associated with air pollution particulate matter. We investigated hippocampal inflammatory cytokines, neurobehavioral alteration, and neuronal morphology following exposure to diesel exhaust particles (DEPs) in mice. Male mice were DEPs exposed for 14 weeks. Mice exposed to DEPs showed more disorders in spatial memory and learning and depressive-like responses than control mice. Expression of hippocampal pro-inflammatory cytokine was increased among DEPs exposure mice. The density of neurons in hippocampus CA1, CA3, and dentate gyrus (DG) regions decreased in DEPs mice. Overall, these findings show that prolonged exposure to DEPs in the world's major cities can alter neurobehavioral and impair cognition.

Long-Term Exposures to Air Pollutants and Risk of Peripheral Arterial Occlusive Disease: A Nationwide Cohort Study in Taiwan

Air pollution is one of the most alarming environmental issues which causes multiple health hazards. An association between air pollution and cardiovascular diseases has been established through many prior studies. In this study, we aimed to evaluate the risk of long-term exposure to air pollution (PM_2.5, CO, and NO₂) and its association with the risk of developing peripheral arterial occlusive disease (PAOD). PAOD is a condition involving impairment of perfusion of blood in the distal parts of the aorta due to narrowing of the arteries (arterial stenosis) and has been reported as a risk factor for developing cardiovascular diseases. Furthermore, the risk of PAOD increases with age, and hence is a serious public health issue and a cause for concern, especially for an aging society such as Taiwan. Two national-scale databases from Taiwan, the national health insurance database (NHIRD) and the Taiwan air quality-monitoring database (TAQMD), were linked to conduct this cohort study between 2003 and 2013. Cox proportional hazards regression with time-dependent modeling was used to evaluate the hazard ratio (HR) for PAOD with respect to daily exposure to air pollutants. The concentrations of each of the pollutants of interest (PM_2.5, NO₂, and CO) were categorized into four categories according to the daily average concentration of air pollutants for every quarter of the year, Q1 to Q4 (Q4 = highest). The cumulative incidence of PAOD was examined by Kaplan–Meier analysis with two-tailed log-rank test. A total of 1,598 PAOD cases were identified during the 10-year follow-up period, along with 98,540 non-PAOD controls. In the multivariate analysis, after adjusting for age, gender, urbanization level, residential area, baseline comorbidities, and medications, the adjusted HRs were PM_2.5 = 1.14 (95% CI 1.13–1.16), NO₂ = 1.03 (95% CI 1.02–1.04), and CO = 2.35 (95% CI 1.95–2.84). Kaplan–Meier analysis showed that CO (P < 0.0001) and PM_2.5 (P < 0.0001) concentrations were strongly and positively associated with the cumulative incidence of PAOD during the follow-up period. Findings from this study established that prolonged exposure to air pollutants CO and PM_2.5 are significant factors that, among other well-known causes, may also play a potential role in PAOD pathogenesis.

Simulated vehicle exhaust exposure induces sex-dependent behavioral deficits in rats

Chronic exposure to vehicle exhaust emissions are known to cause several adverse health effects. In this study, we examined the impact of several parameters of behavioral, cardiovascular and biochemical functions upon exposure of pro-oxidants CO2, NO2 and CO (simulated vehicle exhaust exposure: SVEE) in male and female rats. Adult rats were subjected to SVEE or ambient air in whole body chambers (5 h/day, 2 weeks). Male, but not female, rats developed memory deficits, and exhibited anxiety- and depression-like behavior, accompanied with significantly high levels of serum corticosterone, oxidative stress, and inflammatory markers (CRP and TNFα), associated with lower levels of total antioxidant capacity, glutathione, glyoxalase and superoxide dismutase (SOD) activities. Brain region-specific downregulation of Cu/Zn SOD, Mn SOD, GSR, PKCα, ERK1/2, CaMKIV, CREB, BDNF and NMDAR subunit protein expression were also observed in male, but not female, rats. Blood pressure, heart rate and eGFR were not negatively impacted by SVEE. Our results suggest that SVEE, through its pro-oxidant content, induces oxido-inflammation in susceptible brain regions in a sex-dependent manner.

Short-term exposure to air pollution and biomarkers of cardiovascular effect: A repeated measures study

To help understand the pathophysiologic mechanisms linking air pollutants and cardiovascular disease (CVD), we employed a repeated measures design to investigate the associations of four short-term air pollution exposures - particulate matter less than 2.5 μm in diameter (PM_2.5), nitrogen dioxide (NO₂), ozone (O₃) and sulfur dioxide (SO₂), with two blood markers involved in vascular effects of oxidative stress, soluble lectin-like oxidized LDL receptor-1 (sLOX-1) and nitrite, using data from the Multi-Ethnic Study of Atherosclerosis (MESA). Seven hundred and forty participants with plasma sLOX-1 and nitrite measurements at three exams between 2002 and 2007 were included. Daily PM_2.5, NO₂, O₃ and SO₂ zero to seven days prior to blood draw were estimated from central monitors in six MESA regions, pre-adjusted using site-specific splines of meteorology and temporal trends, and an indicator for day of the week. Unconstrained distributed lag generalized estimating equations were used to estimate net effects over eight days with adjustment for sociodemographic and behavioral factors. The results showed that higher short-term concentrations of PM_2.5, but not other pollutants, were associated with increased sLOX-1 analyzed both as a continuous outcome (percent change per interquartile increase: 16.36%, 95%CI: 0.1-35.26%) and dichotomized at the median (odds ratio per interquartile increase: 1.21, 95%CI: 1.01-1.44). The findings were not meaningfully changed after adjustment for additional covariates or in several sensitivity analyses. Pollutant concentrations were not associated with nitrite levels. This study extends earlier experimental findings of increased sLOX-1 levels following PM inhalation to a much larger population and at ambient concentrations. In light of its known mechanistic role in promoting vascular disease, sLOX-1 may be a suitable translational biomarker linking air pollutant exposures and cardiovascular outcomes.

Urban air pollution induces alterations in redox metabolism and mitochondrial dysfunction in mice brain cortex

Previous reports indicate that the central nervous system (CNS) is a target of air pollution, causing tissue damage and functional alterations. Oxidative stress and neuroinflammation have been pointed out as possible mechanisms mediating these effects. The aim of this work was to study the chronic effects of urban air pollution on mice brain cortex, focusing on oxidative stress markers, and mitochondrial function. Male 8-week-old BALB/c mice were exposed to filtered air (FA, control) or urban air (UA) inside whole-body exposure chambers, located in a highly polluted area of Buenos Aires city, for up to 4 weeks. Glutathione levels, assessed as GSH/GSSG ratio, were decreased after 1 and 2 weeks of exposure to UA (45% and 25% respectively vs. FA; p < 0.05). A 38% increase in lipid peroxidation was found after 1 week of UA exposure (p < 0.05). Regarding protein oxidation, carbonyl content was significantly increased at week 2 in UA-exposed mice, compared to FA-group, and an even higher increment was found after 4 weeks of exposure (week 2: 40% p < 0.05, week 4: 54% p < 0.001). NADPH oxidase (NOX) and glutathione peroxidase (GPx) activities were augmented at all the studied time points, while superoxide dismutase (Cu,Zn-SOD cytosolic isoform) and glutathione reductase (GR) activities were increased only after 4 weeks of UA exposure (p < 0.05). The increased NOX activity was accompanied with higher expression levels of NOX2 regulatory subunit p47^phox, and NOX4 (p < 0.05). Also, UA mice showed impaired mitochondrial function due to a 50% reduction in O₂ consumption in active state respiration (p < 0.05), a 29% decrease in mitochondrial inner membrane potential (p < 0.05), a 65% decrease in ATP production rate (p < 0.01) and a 30% increase in H₂O₂ production (p < 0.01). Moreover, respiratory complexes I-III and II-III activities were decreased in UA group (30% and 36% respectively vs. FA; p < 0.05). UA exposed mice showed alterations in mitochondrial function, increased oxidant production evidenced by NOX activation, macromolecules damage and the onset of the enzymatic antioxidant system. These data indicate that oxidative stress and impaired mitochondrial function may play a key role in CNS damage mechanisms triggered by air pollution.

Relation between Accumulated Air Pollution Exposure and Sub-Clinical Cardiovascular Disease in 33,723 Danish 60-74-Year-Old Males from the Background Population (AIR-CARD): A Method Article

Cardiovascular disease is one of the main causes of death and disability in the Western world, and there is increasing evidence that air pollution is a risk factor for developing sub-clinical cardiovascular diseases. Previous studies have shown a correlation between cardiovascular disease and short-term exposure to elevated air pollution levels. However, the literature on the impact of long-term effect of air pollution is limited. We have a unique opportunity to evaluate this correlation. The DEHM/UBM/AirGIS model system calculates air pollution in a high temporal and spatial resolution and traces air pollution retrospectively to year 1979. The model calculates accumulated exposure using annual exposure from PM2.5 in relation to home and work addresses and takes into account working hours and holidays. We link the results from this model system to a population-based cardiovascular screening cohort of 33,723 individuals in the age of 60-74 to assess the contribution of the specific accumulated air pollution to the presence of sub-clinical arteriosclerosis in the coronary vessels, abdominal aortic aneurysms, and peripheral arterial disease. This correlation will be further analyzed in relation to specific air pollutants. This study will introduce more precise data for a longer period of time and incorporate participant's home and work addresses.

Effects of ambient particulate matter on vascular tissue: a review

Fine and ultra-fine particulate matter (PM) are major constituents of urban air pollution and recognized risk factors for cardiovascular diseases. This review examined the effects of PM exposure on vascular tissue. Specific mechanisms by which PM affects the vasculature include inflammation, oxidative stress, actions on vascular tone and vasomotor responses, as well as atherosclerotic plaque formation. Further, there appears to be a greater PM exposure effect on susceptible individuals with pre-existing cardiovascular conditions.

Impacts of air pollution on health: evidence from longitudinal cohort data of patients with cardiovascular diseases

This study uses longitudinal cohort data to estimate the impacts of air pollution on health outcomes among people first hospitalised with heart diseases. Despite the generally low level of pollution in Australia, we find that acute exposure to pollution increases readmissions to hospitals within 3-12 months after discharge and is more evident among those suffering from heart failure. We further show that chronic exposure to air pollution increases the risk of death within 72 months, hospital admissions and general practitioner (GP) visits. Patients with coronary heart disease or cerebrovascular disease are the most affected groups. Finally, a cost saving of $1.3 billion will be generated to the health sector, if the monthly concentration of PM₁₀ and CO was lowered to 15.49 µg/m³ and 122.99 µg/m³, respectively. The findings from our study emphasize the need for policies that target significant reduction in ambient PM₁₀ and CO to decrease the demand for scarce healthcare resources for cardiac diseases.

Cooking fuels use and carotid intima-media thickness during early pregnancy of women in Myanmar

BACKGROUND

Fuels burned in households for cooking cause indoor air pollution, exposing those who are cooking. Despite the mounting evidence of the effects of fuels use on health, few studies focus on the effect of cooking fuels have on carotid intima-media thickness (CIMT), a surrogate atherosclerosis biomarker in the early stages of pregnancy. This study aimed to examine the association between the use of cooking fuels and CIMT during early trimester of pregnancy among cooking women in Myanmar.

METHODOLOGY

In this cross-sectional study, a part of an ongoing birth cohort analysis, a total of 192 cooking pregnant women over 18 years with gestational weeks less than 18 were recruited from 15 rural health centers in Nay Pyi Taw from September to November 2019. Sociodemographic data, residential data, and fuels use data were collected with semi-structured questionnaires in face-to-face interviews. Anthropometric, hemodynamic, blood lipids, and ultrasound CIMT measurements were performed under standard protocols. Multiple linear regression was modeled to explore associations.

RESULTS

The study included 70 firewood fuel users, 26 charcoal fuel users, and 96 electricity fuel users. Following adjustments for potential confounding factors, firewood use was significantly associated with the increase of all CIMT analyzed. Importantly, a greater increase of mean CIMT of the right common carotid artery (RCCA; β = 0.033 mm; 95%CI: 0.006, 0.058; P<0.05) had significant association with charcoal use compared to firewood use (β = 0.029 mm; 95%CI: 0.010, 0.049; P<0.05).

CONCLUSIONS

Our findings demonstrate that the indoor use of cooking fuels that cause indoor air pollution, such as firewood and charcoal, is a considerable risk factor for human health and is associated with increased CIMT, wherein charcoal use contributes to more increase of mean CIMT of the RCCA. Measures to prevent health risks related to the use of such fuels should be instituted early on during pregnancy.

Involvement of oxidative stress and mitochondrial mechanisms in air pollution-related neurobiological impairments

Background

Vehicle exhaust emissions are known to be significant contributors to physical and psychological stress. Vehicle exhaust-induced stress and associated respiratory and cardiovascular complications are well-known, but the impact of this stress on the brain is unclear. Simulated vehicle exhaust exposure (SVEE) in rats causes behavioral and cognitive deficits. In the present study, the underlying mechanisms were examined. Our postulation is that SVEE, a simulation of physiologically relevant concentrations of pro-oxidants (0.04% carbon dioxide, 0.9 ppm nitrogen dioxide, 3 ppm carbon monoxide) creates a toxic stress environment in the brain that results in an imbalance between production of reactive oxygen species and the counteracting antioxidant mechanisms. This impairs mitochondrial function in the high bioenergetic demand areas of the brain including the hippocampus (HIP), amygdala (AMY) and the prefrontal cortex (PFC), disrupting neuronal network, and causing behavioral deficits. Mitochondria-targeted antioxidant Mito-Q protects against these impairments.

Methods

Sprague Dawley rats were provided with Mito-Q (250 μM) in drinking water for 4 weeks followed by SVEE 5 h/day for 2 weeks, followed by behavioral and biochemical assessments.

Results

SVEE resulted in anxiety- and depression-like behavior, accompanied with increased oxidative stress, diminished antioxidant response and mitochondrial impairment reflected from electron transport chain (ETC) disruption, reduced oxygen consumption, low adenosine tri-phosphate (ATP) synthesis and an alteration in the mitochondrial biochemical dynamics assessed via protein expression profiles of mitochondrial fission marker, dynamin-related protein-1 and fusion markers, mitofusin-1/2 in the HIP, AMY and the PFC. Mito-Q treatment prevented SVEE-induced behavioral deficits, attenuated rise in oxidative stress and also prevented SVEE-induced mitochondrial impairment.

Conclusion

This study demonstrates a causal mechanism mediating SVEE-induced behavioral deficits in rats. We further established that SVEE is a toxicological stressor that induces oxidative stress and results in mitochondrial impairment, which by disrupting neural circuitry impairs cognitive and behavioral functions.

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Simulated vehicle exhaust exposure is a source of toxicological stress.

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Prolonged exposure leads to behavioral deficits and elevated oxidative stress.

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Oxidative stress elevation triggers mitochondrial impairment in the brain.

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Mito-Q prevents exhaust-associated behavioral and biochemical alterations.

Respiratory gases, air pollution and epilepsy

A growing number of studies have shown that exposure to air pollutants such as particulate matter and gases can cause cardiovascular, neurodegenerative and psychiatric diseases. The severity of the changes depends on several factors such as exposure time, age and gender. Inflammation has been considered as one of the main factors associated with the generation of these diseases. Here we present some cellular mechanisms activated by air pollution that may represent risk factors for epilepsy and drug resistance associated to epilepsy.

Cardiovascular Diseases and Long-term Self-reported Exposure to Pollution: RESULTS OF A NATIONAL EPIDEMIOLOGICAL STUDY IN LEBANON

BACKGROUND

Cardiovascular diseases (CVDs) are linked to high mortality and morbidity, particularly in developing countries. Some studies have linked indoor and outdoor pollution to CVD, but results are inconsistent. Our objective was to assess this association in Lebanon, a Middle Eastern country.

METHODS

A national cross-sectional study was conducted across Lebanon. CVD prevalence, which included prevalent ischemic heart and cerebrovascular diseases, was assessed. Moreover, in addition to self-reported items of pollution exposure, we assessed potential predictors of CVD, including sociodemographic characteristics, self-reported health information, and biological measurements.

RESULTS

We assessed the dose-effect relationship of pollution items in relation with CVD. Self-reported indoor and outdoor pollution exposures were associated with CVD, with or without taking biological values into account. Moreover, we found a dose-effect relationship of exposure with risk of disease (44% increase in risk of CVD for every additional pollution exposure item), after adjustment for sociodemographic and biological characteristics.

CONCLUSION

Although additional studies would be necessary to confirm these findings, interventions should start to sensitize the population about the effect of pollution on chronic diseases and the work of reducing pollution and improving air quality should be implemented to decrease the disease burden on the population and health system.

Air Pollution and Cardiovascular Disease: A Focus on Vulnerable Populations Worldwide

Purpose of review

Certain subgroups defined by sociodemographics (race/ethnicity, age, sex and socioeconomic status [SES]), geographic location (rural vs. urban), comorbid conditions and country economic conditions (developed vs. developing) may disproportionately suffer the adverse cardiovascular effects of exposure to ambient air pollution. Yet, previous reviews have had a broad focus on the general population without consideration of these potentially vulnerable populations.

Recent findings

Over the past decade, a wealth of epidemiologic studies have linked air pollutants including particulate matter, oxides of nitrogen, and carbon monoxide to cardiovascular disease (CVD) risk factors, subclinical CVD, clinical cardiovascular outcomes and cardiovascular mortality in certain susceptible populations. Highest risk for poor CVD outcomes from air pollution exist in racial/ethnic minorities, especially in blacks compared to whites in the U.S, those at low SES, elderly populations, women, those with certain comorbid conditions and developing countries compared to developed countries. However, findings are less consistent for urban compared to rural populations.

Summary

Vulnerable subgroups including racial/ethnic minorities, women, the elderly, smokers, diabetics and those with prior heart disease had higher risk for adverse cardiovascular outcomes from exposure to air pollution. There is limited data from developing countries where concentrations of air pollutants are more extreme and cardiovascular event rates are higher than that of developed countries. Further epidemiologic studies are needed to understand and address the marked disparities in CVD risk conferred by air pollution globally, particularly among these vulnerable subgroups.

Effects of Diesel Exhaust on Cardiovascular Function and Oxidative Stress

SIGNIFICANCE

Air pollution is a major global health concern with particulate matter (PM) being especially associated with increases in cardiovascular morbidity and mortality. Diesel exhaust emissions are a particularly rich source of the smallest sizes of PM ("fine" and "ultrafine") in urban environments, and it is these particles that are believed to be the most detrimental to cardiovascular health. Recent Advances: Controlled exposure studies to diesel exhaust in animals and man demonstrate alterations in blood pressure, heart rate, vascular tone, endothelial function, myocardial perfusion, thrombosis, atherogenesis, and plaque stability. Oxidative stress has emerged as a highly plausible pathobiological mechanism by which inhalation of diesel exhaust PM leads to multiple facets of cardiovascular dysfunction.

CRITICAL ISSUES

Diesel exhaust inhalation promotes oxidative stress in several biological compartments that can be directly associated with adverse cardiovascular effects.

FUTURE DIRECTIONS

Further studies with more sensitive and specific in vivo human markers of oxidative stress are required to determine if targeting oxidative stress pathways involved in the actions of diesel exhaust PM could be of therapeutic value. Antioxid. Redox Signal. 28, 819-836.

Self-reported history of stroke and long-term living conditions near air pollution sources: results of a national epidemiological study in Lebanon

Stroke is a disease related to high mortality and morbidity, particularly in developing countries. Some studies have linked self-reported indoor and outdoor pollution to stroke and mini-stroke, while some others showed no association. Our objective was to assess this association in Lebanon, a Middle Eastern developing country. A national cross-sectional study was conducted all over Lebanon. In addition to self-reported items of pollution exposure, we assessed potential predictors of stroke and mini-stroke, including sociodemographic characteristics, self-reported health information, and biological measurements. Moreover, we assessed dose-effect relationship of pollution items in relation with stroke. Self-reported indoor pollution exposure was associated with stroke and mini-stroke, with or without taking biological values into account. Moreover, we found a dose-effect relationship of exposure with risk of disease, but this effect did not reach statistical significance after adjustment for sociodemographics and biological characteristics. No association was found for any outdoor pollution item. Although additional studies would be necessary to confirm these findings, sensitizing the population about the effect of pollution on chronic diseases, working on reducing pollution, and improving air quality should be implemented to decrease the burden of the disease on the population and health system.

A cross-disciplinary evaluation of evidence for multipollutant effects on cardiovascular disease

BACKGROUND

The current single-pollutant approach to regulating ambient air pollutants is effective at protecting public health, but efficiencies may be gained by addressing issues in a multipollutant context since multiple pollutants often have common sources and individuals are exposed to more than one pollutant at a time.

OBJECTIVE

We performed a cross-disciplinary review of the effects of multipollutant exposures on cardiovascular effects.

METHODS

A broad literature search for references including at least two criteria air pollutants (particulate matter [PM], ozone [O₃], oxides of nitrogen, sulfur oxides, carbon monoxide) was conducted. References were culled based on scientific discipline then searched for terms related to cardiovascular disease. Most multipollutant epidemiologic and experimental (i.e., controlled human exposure, animal toxicology) studies examined PM and O₃ together.

DISCUSSION

Epidemiologic and experimental studies provide some evidence for O₃ concentration modifying the effect of PM, although PM did not modify O₃ risk estimates. Experimental studies of combined exposure to PM and O₃ provided evidence for additivity, synergism, and/or antagonism depending on the specific health endpoint. Evidence for other pollutant pairs was more limited.

CONCLUSIONS

Overall, the evidence for multipollutant effects was often heterogeneous, and the limited number of studies inhibited making a conclusion about the nature of the relationship between pollutant combinations and cardiovascular disease.

Ambient Coarse Particulate Matter and the Right Ventricle: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Coarse particulate matter (P10-2.5) is primarily mechanically generated and includes crustal material, brake and tire wear, and biological particles. PM10-2.5 is associated with pulmonary disease, which can lead to right ventricular (RV) dysfunction. Although RV characteristics have been associated with combustion-related pollutants, relationships with PM10-2.5 remain unknown.

OBJECTIVES

To quantify cross-sectional associations between RV dysfunction and PM10-2.5 mass and components among older adults and susceptible populations.

METHODS

We used baseline cardiac magnetic resonance images from 1,490 participants (45-84 y old) from the Multi-Ethnic Study of Atherosclerosis and assigned 5-y residential concentrations of PM10-2.5 mass, copper, zinc, phosphorus, silicon, and endotoxin, using land-use regression models. We quantified associations with RV mass, end-diastolic volume, and ejection fraction after control for risk factors and copollutants using linear regression. We further examined personal susceptibility.

RESULTS

We found positive associations of RV mass and, to a lesser extent, end diastolic volume with PM10-2.5 mass among susceptible populations including smokers and persons with emphysema. After adjustment for copollutants, an interquartile range increase in PM10-2.5 mass (2.2 μg/m3) was associated with 0.5 g (95% CI: 0.0, 1.0), 0.9 g (95% CI: 0.1, 1.7), and 1.4 g (95% CI: 0.4, 2.5) larger RV mass among former smokers, current smokers, and persons with emphysema, respectively. No associations were found with healthy individuals or with ejection fraction.

CONCLUSIONS

Alterations to RV structure may represent a mechanism by which long-term PM10-2.5 exposure increases risks for adverse respiratory and cardiovascular outcomes, especially among certain susceptible populations. https://doi.org/10.1289/EHP658.

Developmental Neurotoxicity of Traffic-Related Air Pollution: Focus on Autism

PURPOSE OF REVIEW

Epidemiological and animal studies suggest that air pollution may negatively affect the central nervous system (CNS) and contribute to CNS diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component.

RECENT FINDINGS

Several studies suggest that young individuals may be particularly susceptible to air pollution-induced neurotoxicity and that perinatal exposure may cause or contribute to developmental disabilities and behavioral abnormalities. In particular, a number of recent studies have found associations between exposures to traffic-related air pollution and autism spectrum disorders (ASD), which are characterized by impairment in socialization and in communication and by the presence of repetitive and unusual behaviors. The cause(s) of ASD are unknown, and while it may have a hereditary component, environmental factors are increasingly suspected as playing a pivotal role in its etiology, particularly in genetically susceptible individuals. Autistic children present higher levels of neuroinflammation and systemic inflammation, which are also hallmarks of exposure to traffic-related air pollution. Gene-environment interactions may play a relevant role in determining individual susceptibility to air pollution developmental neurotoxicity. Given the worldwide presence of elevated air pollution, studies on its effects and mechanisms on the developing brain, genetic susceptibility, role in neurodevelopmental disorders, and possible therapeutic interventions are certainly warranted.

Environmental Exposures and Cardiovascular Disease: A Challenge for Health and Development in Low- and Middle-Income Countries

Environmental exposures in low- and middle-income countries lie at the intersection of increased economic development and the rising public health burden of cardiovascular disease. Increasing evidence suggests an association of exposure to ambient air pollution, household air pollution from biomass fuel, lead, arsenic, and cadmium with multiple cardiovascular disease outcomes, including hypertension, coronary heart disease, stroke, and cardiovascular mortality. Although populations in low- and middle-income countries are disproportionately exposed to environmental pollution, evidence linking these exposures to cardiovascular disease is derived from populations in high-income countries. More research is needed to further characterize the extent of environmental exposures.

Social factors and cardiovascular morbidity

Recent progress in population health at aggregate level, measured by life expectancy, has been accompanied by lack of progress in reducing the difference in health prospects between groups defined by social status. Cardiovascular disease is an important contributor to this undesirable situation. The stepwise gradient of higher risk with lower status is accounted for partly by social gradients in health behaviors. The psychosocial hypothesis provides a stronger explanation, based on social patterning of living and working environments and psychological assets that individuals develop during childhood. Three decades of research based on Whitehall II and other cohort studies provide evidence for psychosocial pathways leading to cardiovascular morbidity and mortality. Job stress is a useful paradigm because exposure is long term and depends on occupational status. Studies of social-biological translation implicate autonomic and neuroendocrine function among the biological systems that mediate between chronic adverse psychosocial exposures and increased cardiometabolic risk and cardiovascular disease incidence.

Neurotoxicity of traffic-related air pollution

The central nervous system is emerging as an important target for adverse health effects of air pollution, where it may contribute to neurodevelopmental and neurodegenerative disorders. Air pollution comprises several components, including particulate matter (PM) and ultrafine particulate matter (UFPM), gases, organic compounds, and metals. An important source of ambient PM and UFPM is represented by traffic-related air pollution, primarily diesel exhaust (DE). Human epidemiological studies and controlled animal studies have shown that exposure to air pollution, and to traffic-related air pollution or DE in particular, may lead to neurotoxicity. In particular, air pollution is emerging as a possible etiological factor in neurodevelopmental (e.g. autism spectrum disorders) and neurodegenerative (e.g. Alzheimer's disease) disorders. The most prominent effects caused by air pollution in both humans and animals are oxidative stress and neuro-inflammation. Studies in mice acutely exposed to DE (250-300μg/m3 for 6h) have shown microglia activation, increased lipid peroxidation, and neuro-inflammation in various brain regions, particularly the hippocampus and the olfactory bulb. An impairment of adult neurogenesis was also found. In most cases, the effects of DE were more pronounced in male mice, possibly because of lower antioxidant abilities due to lower expression of paraoxonase 2.

Sex and genetic differences in the effects of acute diesel exhaust exposure on inflammation and oxidative stress in mouse brain

In addition to increased morbidity and mortality caused by respiratory and cardiovascular diseases, air pollution may also contribute to central nervous system (CNS) diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component. DE contains more than 40 toxic air pollutants and is a major constituent of ambient particulate matter (PM), particularly of ultrafine-PM. Limited information suggests that exposure to DE may cause oxidative stress and neuroinflammation in the CNS. We hypothesized that males may be more susceptible than females to DE neurotoxicity, because of a lower level of expression of paraoxonase 2 (PON2), an intracellular anti-oxidant and anti-inflammatory enzyme. Acute exposure of C57BL/6 mice to DE (250-300μg/m3 for 6h) caused significant increases in lipid peroxidation and of pro-inflammatory cytokines (IL-1α, IL-1β, IL-3, IL-6, TNF-α) in various brain regions (particularly olfactory bulb and hippocampus). In a number of cases the observed effects were more pronounced in male than in female mice. DE exposure also caused microglia activation, as measured by increased Iba1 (ionized calcium-binding adapter molecule 1) expression, and of TSPO (translocator protein) binding. Mice heterozygotes for the modifier subunit of glutamate cysteine ligase (the limiting enzyme in glutathione biosynthesis; Gclm+/- mice) appeared to be significantly more susceptible to DE-induced neuroinflammation than wild type mice. These findings indicate that acute exposure to DE causes neuroinflammation and oxidative stress in brain, and suggest that sex and genetic background may play important roles in modulating susceptibility to DE neurotoxicity.

Neonatal Diesel Exhaust Particulate Exposure Does Not Predispose Mice to Adult Cardiac Hypertrophy or Heart Failure

Background: We have previously reported that in utero and early life exposure to diesel exhaust particulates predisposes mice to adult heart failure, and that in utero exposure alone is sufficient to confer this predisposition. This follow up study addresses whether neonatal exposure alone can also confer this predisposition. Methods: Newborn male C57BL/6 mice were exposed to diesel exhaust (DE) particulates immediately after birth until weaning at 21 days of age, whereupon they were transferred to filtered air (FA) conditions. At the age of 12 weeks, transverse aortic constriction (TAC) was performed followed by weekly echocardiography for three weeks. After the last echocardiogram, mice were euthanized for organ harvest, gravimetry and histology. Results: Neonatal exposure to DE particulates did not increase susceptibility to cardiac hypertrophy or heart failure after TAC when compared to FA exposed controls (ventricular weight/body weight ratio 7.505 vs. 7.517 mg/g, p = Not Significant (NS)). The left ventricular ejection fraction after TAC was similar between groups at one week, two weeks, and three weeks after procedure. Histological analysis showed no difference in the degree of cardiac hypertrophy or fibrosis. Conclusions: Neonatal exposure to DE particulates does not predispose mice to TAC-induced cardiac hypertrophy and heart failure in adulthood, in contrast to previously published results showing susceptibility due to in utero exposure.

Toxicological effects of particulate matter (PM2.5) on rats: Bioaccumulation, antioxidant alterations, lipid damage, and ABC transporter activity

Previous studies have demonstrated the harmful effects of atmospheric pollutants on cardiac systems because of the presence of particulate matter (PM), a complex mixture of numerous substances including trace metals. In this study, the toxicity of PM2.5 from two regions, rural (PM2.5 level of 8.5 ± 4.0 μg m(-3)) and industrial (PM2.5 level of 14.4 ± 4.1 μg m(-3)) in Brazil, was investigated through in vivo experiments in rats. Metal accumulation and biochemical responses were evaluated after rats were exposed to three different concentrations of PM2.5 in saline extract (10× dilution, 5× dilution, and concentrated). The experimental data showed the bioaccumulation of diverse trace metals in the hearts of groups exposed to PM2.5 from both regions. Furthermore, mobilization of the antioxidant defenses and an increase in lipid peroxidation of the cardiac tissue was observed in response to the industrial and rural area PM2.5. Glutathione-S-transferase activity was increased in groups exposed to the 5× and concentrated rural PM2.5. Additionally, ATP-binding cassette (ABC) transporter activity in the cardiac tissue exposed to PM2.5 was reduced in response to the 5× dilution of the rural and industrial region PM2.5. Histological analysis showed a decrease in the percentage of cardiac cells in the heart at all tested concentrations. The results indicate that exposure to different concentrations of PM2.5 from both sources causes biochemical and histological changes in the heart with consequent damage to biological structures; these factors can favor the development of cardiac diseases.

Rat models of cardiometabolic diseases: baseline clinical chemistries, and rationale for their use in examining air pollution health effects

Individuals with cardiovascular and metabolic diseases (CVD) are shown to be more susceptible to adverse health effects of pollutants. Rodent models of CVD are used for examining susceptibility variations. CVD models developed by selective inbreeding are shown to represent the etiology of human disease and metabolic dysfunction. The goal of this article was to review the origin and the pathobiological features of rat models of varying CVD with or without metabolic syndrome and healthy laboratory rat strains to allow better interpretation of the data regarding their susceptibility to air pollutant exposures. Age-matched healthy Sprague-Dawley (SD), Wistar (WIS) and Wistar Kyoto (WKY), and CVD-prone spontaneously hypertensive (SH), Fawn-Hooded hypertensive (FHH), SH stroke-prone (SHSP), SHHF/Mcc heart failure obese (SHHF) and insulin-resistant JCR:LA-cp obese (JCR) rat models were considered for this study. The genetics and the underlying pathologies differ between these models. Normalized heart weights correlated with underlying cardiac disease while wide differences exist in the number of white blood cells and platelets within healthy strains and those with CVD. High plasma fibrinogen and low angiotensin converting enzyme activity in FHH might relate to kidney disease and associated hypertension. However, other obese strains with known kidney lesions do not exhibit decreases in ACE activity. The increased activated partial thromboplastin time only in SHSP correlates with their hemorrhagic stroke susceptibility. Increases plasma lipid peroxidation in JCR might reflect their susceptibility to acquire atherosclerosis. These underlying pathologies involving CVD and metabolic dysfunction are critical in interpretation of findings related to susceptibility variations of air pollution health effects.

Advances in Understanding Air Pollution and CVD

The MESA Air (Multi-Ethnic Study of Atherosclerosis and Air Pollution) leveraged the platform of the MESA cohort into a prospective longitudinal study of relationships between air pollution and cardiovascular health. MESA Air researchers developed fine-scale, state-of-the-art air pollution exposure models for the MESA Air communities, creating individual exposure estimates for each participant. These models combine cohort-specific exposure monitoring, existing monitoring systems, and an extensive database of geographic and meteorological information. Together with extensive phenotyping in MESA-and adding participants and health measurements to the cohort-MESA Air investigated environmental exposures on a wide range of outcomes. Advances by the MESA Air team included not only a new approach to exposure modeling, but also biostatistical advances in addressing exposure measurement error and temporal confounding. The MESA Air study advanced our understanding of the impact of air pollutants on cardiovascular disease and provided a research platform for advances in environmental epidemiology.

Microglia mediate diesel exhaust particle-induced cerebellar neuronal toxicity through neuroinflammatory mechanisms

In addition to the well-established effects of air pollution on the cardiovascular and respiratory systems, emerging evidence has implicated it in inducing negative effects on the central nervous system. Diesel exhaust particulate matter (DEP), a major component of air pollution, is a complex mixture of numerous toxicants. Limited studies have shown that DEP-induced dopaminergic neuron dysfunction is mediated by microglia, the resident immune cells of the brain. Here we show that mouse microglia similarly mediate primary cerebellar granule neuron (CGN) death in vitro. While DEP (0, 25, 50, 100μg/2cm²) had no effect on CGN viability after 24h of treatment, in the presence of primary cortical microglia neuronal cell death increased by 2-3-fold after co-treatment with DEP, suggesting that microglia are important contributors to DEP-induced CGN neurotoxicity. DEP (50μg/2cm²) treatment of primary microglia for 24h resulted in morphological changes indicative of microglia activation, suggesting that DEP may induce the release of cytotoxic factors. Microglia-conditioned medium after 24h treatment with DEP, was also toxic to CGNs. DEP caused a significant increase in reactive oxygen species in microglia, however, antioxidants failed to protect neurons from DEP/microglia-induced toxicity. DEP increased mRNA levels of the pro-inflammatory cytokines IL-6 and IL1-β, and the release of IL-6. The antibiotic minocycline (50μM) and the peroxisome proliferator-activated receptor-γ agonist pioglitazone (50μM) attenuated DEP-induced CGN death in the co-culture system. Microglia and CGNs from male mice appeared to be somewhat more susceptible to DEP neurotoxicity than cells from female mice possibly because of lower paraoxonase-2 expression. Together, these results suggest that microglia-induced neuroinflammation may play a critical role in modulating the effect of DEP on neuronal viability. .

Exposure to Traffic-Related Air Pollution in Relation to Progression in Physical Disability among Older Adults

BACKGROUND

Physical disability is common though not inevitable in older age and has direct bearing on a person's ability to perform activities essential for self-care and independent living. Air pollution appears to increase the risk of several chronic diseases that contribute to the progression of disability.

OBJECTIVE

We evaluated long-term exposure to traffic-related air pollution (TRAP) in relation to progression in physical disability.

METHODS

We conducted our investigation within the Chicago Health and Aging Project. We measured participants' exposures to TRAP using two surrogates: residential proximity to major roads (1993 onwards) and ambient concentrations of oxides of nitrogen (NOX; 1999 onwards), predicted via a geographic information systems-based spatiotemporal smoothing model (cross-validation R2 = 0.87) that incorporated community-based monitoring and resolved intraurban exposure gradients at a spatial scale of tens of meters. Participants' lower-extremity physical ability was assessed every 3 years (1993-2012) via tandem stand, chair stand, and timed walking speed.

RESULTS

In multivariable-adjusted analyses (n = 5,708), higher long-term NOX exposure was associated with significantly faster progression in disability. Compared with the 5-year decline in physical ability score among participants in the lowest quartile of NOX exposure, decline among those in the highest exposure quartile was 1.14 units greater (95% confidence interval [CI]: -1.86, -0.42), equivalent to 3 additional years of decline among those in the lowest exposure quartile. The association was linear across the continuum of NOX exposure: per 10-ppb increment in exposure, the 5-year decline in physical ability score was 0.87 unit greater (95% CI: -1.35, -0.39). Proximity to a major road was not associated with disability progression (n = 9,994).

CONCLUSIONS

These data join a growing body of evidence suggesting that TRAP exposures may accelerate aging-related declines in health.

CITATION

Weuve J, Kaufman JD, Szpiro AA, Curl C, Puett RC, Beck T, Evans DA, Mendes de Leon CF. 2016. Exposure to traffic-related air pollution in relation to progression in physical disability among older adults. Environ Health Perspect 124:1000-1008; http://dx.doi.org/10.1289/ehp.1510089.

Air pollution and diastolic function in elderly women - Results from the SALIA study cohort

BACKGROUND

Studies linking particulate matter (PM) with heart failure (HF) show inconsistent results. However, the association of air pollution with diastolic function, an important determinant of heart failure, has not been studied yet and is addressed in the presented study.

METHODS

402 women (69-79 years) of the clinical follow-up (2007-2010) of the ongoing population-based prospective SALIA (Study on the influence of Air pollution on Lung function, Inflammation and Ageing) cohort were examined using Doppler echocardiography: Of the 291 women with preserved ejection fraction, the ratio of peak early diastolic filling velocity and peak early diastolic mitral annulus velocity (E/E') was collected in 264 and left atrial volume index (LAVI) in 262 women. Residential long-term air pollution exposure (nitrogen oxides, size-fractioned PM) was modeled at baseline and at follow-up, applying land use regression models. We used linear regression to model the cross-sectional associations of air pollutants per interquartile range (IQR) with different measures of diastolic function, adjusting for personal risk factors.

RESULTS

Median concentrations of annual NOx, NO2, PM2.5, and PM10 at follow-up were 37.7, 25.9, 17.4 and 26.4μg/m(3), respectively. In the fully adjusted models, LAVI was associated with an IQR increase in PM2.5 (1.05 [0.99; 1.12]) and NOx (1.04 [1.00; 1.09]) at follow-up, and with NOx and NO2 (both 1.05 [1.00; 1.11]) at baseline. None of the pollutants were clearly associated with E/E'.

CONCLUSIONS

In this analysis of elderly women, we found suggestive evidence for an association of air pollution with impaired diastolic function.

Air pollution and chronic airway diseases: what should people know and do?

The health effects of air pollution remain a public health concern worldwide. Exposure to air pollution has many substantial adverse effects on human health. Globally, seven million deaths were attributable to the joint effects of household and ambient air pollution. Subjects with chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma are especially vulnerable to the detrimental effects of air pollutants. Air pollution can induce the acute exacerbation of COPD and onset of asthma, increase the respiratory morbidity and mortality. The health effects of air pollution depend on the components and sources of pollutants, which varied with countries, seasons, and times. Combustion of solid fuels is a major source of air pollutants in developing countries. To reduce the detrimental effects of air pollution, people especially those with COPD or asthma should be aware of the air quality and take extra measures such as reducing the time outdoor and wearing masks when necessary. For reducing the air pollutants indoor, people should use clean fuels and improve the stoves so as to burn fuel more efficiently and vent emissions to the outside. Air cleaners that can improve the air quality efficiently are recommended.

Spatial Hotspot Analysis of Acute Myocardial Infarction Events in an Urban Population: A Correlation Study of Health Problems and Industrial Installation

BACKGROUND

The current study's objectives were to find any possible spatial patterns and hotspot of cardiovascular events and to perform a correlation study to find any possible relevance between cardiovascular disease (CVE) and location of industrial installation said above.

METHODS

We used the Acute Myocardial Infarction (AMI) hospital admission record in three main hospitals in Yazd, Yazd Province, Iran during 2013, because of CVDs and searched for possible correlation between industries as point-source pollutants and non-random distribution of AMI events.

RESULTS

MI incidence rate in Yazd was obtained 531 per 100,000 person-year among men, 458 per 100,000 person-year among women and 783/100,000 person-yr totally. We applied a GIS Hotspot analysis to determine feasible clusters and two sets of clusters were observed. Mean age of 56 AMI events occurred in the cluster cells was calculated as 62.21±14.75 yr. Age and sex as main confounders of AMI were evaluated in the cluster areas in comparison to other areas. We observed no significant difference regarding sex (59% in cluster cells versus 55% in total for men) and age (62.21±14.7 in cluster cells versus 63.28±13.98 in total for men).

CONCLUSION

We found proximity of AMI events cluster to industries installations, and a steel industry, specifically. There could be an association between road-related pollutants and the observed sets of cluster due to the proximity exist between rather crowded highways nearby the events cluster.

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.

Carotid intima-media thickness, a marker of subclinical atherosclerosis, and particulate air pollution exposure: the meta-analytical evidence

Introduction

Studies on the association between atherosclerosis and long-term exposure to ambient air pollution suggest that carotid intima-media thickness (CIMT), a marker of subclinical atherosclerosis, is positively associated with particulate matter (PM) exposure. However, there is heterogeneity between the different studies concerning the magnitude of this association. We performed a meta-analysis to determine the strength of the association between CIMT and particulate air pollution.

Methods

We queried PubMed citation database and Web of Knowledge up to March 2015 in order to identify studies on CIMT and particulate air pollution. Two investigators selected and computerized all relevant information, independently. Eight of the reviewed epidemiological publications provided sufficient details and met our inclusion criteria. Descriptive and quantitative information was extracted from each selected study. The meta-analysis included 18,349 participants from eight cohorts for the cross-sectional association between CIMT and PM and 7,268 participants from three cohorts for the longitudinal analysis on CIMT progression and PM exposure.

Results

The average exposure to PM_2.5 in the different study populations ranged from 4.1 to 20.8 µg/m³ and CIMT averaged (SD) 0.73 (0.14) mm. We computed a pooled estimate from a random-effects model. In the combined cross-sectional studies, an increase of 5 µg/m³ PM_2.5 was associated with a 1.66% (95% CI: 0.86 to 2.46; P<0.0001) thicker CIMT, which corresponds to an average increase of 12.1 µm. None of the studies moved the combined estimate outside the confidence interval of the overall estimate. A funnel plot suggested absence of publication bias. The combined longitudinal estimate showed for each 5 µg/m³ higher PM_2.5 exposure, a 1.04 µm per year (95% CI: 0.01 to 2.07; P=0.048) greater CIMT progression.

Conclusion

Our meta-analysis supports the evidence of a positive association between CIMT, a marker of subclinical atherosclerosis, and long-term exposure to particulate air pollution.

Residential exposure to urban traffic is associated with increased carotid intima-media thickness in children

Chronic exposure to urban traffic pollution is documented to promote atherosclerosis in adults but little is known about its potential effects in children. Our study examined the association of long-term exposure to traffic with carotid intima-media thickness (cIMT) in 287 healthy children. Residential proximity and distance-weighted traffic density (DWTD) were used as proximity markers for traffic-related air pollution exposure. The multivariable analyses revealed that children residing <100 meters from the nearest heavily trafficked road had cIMT mean and maximum measurements that were increased by 15% and 11% compared to those living ≥ 200 meters away (P = 0.0001). Similar increases in cIMT were identified for children in the highest versus lowest DWTD tertile. Children who resided 100–199 meters from traffic or in the middle DWTD tertile also exhibited increased cIMT but these differences were not statistically significant. No statistically significant differences were identified between residential distance to traffic or DWTD and systemic inflammation indicators (CRP, IL-6). The study results suggest that exposure to urban traffic promotes arterial remodeling in children. This finding is important since even small increases in cIMT over time can potentially lead to earlier progression to atherosclerosis. It is also important because traffic-related pollution is potentially modifiable.

Ambient Air Pollution and Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-analysis

Hypertensive disorders of pregnancy (HDP, including gestational hypertension, preeclampsia, and eclampsia) have a substantial public health impact. Maternal exposure to high levels of air pollution may trigger HDP, but this association remains unclear. The objective of our report is to assess and quantify the association between maternal exposures to criteria air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤ 10, 2.5 μm) on HDP risk. PubMed, EMBASE, MEDLINE, Current Contents, Global Health, and Cochrane were searched (last search: September, 2013). After a detailed screening of 270 studies, 10 studies were extracted. We conducted meta-analyses if a pollutant in a specific exposure window was reported by at least four studies. Using fixed- and random-effects models, odds ratios (ORs) and 95% CIs were calculated for each pollutant with specific increment of concentration. Increases in risks of HDP (OR per 10 ppb = 1.16; 95% CI, 1.03-1.30) and preeclampsia (OR per 10 ppb = 1.10; 95% CI, 1.03-1.17) were observed to be associated with exposure to NO2 during the entire pregnancy, and significant associations between HDP and exposure to CO (OR per 1 ppm = 1.79; 95% CI, 1.31-2.45) and O3 (OR per 10 ppb = 1.09; 95% CI, 1.05-1.13) during the first trimester were also observed. Our review suggests an association between ambient air pollution and HDP risk. Although the ORs were relatively low, the population-attributable fractions were not negligible given the ubiquitous nature of air pollution.

Assessment of metal contaminants in non-small cell lung cancer by EDX microanalysis

Human cardio-respiratory diseases are strongly correlated to concentrations of atmospheric elements. Bioaccumulation of heavy metals is strictly monitored, because of its possible toxic effects. In this work, we utilized the EDX microanalysis in order to identify the potential heavy metal accumulation in the lung tissue.  To this aim, we enrolled 45 human lung biopsies: 15 non-small cell lung cancers, 15 lung benign lesions and 15 control biopsies. Lung samples were both paraffin embedded for light microscopy study and eponepoxid embedded for transmission electron microscopy. EDX microanalysis was performed on 100 nm thick unstained ultrathin-sections placed on specific copper grids. Our results demonstrated that the EDX technology was particularly efficient in the study of elemental composition of lung tissues, where we found heavy metals, such as Cobalt (Co), Chromium (Cr), Manganese (Mn) and Lead (Pb). Furthermore, in malignant lesions we demonstrated the presence of multiple bio-accumulated elements. In fact, a high rate of lung cancers was associated with the presence of 3 or more bio-accumulated elements compared to benign lesions and control tissue (91.7%, 0%, 8.3%, respectively). The environmental impact on pulmonary carcinogenesis could be better clarified by demonstrating the presence of polluting agents in lung tissues. The application of EDX microanalysis on biological tissuescould shed new light in the study of the possible bioaccumulation of polluting agents in different human organs and systems.

Survey on air pollution and cardiopulmonary mortality in shiraz from 2011 to 2012: an analytical-descriptive study

BACKGROUND

Expanding cities with rapid economic development has resulted in increased energy consumption leading to numerous environmental problems for their residents. The aim of this study was to investigate the correlation between air pollution and mortality rate due to cardiovascular and respiratory diseases in Shiraz.

METHODS

This is an analytical cross-sectional study in which the correlation between major air pollutants (including carbon monoxide [CO], sulfur dioxide [SO2], nitrogen dioxide [NO2] and particle matter with a diameter of less than 10 μ [PM10]) and climatic parameters (temperature and relative humidity) with the number of those whom expired from cardiopulmonary disease in Shiraz from March 2011 to January 2012 was investigated. Data regarding the concentration of air pollutants were determined by Shiraz Environmental Organization. Information about climatic parameters was collected from the database of Iran's Meteorological Organization. The number of those expired from cardiopulmonary disease in Shiraz were provided by the Department of Health, Shiraz University of Medical Sciences. We used non-parametric correlation test to analyze the relationship between these parameters.

RESULTS

The results demonstrated that in all the recorded data, the average monthly pollutants standard index (PSI) values of PM10 were higher than standard limits, while the average monthly PSI value of NO2 were lower than standard. There was no significant relationship between the number of those expired from cardiopulmonary disease and the air pollutant (P > 0.05).

CONCLUSIONS

Air pollution can aggravate chronic cardiopulmonary disease. In the current study, one of the most important air pollutants in Shiraz was the PM10 component. Mechanical processes, such as wind blowing from neighboring countries, is the most important parameter increasing PM10 in Shiraz to alarming conditions. The average monthly variation in PSI values of air pollutants such as NO2, CO, and SO2 were lower than standard limits. Moreover, there was no significant correlation between the average monthly variation in PSI of NO2, CO, PM10, and SO2 and the number of those expired from cardiopulmonary disease in Shiraz.

Neurotoxicants are in the air: convergence of human, animal, and in vitro studies on the effects of air pollution on the brain

In addition to increased morbidity and mortality caused by respiratory and cardiovascular diseases, air pollution may also negatively affect the brain and contribute to central nervous system diseases. Air pollution is a mixture comprised of several components, of which ultrafine particulate matter (UFPM; <100 nm) is of much concern, as these particles can enter the circulation and distribute to most organs, including the brain. A major constituent of ambient UFPM is represented by traffic-related air pollution, mostly ascribed to diesel exhaust (DE). Human epidemiological studies and controlled animal studies have shown that exposure to air pollution may lead to neurotoxicity. In addition to a variety of behavioral abnormalities, two prominent effects caused by air pollution are oxidative stress and neuroinflammation, which are seen in both humans and animals and are confirmed by in vitro studies. Among factors which can affect neurotoxic outcomes, age is considered the most relevant. Human and animal studies suggest that air pollution (and DE) may cause developmental neurotoxicity and may contribute to the etiology of neurodevelopmental disorders, including autistic spectrum disorders. In addition, air pollution exposure has been associated with increased expression of markers of neurodegenerative disease pathologies.

Ambient air pollution and hypertensive disorder of pregnancy

BACKGROUND

Ambient air pollution has been implicated in the development of hypertensive disorders of pregnancy (HDP). However, evidence of the association between air pollution and HDP is still limited, and the effects of gaseous air pollutants on HDP and their time windows of exposure have not been well studied.

METHODS

We used the Florida birth registry data to investigate the associations between air pollutants (NO2, SO2, PM(2.5), O3 and CO) and the risks of HDP in 22,041 pregnant women in Jacksonville, Florida, USA from 2004 to 2005. Further, we examined whether air pollution exposure during different time windows defined by trimesters and the entire pregnancy had different effects on HDP.

RESULTS

The single-pollutant logistic regression model showed that exposure to four pollutants during the full pregnancy period was significantly associated with prevalence of HDP after adjusting for covariates: NO2 (OR=1.21, 95% CI 1.09 to 1.35), PM2.5 (OR=1.24, 95% CI 1.08 to 1.43), SO2 (OR=1.13, 95% CI 1.01 to 1.25) and CO (OR=1.12, 95% CI 1.03 to 1.22) per IQR increase. Similar effects were observed when first trimester exposure to NO2, SO2 and CO, and second trimester exposures to PM2.5 were examined. Consistent results were confirmed in multiple-pollutant models.

CONCLUSIONS

This study suggests that exposure to high levels of air pollution during early pregnancy and the full gestational period was associated with increased prevalence of HDP in Florida, USA.

From particles to patients: oxidative stress and the cardiovascular effects of air pollution

Air pollution, especially airborne particulate matter (PM), is associated with an increase in both morbidity and mortality from cardiovascular disease, although the underlying mechanisms remain incompletely established. The one consistent observation that links the pulmonary and cardiovascular effects of inhaled PM is oxidative stress. This article examines the evidence for the role of oxidative stress in the cardiovascular effects of air pollution, beginning with observations from epidemiological and controlled exposure studies and then exploring potential mechanistic pathways involving free radical generation from PM itself, to effects of PM on cell cultures, isolated organs, healthy animals and animal models of disease. Particular emphasis is placed on the vascular and atherosclerotic effects of urban air pollution and diesel exhaust emissions as rich sources of environmental ultrafine particles.