Global association between ambient air pollution and blood pressure: A systematic review and meta-analysis

The global and national burden of chronic kidney disease attributable to ambient fine particulate matter air pollution: a modelling study

Introduction

We aimed to integrate all available epidemiological evidence to characterise an exposure-response model of ambient fine particulate matter (PM2.5) and the risk of chronic kidney disease (CKD) across the spectrum of PM2.5 concentrations experienced by humans. We then estimated the global and national burden of CKD attributable to PM2.5.

Methods

We collected data from prior studies on the association of PM2.5 with CKD and used an integrative meta-regression approach to build non-linear exposure-response models of the risk of CKD associated with PM2.5 exposure. We then estimated the 2017 global and national incidence, prevalence, disability-adjusted life-years (DALYs) and deaths due to CKD attributable to PM2.5 in 194 countries and territories. Burden estimates were generated by linkage of risk estimates to Global Burden of Disease study datasets.

Results

The exposure-response function exhibited evidence of an increase in risk with increasing PM2.5 concentrations, where the rate of risk increase gradually attenuated at higher PM2.5 concentrations. Globally, in 2017, there were 3 284 358.2 (95% UI 2 800 710.5 to 3 747 046.1) incident and 122 409 460.2 (108 142 312.2 to 136 424 137.9) prevalent cases of CKD attributable to PM2.5, and 6 593 134.6 (5 705 180.4 to 7 479 818.4) DALYs and 211 019.2 (184 292.5 to 236 520.4) deaths due to CKD attributable to PM2.5. The burden was disproportionately borne by low income and lower middle income countries and exhibited substantial geographic variability, even among countries with similar levels of sociodemographic development. Globally, 72.8% of prevalent cases of CKD attributable to PM2.5 and 74.2% of DALYs due to CKD attributable to PM2.5 were due to concentrations above 10 µg/m3, the WHO air quality guidelines.

Conclusion

The global burden of CKD attributable to PM2.5 is substantial, varies by geography and is disproportionally borne by disadvantaged countries. Most of the burden is associated with PM2.5 levels above the WHO guidelines, suggesting that achieving those targets may yield reduction in CKD burden.

Diversity of and initiatives for hypertension management in Asia-Why we need the HOPE Asia Network

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving "zero" cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia-specific features of hypertension and hypertension-related cardiovascular complications, which means that a region-specific approach is needed. White-coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white-coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia-specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology-based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region-wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.

Associations between long-term exposure to air pollution and blood pressure and effect modifications by behavioral factors

BACKGROUND

Studies on the hypertensive effect of long-term air pollution exposure were inconclusive and showed scarce evidence from rural areas in developing countries. In this context, we examined the associations of air pollution exposure with hypertension and blood pressure, and their effect modifiers in rural Chinese adults.

METHODS

We studied 39,259 participants from a cohort established in five rural regions of central China. Individual exposures to PM2.5 and PM10 (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm and 10 μm) and nitrogen dioxide (NO2) was evaluated using satellite-based spatiotemporal models. Mixed-effect regression models were applied to examine the associations of long-term exposure to air pollution with hypertension and four blood pressure component measurements, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). Several potential effect modifiers related to demographic and behavioral factors were also examined.

RESULTS

The results showed that for each 1 μg/m3 increase in PM2.5, PM10 and NO2, the adjusted odds ratio of hypertension was 1.029 (95%CI: 1.001,1.057), 1.015 (95%CI: 1.001, 1.029) and 1.069 (95%CI: 1.038, 1.100), respectively. These three air pollutants were also associated with increased SBP (except for PM10), DBP and MAP. The hypertensive effects of air pollution were more pronounced among males, smokers, drinkers, individuals with a high-fat diet, and those with high-level physical activity.

CONCLUSION

Long-term exposure to PM2.5, PM10 and NO2 was associated with increased blood pressure and hypertension in rural Chinese adults, and the associations were modified by several behavioral factors.

Air pollution and cardiovascular disease: car sick

The cardiovascular effects of inhaled particle matter (PM) are responsible for a substantial morbidity and mortality attributed to air pollution. Ultrafine particles, like those in diesel exhaust emissions, are a major source of nanoparticles in urban environments, and it is these particles that have the capacity to induce the most significant health effects. Research has shown that diesel exhaust exposure can have many detrimental effects on the cardiovascular system both acutely and chronically. This review provides an overview of the cardiovascular effects on PM in air pollution, with an emphasis on ultrafine particles in vehicle exhaust. We consider the biological mechanisms underlying these cardiovascular effects of PM and postulate that cardiovascular dysfunction may be implicated in the effects of PM in other organ systems. The employment of multiple strategies to tackle air pollution, and especially ultrafine particles from vehicles, is likely to be accompanied by improvements in cardiovascular health.

How Birth Season Affects Vulnerability to the Effect of Ambient Ozone Exposure on the Disease Burden of Hypertension in the Elderly Population in a Coastal City in South China

Birth season is an important factor that reflects prenatal nutritional conditions during early development, and which might have lifelong impacts on health. Moreover, ambient ozone pollution has been considered an important environmental risk factor for hypertension. However, whether birth season affects vulnerability to the effect of ambient ozone exposure on late-life hypertension is still unknown. A flexible case–crossover design was used to explore the effect of ambient ozone exposure on the disease burden of hypertension using years of life lost (YLL) in the elderly population in a coastal city in South China from 2013 to 2016. The influence of birth season was also explored. Ozone exposure was significantly associated with increased YLL from hypertension. The association was higher in the elderly individuals who were born in autumn than in those born in other seasons. Specifically, every 10 μg/m³ increase in ozone was associated with 0.68 (95% CI: 0.27, 1.10) YLL from hypertension in the elderly population born in autumn, while nonsignificant associations were found for those born in other seasons. The birth season, which affects the nutritional condition during early development, could affect vulnerability to the effect of ambient ozone exposure on the disease burden of hypertension in late life. The findings highlighted the importance of taking birth season into consideration when exploring the hypertensive effects of ozone exposure.

Occupational and environmental influences on hypertension

In this review I try to summarize concisely available information on common effectors on blood pressure, occupational, and environmental ones, which are sometimes overlooked, so that clinicians involved in caring for patients with hypertension may have somewhat better vision of what our patients are exposed to.

Ambient air pollution and depression: A systematic review with meta-analysis up to 2019

Although epidemiological studies have evaluated the associations of ambient air pollution with depression, the results remained mixed. To clarify the nature of the association, we performed a comprehensive systematic review and meta-analysis with the Inverse Variance Heterogeneity (IVhet) model to estimate the effect of ambient air pollution on depression. Three English and four Chinese databases were searched for epidemiologic studies investigating associations of ambient particulate (diameter ≤ 2.5 μm (PM_2.5), ≤10 μm (PM₁₀)) and gaseous (nitric oxide (NO), nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂) and ozone (O₃)) air pollutants with depression. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated to evaluate the strength of the associations. We identified 22 eligible studies from 10 countries of the world. Under the IVhet model, per 10 µg/m³ increase in long-term exposure to PM_2.5 (OR: 1.12, 95% CI: 0.97-1.29, I²: 51.6), PM₁₀ (OR: 1.04, 95% CI: 0.88-1.25, I²: 85.7), and NO₂ (OR: 1.05, 95% CI: 0.83-1.34, I²: 83.6), as well as short-term exposure to PM_2.5 (OR: 1.01, 95% CI: 0.99-1.04, I²: 51.6), PM₁₀ (OR: 1.01, 95% CI: 0.98-1.04, I²: 86.7), SO₂ (OR: 1.03, 95% CI: 0.99-1.07, I²: 71.2), and O₃ (OR: 1.01, 95% CI: 0.99-1.03, I²: 82.2) was not significantly associated with depression. However, we observed significant association between short-term NO₂ exposure (per 10 µg/m³ increase) and depression (OR: 1.02, 95% CI: 1.00-1.04, I²: 65.4). However, the heterogeneity was high for all of the pooled estimates, which reduced credibility of the cumulative evidence. Additionally, publication bias was detected for six of eight meta-estimates. In conclusion, short-term exposure to NO₂, but not other air pollutants, was significantly associated with depression. Given the limitations, a larger meta-analysis incorporating future well-designed longitudinal studies, and investigations into potential biologic mechanisms, will be necessary for a more definitive result.

Association Between Metabolic and Hormonal Derangements and Professional Exposure to Urban Pollution in a High Intensity Traffic Area

Rationale: Studies suggest a relation between exposure to air particulate matter (PM)_2.5 pollution and greater cardiovascular morbidity, as well as increased risk for obesity and diabetes. We aimed to identify association(s) between nutritional and metabolic status and exposure to environmental pollution in a cohort of policemen exposed to high levels of air pollution. Methods: We considered adult municipal policemen, working in an urban area at high-traffic density with documented high levels of air PM_2.5 (exposed group) compared to non-exposed policemen. Clinical characteristics, including the presence/absence of metabolic syndrome, were recorded, and serum biomarkers, including adiponectin, leptin, and ghrelin, were assessed. Results: One hundred ninety-nine participants were enrolled, 100 in the exposed group and 99 in the non-exposed group. Metabolic syndrome was documented in 32% of exposed group and in 52.5% of non-exposed group (P = 0.008). In the exposed group, we found a positive correlation between body mass index and serum leptin as well as in the non-exposed group (P < 0.0001). Within the exposed group, subjects with metabolic syndrome showed lower serum adiponectin (P < 0.0001) and higher leptin (P = 0.002) levels with respect to those without metabolic syndrome, whereas in the non-exposed group, subjects with metabolic syndrome showed only higher leptin levels when compared to those without metabolic syndrome (P = 0.01). Among the participants with metabolic syndrome, we found lower adiponectin levels in those of the exposed group with respect to the non-exposed ones (P = 0.007). When comparing the exposed and non-exposed groups, after stratifying participants for Homeostatic Model Assessment for Insulin Resistance >2.5, we found lower adiponectin levels in those of the exposed group with respect to the non-exposed ones (P = 0.038). Conclusions: Exposure to air PM pollution was associated with lower levels of adiponectin in adult males with metabolic syndrome.

Ambient air pollution and diabetes: A systematic review and meta-analysis

BACKGROUND

Air pollutants are suggested to be related to type 2 diabetes (T2D). Since several high quality papers on air pollutants and T2D have been published beyond the last reviews, an extended systematic review is highly warranted. We review epidemiological studies to quantify the association between air pollutants and T2D, and to answer if diabetes patients are more vulnerable to air pollutants.

METHODS

We systematically reviewed the databases of PubMed and Web of Science based on the guidelines of the Preferred Reporting Items for Systematic review and Meta-analysis (PRISMA). We calculated odds ratios (OR) or hazard ratios (HR) and their 95% confidence intervals (CI) to assess the strength of the associations between air pollutants [e.g., particulate matter with diameter ≤ 2.5 μm (PM_2.5), particulate matter with diameter ≤ 10 μm (PM₁₀), and nitrogen dioxide (NO₂)] and T2D. We evaluated the quality and risk of bias of the included studies and graded the credibility of the pooled evidence using several recommended tools. We also performed sensitivity analysis, meta-regression analysis, and publication bias test.

RESULTS

Out of 716 articles identified, 86 were used for this review and meta-analysis. Meta-analyses showed significant associations of PM_2.5 with T2D incidence (11 studies; HR = 1.10, 95% CI = 1.04-1.17 per 10 μg/m³ increment; I² = 74.4%) and prevalence (11 studies; OR = 1.08; 95% CI = 1.04-1.12 per 10 μg/m³ increment; I² = 84.3%), of PM₁₀ with T2D prevalence (6 studies; OR = 1.10; 95% CI = 1.03-1.17 per 10 μg/m³ increment; I² = 89.5%) and incidence (6 studies; HR = 1.11; 95% CI = 1.00-1.22 per μg/m³ increment; I² = 70.6%), and of NO₂ with T2D prevalence (11 studies; OR = 1.07; 95% CI = 1.04-1.11 per 10 μg/m³ increment; I² = 91.1%). The majority of studies on glucose-homoeostasis markers also showed increased risks with higher air pollutants levels, but the studies were too heterogeneous for meta-analysis. Overall, patients with diabetes might be more vulnerable to PM.

CONCLUSIONS

Recent publications strengthened the evidence for adverse effects of ambient air pollutants exposure (especially for PM) on T2D and that diabetic patients might be more vulnerable to air pollutants exposure.

Greenness around schools associated with lower risk of hypertension among children: Findings from the Seven Northeastern Cities Study in China

Evidence suggests that residential greenness may be protective of high blood pressure, but there is scarcity of evidence on the associations between greenness around schools and blood pressure among children. We aimed to investigate this association in China. Our study included 9354 children from 62 schools in the Seven Northeastern Cities Study. Greenness around each child's school was measured by NDVI (Normalized Difference Vegetation Index) and SAVI (Soil-Adjusted Vegetation Index). Particulate matter ≤ 1 μm (PM₁) concentrations were estimated by spatiotemporal models and nitrogen dioxide (NO₂) concentrations were collected from air monitoring stations. Associations between greenness and blood pressure were determined by generalized linear and logistic mixed-effect models. Mediation by air pollution was assessed using mediation analysis. Higher greenness was consistently associated with lower blood pressure. An increase of 0.1 in NDVI corresponded to a reduction in SBP of 1.39 mmHg (95% CI: 1.86, -0.93) and lower odds of hypertension (OR = 0.76, 95% CI: 0.69, 0.82). Stronger associations were observed in children with higher BMI. Ambient PM₁ and NO₂ mediated 33.0% and 10.9% of the association between greenness and SBP, respectively. In summary, greater greenness near schools had a beneficial effect on blood pressure, particularly in overweight or obese children in China. The associations might be partially mediated by air pollution. These results might have implications for policy makers to incorporate more green space for both aesthetic and health benefits.

Is air pollution affecting the disease activity in patients with systemic lupus erythematosus? State of the art and a systematic literature review

OBJECTIVE

It has been documented that several major components of air pollution, including trace elements and polycyclic aromatic hydrocarbons, are associated with the prevalence of systemic lupus erythematosus (SLE). However, the impact of air pollution on the SLE disease activity is still elusive. In this paper, we review the current evidence investigating the link between air pollution, especially when measured as PM2.5, and SLE severity and activity.

METHODS

A detailed literature search was applied a priori to the Ovid MEDLINE In-Process and Other Non-Indexed Citation 1986 to present. Presented abstracts from the European League Against Rheumatism and American College of Rheumatology (ACR)/Association for Rheumatology Health Professionals (ARHP) Annual Meetings (2011-2018) were also screened.

RESULTS

Out of a total of 1354 papers retrieved from search and references list for detailed evaluation, data from 652 patients with SLE from three studies were analyzed. Two studies had an observational longitudinal design, counting for 348 patients with a follow-up of 24 months and 79 months. Retrieved studies differed for disease activity assessment and air pollution quantifications.

CONCLUSION

Current evidence suggests that variations in air pollution may influence the disease activity in patients with SLE. However, the sample size, methodological biases, and differences across the studies make further research mandatory. Understanding the increased burden of SLE and its complications, not only from a medical, but also from a socio-demographic perspective, including an exposure to pollutants, should have implications for resource allocation and access to subspecialty care.

Ambient Airborne Particulates of Diameter ≤1 μm, a Leading Contributor to the Association Between Ambient Airborne Particulates of Diameter ≤2.5 μm and Children's Blood Pressure

Evidence on the associations between airborne particulates of diameter ≤1 μm (PM₁) and airborne particulates of diameter ≤2.5 μm (PM_2.5) and childhood blood pressure (BP) is scarce. To help to address this literature gap, we conducted a study to explore the associations in Chinese children. Between 2012 and 2013, we recruited 9354 children, aged 5 to 17 years, from 62 schools in 7 northeastern Chinese cities. We measured their BP with a mercury sphygmomanometer. We used a spatiotemporal model to estimate daily ambient PM₁ and PM_2.5 exposures, which we assigned to participants' home addresses. Associations between particulate matter exposure and BP were evaluated with generalized linear mixed regression models. The findings indicated that exposure to each 10 mg/m³ greater PM₁ was significantly associated with 2.56 mm Hg (95% CI, 1.47-3.65) higher systolic BP and 61% greater odds for hypertension (odds ratio=1.61 [95% CI, 1.18-2.18]). PM₁ appears to play an important role in associations reported between PM_2.5 exposure and BP, and we found that the ambient PM₁/PM_2.5 ratio (range, 0.80-0.96) was associated with BP and with hypertension. Age and body weight modified associations between air pollutants and BP (P<0.01), with stronger associations among younger (aged ≤11 years) and overweight/obese children. This study provides the first evidence that long-term exposure to PM₁ is associated with hypertension in children, and that PM₁ might be a leading contributor to the hypertensive effect of PM_2.5. Researchers and policy makers should pay closer attention to the potential health impacts of PM₁.

Short-term effects of ambient particulate matter on blood pressure among children and adolescents:A cross-sectional study in a city of Yangtze River delta, China

Several studies have demonstrated associations between short-term exposure to particulate matter (PM) and blood pressure (BP) among various adults groups, but evidence in children and adolescents is still rare. In 2016, a cross-sectional survey was conducted among 194 104 participants aged 6-17 years in Suzhou, China. Daily concentrations of particulate matters with an aerodynamic diameter of ≤10 μg/m³ (PM₁₀) and aerodynamic diameter ≤2.5 μg/m³ (PM_2.5) on 0-6 days preceding BP examination were collected from nearby air monitoring stations. Using generalized linear mixed-effects models, short-term effects of PM on personal BP were estimated. A 10 μg/m³ increment in the 0-6 day mean of PM_2.5 was significantly associated with elevation of 0.20 mmHg [95% confidence interval (95% CI) 0.16-0.23] in systolic BP (SBP), 0.49 mmHg (95% CI 0.45-0.53) in diastolic BP (DBP), respectively. Similarly, 0.14 mmHg (95% CI 0.12-0.16) higher SBP and 0.32 mmHg (95% CI 0.30-0.34) higher DBP were found for each 10 μg/m³ increase in 0-6 day mean of PM₁₀. More apparent associations were observed in females than in males. Odds ratio (95%CI) of for PM_2.5 exposure at 0-6 d mean was 1.06 (1.03-1.08) in females, while it was 1.01 (0.99-1.03) in males. Participants with young ages, underweight and obesity were also associated with increased susceptibility to PM-induced BP effects. Short-term exposure in PM was significantly associated with elevated BP in children, indicating a need to control PM levels and protect children from PM exposure in China.

Burden of Cause-Specific Mortality Associated With PM2.5 Air Pollution in the United States

IMPORTANCE

Ambient fine particulate matter (PM2.5) air pollution is associated with increased risk of several causes of death. However, epidemiologic evidence suggests that current knowledge does not comprehensively capture all causes of death associated with PM2.5 exposure.

OBJECTIVE

To systematically identify causes of death associated with PM2.5 pollution and estimate the burden of death for each cause in the United States.

DESIGN, SETTING, AND PARTICIPANTS

In a cohort study of US veterans followed up between 2006 and 2016, ensemble modeling was used to identify and characterize morphology of the association between PM2.5 and causes of death. Burden of death associated with PM2.5 exposure in the contiguous United States and for each state was then estimated by application of estimated risk functions to county-level PM2.5 estimates from the US Environmental Protection Agency and cause-specific death rate data from the Centers for Disease Control and Prevention.

MAIN OUTCOMES AND MEASURES

Nonlinear exposure-response functions of the association between PM2.5 and causes of death and burden of death associated with PM2.5.

EXPOSURES

Annual mean PM2.5 levels.

RESULTS

A cohort of 4 522 160 US veterans (4 243 462 [93.8%] male; median [interquartile range] age, 64.1 [55.7-75.5] years; 3 702 942 [82.0%] white, 667 550 [14.8%] black, and 145 593 [3.2%] other race) was followed up for a median (interquartile range) of 10.0 (6.8-10.2) years. In the contiguous United States, PM2.5 exposure was associated with excess burden of death due to cardiovascular disease (56 070.1 deaths [95% uncertainty interval {UI}, 51 940.2-60 318.3 deaths]), cerebrovascular disease (40 466.1 deaths [95% UI, 21 770.1-46 487.9 deaths]), chronic kidney disease (7175.2 deaths [95% UI, 5910.2-8371.9 deaths]), chronic obstructive pulmonary disease (645.7 deaths [95% UI, 300.2-2490.9 deaths]), dementia (19 851.5 deaths [95% UI, 14 420.6-31 621.4 deaths]), type 2 diabetes (501.3 deaths [95% UI, 447.5-561.1 deaths]), hypertension (30 696.9 deaths [95% UI, 27 518.1-33 881.9 deaths]), lung cancer (17 545.3 deaths [95% UI, 15 055.3-20 464.5 deaths]), and pneumonia (8854.9 deaths [95% UI, 7696.2-10 710.6 deaths]). Burden exhibited substantial geographic variation. Estimated burden of death due to nonaccidental causes was 197 905.1 deaths (95% UI, 183 463.3-213 644.9 deaths); mean age-standardized death rates (per 100 000) due to nonaccidental causes were higher among black individuals (55.2 [95% UI, 50.5-60.6]) than nonblack individuals (51.0 [95% UI, 46.4-56.1]) and higher among those living in counties with high (65.3 [95% UI, 56.2-75.4]) vs low (46.1 [95% UI, 42.3-50.4]) socioeconomic deprivation; 99.0% of the burden of death due to nonaccidental causes was associated with PM2.5 levels below standards set by the US Environmental Protection Agency.

CONCLUSIONS AND RELEVANCE

In this study, 9 causes of death were associated with PM2.5 exposure. The burden of death associated with PM2.5 was disproportionally borne by black individuals and socioeconomically disadvantaged communities. Effort toward cleaner air might reduce the burden of PM2.5-associated deaths.

Ambient air pollution and lipid profile: Systematic review and meta-analysis

Ambient air pollution (AAP) is recognized a cardiovascular risk factor and lipid profile dysregulation seems to be one of the potential mediators involved. However, results from epidemiologic research on the association between exposure to AAP and altered lipid profile have been inconsistent. This study aims to systematically review and meta-analyse epidemiologic evidence on the association between exposure to ambient air pollutants (particulate matter, nitrogen oxides, sulphur dioxide, ozone, carbon monoxide, back carbon) and lipid profile parameters (Total cholesterol; High-Density Lipoprotein Cholesterol; Low-Density Lipoprotein Cholesterol; TG-Triglycerides) or dyslipidaemia. Systematic electronic literature search was performed in PubMed, Web of Science and Scopus databases (last search on 24th May 2019) using keywords related to the exposure (ambient air pollutants) and to the outcomes (lipid profile parameters/dyslipidaemia). Qualitative and quantitative information of the studies were extracted and fixed or random-effects models were used to obtain a pooled effect estimate per each pollutant/outcome combination. 22 studies were qualitatively analysed and, from those, 3 studies were quantitatively analysed. Particulate matters were the most studied pollutants and a considerable heterogeneity in air pollution assessment methods and outcomes definitions was detected. Age, obesity related measures, tobacco consumption, sex and socioeconomic factors were the most frequent considered variables for confounding adjustment in the models. In a long-term exposure scenario, we found a 3.14% (1.36%-4.95%) increase in TG levels per 10 μg/m³ PM₁₀ increment and a 4.24% (1.37%-7.19%) increase in TG levels per 10 μg/m³ NO₂ increment. No significant associations were detected for the remaining pollutant/outcome combinations. Despite the few studies included in the meta-analysis, our study suggests some epidemiologic evidence supporting the association between PM₁₀ and NO₂ exposures and increased TG levels. Due to the very low level of evidence, more studies are needed to clarify the role of lipid profile dysregulation as a mediator on the AAP adverse cardiovascular effects.

The impact of air pollutants on ambulance dispatches: A systematic review and meta-analysis of acute effects

A number of systematic reviews have investigated the association between air pollutants and health impacts, these mostly focus on morbidity and mortality from hospital data. Previously, no reviews focused solely on ambulance dispatch data. These data sets have excellent potential for environmental health research. For this review, publications up to April 2019 were identified using three main search categories covering: ambulance services including dispatches; air pollutants; and health outcomes. From 308 studies initially identified, 275 were excluded as they did not relate to ambulance service dispatches, did not report the air pollutant association, and/or did not study ambient air pollution. The main health outcomes in the remaining 33 studies were cardiac arrest (n = 14), cardiovascular (n = 11) and respiratory (n = 10) dispatches. Meta-analyses were performed to summarise pooled relative risk (RR) of pollutants: particulate matter less than 2.5 and 10 μm (PM_2.5, PM₁₀), the fraction between PM₁₀ and PM_2.5 (coarse) and suspended particulate matter (SPM) per 10 μg/m³ increase, carbon monoxide (CO) per 1 ppm increase and of sulphur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃) per 10 ppb increment and ambulance dispatches. Statistically significant associations were found for ambulance dispatch data for all-respiratory and PM_2.5 at 1.03 (95% CI:1.02-1.04) and at 1.10 (95% CI:1.00-1.21) for asthma and NO₂ associations. For dispatches with subsequent paramedic assessment for cardiac arrest with PM_2.5, CO and coarse dispatches at 1.05 (95% CI:1.03-1.08), 1.10 (95% CI:1.02-1.18) and 1.04 (95% CI:1.01-1.06) respectively. For dispatches with subsequent physician diagnosis for all-respiratory and PM_2.5 at 1.02 (95% CI:1.01-1.03). In conclusion, air pollution was significantly associated with an increase in ambulance dispatch data, including those for cardiac arrest, all-respiratory, and asthma dispatches. Ambulance services should plan accordingly during pollution events. Furthermore, efforts to improve air quality should lead to decreases in ambulance dispatches.

Short-term exposure to air pollution and incidence of stroke in the Women's Health Initiative

BACKGROUND

Evidence of the association between daily variation in air pollution and risk of stroke is inconsistent, potentially due to the heterogeneity in stroke etiology.

OBJECTIVES

To estimate the associations between daily variation in ambient air pollution and risk of stroke and its subtypes among participants of the Women's Health Initiative, a large prospective cohort study in the United States.

METHODS

We used national-scale, log-normal ordinary kriging models to estimate daily concentrations of fine particulate matter (PM2.5), respirable particulate matter (PM10), nitrogen dioxide (NO2), nitrogen oxides (NOx), sulphur dioxide, and ozone at participant addresses. Stroke was adjudicated by trained neurologists and classified as ischemic or hemorrhagic. Ischemic strokes were further classified according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. We used a time-stratified case-crossover approach to estimate the odds ratio (OR) of the risk of stroke associated with an interquartile range (IQR) increase in concentrations of each air pollutant. We performed stratified analysis to examine whether associations varied across subgroups defined by age at stroke onset, US census region, smoking status, body mass index, and prior history of diabetes mellitus, hypertension, heart or circulation problems, or arterial fibrillation at enrollment.

RESULTS

Among 5417 confirmed strokes between 1993 and 2012, 4300 (79.4%) were classified as ischemic and 924 (17.1%) as hemorrhagic. No association was observed between day-to-day variation in any pollutant and risk of total stroke, ischemic stroke, or specific etiologies of ischemic stroke. We observed a positive association between risk of hemorrhagic stroke and NO2 and NOx in the 3 days prior to stroke with OR of 1.24 (95% CI: 1.01, 1.52) and 1.18 (95% CI: 1.03, 1.34) per IQR increase, respectively. The observed associations with hemorrhagic stroke were more pronounced among non-obese participants.

CONCLUSIONS

In this large cohort of post-menopausal US women, daily NO2 and NOx were associated with higher risk of hemorrhagic stroke, but ambient levels of four other air pollutants were not associated with higher risk of total stroke, ischemic stroke, or ischemic stroke subtypes.

Fine particle environmental pollution and cardiovascular diseases

Air pollution affects 90% of the world's population and has caused 9 million deaths in 2015, becoming the most important cause of premature deaths in the world. Exposure to fine particulate matter, a major component of urban air pollution, has been associated with an increase in cardiovascular risk and associated mortality. Impact of fine particles on the cardiovascular system includes inflammation, activation of prothrombotic pathways, oxidative stress, vascular dysfunction and remodeling, and neurological dysfunction. Genetic and epigenetic factors might also increase the susceptibility to air pollution. Consequently, epidemiologic studies have identified correlations between air particulate matter concentrations and acute coronary events, ischemic cardiomyopathy, acute heart failure, and stroke. Interestingly, these effects are present even for fine particulate matter concentrations below current US and EU regulatory standards, and seems to be more harmful in the most fragile population such as low-income or elderly subjects, or patients with previous cardiovascular disease. This review aims to summarize recent data on the pathophysiology and epidemiology of cardiovascular disease after particulate matter exposure. It will also discuss potential strategies to reduce the impact of air pollution on current and future populations' health.

Acute Effects of High-Level PM2.5 Exposure on Central Blood Pressure

Central aortic blood pressure (BP) has been increasingly recognized as having a closer relationship with cardiovascular risks than peripheral BP. However, the effects of particulate matter pollution on central aortic BP have not been clearly demonstrated. In this study, we assessed the association between short-term ambient fine particulate matter (with an aerodynamic diameter ≤2.5 μm; PM_2.5) exposure and central aortic BP in a Chinese community-based population. A total of 4715 visits were in our final analysis, including 2151 visits at the baseline and 2564 visits at the follow-up. Central aortic systolic BP (cSBP) was measured noninvasively using the method of radial artery tonometry with Omron HEM-9000AI machine. Data from air pollution monitoring stations were used to estimate daily PM_2.5 exposure. Generalized additive mixed models with clinical and meteorologic covariates adjusted were used to examine the association between PM_2.5 exposure and cSBP. The relationships between PM_2.5 exposure and cSBP were nonlinear, and significant increments of cSBP were observed when the PM_2.5 exposure concentration was above 100 μg/cm³. An interquartile range increase (80.25 μg/m³) in daily PM_2.5 on the day of cSBP measurement (lag 0 day) was associated with 2.54 mm Hg (95% CI, 0.92-4.16) elevation in cSBP. The associations of PM_2.5 with cSBP were not modified by age, sex, body mass index, medications, and comorbid diseases except for cardiovascular disease. Our findings demonstrated that short-term exposure to high concentration of ambient PM_2.5 above 100 μg/cm³ was associated with significant increases in central aortic BP in a Chinese community-based population.

Quantification of the Cost and Potential Environmental Effects of Unused Pharmaceutical Products in Cataract Surgery

Importance

Pharmaceutical products, including unused portions, may contribute to financial and environmental costs in the United States. Because cataract surgery is performed millions of times each year in the United States and throughout the rest of the world, understanding these financial and environmental costs associated with cataract surgery is warranted.

Objective

To investigate the financial and environmental costs of unused pharmaceutical products after phacoemulsification surgery.

Design, Setting, and Participants

This descriptive qualitative study included 4 surgical sites in the northeastern United States (a private ambulatory care center, private tertiary care center, private outpatient center, and federally run medical center for veterans). Prices and data for use of services and pharmaceuticals were obtained for the tertiary care and outpatient centers from January 1 through April 30, 2016; for the ambulatory care center from June 1, 2017, through March 31, 2018; and the federal medical center from November 1, 2017, through February 28, 2018. Data were collected from routine phacoemulsification surgical procedures without vitreous loss or other complications. Volume or weight of medications remaining after surgery was measured. Total and mean costs of medications per case and month were calculated. Environmental effects were estimated using economic input-output life cycle assessment methods. Data were analyzed from December 1, 2017, through June 30, 2018.

Main Outcomes and Measures

Cost of unused pharmaceutical products (in US dollars) and kilogram equivalents of carbon emissions (carbon dioxide [CO2-e]), air pollution (fine particulate matter emissions of ≤10 μm in diameter [PM10-e]), and eutrophication potential (nitrogen [N-e]).

Results

A total of 116 unique drugs were surveyed among the 4 centers. Assuming unmeasured medications had no materials left unused, a cumulative mean 83 070 of 183 304 mL per month (45.3%) of pharmaceuticals were unused by weight or volume across all sites. Annual unused product cost estimates reached approximately $195 200 per site. A larger percentage of eyedrops (65.7% by volume) were unused compared with injections (24.8%) or systemic medications (59.9%). Monthly unused quantities at the ambulatory care center (65.9% by volume [54 971 of 83 440 mL]), tertiary care center (21.3% [17 143 of 80 344 mL]), federal medical center (38.5% [265 of 689 mL]), and outpatient center (56.8% [10 691 of 18 832 mL]) resulted in unnecessary potential emissions at each center of 2135, 2498, 418, and 711 kg CO2-e/mo, respectively. Unnecessary potential air pollution between sites varied from 0.8 to 4.5 kg PM10-e/mo, and unnecessary eutrophication potential between sites varied from 0.07 to 0.42 kg N-e/mo.

Conclusions and Relevance

This study suggests that unused pharmaceutical products during phacoemulsification result in relatively high financial and environmental costs. If these findings can be substantiated and shown to be generalizable in the United States or elsewhere, reducing these costs may be of value.

Associations Between Sub-Clinical Markers of Cardiometabolic Risk and Exposure to Residential Indoor Air Pollutants in Healthy Adults in Perth, Western Australia: A Study Protocol

BACKGROUND

A growing body of epidemiological and clinical evidence has implicated air pollution as an emerging risk factor for cardiometabolic disease. Whilst individuals spend up to two-thirds of daily time in their domestic residential environment, very few studies have been designed to objectively measure the sub-clinical markers of cardiometabolic risk with exposure to domestic indoor air pollutants. This cross-sectional study aims to investigate associations between the components of domestic indoor air quality and selected sub-clinical cardiometabolic risk factors in a cohort of healthy adults living in Perth, Western Australia.

METHODS

One hundred and eleven non-smoking adults (65% female) living in non-smoking households who were aged between 35-69 years were recruited for the project. Study subjects were invited to participate in all sections of the study, which included: Domestic indoor air monitoring along with the concurrent 24 h ambulatory monitoring of peripheral and central blood pressure and measures of central hemodynamic indices, standardized questionnaires on aspects relating to current health status and the domestic environment, a 24 h time-activity diary during the monitoring period, and clinic-based health assessment involving collection of blood and urine biomarkers for lipid and glucose profiles, as well as measures of renal function and an analysis of central pulse wave and pulse wave velocity.

RESULTS

This study provides a standardized approach to the study of sub-clinical cardiometabolic health effects that are related to the exposure to indoor air pollution.

CONCLUSION

The findings of this study may provide direction for future research that will further contribute to our understanding of the relationship that exists between indoor air pollution and sub-clinical markers of cardiometabolic risk.

Air Pollution and Cardiovascular Disease: JACC State-of-the-Art Review

Fine particulate matter <2.5 μm (PM_2.5) air pollution is the most important environmental risk factor contributing to global cardiovascular (CV) mortality and disability. Short-term elevations in PM_2.5 increase the relative risk of acute CV events by 1% to 3% within a few days. Longer-term exposures over several years increase this risk by a larger magnitude (∼10%), which is partially attributable to the development of cardiometabolic conditions (e.g., hypertension and diabetes mellitus). As such, ambient PM_2.5 poses a major threat to global public health. In this review, the authors provide an overview of air pollution and health, including assessment of exposure, impact on CV outcomes, mechanistic underpinnings, and impact of air pollution reduction strategies to mitigate CV risk. The review concludes with future challenges, including the inextricable link between air pollution and climate change, and calls for large-scale trials to allow the promulgation of formal evidence-based recommendations to lower air pollution-induced health risks.

Early-Life Environmental Exposures and Blood Pressure in Children

BACKGROUND

Growing evidence exists about the fetal and environmental origins of hypertension, but mainly limited to single-exposure studies. The exposome has been proposed as a more holistic approach by studying many exposures simultaneously.

OBJECTIVES

This study aims to evaluate the association between a wide range of prenatal and postnatal exposures and blood pressure (BP) in children.

METHODS

Systolic and diastolic BP were measured among 1,277 children from the European HELIX (Human Early-Life Exposome) cohort aged 6 to 11 years. Prenatal (n = 89) and postnatal (n = 128) exposures include air pollution, built environment, meteorology, natural spaces, traffic, noise, chemicals, and lifestyles. Two methods adjusted for confounders were applied: an exposome-wide association study considering the exposures independently, and the deletion-substitution-addition algorithm considering all the exposures simultaneously.

RESULTS

Decreases in systolic BP were observed with facility density (β change for an interquartile-range increase in exposure: -1.7 mm Hg [95% confidence interval (CI): -2.5 to -0.8 mm Hg]), maternal concentrations of polychlorinated biphenyl 118 (-1.4 mm Hg [95% CI: -2.6 to -0.2 mm Hg]) and child concentrations of dichlorodiphenyldichloroethylene (DDE: -1.6 mm Hg [95% CI: -2.4 to -0.7 mm Hg]), hexachlorobenzene (-1.5 mm Hg [95% CI: -2.4 to -0.6 mm Hg]), and mono-benzyl phthalate (-0.7 mm Hg [95% CI: -1.3 to -0.1 mm Hg]), whereas increases in systolic BP were observed with outdoor temperature during pregnancy (1.6 mm Hg [95% CI: 0.2 to 2.9 mm Hg]), high fish intake during pregnancy (2.0 mm Hg [95% CI: 0.4 to 3.5 mm Hg]), maternal cotinine concentrations (1.2 mm Hg [95% CI: -0.3 to 2.8 mm Hg]), and child perfluorooctanoate concentrations (0.9 mm Hg [95% CI: 0.1 to 1.6 mm Hg]). Decreases in diastolic BP were observed with outdoor temperature at examination (-1.4 mm Hg [95% CI: -2.3 to -0.5 mm Hg]) and child DDE concentrations (-1.1 mm Hg [95% CI: -1.9 to -0.3 mm Hg]), whereas increases in diastolic BP were observed with maternal bisphenol-A concentrations (0.7 mm Hg [95% CI: 0.1 to 1.4 mm Hg]), high fish intake during pregnancy (1.2 mm Hg [95% CI: -0.2 to 2.7 mm Hg]), and child copper concentrations (0.9 mm Hg [95% CI: 0.3 to 1.6 mm Hg]).

CONCLUSIONS

This study suggests that early-life exposure to several chemicals, as well as built environment and meteorological factors, may affect BP in children.

Associations between ambient air pollution and mortality from all causes, pneumonia, and congenital heart diseases among children aged under 5 years in Beijing, China: A population-based time series study

BACKGROUND

Previous studies have mainly focused on the associations between particulate matters and infant mortality. However, evidence regarding the associations between gaseous pollutants and mortality among children aged <5 years remains sparse.

OBJECTIVES

The aim of this study was to investigate the associations between ambient air pollution and death among children aged <5 years in Beijing, China, and explore the impact of age, gender and specific causes of death on these associations.

METHODS

Concentrations of ambient air pollution and the number of deaths among children aged <5 years in Beijing from January 2014 to September 2016 were extracted from authoritative electronic databases. The associations were estimated for a single-month lag from the current month up to the previous 5 months (lag0-lag5) and moving averages of the current and previous months (lag01-lag05) using generalized additive Poisson regression (adjusted for time trends, season, meteorological variables and holidays). Subgroup analyses related to age, gender and specific diseases were performed. Two-pollutant models were used to evaluate the possible role of single pollutants.

RESULTS

Sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO) demonstrated the strongest associations with death among children aged <5 years at lag0, and the estimates decreased or even turned negative with the increasing lag periods. For an interquartile range increase in SO₂, NO₂ and CO at lag0, the odds ratios (OR) were 1.332 (95% CI 1.152-1.539), 1.383 (95% CI 1.113-1.718) and 1.273 (95% CI 1.028-1.575). However, CO lost significance after adjusting for SO₂ and NO₂, and PM_2.5 gained significance (OR 1.548, 95% CI 1.061-2.258) after adjusting for PM₁₀. The ORs for SO₂ and NO₂ remained the most stable across all two-pollutant models. The associations for children aged 1-5 years were stronger than those reported for infants at lag0 but lower at the other lag months. The pollutant associations were stronger for congenital heart disease-related death than overall and pneumonia-related death. We did not find significant differences in terms of gender.

CONCLUSION

Exposure to air pollution may increase the incidence of death among children aged <5 years. SO₂ and NO₂ may be the most stable pollutants reflecting associations between air pollution and death, deserving further attention. Children with congenital heart diseases are more susceptible to air pollution. Therefore, it is urgent to implement the clean air targets established by WHO and reduce the exposure of children to air pollution.

Economic fluctuations and cardiovascular diseases: A multiple-input time series analysis

Objectives

Little is known about the gender and age differences associated with the effects of economic fluctuations on hospitalization for cardiovascular diseases. This paper investigates the impact of economic fluctuations on hospitalization for ischemic heart disease (IHD), stroke, and hypertension by age and gender between January 1996 and December 2012 in Taiwan.

Methods

We adopted a multiple-input time series analysis to examine the strength of the immediate and latent effects of the 17-year quarterly unemployment rates (UR), air pollution exposure (APE), gross domestic product (GDP), per capita consumption expenditure in cigarette and alcohol (ECA), and per capita healthcare expenditure (HE) on the adjusted quarterly incidence rate of hospitalization. The data used in this paper were retrieved from the National Health Insurance Research Database and the website of the Directorate-General of Budget, Accounting and Statistics (DGBAS), Executive Yuan.

Results

Our findings indicate that higher UR increased IHD hospitalization in young men and women and middle-aged women but reduced stroke hospitalization in young men. Higher APE increased IHD hospitalization in young men but reduced it for young women, increased stroke hospitalization in old men and middle-aged women but reduced it for young men, and increased hypertension hospitalization in middle-aged men and young women. Higher ECA reduced IHD hospitalization in middle-aged men, increased stoke hospitalization in middle-aged and old men and middle-aged women. Higher HE reduced IHD hospitalization in old men, young and old women, reduced stroke hospitalization in old women, and reduced hypertension hospitalization in young and middle-aged women.

Conclusions

Overall, we found that the economic fluctuations caused increased harmful effects in certain population subgroups but also brought some soothing effects to some groups.

Dynamic Changes in Long-Term Exposure to Ambient Particulate Matter and Incidence of Hypertension in Adults

Many countries dedicated in mitigation of air pollution in the past several decades. However, little is known about how air quality improvement affects health. Therefore, we conducted current study to investigate dynamic changes in long-term exposure to ambient particulate matter (PM_2.5) and incidence of hypertension in a large longitudinal cohort. We recruited 134 978 adults aged 18 years or above between 2001 and 2014. All the participants received a series of standard medical examinations, including measurements of blood pressure. The PM_2.5 concentration was estimated using a satellite-based spatiotemporal model at a high resolution (1×1 km²). The change in long-term exposure to PM_2.5 (ΔPM_2.5) was defined as the difference between the values measured during follow-up and during the immediately preceding visit, and a negative value indicated an improvement in PM_2.5 air quality. Time-varying Cox model was used to examine the associations between ΔPM_2.5 and the development of hypertension. The results show that PM_2.5 concentrations increased in 2002, 2003, and 2004, but began to decrease in 2005. Every 5 µg/m³ change in exposure to PM_2.5 (ie, a ΔPM_2.5 of 5 µg/m³) was associated with a 16% change in the incidence of hypertension (hazard ratio, 0.84; 95% CI, 0.82-0.86). Both stratified and sensitivity analyses generally yielded similar results. We found that an improvement in PM_2.5 exposure is associated with a decreased incidence of hypertension. Our findings demonstrate that air pollution mitigation is an effective strategy to reduce the risk of cardiovascular disease.

Exposure to ambient particulate matter air pollution, blood pressure and hypertension in children and adolescents: A national cross-sectional study in China

BACKGROUND

Air pollution has been associated with elevated blood pressure in adults. However, epidemiological evidence from children and adolescents is limited. We investigated the associations between long-term exposure to particulate matter (PM) air pollution and blood pressure in a large population of children and adolescents.

METHODS

A cross-sectional analysis was performed in a nationally representative sample consisting of 43,745 children and adolescents aged 7 to 18 years in seven provinces in China. Exposure to ambient fine particles (PM_2.5) and thoracic particles (PM₁₀) was estimated using spatiotemporal models based on satellite remote sensing, meteorological data and land use information. Mixed-effects (two-level) linear and logistic regression models were used to investigate the associations between PM exposure and systolic blood pressure (SBP), diastolic blood pressure (DBP) and hypertension.

RESULTS

After adjustment for a wide range of covariates, every 10 μg/m³ increment in PM_2.5 and PM₁₀ concentration was associated with 1.46 [95% confidence interval (CI): 0.05, 2.88] and 1.36 (95% CI: 0.34, 2.39) mmHg increases in SBP, respectively. PM₁₀ was also associated with higher prevalence of hypertension [odds ratio per 10 μg/m³ increment: 1.45 (95% CI: 1.07, 1.95)].

CONCLUSIONS

Long-term exposure to ambient PM air pollution was associated with increased blood pressure and higher prevalence of hypertension in children and adolescents. Our findings support air pollution reduction strategies as a prevention measure of childhood hypertension, a well-recognized risk factor of future cardiovascular health.

Associations of long-term exposure to ambient PM1 with hypertension and blood pressure in rural Chinese population: The Henan rural cohort study

BACKGROUND

The epidemiological evidence on relationships between long-term exposure to particulate matter and hypertension and blood pressure has been inconclusive. Limited evidence was available for particulate matter with an aerodynamic diameter ≤ 1 μm (PM1) in rural areas of developing countries.

OBJECTIVE

This study aimed to investigate the associations between long-term exposure to PM1 and hypertension and blood pressure among rural Chinese population.

METHODS

This study included 39,259 participants who had completed the baseline survey from Henan Rural Cohort. Participants' exposure to PM1 was assessed by a satellite-based spatiotemporal model. The binary logistic regression model was used to examine the association between long-term PM1 exposure and hypertension, and multivariable linear regression model was used to investigate the associations between long-term PM1 exposure and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). Moreover, we examined potential effect modifications by demographic, lifestyle and diet factors.

RESULTS

The mean concentration of PM1 for all participants during the 3-year before baseline survey was 59.98 μg/m3. Each 1 μg/m3 increase in PM1 concentration was significantly associated with an increase of 4.3% [Odds ratio(OR) = 1.043, 95% confidence interval(CI): 1.033, 1.053] in odds for hypertension, an increase of 0.401 mm Hg (95% CI, 0.335, 0.467), 0.328 mm Hg (95% CI, 0.288, 0.369), 0.353 mm Hg (95% CI, 0.307, 0.399) and 0.073 mm Hg (95% CI, 0.030, 0.116) in SBP, DBP, MAP and PP, respectively. Further stratified analyses showed that the effect of PM1 on hypertension and blood pressure could be modified by sex, lifestyle and diet.

CONCLUSIONS

This study suggests that long-term exposure to ambient PM1 increases the risk of hypertension and is associated with elevations in blood pressure in rural Chinese adults, especially in male and those with unhealthy habits.

Personal exposure to PM2.5 constituents associated with gestational blood pressure and endothelial dysfunction

Ambient fine particulate matter (PM_2.5) pollution has been implicated in the development of hypertensive disorders of pregnancy. However, evidence on the effects of PM_2.5-derived chemical constituents on gestational blood pressure (BP) is limited, and the potential mechanisms underlying the association remain unclear. In this study, we repeated three consecutive 72-h personal air sampling and BP measurements in 215 pregnant women for 590 visits during pregnancy. Individual PM_2.5 exposure level was assessed by gravimetric method and 28 PM_2.5 chemical constituents were analyzed by ED-XRF method. Plasma biomarkers of endothelial function and inflammation were measured using multiplexed immunoassays. Robust multiple linear regression models were used to estimate the associations among personal PM_2.5 exposure and chemical constituents, BP changes (compared with pre-pregnancy BP) and plasma biomarkers. Mediation analyses were performed to evaluate underlying potential pathways. Result showed that exposure to PM_2.5 was significantly associated with increases in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) in the early second trimester. Meanwhile, elevated concentration of lead (Pb) constituent in PM_2.5 was significant associated with increases in DBP and MAP after adjusting for PM_2.5 total mass. PM_2.5 and Pb constituent also presented positive associations with plasma biomarkers of endothelial function (ET-1, E-selectin, ICAM-1) and inflammation (IL-1β, IL-6, TNFα) significantly. After multiple adjustment, elevated ET-1 and IL-6 were significantly correlated with increased gestational BP, and respectively mediated 1.24%-25.06% and 7.01%-10.69% of the increased BP due to PM_2.5 and Pb constituent exposure. In conclusion, our results suggested that personal exposure to PM_2.5 and Pb constituent were significantly associated with increased BP during pregnancy, and the early second trimester might be the sensitive window of PM_2.5 exposure. The endothelial dysfunction and elevated inflammation partially mediated the effect of PM_2.5 and Pb constituent on BP during pregnancy.

Ambient Particulate Air Pollution and Blood Pressure in Peri-urban India

BACKGROUND

Evidence linking long-term exposure to particulate air pollution to blood pressure (BP) in high-income countries may not be transportable to low- and middle-income countries. We examined cross-sectional associations between ambient fine particulate matter (PM2.5) and black carbon (BC) with BP (systolic [SBP] and diastolic [DBP]) and prevalent hypertension in adults from 28 peri-urban villages near Hyderabad, India.

METHODS

We studied 5531 participants from the Andhra Pradesh Children and Parents Study (18-84 years, 54% men). We measured BP (2010-2012) in the right arm and defined hypertension as SBP ≥130 mmHg and/or DBP ≥80 mmHg. We used land-use regression models to estimate annual average PM2.5 and BC at participant's residence. We applied linear and logistic nested mixed-effect models stratified by sex and adjusted by cooking fuel type to estimate associations between within-village PM2.5 or BC and health.

RESULTS

Mean (SD) PM2.5 was 33 µg/m (2.7) and BC was 2.5 µg/m (0.23). In women, a 1 µg/m increase in PM2.5 was associated with 1.4 mmHg higher SBP (95% confidence interval [CI]: 0.12, 2.7), 0.87 mmHg higher DBP (95% CI: -0.18, 1.9), and 4% higher odds of hypertension (95% CI: 0%, 9%). In men, associations with SBP (0.52 mmHg; 95% CI: -0.82, 1.8), DBP (0.41 mmHg; 95% CI: -0.69, 1.5), and hypertension (2% higher odds; 95% CI: -2%, 6%) were weaker. No associations were observed with BC.

CONCLUSION

We observed a positive association between ambient PM2.5 and BP and hypertension in women. Longitudinal studies in this region are needed to corroborate our findings.

Exposure to fine particles increases blood pressure of hypertensive outdoor workers: A panel study

BACKGROUND

Hypertension and air pollution are two important risk factors for cardiovascular morbidity and mortality. Although several studies suggest that air pollution has a significant impact on blood pressure, studies on long-term effects are sparse and still controversial.

OBJECTIVE

To evaluate the effects of exposure of outdoor workers to different levels of traffic-generated PM_2.5 on blood pressure.

DESIGN

This is an observational panel study.

PARTICIPANTS

88 non-smoking workers exposed to different concentrations of air pollution were evaluated weekly along four successive weeks.

MEASUREMENTS

In each week, personal monitoring of 24-h PM_2.5 concentration and 24-h ambulatory blood pressure were measured. The association between blood pressure variables and PM_2.5, adjusted for age, body mass index, time in job, daily work hours, diabetes, hypertension and cholesterol was assessed by means of multiple linear regression models fitted by least squares.

RESULTS

Exposure to PM_2.5 (ranging from 8.5 to 89.7 μg/m³) is significantly and consistently associated with an increase in average blood pressure. An elevation of 10 μg/m³ in the concentration of PM_2.5 is associated with increments of 3.9 mm Hg (CI 95% = [1.5; 6.3]) in average systolic 24-h blood pressure for hypertensive and/or diabetic workers.

CONCLUSION

Exposure to fine particles, predominantly from vehicular traffic, is associated with elevated blood pressure in hypertensive and/or diabetic workers.

Personal NO2 and Volatile Organic Compounds Exposure Levels are Associated with Markers of Cardiovascular Risk in Women in the Cape Town Region of South Africa

Exposure to ambient NO2 and benzene, toluene ethyl-benzene and m+p- and o-xylenes (BTEX) is associated with adverse cardiovascular effects, but limited information is available on the effects of personal exposure to these compounds in South African populations. This 6-month follow-up study aims to determine 7-day personal ambient NO2 and BTEX exposure levels via compact passive diffusion samplers in female participants from Cape Town, and investigate whether exposure levels are associated with cardiovascular risk markers. Overall, the measured air pollutant exposure levels were lower compared to international standards. NO2 was positively associated with systolic and diastolic blood pressure (SBP and DBP), and inversely associated with the central retinal venular equivalent (CRVE) and mean baseline brachial artery diameter. o-xylene was associated with DBP and benzene was strongly associated with carotid intima media thickness (cIMT). Our findings showed that personal air pollution exposure, even at relatively low levels, was associated with several markers of cardiovascular risk in women residing in the Cape Town region.

Long-Term Exposure to Fine Particulate Matter and Hypertension Incidence in China

The risk of incident hypertension associated with long-term exposure to fine particulate matter (PM2.5) was still unclear by studies conducted in North America and Europe, and this relationship has rarely been quantified at higher ambient concentrations typically found in developing countries. We aimed to investigate the association between PM2.5 and incident hypertension using the large-scale prospective cohorts in China. We included 59 456 participants without hypertension aged ≥18 years from the China-PAR (Prediction for Atherosclerotic Cardiovascular Disease Risk in China) project. Data on ambient PM2.5 at participants' residential address were obtained during 2004 to 2015 using a satellite-based spatial-temporal model. Hazard ratios and 95% CIs were calculated for incident hypertension using stratified Cox proportional hazards models with adjustment of potential confounders. The findings indicated that average PM2.5 concentration from 2004 to 2015 at study participants' address was 77.7 μg/m3. During the follow-up of 364 947 person-years, we identified 13 981 incident hypertension cases. Compared with the lowest quartile exposure of PM2.5, participants in the highest quartile had an increased risk of incident hypertension with a hazard ratio (95% CI) of 1.77 (1.56-2.00). Each 10 μg/m3 increment of PM2.5 concentration could increase 11% risk of hypertension (hazard ratio, 1.11; 95% CI, 1.05-1.17). This cohort study provided the first evidence from China that long-term exposure to PM2.5 was independently associated with incident hypertension at relatively high ambient concentrations. Stringent strategies on PM2.5 pollution control are warranted to improve the air quality and contribute to the reduction of disease burden of hypertension in China.

Effects of physical activity and air pollution on blood pressure

AIM

To assess the main and interaction effects of black carbon and physical activity on arterial blood pressure in a healthy adult population from three European cities using objective personal measurements over short-term (hours and days) and long-term exposure.

METHODS

A panel study of 122 healthy adults was performed in three European cities (Antwerp, Barcelona, and London). In 3 seasons between March 2015 and March 2016, each participant wore sensors for one week to objectively measure their exposure to black carbon and monitor their physical activity continuously. Blood pressure was assessed three times during the week: at the beginning (day 0), in the middle (day 4), and at the end (day 7). Associations of black carbon and physical activity with blood pressure and their interactions were investigated with linear regression models and multiplicative interaction terms, adjusting for all the potential confounders.

RESULTS

In multiple exposure models, we did not see any effects of black carbon on blood pressure but did see effects on systolic blood pressure of moderate-to-vigorous physical activity effect that were statistically significant from 1 h to 8 h after exposure and for long-term exposure. For a 1METhour increase of moderate-to-vigorous physical activity, the difference in the expected mean systolic blood pressure varied from -1.46 mmHg (95%CI -2.11, -0.80) for 1 h mean exposure, to -0.29 mmHg (95%CI -0.55, -0.03) for 8 h mean exposure, and -0.05 mmHg (95%CI -0.09, -0.00) for long-term exposure. There were little to no interaction effects.

CONCLUSIONS

Results from this study provide evidence that short-term and long-term exposure to moderate-to-vigorous physical activity is associated with a decrease in systolic blood pressure levels. We did not find evidence for a consistent main effect of black carbon on blood pressure, nor any interaction between black carbon and physical activity levels.

Community greenness, blood pressure, and hypertension in urban dwellers: The 33 Communities Chinese Health Study

BACKGROUND

Living in greener areas has many health benefits, but evidence concerning the effects on blood pressure remains mixed. We sought to assess associations between community greenness and both blood pressure and hypertension in Chinese urban dwellers, and whether the associations were mediated by air pollution, body mass index, and physical activity.

METHODS

We analyzed data from 24,845 adults participating in the 33 Communities Chinese Health Study, which was conducted in Northeastern China during 2009. We measured each participant's blood pressure according to a standardized protocol. We assessed community greenness using two satellite-derived vegetation indexes - the Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI). Particulate matter ≤2.5 μm and nitrogen dioxide were used as proxies of ambient air pollution. We applied generalized linear mixed models to investigate the association between greenness and blood pressure. We also performed mediation analyses.

RESULTS

Living in greener areas was associated with lower blood pressure and hypertension prevalence; an interquartile range increase in both NDVI_500-m and SAVI_500-m were significantly associated with reductions in systolic blood pressure of 0.82 mm Hg (95% CI: -1.13, -0.51) and 0.89 mm Hg (95% CI: -1.21, -0.57), respectively. The same increases in greenness were also significantly associated with a 5% (95% CI: 1%, 8%) and 5% (95% CI: 1%, 9%) lower odds of having hypertension, respectively. These associations remained consistent in sensitivity analyses. The associations were stronger among women than men. Air pollutants and body mass index partly mediated the associations, but there was no evidence of mediation effects for physical activity.

CONCLUSIONS

Our findings indicate beneficial associations between community greenness and blood pressure in Chinese adults, especially for women. Air pollution and body mass index only partly mediated the associations.

Acute effect of ambient air pollution on hospitalization in patients with hypertension: A time-series study in Shijiazhuang, China

Although numerous studies have investigated the association between air pollution and hospitalization, few studies have focused on the health effect of air pollution on populations with hypertension. In this study, we conducted a time-series study to investigate the acute adverse effect of six criteria ambient air pollutants (fine particulate matter [PM_2.5], inhalable particulate matter [PM₁₀], nitrogen dioxide [NO₂], sulfur dioxide [SO₂], ozone [O₃], and carbon monoxide [CO]) on hospitalization of patients for hypertension in Shijiazhuang, China, from 2013 to 2016. An over-dispersed Poisson generalized addictive model adjusting for weather conditions, day of the week, and long-term and seasonal trends was used. In addition, we evaluated the effect of modification by season, sex, and age. A total of 650,550 hospitalization records were retrieved during the study period. A 10 μg/m³ increase of PM_2.5 (lag06), PM₁₀ (lag06), NO₂ (lag03), O₃ (lag6), and CO (lag04) corresponded to 0.56% (95% confidence interval [CI]: 0.28-0.83%), 0.31% (95% CI: 0.12-0.50%), 1.18% (95% CI: 0.49-1.87%), 0.40% (95% CI: 0.09-0.71%), and 0.03% (95% CI: 0.01-0.05%) increments in hospitalization of patients for hypertension, respectively. We observed statistically significant associations with PM_2.5, PM₁₀, NO₂, O₃, and CO, while positive but insignificant associations with SO₂. The effects of PM_2.5, PM₁₀, NO₂, O₃, and CO were robust when adjusted for co-pollutants. We found stronger associations in the cool season than in the warm season. Moreover, there were non-significant differences in the associations between air pollution and sex or age group. This study suggests that patients with hypertension had an increased risk of hospital admission when exposed to air pollution.

Association of Long-term Exposure to Ambient Air Pollutants With Risk Factors for Cardiovascular Disease in China

IMPORTANCE

Which cardiometabolic risk factors (eg, hypertension, type 2 diabetes, overweight or obesity, and dyslipidemia) are more sensitive to long-term exposure to ambient air pollution and whether participants with these conditions are more susceptible to the cardiovascular effects of air pollution remain unclear.

OBJECTIVES

To evaluate the associations among long-term exposure to air pollutants, cardiometabolic risk factors, and cardiovascular disease (CVD) prevalence.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cross-sectional study was conducted from April 1 through December 31, 2009, in 3 cities in Northeastern China. Participants were adults aged 18 to 74 years who had lived in study area for 5 years or longer. Data analysis was performed from May 1 through December 31, 2018.

EXPOSURES

Long-term (2006-2008) exposure to air pollutants was measured using a spatiotemporal statistical model (particulate matter with an aerodynamic diameter of ≤2.5 μm [PM2.5] and ≤1.0 μm [PM1.0]) and data from air monitoring stations (particulate matter with an aerodynamic diameter of ≤10.0 μm [PM10.0], sulfur dioxide [SO2], nitrogen dioxide [NO2], and ozone [O3]).

MAIN OUTCOMES AND MEASURES

Cardiovascular disease was determined by self-report of physician-diagnosed CVD. Blood pressure, body mass index, and levels of triglycerides and low-density lipoprotein cholesterol were measured using standard methods.

RESULTS

Participants included 15 477 adults (47.3% women) with a mean (SD) age of 45.0 (13.5) years. The prevalence of CVD was 4.8%, and the prevalence of cardiometabolic risk factors ranged from 8.6% (hyperbetalipoproteinemia) to 40.5% (overweight or obesity). Mean (SD) air pollutant concentrations ranged from 35.3 (5.5) μg/m3 (for NO2) to 123.1 (14.6) μg/m3 (for PM10.0). Associations with air pollutants were identified for individuals with hyperbetalipoproteinemia (eg, odds ratio [OR], 1.36 [95% CI, 1.03-1.78] for a 10-μg/m3 increase in PM1.0) and the weakest association for those with for overweight or obesity (eg, OR, 1.06 [95% CI, 1.02-1.09] for a 10-μg/m3 increase in PM1.0). Cardiometabolic risk factors only partially mediated associations between air pollution and CVD. However, they modified the associations such that greater associations were found in participants with these cardiometabolic conditions (eg, ORs for CVD and per 10-μg/m3 increase in PM1.0, 1.22 [95% CI, 1.12-1.33] in participants with hyperbetalipoproteinemia and 1.07 [95% CI, 0.98-1.16] in participants without hyperbetalipoproteinemia).

CONCLUSIONS AND RELEVANCE

In this population-based study of Chinese adults with CVD, long-term exposure to air pollution was associated with a higher prevalence of cardiometabolic risk factors, and the strongest associations were observed for hyperbetalipoproteinemia. In addition, participants with cardiometabolic risk factors may have been more vulnerable to the effects of air pollution on CVD.

Ambient PM1 air pollution, blood pressure, and hypertension: Insights from the 33 Communities Chinese Health Study

No evidence exists concerning the association between blood pressure and ambient particles with aerodynamic diameter ≤ 1.0 µm (PM₁), a major component of PM_2.5 (≤ 2.5 µm) particles, and potentially causing more hazardous health effects than PM_2.5. We aimed to examine the associations of blood pressure in adults with both PM₁ and PM_2.5 in China. In 2009, we randomly selected 24,845 participants aged 18-74 years from 33 communities in China. Using a standardized mercuric-column sphygmomanometer, we measured blood pressure. Long-term exposure (2006-08) to PM₁ and PM_2.5 were estimated using a spatial statistical model. Generalized linear mixed models were used to evaluate the associations between air pollutants and blood pressure and hypertension prevalence, controlling for multiple covariates. A 10-μg/m³ increase in PM₁ was significantly associated with an increase of 0.57 (95% CI 0.31-0.83) mmHg in systolic blood pressure (SBP), 0.19 (95% CI 0.03-0.35) mmHg increase in diastolic blood pressure (DBP), and a 5% (OR=1.05; 95% CI 1.01-1.10) increase in odds for hypertension. Similar associations were detected for PM_2.5. Furthermore, PM_1-2.5 showed no association with blood pressure or hypertension. In summary, both PM₁ and PM_2.5 exposures were associated with elevated blood pressure levels and hypertension prevalence in Chinese adults. In addition, most of the pro-hypertensive effects of PM_2.5 may come from PM₁. Further longitudinal designed studies are warranted to validate our findings.

Prevalence of high blood pressure and high normal blood pressure among 7- to 17-year-old children and adolescents in developed regions, China from 2014 to 2017: using new national blood pressure reference for Chinese children and adolescents

As the first blood pressure (BP) reference considering influence of height in China, national blood pressure reference for Chinese han children and adolescents aged 7 to 17 years (CCBP) was issued in 2017. The current study aimed to observe the short-term trends in BP and prevalence of high blood pressure (HBP) and high normal blood pressure (HNBP) using this CCBP reference in Suzhou, China. Data of children and adolescents aged 7 to 17 years were collected from 2014 to 2017. Total population of 2014 to 2017 were 617,383, 684,453, 695,302, and 774,605, respectively, and proportions of males were 54.1%, 54.0%, 53.9%, and 53.8%, respectively. P-trend tests were conducted to examine the trends of BP among different age, region, body mass index, and socioeconomic status groups for each gender. Multivariate logistic regression analyses found secular decreases in prevalence of HBP and HNBP, after adjustment for potential confounders. Compared with that in 2014, the odds ratios (95% confidence intervals) for total study population were 0.936 (0.928, 0.944) in 2015, 0.879 (0.872, 0.887) in 2016, and 0.934 (0.926, 0.941) in 2017. In conclusion, prevalence of HBP and HNBP decreased among children and adolescents in developed regions of China from 2014 to 2017, and a slight rise were found in 2017.

Ambient PM1 air pollution and cardiovascular disease prevalence: Insights from the 33 Communities Chinese Health Study

BACKGROUNDS

Evidence on the association between long-term exposure to particulate matter with aerodynamic diameter ≤2.5 μm (PM_2.5) and cardiovascular disease (CVD) is scarce in developing countries. Moreover, few studies assessed the role of the PM₁ (≤1.0 μm) size fraction and CVD. We investigated the associations between PM₁ and PM_2.5 and CVD prevalence in Chinese adults.

METHODS

In 2009, we randomly recruited 24,845 adults at the age of 18-74 years from 33 communities in Northeastern China. CVD status was determined by self-report of doctor-diagnosed CVD. Three-year (2006-08) average concentrations of PM₁ and PM_2.5 were assigned using a satellite-based exposure. We used spatial Generalized Linear Mixed Models to evaluate the associations between air pollutants and CVD prevalence, adjusting for multiple covariates. Stratified and interaction analyses and sensitivity analyses were also performed.

RESULTS

A 10 μg/m³ increase in long-term exposure to ambient PM₁ levels was associated a 12% higher odds for having CVD (OR = 1.12; 95% CI = 1.05-1.20). Compared to PM₁, association between PM_2.5 and CVD was lower (OR = 1.06; 95% CI = 1.01-1.11). No significant association was observed for PM_1-2.5 (1-2.5 μm) size fraction (OR = 0.98; 95% CI = 0.85-1.13). Stratified analyses showed greater effect estimates in men and the elder.

CONCLUSIONS

Long-term PM₁ exposure was positively related to CVD, especially in men and the elder. In addition, PM₁ may play a greater role than PM_2.5 in associations with CVD. Further longitudinal studies are warranted to confirm our findings.

Long- and short-term air pollution exposure and measures of arterial stiffness in the Framingham Heart Study

BACKGROUND

Studies of air pollution exposure and arterial stiffness have reported inconsistent results and large studies employing the reference standard of arterial stiffness, carotid-femoral pulse-wave velocity (CFPWV), have not been conducted.

AIM

To study long-term exposure to ambient fine particles (PM2.5), proximity to roadway, and short-term air pollution exposures in relation to multiple measures of arterial stiffness in the Framingham Heart Study.

METHODS

We assessed central arterial stiffness using CFPWV, forward pressure wave amplitude, mean arterial pressure and augmentation index. We investigated long-and short-term air pollution exposure associations with arterial stiffness with linear regressions using long-term residential PM2.5 (2003 average from a spatiotemporal model using satellite data) and proximity to roadway in addition to short-term averages of PM2.5, black carbon, particle number, sulfate, nitrogen oxides, and ozone from stationary monitors.

RESULTS

We examined 5842 participants (mean age 51 ± 16, 54% women). Living closer to a major roadway was associated with higher arterial stiffness (0.11 m/s higher CFPWV [95% CI: 0.01, 0.22] living <50 m vs 400 ≤ 1000 m). We did not observe association between arterial stiffness measures and long-term PM2.5 or short-term levels of PM2.5, particle number, sulfate or ozone. Higher levels of black carbon and nitrogen oxides in the previous days were unexpectedly associated with lower arterial stiffness.

CONCLUSIONS

Long-term exposure to PM2.5 was not associated with arterial stiffness but positive associations with living close to a major road may suggest that pollutant mixtures very nearby major roads, rather than PM2.5, may affect arterial stiffness. Furthermore, short-term air pollution exposures were not associated with higher arterial stiffness.

Greenspace seems protective of both high and low blood pressure among residents of an Alpine valley

BACKGROUND

There is some data suggesting that residential greenspace may protect against high blood pressure in urbanized areas, but there is no evidence of effects on hypotension, in less urbanized areas, and in idiosyncratic geographic contexts such as mountain valleys.

OBJECTIVES

The current study aimed to investigate the associations between residential greenspace and blood pressure in an alpine valley in Austria.

METHODS

We conducted a cross-sectional survey of a representative sample of 555 adults living in the Lower Inn Valley, Austria. Several definitions of blood pressure were employed: continuously-measured systolic (SBP) and diastolic blood pressure (DBP), doctor-diagnosed hyper- and hypotension, and high- and low blood pressure medication use. Greenspace metrics considered were: Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and tree cover as measures of surrounding greenness in circular buffers of 100 m, 300 m, 500 m, and 1000 m around the home; distance to different types of structured green space; and having a domestic garden and a balcony. Relationships were examined across different definitions of blood pressure and greenspace and evaluated for potential effect modification by demographic factors, presence of a domestic garden/balcony, adiposity, and traffic sensitivity.

RESULTS

Higher overall greenness was associated with 30-40% lower odds of hyper/hypotension and 2-3 mm Hg lower SBP. Similar pattern was revealed for tree cover, however, associations with hypertension were less consistent across buffers, and SBP and DBP were lower only in association with greenness in the 100-m buffer. Having a domestic garden also seemed protective of high DBP. Residing near to forests, agricultural land, or urban green spaces was not related to blood pressure. Higher NDVI_500-m was stronger associated with lower SBP in those having a domestic garden, while the effect on DBP was stronger in overweight/obese participants.

CONCLUSION

These findings support the idea that greenspace should be considered as protective of both high and low blood pressure, however, underlying mechanisms remain insufficiently understood.

Air pollution and kidney disease: review of current evidence

Along with amazing technological advances, the industrial revolution of the mid-19th century introduced new sources of pollution. By the mid-20th century, the effects of these changes were beginning to be felt around the world. Among these changes, health problems due to environmental air pollution are increasingly recognized. At the beginning, respiratory and cardiovascular diseases were emphasized. However, accumulated data indicate that every organ system in the body may be involved, and the kidney is no exception. Although research on air pollution and kidney damage is recent, there is now scientific evidence that air pollution harms the kidney. In this holistic review, we have summarized the epidemiology, disease states and mechanisms of air pollution and kidney damage.

Effects of Personal Short-Term Exposure to Ambient Ozone on Blood Pressure and Vascular Endothelial Function: A Mechanistic Study Based on DNA Methylation and Metabolomics

Short-term exposure to ambient ozone is associated with adverse cardiovascular effects, with inconsistent evidence on the molecular mechanisms. We conducted a longitudinal panel study among 43 college students in Shanghai to explore the effects of personal ozone exposure on blood pressure (BP), vascular endothelial function, and the potential molecular mechanisms. We measured real-time personal ozone exposure levels, serum angiotensin-converting enzyme (ACE) and endothelin-1 (ET-1), and locus-specific DNA methylation of ACE and EDN1 (coding ET-1). We used an untargeted metabolomic approach to explore potentially important metabolites. We applied linear mixed-effect models to examine the effects of ozone on the above biomarkers. An increase in 2 h-average ozone exposure was significantly associated with elevated levels of BP, ACE, and ET-1. ACE and EDN1 methylation decreased with ozone exposure, but the magnitude differed by genomic loci. Metabolomics analysis showed significant changes in serum lipid metabolites following ozone exposure that are involved in maintaining vascular endothelial function. Our findings suggested that acute exposure to ambient ozone can elevate serum levels of ACE and ET-1, decrease their DNA methylation, and alter the lipid metabolism, which may be partly responsible for the effects of ozone on BP and vascular endothelial function.

Exposure to ambient air pollution and blood lipids in adults: The 33 Communities Chinese Health Study

BACKGROUND

Little information exists on the lipidemic effects of air pollution, particularly in developing countries. We aimed to investigate the associations of long-term exposure to ambient air pollutants with lipid levels and dyslipidemias in China.

METHODS

In 2009, a total of 15,477 participants aged 18-74 years were recruited from the 33 Communities Chinese Health Study conducted in three Northeastern China cities. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured in participants' blood specimens. Three year (2006-08) average air pollution concentrations were assessed using data from 33 communities (particles with diameters ≤1.0 μm (PM₁) and ≤2.5 μm (PM_2.5) were predicted using a spatial statistical model) or 11 air monitoring stations (particles with diameters ≤10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃)). Associations were evaluated by two-level logistic and generalized linear regression models.

RESULTS

We detected many significant associations between exposure to air pollutants (especially for PM₁ and PM_2.5) and blood lipid levels. Most of the associations suggested deleterious effects on blood lipid markers (e.g., a 10 μg/m³ increase in PM₁ was associated with 1.6% (95% confidence interval (CI): 1.1, 2.0), 2.9% (95% CI: -3.3, 9.3), and 3.2% (95% CI: 2.6, 3.9) higher levels of TC, TG, and LDL-C, respectively, but 1.4% (95% CI: -1.8, -0.9) lower HDL-C levels), although beneficial associations were found for O₃. In analysis with dyslipidemias, all the observed associations suggested deleterious lipidemic effects of air pollutants, and no significant beneficial association was observed for O₃. Stratified analyses showed that the associations were stronger in overweight or obese participants; sex and age modified the associations, but the pattern of effects was mixed.

CONCLUSIONS

Long-term ambient air pollution was associated with both altered lipid profiles and dyslipidemias, especially among overweight or obese participants.

Pet exposure in utero and postnatal decreases the effects of air pollutants on hypertension in children: A large population based cohort study

The effect of ambient air pollution exposure on childhood hypertension has emerged as a concern in China, and previous studies suggested pet ownership is associated with lower blood pressure (BP). However, limited information exists on the interactive effects pet ownership and air pollution exposure has on hypertension. We investigated the interactions between exposure to pet ownership and air pollutants on hypertension in Chinese children. 9354 students in twenty-four elementary and middle schools (aged 5-17 years) in Northeastern China were evaluated during 2012-2013. Four-year average concentrations of particulate matter with aerodynamic diameter of ≤10 μm (PM10), SO2, NO2, and O3, were collected in the 24 districts from 2009 to 2012. Hypertension was defined as average diastolic or systolic BP (three time measurements) in the 95th percentile or higher based on height, age, and sex. To examine effects, two-level regression analysis was used, controlling covariates. Consistent interactions between exposure to pet and air pollutants were observed. Compared to children exposed to pet, those not exposed exhibited consistently stronger effects of air pollution. The highest odds ratios (ORs) per 30.6 μg/m3 increase in PM10 were 1.79 (95%confidence interval [95%CI]: 1.29-2.50) in children without current pet exposure compared to 1.24 (95%CI: 0.85-1.82) in children with current pet exposure. As for BP, only O3 had an interaction for all exposure to pet ownership types, and showed lower BP in children exposed to pet. The increases in mean diastolic BP per 46.3 μg/m3 increase in O3 were 0.60  mmHg (95%CI: 0.21, 0.48) in children without pet exposure in utero compared with 0.34  mmHg (95%CI: 0.21, 0.48) in their counterparts. When stratified by age, pet exposure was more protective among younger children. In conclusion, in this large population-based cohort, pet ownership is associated with smaller associations between air pollution and hypertension in children, suggesting pet ownership reduces susceptibility to the health effects of pollutants.

Long-term exposure to ambient air pollution (including PM1) and metabolic syndrome: The 33 Communities Chinese Health Study (33CCHS)

Little evidence exists about the effects of long-term exposure to ambient air pollution on metabolic syndrome (MetS). This study aimed to determine the association between long-term ambient air pollution and MetS in China. A total of 15,477 adults who participated in the 33 Communities Chinese Health Study (33CCHS) in 2009 were evaluated. MetS was defined based on the recommendation by the Joint Interim Societies. Exposure to air pollutants was assessed using data from monitoring stations and a spatial statistical model (including particles with diameters ≤ 1.0 µm (PM₁), ≤ 2.5 µm (PM_2.5), and ≤ 10 µm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃)). Two-level logistic regression analyses were utilized to assess the associations between air pollutants and MetS. The prevalence of MetS was 30.37%. The adjusted odds ratio of MetS per 10 µg/m³ increase in PM₁, PM_2.5, PM₁₀, SO₂, NO₂, and O₃ were 1.12 (95% CI = 1.00-1.24), 1.09 (95% CI = 1.00-1.18), 1.13 (95% CI = 1.08-1.19), 1.10 (95% CI = 1.02-1.18), 1.33 (95% CI = 1.12-1.57), and 1.10 (95% CI = 1.01-1.18), respectively. Stratified analyses indicated that the above associations were stronger in participants with the demographic variables of males, < 50 years of age, and higher income, as well as with the behavioral characteristics of smoking, drinking, and consuming sugar-sweetened soft drinks frequently. This study indicates that long-term exposure to ambient air pollutants may increase the risk of MetS, especially among males, the young to middle aged, those of low income, and those with unhealthy lifestyles.

Echoes from Gaea, Poseidon, Hephaestus, and Prometheus: environmental risk factors for high blood pressure

High blood pressure (BP) affects over one billion people and is the leading risk factor for global mortality. While many lifestyle and genetic risk factors are well-accepted to increase BP, the role of the external environment is typically overlooked. Mounting evidence now supports that numerous environmental factors can promote an elevation in BP. Broadly speaking these include aspects of the natural environment (e.g., cold temperatures, higher altitude, and winter season), natural disasters (e.g., earthquakes, volcanic eruptions), and man-made exposures (e.g., noise, air pollutants, and toxins/chemicals). This is important for health care providers to recognize as one (or several) of these environmental factors could be playing a clinically meaningful role in elevating BP or disrupting hypertension control among their patients. At the population level, certain environmental exposures may even be contributing to the growing pandemic of hypertension. Here we provide an updated review of the literature linking environment exposures with high BP and outline practical recommendations for clinicians.