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

Exposomic Determinants of Atherosclerosis: Recent Evidence

PURPOSE OF REVIEW

The exposome refers to the total environmental exposures a person encounters throughout life, and its relationship with human health is increasingly studied. This non-systematic review focuses on recent research investigating the effects of environmental factors-such as air pollution, noise, greenspace, neighborhood walkability, and metallic pollutants-on atherosclerosis, a major cause of cardiovascular disease.

RECENT FINDINGS

Studies show that long-term exposure to airborne particulate matter can impair endothelial function and elevate adhesion molecule levels, leading to vascular damage. Nighttime traffic noise also negatively impacts endothelial health. On the other hand, living in areas with more greenspace and better neighborhood walkability is linked to reduced arterial stiffness, suggesting protective cardiovascular effects. Mechanisms involved include oxidative stress, inflammation, and sympathetic activation from air pollution and noise. Metallic pollutants, including lead, cadmium, and arsenic, are linked to early signs of atherosclerosis through mechanisms involving oxidative stress. However, the effects of specific pollutants and their interactions remain incompletely understood. There is a growing need to mitigate harmful environmental exposures, such as air pollution and noise, while promoting beneficial ones like greenspace, to improve cardiovascular health. Emerging technologies like remote sensing and artificial intelligence can help further our understanding of how the exposome influences cardiovascular outcomes. More research is necessary to clarify the impact of specific pollutants as well as their interactions and how they contribute to atherosclerosis.

A Scoping Review and Assessment of the Area-Level Composite Measures That Estimate Social Determinants of Health Across the United States

OBJECTIVES

Evidence-informed population health initiatives often leverage data from various sources, such as epidemiologic surveillance data and administrative datasets. Recent interest has arisen in using area-level composite measures describing a community's social risks to inform the development and implementation of health policies, including payment reform initiatives. Our objective was to capture the breadth of available area-level composite measures that describe social determinants of health (SDH) and have potential for application in population health and policy work.

METHODS

We conducted a scoping review of the scientific literature from 2010 to 2022 to identify multifactorial indices and rankings reflected in peer-reviewed literature that estimate SDH and that have publicly accessible data sources. We discovered several additional composite measures incidental to the scoping review process. Literature searches for each composite measure aimed to contextualize common applications in public health investigations.

RESULTS

From 491 studies, we identified 31 composite measures and categorized them into 8 domains: environmental conditions and pollution, opportunity and infrastructure, deprivation and well-being, COVID-19, rurality, food insecurity, emergency response and community resilience, and health. Composite measures are applied most often as an independent variable associated with disparities, risk factors, and/or outcomes affecting individuals, populations, communities, and health systems.

CONCLUSIONS

Area-level composite measures describing SDH have been applied to wide-ranging population health work. Social risk indicators may enable policy makers, evaluators, and researchers to better assess community risks and needs, thereby facilitating the evidence-informed development, implementation, and study of initiatives that aim to improve population health.

Meta-analysis of the association between low concentration PM2.5 and cardiovascular mortality in the United States and Canada

OBJECTIVES

The adverse effects of fine particulate matter (PM2.5), including cardiovascular outcomes, are well established. This review and meta-analysis investigates the association between long-term exposure to low concentration PM2.5 (<12 µg/m3) and CVD mortality in U.S. and Canadian populations.

METHODS

We conducted a literature search and completed random effect meta-analyses.

RESULTS

Twenty-four studies were reviewed, with 12 from each of the U.S. and Canada. Fifteen of eighteen studies that reported hazard ratios (HRs) for total CVD mortality reported statistically significant positive associations with low concentration PM2.5. For cause-specific CVD mortality, more consistent results were shown for ischemic heart disease (IHD) mortality, with all eleven studies reporting statistically significant associations (HR = 1.09 to 2.48). Only three of 12 studies evaluating cerebrovascular mortality reported statistically significant associations (HR = 1.10 to 1.27). Studies that restricted analyses to participants with mean exposures <12 µg/m3 found statistically significant associations between PM2.5 and at least some of the CVD mortality outcomes of interest. However, the shape of the concentration-response functions varied widely. Only six studies controlled for at least one additional air pollutant, and multi-pollutant models generally showed an attenuated impact of PM2.5. Despite existing gaps in understanding the association between low concentrations of PM2.5 and cardiovascular mortality, this review highlights the critical importance of ongoing efforts to improve air quality for public health benefits.

CONCLUSIONS

Continued focus on understanding the shape of the concentration-response function for PM2.5, the impact of co-pollutants on observed effects, and how particle composition may impact effect estimates, is recommended.

Green Streets, Healthy Hearts: Exploring the Roles of Urban Nature and Walkability in Cardiovascular Health

With the growing evidence that connects urban environments with public health outcomes, the role of urban planning has become increasingly critical in addressing public health challenges. Cardiovascular diseases (CVDs) are the leading cause of mortality in urban areas and worldwide and are impacted by characteristics of the built environment, such as walkability and nature exposure. In this literature view, we explore the influence of the physical built environment, specifically green spaces and walkability, on cardiovascular health. Results from prior studies show a clear reduction in cardiovascular disease-related risk factors, morbidity, and mortality in neighborhoods that integrate green spaces and/or walkability. Cumulative evidence suggests that urban environments that integrate green spaces (such as parks) and walkability (eg, safe sidewalks) can significantly improve cardiovascular health. Urban planning policies and strategies that prioritize the integration of green infrastructure and walkable designs can contribute to improving cardiovascular health in urban residents while also enhancing the overall well-being and quality of life.

Joint associations of neighbourhood walkability and greenery with walking among middle-aged and older adults: Findings from diverse urban settings in Australia

There is evidence that neighbourhood walkability and greenery are associated with walking, but less is known about their joint associations. We investigated this using data from the AusDiab3 study (2011/12) with 3032 adults (mean age 60 years). Two-level logistic regression models were used with binary walking outcomes. There was an inverse relationship (r = -0.5) between walkability (a composite measure of residential, destinations and intersections densities) and greenery (the size of densely vegetated areas). However, both walkability and greenery were independently positively associated with odds of walking. Regarding joint associations, in low-walkability neighbourhoods, greenery was positively associated with walking. In high-walkability neighbourhoods, greenery was not associated with walking.

PM2.5, vegetation density, and childhood cancer: a case-control registry-based study from Texas 1995-2011

BACKGROUND

Air pollution is positively associated with some childhood cancers, whereas greenness is inversely associated with some adult cancers. The interplay between air pollution and greenness in childhood cancer etiology is unclear. We estimated the association between early-life air pollution and greenness exposure and childhood cancer in Texas (1995 to 2011).

METHODS

We included 6101 cancer cases and 109 762 controls (aged 0 to 16 years). We linked residential birth address to census tract annual average fine particulate matter <2.5 µg/m³ (PM2.5) and Normalized Difference Vegetation Index (NDVI). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) between PM2.5/NDVI interquartile range increases and cancer. We assessed statistical interaction between PM2.5 and NDVI (likelihood ratio tests).

RESULTS

Increasing residential early-life PM2.5 exposure was associated with all childhood cancers (OR = 1.10, 95% CI = 1.06 to 1.15), lymphoid leukemias (OR = 1.15, 95% CI = 1.07 to 1.23), Hodgkin lymphomas (OR = 1.27, 95% CI = 1.02 to 1.58), non-Hodgkin lymphomas (OR = 1.24, 95% CI = 1.02 to 1.51), ependymoma (OR = 1.27, 95% CI = 1.01 to 1.60), and others. Increasing NDVI exposure was inversely associated with ependymoma (0- to 4-year-old OR = 0.75, 95% CI = 0.58 to 0.97) and medulloblastoma (OR = 0.75, 95% CI = 0.62 to 0.91) but positively associated with malignant melanoma (OR = 1.75, 95% CI = 1.23 to 2.47) and Langerhans cell histiocytosis (OR = 1.56, 95% CI = 1.07 to 2.28). There was evidence of statistical interaction between NDVI and PM2.5 (P < .04) for all cancers.

CONCLUSION

Increasing early-life exposure to PM2.5 increased the risk of childhood cancers. NDVI decreased the risk of 2 cancers yet increased the risk of others. These findings highlight the complexity between PM2.5 and NDVI in cancer etiology.

Green space and stroke: A scoping review of the evidence

BACKGROUND

Global industrialisation and urbanisation has led to an increased interest in the link between the environment and health. Stroke is a major cause of morbidity and mortality, and there is increased evidence that environmental factors may affect both the incidence and severity of stroke. This review summarises the evidence for relationship between green space exposure and stroke incidence and outcomes.

METHODS

We conducted a literature search in Medline and Scopus until 1 August 2023, and screened references of relevant articles. Selected articles were appraised for their relevance, and critically reviewed. The findings were thematically categorised.

RESULTS

Of the 1342 papers identified, 27 were included. These involved a mix of study designs (cohort, cross-sectional, quasi-experimental, time stratified case crossover and ecological). There was consistent evidence indicating a protective association between green space exposure and disability and stroke-related death with mortality hazard ratios between 0.66 and 0.95. Most studies also showed that green space was inversely associated with stroke risk, with risk estimates from studies showing a protective effect ranging between 0.4 and 0.98; however, results were more mixed and some did not reach statistical significance. The moderating effects of green spaces on ambient temperatures, noise and air pollution, and psychosocial health plus greater enjoyment and opportunity for exercise and enrichment of the human microbiome may underly these associations.

CONCLUSION

There is likely some protective effect of green space on stroke, with the benefits most convincingly shown for post-stroke outcomes. More research is recommended to confirm the protective association between green space exposure and reduced stroke risk.

Sociodemographic inequalities in long-term exposure to air pollution, road traffic noise, and greenness: A population-based cohort study of women

Background

Recent evidence suggests environmental health inequalities both within and between European countries and socially deprived groups may be more susceptible to pollution. However, evidence is still inconclusive and additional studies are warranted. This study aims to investigate sociodemographic inequalities in long-term residential exposure to air pollution, road traffic noise, and greenness, taking lifestyle and degree of urbanization into account.

Methods

In total 20,407 women, born 1914-48 residing in Uppsala County, Sweden, were followed between 1997 and 2017. Time-varying sociodemographic variables were obtained from registers, and questionnaires provided lifestyle information. Generalized estimating equations were used to compute beta-coefficients (β) and 95% confidence intervals (95% CI) for associations between sociodemographic and lifestyle variables and spatial-temporal modeled particulate matter (PM2.5, PM10), nitrogen dioxide (NO2), road traffic noise and greenness. All models were additionally stratified by urbanization type.

Results

Urban area residency was the most important predictor of high exposure to air pollution and noise, and to low greenness. For instance, β for NO2 was -2.92 (95% CI = -3.00, -2.83) and -3.10 (95% CI = -3.18, -3.01) µg/m3 in suburban and rural areas, respectively, compared with urban areas. For greenness, the opposite held true with corresponding β of 0.059 (95% CI = 0.056, 0.062) and 0.095 (95% CI = 0.092, 0.098). Within urban areas, elderly, unmarried and well-educated women had the highest environmental burden. However, less pronounced, and even reversed associations were found in suburban and rural areas.

Conclusion

This study provides evidence of a mixed pattern of environmental health inequalities across sociodemographic groups in urban areas.

Effect of neighbourhood greenness on the association between air pollution and risk of stroke first onset: A case-crossover study in shandong province, China

BACKGROUND

Higher neighbourhood greenness is associated with beneficial health outcomes, and short-term exposure to air pollution is associated with an elevated risk of stroke onset. However, little is known about their interactions.

METHODS

Daily data on stroke first onset were collected from 20 counties in Shangdong Province, China, from 2013 to 2019. The enhanced vegetation index (EVI) and concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and sulfur dioxide (SO2) were calculated for each individual at the village or community level based on their home address to measure their neighbourhood exposure to greenness and air pollution. EVI was categorised as low or high, and a time-stratified case-crossover design was used to estimate the percent excess risk (ER%) of stroke associated with short-term exposure to air pollution. We further stratified greenness on the basis of EVI values into quartiles and introduced interaction terms between air pollutant concentrations and the median EVI values of the quartiles to assess the effect of greenness on the associations between short-term exposure and stroke.

RESULTS

Individuals living in the high-greenness areas had weaker associations between total stroke risk and exposure to NO2 (low greenness: ER% = 1.765% [95% CI 1.205%-2.328%]; high greenness: ER% = 0.368% [95% CI -0.252% to 0.991%]; P = 0.001), O3 (low greenness: 0.476% [95% CI 0.246%-0.706%]; high greenness: ER% = 0.085% [95% CI -0.156% to 0.327%]; P = 0.011), and SO2 (low greenness: 0.632% [95% CI 0.138%-1.129%]; high greenness: ER% = -0.177% [95% CI -0.782% to 0.431%]; P = 0.035).

CONCLUSION

Residence in areas with higher greenness was related to weaker associations between air pollution and stroke risk, suggesting that effectively planning green spaces can improve public health.

Associations of Urban Built Environment with Cardiovascular Risks and Mortality: a Systematic Review

With rapid urbanization, built environment has emerged as a set of modifiable factors of cardiovascular disease (CVD) risks. We conducted a systematic review to synthesize evidence on the associations of attributes of urban built environment (e.g. residential density, land use mix, greenness and walkability) with cardiovascular risk factors (e.g. hypertension and arterial stiffness) and major CVD events including mortality. A total of 63 studies, including 31 of cross-sectional design and 32 of longitudinal design conducted across 21 geographical locations and published between 2012 and 2023 were extracted for review. Overall, we report moderately consistent evidence of protective associations of greenness with cardiovascular risks and major CVD events (cross-sectional studies: 12 of 15 on hypertension/blood pressure (BP) and 2 of 3 on arterial stiffness; and longitudinal studies: 6 of 8 on hypertension/BP, 7 of 8 on CVD mortality, 3 of 3 on ischemic heart disease mortality and 5 of 8 studies on stroke hospitalization or mortality reporting significant inverse associations). Consistently, walkability was associated with lower risks of hypertension, arterial stiffness and major CVD events (cross-sectional studies: 11 of 12 on hypertension/BP and 1 of 1 on arterial stiffness; and longitudinal studies: 3 of 6 on hypertension/BP and 1 of 2 studies on CVD events being protective). Sixty-seven percent of the studies were rated as "probably high" risk of confounding bias because of inability to adjust for underlying comorbidities/family history of diseases in their statistical models. Forty-six percent and 14% of the studies were rated as "probably high" risk of bias for exposure and outcome measurements, respectively. Future studies with robust design will further help elucidate the linkages between urban built environment and cardiovascular health, thereby informing planning policies for creating healthy cities.

Associations of residential greenness, ambient air pollution, biological sex, and glucocorticoids levels in rural China

AIMS

To evaluate the associations between residential greenness and glucocorticoid levels and whether air pollutants and sex modify the relationship between greenness and glucocorticoid level in Chinese rural adults.

METHODS

We collected cross-sectional survey data from 6055 participants from the Henan Rural cohort. The three-year average residential greenness for participants was assessed using normalized difference vegetation index (NDVI) values from a satellite platform. Liquid chromatography-tandem mass spectrometry was employed to quantify the concentrations of glucocorticoids, which were measured by morning blood draw after at least 8 hr of fasting. A random forest model was employed to obtain the average concentrations of PM₁, PM_2.5, and PM₁₀. A general linear regression model was performed to estimate the associations of NDVI_500-m values with cortisol, 11-deoxycortisol, and cortisone. Furthermore, interaction plots were used to present the interaction effects of particulate matter, sex, and green space on glucocorticoid levels.

RESULTS

After adjusting for multiple variables, an elevated average NDVI_500-m value in the total population was associated with a decrease in cortisol levels (β = -0.063, 95 % confidence interval (CI): - 0.118, - 0.008), and 11-deoxycortisol levels (β = -0.118, 95 % CI: -0.190, -0.047), as well as an increase in cortisone levels (β = 0.130, 95 % CI: 0.079, 0.181). By adding the interaction terms of air pollutants and residential greenness into the regression model, interaction effects between air pollutants and residential greenness were found (cortisol, PM_2.5: P interaction=:0.018; PM₁₀: P interaction=0.016; 11-deoxycortisol, all pollutants: P interaction< 0.001), suggesting that the protective effect of residential greenness on serum glucocorticoids disappeared accompanying with increased concentrations of particulate matter. Moreover, trends towards modification in the association between green space and glucocorticoid levels were also evident by sex, but these did not reach statistical significance (for all glucocorticoids: P interaction> 0.05).

CONCLUSION

Long-term exposure to green space was negatively correlated with cortisol and 11-deoxycortisol levels, and positively correlated with cortisone levels. There may be sex differences in these associations. Moreover, the protective effect of residential greenness on serum glucocorticoids was altered by high levels of particulate matter.