Structural Characteristics of Tree Cover and the Association with Cardiovascular and Respiratory Health in Tampa, FL

Assessing potential benefits of visits to neighborhoods with higher tree canopy coverage using mobility data: Associations with cardiovascular health outcomes in twenty US metropolitan areas

BACKGROUND

Research on health benefits due to exposure to green space, such as tree canopy coverage, has predominantly focused on canopy coverage in home neighborhoods. Yet exposures to tree canopy coverage in other spaces visited during the week or on weekends outside the home neighborhoods remains largely unexplored.

OBJECTIVES

We examined whether differences in coverage levels of tree canopy in neighborhoods visited compared to home neighborhoods was associated with lower prevalence of coronary heart disease (CHD) and stroke, adjusting for exposure to home canopy coverage. We further investigated if the associations varied across levels of home canopy coverage, and if they were more pronounced on weekdays or weekends.

METHODS

We used 2018 mobile phone data from the twenty largest U.S. Metropolitan Statistical Areas (MSAs). For each home census tract, we derived a weighted tree canopy coverage exposure from all visited tracts based on the proportion of visits to other tracts by home tract residents. We subtracted home canopy coverage from the weighted canopy coverage in each of the visited tracts to calculate tract-specific differences. We evaluated associations between differences in tree canopy coverage and prevalence of CHD and stroke via spatial error models, adjusting for tract-level home canopy coverage, MSA, socioeconomic and built environment characteristics.

RESULTS

For every ten-percentage-point increase in tree canopy coverage in visited tracts relative to home tracts, there was a 0.32-0.34% decrease in stroke prevalence. Association with CHD prevalence was not observed after adjusting for spatial autocorrelation. Variations between weekdays and weekends were minimal. The difference in tree canopy coverage was associated with CHD prevalence only for home tracts with low tree canopy coverage, while the difference was associated with stroke prevalence across home tracts with low, moderate, and high tree canopy coverage, with diminishing effect size.

DISCUSSION

This study identified that greater tree canopy coverage in visited neighborhoods relative to home neighborhoods was associated with lower stroke prevalence, and associations varied across home neighborhoods with different tree canopy coverage levels. It emphasized the need to factor in the neighborhood mobility networks in urban planning initiatives to promote cardiovascular health.

Greenness exposure: beneficial but multidimensional

Many studies have shown that greenness has beneficial health effects, particularly on psychological and cardiovascular outcomes. In this narrative review, we provide a synthesis of knowledge regarding greenness exposure and respiratory health. The following outcomes were reviewed: respiratory mortality, lung cancer mortality, lung cancer incidence, respiratory hospitalisations, lung function, COPD, and asthma. We identified 174 articles through a literature search in PubMed, of which 42 were eligible for inclusion in this review. The most common marker for greenness exposure was the normalised difference vegetation index (NDVI), which was used in 29 out of 42 papers. Other markers used were tree canopy cover, landcover/land-use, plant diversity, density of tall trees and subjectively perceived greenness. We found beneficial effects of greenness in most studies regarding respiratory mortality, lung cancer incidence, respiratory hospitalisations and lung function. For lung cancer mortality, asthma and COPD, the effects of greenness were less clear cut. While many aspects of greenness are beneficial, some aspects may be harmful, and greenness may have different health effects in different population subgroups. Future studies of greenness and respiratory diseases should focus on asthma and COPD, on effects in different population subgroups and on disentangling the health effects of the various greenness dimensions.

Impacts of Urban Green on Cardiovascular and Cerebrovascular Diseases-A Systematic Review and Meta-Analysis

Cardiovascular diseases (CVDs) are a leading cause of mortality globally. In particular, ischemic heart diseases (IHDs) and cerebrovascular diseases (CBVDs) represent the main drivers of CVD-related deaths. Many literature examples have assessed the association between CVD risk factors and urban greenness. Urban green (UG) may positively affect physical activity, reduce air and noise pollution, and mitigate the heat island effect, which are known risk factors for CVD morbidity. This systematic review aims to assess the effects of urban green spaces on CVD morbidity and mortality. Peer-reviewed research articles with a quantitative association between urban green exposure variables and cardiovascular and cerebrovascular outcomes were included. Meta-analyses were conducted for each outcome evaluated in at least three comparable studies. Most of the included studies' results highlighted an inverse correlation between exposure to UG and CVD outcomes. Gender differences were found in four studies, with a protective effect of UG only statistically significant in men. Three meta-analyses were performed, showing an overall protective effect of UG on CVD mortality (HR (95% CI) = 0.94 (0.91, 0.97)), IHD mortality (HR (95% CI) = 0.96 (0.93, 0.99)), and CBVD mortality (HR (95% CI) = 0.96 (0.94, 0.97)). The results of this systematic review suggest that exposure to UG may represent a protective factor for CVDs.

Impact of residential greenness on myocardial infarction in the population with diabetes: A sex-dependent association?

Living in urban areas with abundant greenness might provide health benefits in general population. Literature suggests that sex/gender plays a role in the association between greenness and health outcomes. But the impact of greenness in populations with moderate to high cardiovascular risk, such as persons with diabetes, is still unknown. Our aim was to evaluate the relationship between urban greenness and myocardial infarction incidence in persons with type 2 diabetes in Barcelona (Catalonia, Spain), and seek potential gender/sex differences in this association. This retrospective cohort study is based on data from the System for the Development of Research in Primary Care (SIDIAP database). We used Cox models to estimate if a 0.01 increase in Normalized Difference Vegetation Index (NDVI) at census tract level was associated to reduced risk of developing a myocardial infarction. Models were adjusted by demographic and clinical characteristics at individual level, and by environmental and socioeconomic variables at census tract level. Amongst 41,463 persons with diabetes and 154,803.85 person-years of follow-up, we observed 449 incident cases of acute myocardial infarction. For each 0.01 increment in NDVI the risk of developing a myocardial infarction decreased by 6% (Hazard Ratio, HR = 0.94; 95%CI, 0.89-0.99) in the population with diabetes. When stratifying by sex, we observed a significant association only in men (HR = 0.91; 95%CI, 0.86-0.97). People with diabetes living in urban greener areas might benefit from reduced cardiovascular risk, specially men. We observed sex/gender disparities, which could be related to different exposures and activities performed in green spaces between men and women. Further studies are needed to confirm sex/gender disparities between greenness exposure and cardiovascular outcomes. Our findings contribute to improve the health of people with diabetes who should be recommended to spent time and exercise in green areas.

An Empirical Study of the Restoration Potential of Urban Deciduous Forest Space to Youth

Urban deciduous forests are an important ecological resource and seasonal landscape in the urban environment. However, in the abundant literature on how urban green space promotes human health and well-being, research on urban seasonal deciduous forests is limited. This study aimed to investigate the physiological and psychological recovery potential provided of urban deciduous forest space for youths and the spatial preferences of youths regarding such spaces. We recruited 120 participants to study the restorative potential of two typical urban deciduous forest landscape spaces (experimental groups) and one urban road environment (control group). The results showed that after 15 min of observation, the blood pressure (especially the diastolic blood pressure (p < 0.01)) and pulse of the deciduous forest trail setting (DFTS) group effectively decreased, and the restorative mood significantly increased. Regarding change in emotional parameters, the DFTS group scored higher on “interest” and significantly higher than the other two groups on positive emotion. The correlation results show that density and level are the key factors affecting spatial preferences regarding complex deciduous forests. An increase in density reduces the mood of re-laxation, and an increase in level decreases fatigue and interest. We suggest (1) constructing foot-paths in urban deciduous forests to reduce their spatial density as to improve the relaxation effect and (2) increasing landscape diversity according to the forest space to facilitate user participation and interest. This study provides a scientific basis for the environmental restoration of deciduous landscapes and for urban forestry management decision-makers based on space type construction.

Study on Structural Characteristics of Composite Smart Grille Based on Principal Component Analysis

In recent years, many scholars have conducted in-depth and extensive research on the mechanical properties, preparation methods, and structural optimization of grid structural materials. In this paper, the structural characteristics of composite intelligent grid are studied by combining theoretical analysis with experiments. According to the existing conditions in the laboratory, the equilateral triangular grid structure experimental pieces were prepared. In this paper, principal component analysis combined with nearest neighbor method was used to detect the damage of composite plates. On this basis, the multiobjective robustness optimization of the structure is carried out based on artificial intelligence algorithm, which makes the structure quality and its sensitivity to uncertain parameters lower. Particle swarm optimization (PSO) is used in neural network training. The damage characteristics of different grid structures, different impact positions, and different impact energies were studied. The results show that the structural damage types, areas, and propagation characteristics are very different when the structure is impacted at different positions, which verifies that the grid structure has a good ability to limit the damage diffusion and shows that the grid structure has a good ability to resist damage.

Green infrastructure can limit but not solve air pollution injustice

Outdoor air pollution contributes to millions of deaths worldwide yet air pollution has differential exposures across racial/ethnic groups and socioeconomic status. While green infrastructure has the potential to decrease air pollution and provide other benefits to human health, vegetation alone cannot resolve health disparities related to air pollution injustice. We discuss how unequal access to green infrastructure can limit air quality improvements for marginalized communities and provide strategies to move forward.

Residential green space, air pollution, socioeconomic deprivation and cardiovascular medication sales in Belgium: A nationwide ecological study

Green space may improve cardiovascular (CV) health, for example by promoting physical activity and by reducing air pollution, noise and heat. Socioeconomic and environmental factors may modify the health effects of green space. We examined the association between residential green space and reimbursed CV medication sales in Belgium between 2006 and 2014, adjusting for socioeconomic deprivation and air pollution. We analyzed data for 11,575 census tracts using structural equation models for the entire country and for the administrative regions. Latent variables for green space, air pollution and socioeconomic deprivation were used as predictors of CV medication sales and were estimated from the number of patches of forest, census tract relative forest cover and relative forest cover within a 600 m buffer around the census tract; annual mean concentrations of PM_2.5, BC and NO₂; and percentages of inhabitants that were foreign-born from lower- and mid-income countries, unemployed or had no higher education. A direct association between socioeconomic deprivation and CV medication sales [parameter estimate (95% CI): 0.26 (0.25; 0.28)] and inverse associations between CV medication sales and green space [-0.71 (-0.80; -0.61)] and air pollution [-1.62 (-1.69; -0.61)] were observed. In the regional models, the association between green space and CV medication sales was stronger in the region with relatively low green space cover (Flemish Region, standardized estimate -0.16) than in the region with high green space cover (Walloon Region, -0.10). In the highly urbanized Brussels Capital Region the association tended towards the null. In all regions, the associations between CV medication sales and socioeconomic deprivation were direct and more prominent. Our results suggest that there may be an inverse association between green space and CV medication sales, but socioeconomic deprivation was always the strongest predictor of CV medication sales.