A Study of Perceived Nature, Shade and Trees and Self-Reported Physical Activity in Denver

Do environmental attitudes and personal characteristics influence how people perceive their exposure to green spaces?

Background

This study explores the relationship between perceived and objective greenspace exposure, and how sociodemographic traits and environmental attitudes influence peoples' perceptions of greenspace.

Methods

We leveraged a cross-sectional survey on greenspace exposure among residents of Denver, CO that ran from November 2019 through April 2021. We measured objective greenspace using the average NDVI (normalized difference vegetation index), average percent vegetation, and median GVI (green view index) within 300, 500, and 1,000 m of participants' residences, and in participant-drawn polygons representing their neighborhoods. We measured perceived greenspace exposure using survey responses from questions about greenspace abundance, visibility, access, usage, and quality near participants' homes. We assessed relationships between perceived and objective greenspace measures using linear models. Then, we used latent class analysis to create perceived greenspace exposure classes, and used linear models to evaluate the relationship between these classes and sociodemographic and environmental attitude variables.

Results

We found that the relationship between perceived and objective measures (NDVI in the 300-meter buffer) was strongest for abundance (OR: 5.14, [4.0, 6.28]) and visibility (OR: 3.71, [2.58, 4.84]) compared to perceived access (OR: 2.17, [1.02, 3.32]), usage (OR: 2.28, [1.19, 3.37]), and quality (OR: 2.33, [1.25, 3.41]). In fully adjusted models, objective greenspace exposure and environmental attitudes predicted perceived greenspace exposure classes, but sociodemographic variables-other than age-did not.

Conclusion

Our work suggests that objective greenspace exposure is only one factor influencing peoples' perceived greenspace exposure, and that environmental attitude variables may play an additional role in shaping peoples' perceptions.

Seeking shade equity: Tree canopy coverage in public schools in Austin, TX

BACKGROUND/OBJECTIVES

Tree canopies have dermatologic and environmental benefits, especially on school campuses. However, inequities likely exist, and tree planting initiatives may further exacerbate disparities. We sought to identify any relationship between tree canopy shade on public school campuses in Austin, TX and the socioeconomic makeup of the student population, as well as whether current initiatives appropriately address any inequities.

METHODS

In this cross-sectional study, we used ArcGIS, a publicly available geographic information system (GIS), to calculate the percentage of tree canopy on campuses within the Austin Independent School District (AISD) for the years 2006 and 2022. We compared this with the percentage of students eligible for free and reduced meals (FRM) at each school. The percentages of FRM-eligible students were also compared for "low priority" versus "high priority" neighborhoods, as assigned by Austin's Tree Priority Map.

RESULTS

Among 112 schools analyzed, schools with minority FRM-eligible students had significantly more tree canopy compared to schools with majority FRM-eligible students (19.9% vs. 12.4%, p < .001). When comparing tree priorities, there was a significant difference between the percentage of FRM-eligible students in "low priority" schools compared to "high priority" schools (23.8% vs. 62.2%, p < .001).

CONCLUSIONS

Additional work is needed to rectify inequities in tree canopy access for public school students. Designations such as those used in Austin's Tree Priority Map would likely help direct such efforts. We hope this study encourages future research with GIS by both dermatologists and other health care professionals to promote interdisciplinary work with urban planners.

Effects of greenery at different heights in neighbourhood streetscapes on leisure walking: a cross-sectional study using machine learning of streetscape images in Sendai City, Japan

BACKGROUND

It has been pointed out that eye-level greenery streetscape promotes leisure walking which is known to be a health -positive physical activity. Most previous studies have focused on the total amount of greenery in the eye-level streetscape to investigate its association with walking behaviour. While it is acknowledged that taller trees contribute to greener environments, providing enhanced physical and psychological comfort compared to lawns and shrubs, the examination of streetscape metrics specifically focused on greenery height remains largely unexplored. Therefore, this study examined the relationship between objective indicators of street greenery categorized by height from a pedestrian viewpoint and leisure walking time.

METHODS

We created streetscape indices of street greenery using Google Street View Images at 50-m intervals in an urban area in Sendai City, Japan. The indices were classified into four ranges according to the latitude of the virtual hemisphere centred on the viewer. We then investigated their relationship to self-reported leisure walking.

RESULTS

Positive associations were identified between the street greenery in higher positions and leisure walking time, while there was no significant association between the greenery in lower positions.

CONCLUSION

The findings indicated that streets with rich greenery in high positions may promote residents' leisure walking, indicating that greenery in higher positions contributes to thermally comfortable and aesthetic streetscapes, thus promoting leisure walking. Increasing the amount of greenery in higher positions may encourage residents to increase the time spent leisure walking.

Impact of Playground Shade Structures on Ultraviolet Radiation Exposure and Physical Activity among Children at a Childcare Facility

Skin cancer is the most common cancer in Canada, and rates continue to rise. While sunscreen and protective clothing remain critical strategies to reduce skin cancer risk, shade is generally the most effective way to control exposure. There remains a lack of data, particularly in British Columbia (BC), demonstrating the extent to which shade availability reduces ultraviolet radiation (UVR) exposure in a real-world setting and the potential impacts of shade provision on physical activity. We evaluated the impact of shade structures on UVR exposure and physical activity at a Vancouver-area childcare center with an outdoor play area with limited existing shade. 22 children, aged 3-5 years, participated in the study. Three removable shade sails were installed in the outdoor play space, and UVR and physical activity measurements were collected during the spring, summer, and fall months. Ultraviolet B (UVB) radiation data was measured using UVB dosimeters, and physical activity data was measured using accelerometers. Data were collected during each season over a total of four days-two days with shade sails installed and two days with shade sails removed. Overall, with shade installation, UVR exposures and physical activity levels among children were reduced by 50% and 20%, respectively. This study supports the use of shade sails to significantly reduce UVR exposures among preschool-aged children in BC; however, the potential for decreased physical activity from shade sails should be further explored in future research.

Perceptions of greenspace and social determinants of health across the life course: The Life Course Sociodemographics and Neighborhood Questionnaire (LSNEQ)

We developed the Life Course Sociodemographics and Neighborhood Questionnaire (LSNEQ) to query older adults about perceived neighborhood greenspaces across the life course (i.e., distance to park, number of neighborhood parks/playgrounds, and neighborhood greenness) and about characteristics hypothesized to confound or moderate/mediate greenspace-health associations. Six perceived life course indices are derived from the LSNEQ: neighborhood socioeconomic status, neighborhood walking/biking, urbanicity, neighborhood amenities, neighborhood park access, and neighborhood greenness. Older adults from St. Louis, Missouri, and Sacramento, California, completed the LSNEQ in 2020-2021. The indices demonstrated borderline acceptable to good internal consistency (alpha = 0.60-0.79) and good to excellent test-retest reliability (ICC = 0.71-0.96) and detected different patterns of park access and neighborhood greenness by racialized group and location. Individuals with index scores indicating more neighborhood walking/biking and greater presence of neighborhood amenities over their life course were more likely to report neighborhood-based walking in older age. Overall, the LSNEQ is a reliable instrument to assess perceptions of life course social determinants of health including neighborhood greenspaces.

The Relationship between Perceptions and Objective Measures of Greenness

Exposure to greenness has been studied through objective measures of remote visualization of greenspace; however, the link to how individuals interpret spaces as green is missing. We examined the associations between three objective greenspace measures with perceptions of greenness. We used a subsample (n = 175; 2018-2019) from an environmental cardiovascular risk cohort to investigate perceptions of residential greenness. Participants completed a 17-item survey electronically. Objective measurements of greenness within 300 m buffer around participants home included normalized difference vegetation index (NDVI), tree canopy and leaf area index. Principal component analysis reduced the perceived greenspaces to three dimensions reflecting natural vegetation, tree cover and built greenspace such as parks. Our results suggest significant positive associations between NDVI, tree canopy and leaf area and perceived greenness reflecting playgrounds; also, associations between tree canopy and perceived greenness reflecting tree cover. These findings indicate that the most used objective greenness measure, NDVI, as well as tree canopy and leaf area may most align with perceptions of parks, whereas tree canopy alone captures individuals' perceptions of tree cover. This highlights the need for research to understand the complexity of green metrics and careful interpretation of data based on the use of subjective or objective measures of greenness.

Perceptions of green space usage, abundance, and quality of green space were associated with better mental health during the COVID-19 pandemic among residents of Denver

BACKGROUND

The COVID-19 pandemic has impacted both physical and mental health. This study aimed to understand whether exposure to green space buffered against stress and distress during the COVID-19 pandemic while taking into account significant stressors of the pandemic.

METHODS

We leveraged a cross-sectional survey on green space exposure and mental health among residents of Denver, CO that ran from November 2019 through January 2021. We measured objective green space as the average NDVI (normalized difference vegetation index) from aerial imagery within 300m and 500m of the participant's residence. Perceived green space was measured through Likert scores on five questions about vegetation near the home that captured perceived abundance, visibility, access, usage, and quality of green space. We used generalized linear models to assess the relationship between each green space exposure variable and perceived stress (PSS-4), depression (CES-D-10), or anxiety (MMPI-2) adjusted for sociodemographic and COVID-19 impact variables.

RESULTS

We found significantly higher depression scores for all covid periods compared to the "before covid" period, and significantly higher anxiety scores during the "fall wave" compared to earlier periods. Adjusted for sociodemographic and pandemic stressors, we found that spending a lot of time in green space (usage) was significantly associated with lower anxiety and depression. We also observed significantly lower depression scores associated with NDVI in both buffers (objective abundance) and significantly lower anxiety scores with perceived abundance of green space. There was some evidence of lower anxiety scores for people reporting having high quality green spaces near the home (quality). We did not observe significant associations for any green space metric and perceived stress after adjustment for confounding variables.

CONCLUSION

Our work provides further evidence of mental health benefits associated with green space exposure during the COVID-19 pandemic even after adjustment for sociodemographic variables and significant pandemic-related stressors.

Effects of tree canopy on psychological distress: A repeated cross-sectional study before and during the COVID-19 epidemic

BACKGROUND

During the COVID-19 epidemic period, people showed a stronger connection to the environment within their communities. Although tree canopy in residential areas has been shown to positively affect psychological distress, it is not clear whether the COVID-19 epidemic played a role in this process. Elucidation of the relationship between tree canopy and the impact on psychological distress during the COVID-19 epidemic could provide valuable information as to the best methods to help individuals cope with urban mental stress events.

METHODS

A total of 15 randomly selected residential areas of Beijing were enrolled in this repeated cross-sectional study. A total of 900 residents were included in the two-waves of the investigation (450 residents per wave) before and during the COVID-19 epidemic (i.e., May 2019 and May 2020). Psychological distress was estimated using the 12-question General Health Questionnaire (GHQ-12). Tree canopy coverage (TCC) was measured through visual interpretation based on the 2013 data sources (World View 2 satellite imagery of Beijing urban areas with a resolution of 0.5 m). The demographic characteristics, distance to the nearest surrounding green or blue space, residential area house price, household density, and construction year were also collected in this study. A multivariate logistic regression, relative risk due to interaction (RERI), and synergy index (SI) were used to explore the relationships among tree canopy, COVID-19, and psychological distress.

RESULTS

The negative impact of the COVID-19 epidemic on mental health was significant, with the prevalence of psychological distress increased 7.84 times (aOR = 7.84, 95% CI = 4.67-13.95) during the COVID-19 epidemic period. Tree canopy coverage in the group without psychological distress was significantly higher than that of the psychologically distressed group (31.07 ± 11.38% vs. 27.87 ± 12.97%, P = 0.005). An increase in 1% of TCC, was related to a 5% decrease in the prevalence of psychological distress (aOR = 0.95, 95% CI = 0.93-0.98). An antagonism joint action between tree canopy and the COVID-19 epidemic existed (RERI = 1.09, 95% CI = 0.72-1.47; SI = 0.16, 95% CI = 0.05-0.52), and persisted enhancing only in medium (26.45%-33.21%) and above TCC level. Correlation of GHQ items and TCC significantly differed between the COVID-19 non-epidemic and epidemic periods, with the effects of tree canopy on GHQ-12 items covering topics, such as social function and depression, presumably absent because of epidemic limitations.

CONCLUSIONS

This study indicates that the COVID-19 epidemic harmed mental health and verified the positive effects of residential tree canopy on psychological distress in Beijing. We suggest paying more attention to residents in areas of low TCC and dealing with psychological distress caused by public health stress events based on tree canopy strategies.

Associations of objective and perceived greenness measures with cardiovascular risk factors in Philadelphia, PA: A spatial analysis

There is mounting scientific evidence that greenness is associated with improved cardiovascular health. However, few studies have distinguished between vegetation type, measured perceived green space access, or investigated heterogeneity of associations across categories of neighborhood sociodemographic and racial/ethnic composition. We conducted an ecologic spatial analysis of associations of three objective measures of greenness (percent vegetation cover, percent tree canopy cover, and greenness density), and one measure of perceived access to green spaces with census tract level percentages of the adult population who were obese, ever had a high blood pressure diagnosis, and ever had a diabetes diagnosis, in the city of Philadelphia, PA, year 2013. We explored effect modification by census-tract level percent living in poverty and percent non-Hispanic Black categories. We used data from the Southeastern Pennsylvania Household Health Survey (SEPAHH) linked with high-resolution landcover, remotely sensed, and American Community Survey data and estimated associations using spatial lag models. We observed modest protective associations between percent of the adult population reporting perceived access to green spaces and percent with the cardiovascular risk factors, particularly in moderate and high poverty census tracts. Percent tree canopy cover was also protective against the cardiovascular risk factors, particularly in census tracts with low percentages of the population living in poverty and with low percent non-Hispanic Black populations. These results suggest that perceived access to green spaces and objectively measured high tree canopy cover, may protect against cardiovascular disease, but associations may vary across neighborhood sociodemographic categories.

Is the perceived neighborhood built environment associated with domain-specific physical activity in Latin American adults? An eight-country observational study

Background

Characteristics of the neighborhood built environment are associated with physical activity (PA). However, few studies with representative samples have examined environmental correlates of domain-specific PA in Latin America. We examined the associations of the perceived neighborhood built environment with domain-specific PA in a large sample of adults from eight Latin American countries.

Methods

This study examined data from 8185 adults (aged 18–65 years) from eight Latin American countries. The Neighbourhood Environment Walkability Survey - Abbreviated (NEWS-A) scale was used to assess perceptions of land use mix–diversity, land use mix-access, street connectivity, walking/cycling facilities, aesthetics, safety from traffic, and safety from crime. Perceived proximity from home to public open spaces (metropolitan parks, playgrounds, public squares) and to shopping centers was also measured. Transport-related and leisure-time PA were assessed using the long form of the International Physical Activity Questionnaire. Both logistic and linear regression models were estimated on pooled data.

Results

Perceptions of higher land use mix-access (OR: 1.40; 95% CI: 1.22,1.61), the existence of many alternative routes in the neighbourhood (1.12; 1.04,1.20), slow speed of traffic (1.19; 1.03,1.35) and few drivers exceeding the speed limits (1.09; 1.03,1.15) were associated with greater odds of reporting at least 10 min/week of transport-related PA. Perceptions of higher levels of land use mix-diversity, better aesthetics and greater safety from crime, the presence of crosswalks and pedestrian signals, and greater proximity of shopping centers were associated with more min/week of transport-related PA. Perceptions of higher land use mix-diversity (1.12; 1.05,1.20), higher land use mix-access (1.27; 1.13,1.43), more walking/cycling facilities (1.18; 1.09,1.28), and better aesthetics (1.10; 1.02,1.18) were associated with greater odds of engaging in at least 10 min/week of leisure-time PA versus none. Perceptions of higher land use mix-diversity were associated with more min/week of leisure PA.

Conclusions

Different perceived neighborhood built environment characteristics were associated with domain-specific PA among adults from Latin America countries. Interventions designed to modify perceptions of the neighbourhood built environment might influence initiation or maintenance of domain-specific PA.

Trial registration

ClinicalTrials. Gov NCT02226627. Retrospectively registered on August 27, 2014.

Testing the Multiple Pathways of Residential Greenness to Pregnancy Outcomes Model in a Sample of Pregnant Women in the Metropolitan Area of Donostia-San Sebastián

Residential greenness may positively impact diverse human health indicators through the reduction of air pollution, the improvement of psychological health, and the promotion of physical activity. Previous studies indicate a weak but positive association with pregnancy outcomes. Our aim was to test the multiple pathways from residential greenness to pregnancy outcomes model, using residential NO₂ concentrations, psychological health, and moderate-to-vigorous physical activity (MVPA) during the first trimester of pregnancy, in a sample of 440 pregnant women residing in Donostia, Spain. Three metrics of residential greenness were calculated around each participant’s home address: normalized difference vegetation index (NDVI) within 300 m, and green space (>5000 m²) availability within 300 and 500 m. Residential NO₂ concentrations, psychological health, and MVPA were explored as mediators of the associations between these metrics and the following pregnancy outcomes: birth weight (BW), low birth weight (LBW), prematurity, small for gestational age (SGA), and large for gestational age (LGA). Educational attainment, parity, and body mass index (BMI) were treated as covariates. Counterfactual mediation analyses showed very low to null statistical support for an association between any of the greenspace metrics and pregnancy outcomes in the full sample. Green space availability (300 m) was associated with lower BW and showed a marginal protective effect against LGA.