Green Space and Health Equity: A Systematic Review on the Potential of Green Space to Reduce Health Disparities

Nature's contributions in coping with a pandemic in the 21st century: A narrative review of evidence during COVID-19

While COVID-19 lockdowns have slowed coronavirus transmission, such structural measures also have unintended consequences on mental and physical health. Growing evidence shows that exposure to the natural environment (e.g., blue-green spaces) can improve human health and wellbeing. In this narrative review, we synthesized the evidence about nature's contributions to health and wellbeing during the first two years of the COVID-19 pandemic. We found that during the pandemic, people experienced multiple types of nature, including both outdoors and indoors. Frequency of visits to outdoor natural areas (i.e., public parks) depended on lockdown severity and socio-cultural contexts. Other forms of nature exposure, such as spending time in private gardens and viewing outdoor greenery from windows, may have increased. The majority of the evidence suggests nature exposure during COVID-19 pandemic was associated with less depression, anxiety, stress, and more happiness and life satisfaction. Additionally, nature exposure was correlated with less physical inactivity and fewer sleep disturbances. Evidence was mixed regarding associations between nature exposure and COVID-related health outcomes, while nature visits might be associated with greater rates of COVID-19 transmission and mortality when proper social distancing measures were not maintained. Findings on whether nature exposure during lockdowns helped ameliorate health inequities by impacting the health of lower-socioeconomic populations more than their higher-socioeconomic counterparts for example were mixed. Based on these findings, we argue that nature exposure may have buffered the negative mental and behavioral impacts of lockdowns during the COVID-19 pandemic. Recovery and resilience during the current crises and future public health crises might be improved with nature-based infrastructure, interventions, designs, and governance.

Nature's contributions in coping with a pandemic in the 21st century: A narrative review of evidence during COVID-19

While COVID-19 lockdowns have slowed coronavirus transmission, such structural measures also have unintended consequences on mental and physical health. Growing evidence shows that exposure to the natural environment (e.g., blue-green spaces) can improve human health and wellbeing. In this narrative review, we synthesized the evidence about nature's contributions to health and wellbeing during the first two years of the COVID-19 pandemic. We found that during the pandemic, people experienced multiple types of nature, including both outdoors and indoors. Frequency of visits to outdoor natural areas (i.e., public parks) depended on lockdown severity and socio-cultural contexts. Other forms of nature exposure, such as spending time in private gardens and viewing outdoor greenery from windows, may have increased. The majority of the evidence suggests nature exposure during COVID-19 pandemic was associated with less depression, anxiety, stress, and more happiness and life satisfaction. Additionally, nature exposure was correlated with less physical inactivity and fewer sleep disturbances. Evidence was mixed regarding associations between nature exposure and COVID-related health outcomes, while nature visits might be associated with greater rates of COVID-19 transmission and mortality when proper social distancing measures were not maintained. Findings on whether nature exposure during lockdowns helped ameliorate health inequities by impacting the health of lower-socioeconomic populations more than their higher-socioeconomic counterparts for example were mixed. Based on these findings, we argue that nature exposure may have buffered the negative mental and behavioral impacts of lockdowns during the COVID-19 pandemic. Recovery and resilience during the current crises and future public health crises might be improved with nature-based infrastructure, interventions, designs, and governance.

Evolving norms: social media data analysis on parks and greenspaces perception changes before and after the COVID 19 pandemic using a machine learning approach

This study provides a novel approach to understand human perception changes in their experiences of and interactions with public greenspaces during the early months of COVID-19. Using social media data and machine learning techniques, the study delivers new understandings of how people began to feel differently about their experiences compared to pre-COVID times. The study illuminates a renewed appreciation of nature as well as an emerging but prominent pattern of emotional and spiritual experiences expressed through a social media platform. Given that most park and recreational studies have almost exclusively examined whether park use increased or decreased during the pandemic, this research provides meaningful implications beyond the simple extensional visit pattern and lends weight to the growing evidences on changing perceptions over and the positive psychological impacts of nature. The study highlights the preeminent roles parks and greenspaces play during the pandemic and guides a new direction in future park development to support more natural elements and nature-oriented experiences from which emotional and spiritual well-being outcomes can be drawn.

Greening, Revitalization, and Health in South Wilmington, Delaware

We highlight the potential for paradoxical impacts of green infrastructure integrated with urban redevelopment. Absent directly addressing social inequalities in parallel efforts, green infrastructure may lead to negative health outcomes of disadvantaged residents, including eventual displacement. We present the research literature and reviews on this topic. We next highlight the case of recent in-migration of higher-income Whites and others in South Wilmington, Delaware, spurred on by high-end Riverfront redevelopment at Christina Landing. This migration may obscure how greening efforts—such as a new wetlands park to control area flooding—influence health outcomes in Southbridge, a low-income, African American neighborhood also within South Wilmington. The area’s Census tract boundary, often used in both health and equity assessments, is shared by these distinctive communities. When viewed through the lens of inequality, greening can have multi-faceted impacts that structure health outcomes. We underscore the importance of the mitigation of its potentially harmful effects.

Environmentally related gender health risks: findings from citizen science cross-sectional study

Background

Public engagement in the research of environmental epidemiological problems is becoming an important measure to empower citizens to identify the local environmental and health problems and to explain different environmental exposures affect estimates for males and females. This HORIZON2020 CitieS-Health Kaunas Pilot study examines the relationship between urban built and social environment, health behaviors, and health in men and women.

Methods

This cross-sectional study included 1086 18–74-year-old participants residing in 11 districts of Kaunas city, Lithuania. Using GIS, we measured traffic flow, noise, NO2, PM2.5, PM10, and greenness NDVI for the participants’ home addresses, determined participants’ perceptions of environmental quality, linked this information with personal sociodemographic data, and used multivariate logistic regression to assess the associations with health issues (physician-diagnosed chronic disease and self-rated general health) in men and women.

Results

Men and women similar rated the quality of the neighborhood environment, except for air pollution and satisfaction with the public transport in the district. The traffic-related health associations were stronger for women than for men. The prevalence of poor health increased with the increasing age of men and women, yet no significant differences between gender health risks were found in the total sample. Perceived air pollution, irregular visits to green space, and chronic diseases were consistently associated with poor health risks in men and women, yet part-time jobs and low income had a higher impact on women’s poor health.

Conclusions

Quality of the built neighborhood, air pollution, irregular visits to the green space, and chronic disease had a joint effect on the magnitude of the prevalence of poor health in men and women. Our results suggest that decreasing air pollution and improving the urban built neighborhood supporting citizens’ physical activity in green spaces, might reduce health risks for all.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13824-3.

Green Space for Mental Health in the COVID-19 Era: A Pathway Analysis in Residential Green Space Users

Residential green space is among the most accessible types of urban green spaces and may help maintain mental health during the COVID-19 pandemic. However, it is insufficiently understood how residents use residential green space for exercise during the epidemic. The pathways between residential green space and mental health also merit further exploration. Therefore, we conducted an online study among Chinese residents in December 2021 to capture data on engagement with urban green space for green exercise, the frequency of green exercise, perceived pollution in green space, perceptions of residential green space, social cohesion, depression, and anxiety. Among the 1208 respondents who engaged in green exercise last month, 967 (80%) reported that green exercise primarily occurred in residential neighborhoods. The rest (20%) reported that green exercise occurred in more distant urban green spaces. The most common reasons that respondents sought green exercise in urban green spaces were better air and environmental qualities. Structural equation modeling (SEM) was then employed to explore the pathways between the perceived greenness of residential neighborhoods and mental health among respondents who used residential green space for exercise. The final model suggested that residential green space was negatively associated with anxiety (β = −0.30, p = 0.001) and depression (β = −0.33, p < 0.001), mainly through indirect pathways. Perceived pollution and social cohesion were the two mediators that contributed to most of the indirect effects. Perceived pollution was also indirectly associated with green exercise through less social cohesion (β = −0.04, p = 0.010). These findings suggest a potential framework to understand the mental health benefits of residential green space and its accompanying pathways during the COVID-19 era.

Changes in neighborhood environments and the increasing socioeconomic gap in child obesity risks: Evidence from Singapore

Most empirical research studying the link between neighborhood environments and child obesity risks are conducted in contexts such as the U.S., with pronounced patterns of residential segregation, making it difficult to extrapolate how far built environment characteristics contribute to socioeconomic disparities in obesity risks in less segregated contexts. Using a large national dataset of almost 625,000 students' height and weight data collected at ages 7, 11 and 14, between 2004 and 2015, this paper explores whether differences in eight neighborhood characteristics measuring access to different type of food outlets, parks and other active spaces, and public transport infrastructure might be responsible for socioeconomic differences in child obesity risks in Singapore, a city-state with relatively low levels of residential segregation. Through descriptive analyses we find that socioeconomic disparities in child BMIz in Singapore widened from 2004 onwards. However, while longitudinal regression models with individual and time fixed effects suggest that family socioeconomic status modified the relationship between environmental exposures and BMIz, there does not seem to be a clear, unequivocal relationship between built environment changes and the observed widening of the socioeconomic obesity gap.

Mapping of Research in the Field of Forest Therapy-Related Issues: A Bibliometric Analysis for 2007-2021

Exposure to forest environments promotes human health. The number of relevant studies in this area has increased rapidly. However, an overall review of relevant analyses from the perspectives of bibliometrics and visualization is lacking. A scientometric analysis of 2,545 publications from 2007 to 2021 via the Web of Science database was conducted to identify the knowledge structure and frontiers objectively. The publications were subsequently analyzed in terms of the distribution of journals and countries, citation bursts, major subject areas, and evolutionary stages. The findings showed that the knowledge foundation of forest therapy was multidisciplinary with most published in the fields of environmental sciences and ecology but lacking input from social disciplines. The research hotspots evolved from the early focus on individual benefits obtained from nature to increasing attention on human well-being at the social-ecological scale. More rigorous experiments with strict randomized controlled trials and blinding are needed to accommodate the trend of forest therapy toward non-pharmacological treatments. According to Shneider's four-stage theory, forest therapy research is in the third stage of the scientific research process. More future studies utilizing novel technologies and decision-making frameworks to solve practical issues are needed for introducing health into policies and promoting human well-being.

Associations between neighborhood characteristics and dating violence: does spatial scale matter?

Background

Dating violence (DV) is a public health problem that could have serious repercussions for the health and well-being of a large number of adolescents. Several neighborhood characteristics could influence these behaviors, but knowledge on such influences is still limited. This study aims at (1) evaluating the associations between neighborhood characteristics and DV, and (2) assessing how spatial scale influences the estimations of the latter associations.

Methods

The Québec Health Survey of High School Students (2016–2017) was used to describe DV. Neighborhoods were operationalized with polygon-based network buffers of varying sizes (ranging from 250 to 1000 m). Multiple data sources were used to describe neighborhood characteristics: crime rate, alcohol outlet density (on-premises and off-premises), walkability, greenness, green spaces density, and youth organizations density. Gendered-stratified logistic regressions were used for assessing the association between neighborhood characteristics and DV.

Results

For boys, off-premises alcohol outlet density (500 m) is associated with an increase in perpetrating psychological DV. Crime rate (500 m) is positively associated with physical or sexual DV perpetration, and crime rate (250 m) is positively associated with physical or sexual DV victimization. Greenness (1000 m) has a protective effect on psychological DV victimization. For girls, walkability (500 m to 1000 m) is associated with a decrease in perpetrating and experiencing psychological DV, and walkability (250 m) is negatively associated with physical or sexual DV victimization.

Conclusions

Several neighborhood characteristics are likely to influence DV, and their effects depend on the form of DV, gender, and spatial scale. Public policies should develop neighborhood-level interventions by improving neighborhood living conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12942-022-00306-3.

Decision Tree Analyses to Explore the Relevance of Multiple Sex/Gender Dimensions for the Exposure to Green Spaces: Results from the KORA INGER Study

Recently, attention has been drawn to the need to integrate sex/gender more comprehensively into environmental health research. Considering theoretical approaches, we define sex/gender as a multidimensional concept based on intersectionality. However, operationalizing sex/gender through multiple covariates requires the usage of statistical methods that are suitable for handling such complex data. We therefore applied two different decision tree approaches: classification and regression trees (CART) and conditional inference trees (CIT). We explored the relevance of multiple sex/gender covariates for the exposure to green spaces, measured both subjectively and objectively. Data from 3742 participants from the Cooperative Health Research in the Region of Augsburg (KORA) study were analyzed within the INGER (Integrating gender into environmental health research) project. We observed that the participants’ financial situation and discrimination experience was relevant for their access to high quality public green spaces, while the urban/rural context was most relevant for the general greenness in the residential environment. None of the covariates operationalizing the individual sex/gender self-concept were relevant for differences in exposure to green spaces. Results were largely consistent for both CART and CIT. Most importantly we showed that decision tree analyses are useful for exploring the relevance of multiple sex/gender dimensions and their interactions for environmental exposures. Further investigations in larger urban areas with less access to public green spaces and with a study population more heterogeneous with respect to age and social disparities may add more information about the relevance of multiple sex/gender dimensions for the exposure to green spaces.

Do sex and gender modify the association between green space and physical health? A systematic review

A growing literature shows that green space can have protective effects on human health. As a marginalized group, women often have worse life outcomes than men, including disparities in some health outcomes. Given their marginalization, women might have "more to gain" than men from living near green spaces. Yet, limited research has deliberately studied whether green space-health associations are stronger for women or men. We conducted a systematic review to synthesize empirical evidence on whether sex or gender modifies the protective associations between green space and seven physical health outcomes (cardiovascular disease, cancer, diabetes, general physical health, non-malignant respiratory disease, mortality, and obesity-related health outcomes). After searching five databases, we identified 62 articles (including 81 relevant analyses) examining whether such effect modification existed. We classified analyses based on whether green space-health were stronger for women, no sex/gender differences were detected, or such associations were stronger for men. Most analyses found that green space-physical health associations were stronger for women than for men when considering study results across all selected health outcomes. Also, women showed stronger protective associations with green space than men for obesity-related outcomes and mortality. Additionally, the protective green space-health associations were slightly stronger among women for green land cover (greenness, NDVI) than for public green space (parks), and women were also favored over men when green space was measured very close to one's home (0-500 m). Further, the green space-health associations were stronger for women than for men in Europe and North America, but not in other continents. As many government agencies and nongovernmental organizations worldwide work to advance gender equity, our review shows that green space could help reduce some gender-based health disparities. More robust empirical studies (e.g., experimental) are needed to contribute to this body of evidence.

Relationships between Green Space Attendance, Perceived Crowdedness, Perceived Beauty and Prosocial Behavior in Time of Health Crisis

An emergent body of evidence shows the impact of exposure to nature on prosocial attitudes and interpersonal relationships. This study examines relationships between green space (GS) attendance, perceived beauty of the space, perceived crowdedness of the space, and prosocial behavior. A cross-sectional study with snowball sampling was conducted in April 2020. All participants (N = 1206) responded to an online survey that included a French version of the social value orientation slider measure (used as a proxy for prosocial behavior), questions about the lockdown, and their GS attendance. After retaining only participants who had visited a GS at least once since the beginning of their lockdown (N = 610), multiple linear regressions showed that social orientation scores demonstrated associations with the interaction between GS attendance and perceived crowdedness of the GS, suggesting that attending low crowded GS is linked to increasing prosociality. These results provide insight into the roles that GS can have during a health crisis and suggest some practical implications.

Association between built environments and weight status: evidence from longitudinal data of 9589 Australian children

Background

No studies appear to examine potential associations between changes in built environments across childhood and the developmental trajectories of child weight status.

Objective

Examine the developmental trajectories of child weight status with respect to changes in childhood exposure to the built environments.

Methods

This study used data of 9589 children with biennial follow-up (2004–2016), retrieved from the Longitudinal Study of Australian Children. Changes in objectively-measured child weight status (i.e., body mass index-BMI, waist circumference) were investigated in relation to changes in seven built environments (i.e., neighbourhood safety; green space quality; footpaths and street conditions; public transport; shopping facilities; basic services; and local traffic) subjectively reported by caregivers. Group-based discrete trajectory mixture models were used to classify children according to their developmental trajectories of built environments and weight status. Multilevel multinomial logistic regression was employed to examine associations between built environments and child weight status adjusted for confounding.

Results

Two, four, and six trajectory groups were developed for built environment variables. Three groups namely “moderate”, “high”, and “extreme increase” were generated for each BMI and waist circumference. Findings from multilevel analyses indicated that growing up in neighbourhoods that are considered highly safe, with better quality of green space nearby, and in areas with low local traffic over time are protective against unhealthy weight increase in childhood. Meanwhile, living with better access to shopping facilities and basic services was associated with an unhealthy increase in BMI and/or waist circumference. No clear associations appeared between the quality of footpath and street conditions, access to public transport, and child weight status.

Conclusions

Built environments might act either as a risk or protective factor of an unhealthy increase in child weight status. Enabling health-promoting neighbourhoods (i.e., highly safe, quality green space nearby, low local traffic) is important to support a healthy weight trajectory across childhood.

Increased Wellbeing following Engagement in a Group Nature-Based Programme: The Green Gym Programme Delivered by the Conservation Volunteers

The wellbeing benefits of engaging in a nature-based programme, delivered by the Voluntary, Community and Social Enterprise sector, were examined in this study. Prior to attending The Conservation Volunteers’ Green Gym™, attendees (n = 892) completed demographics, health characteristics and the Warwick Edinburgh Mental Wellbeing Short-Form Scale. Attendees (n = 253, 28.4%) provided a measure on average 4.5 months later. There were significant increases in wellbeing after engaging in Green Gym, with the greatest increases in those who had the lowest starting levels of wellbeing. Wellbeing increases were sustained on average 8.5 months and 13 months later in those providing a follow up measure (n = 92, n = 40, respectively). Attendees who continued to engage in Green Gym but not provide follow up data (n = 318, 35.7%) tended to be more deprived, female and self-report a health condition. Attendees who did not continue to engage in Green Gym (n = 321, 36.0%) tended to be less deprived and younger. These findings provide evidence of the wellbeing benefits of community nature-based activities and social (‘green’) prescribing initiatives and indicate that Green Gym targets some groups most in need.

The association of hypertension and prehypertension with greenness and PM2.5 in urban environment

BACKGROUND

The interplay of air pollution and urban greenness on hypertension (HTN) is not fully understood.

METHODS

We conducted a cross-sectional study to explore the role of greenness and PM_2.5 on HTN for 40,375 adult residents in the New Taipei City, Taiwan. Normalized Difference Vegetation Index (NDVI) defined greenness and land use regression derived exposures of PM_2.5 were used to calculate odds ratios (ORs) of HTN in logistic regression models and common OR of normal to stage 3 HTN in ordinal logistic regression models. Linear regression model was used to evaluate the association between NDVI and blood pressures, including systolic (SBP), diastolic (DBP) and mean (MBP) pressures. The mediation and moderation analysis were used to assess the mediation and moderation effect of PM_2.5 on the association between greenness and SBP.

RESULTS

We found 37.3%, 21.4%, 8.2% and 2.7% of prehypertension and stage 1-3 hypertensions, respectively, for our study participants with annual PM_2.5 exposures of 10.96-43.59 μg/m³ living in an urban environment with NDVI within 500 m buffer ranging from -0.22 to 0.26. The ORs of HTN were 0.744 (95% CI: 0.698-0.793) for NDVI (quartile 4 vs. quartile 1) and 1.048 (1.012-1.085) for each IQR (8.69 μg/m³) increase in PM_2.5, respectively. The common OR of the higher level of 5 categories of BP was 1.1310 (1.241-1.383). With each IQR increase of NDVI (0.03), we found SBP, DBP and MBP were decreased by 0.78 mm Hg (-0.93-0.64), 0.52 mm Hg (-0.62-0.43) and 0.61 mm Hg (-0.71-0.51), respectively, in linear regression models. Stratified analysis found greenness effect was more prominent for people who are younger, female, never smoking, and without chronic diseases. PM_2.5 is moderated rather than mediated the association between greenness and SBP.

CONCLUSIONS

Greenness was associated with lower prevalence of prehypertension and all stages of HTN and this relationship was moderated by PM_2.5.

Green space and cardiovascular disease: A systematic review with meta-analysis

Exposure to green space has been proposed to be beneficially associated with cardiovascular morbidity and mortality. Many studies have explored this topic, but the results remain conflicting. We aimed to evaluate the epidemiological evidence on this topic by performing a systematic review with meta-analysis. We searched PubMed, Web of Science and Embase for studies on the association between green space and cardiovascular disease (CVD) that were published till January 2022. Two authors independently performed study selection, data extraction, quality assessment, and risk of bias assessment. For studies providing detailed numeric data, we also conducted quantitative meta-analyses and calculated the pooled odd ratios (ORs) for associations between the most commonly used exposure estimate (normalized difference vegetative index [NDVI]) and five CVD events: CVD mortality, ischemic heart disease (IHD) mortality, cerebrovascular disease (CBVD) mortality, and stroke incidence/prevalence. Additional analyses were conducted to explore the geographical scale effects of NDVI. Publication bias tests were also conducted. Of the 6787 records identified, 53 studies were eligible for inclusion. These studies covered 18 countries and included data from more than 100 million persons. Meta-analyses showed that a 0.1 increase in NDVI was significantly associated with 2-3% lower odds of CVD mortality (OR: 0.97, 95% CI: 0.96-0.99), IHD mortality (OR: 0.98, 95% CI: 0.96-1.00), CBVD mortality (OR: 0.98, 95% CI: 0.97-1.00), and stroke incidence/prevalence (OR: 0.98, 95% CI: 0.96-0.99). There was no significant difference between the pooled estimates for different buffer sizes. No evidence of publication bias was detected. We provide strong and robust evidence for the beneficial effects of green space exposure on cardiovascular health. More prospective studies and mechanistic studies, especially that conducted in low- and middle-income countries, are merited to strengthen our conclusions.

Long-term exposure to residential greenness and neurodegenerative disease mortality among older adults: a 13-year follow-up cohort study

BACKGROUND

Living in greener areas is associated with slower cognitive decline and reduced dementia risk among older adults, but the evidence with neurodegenerative disease mortality is scarce. We studied the association between residential surrounding greenness and neurodegenerative disease mortality in older adults.

METHODS

We used data from the 2001 Belgian census linked to mortality register data during 2001-2014. We included individuals aged 60 years or older and residing in the five largest Belgian urban areas at baseline (2001). Exposure to residential surrounding greenness was assessed using the 2006 Normalized Difference Vegetation Index (NDVI) within 500-m from residence. We considered all neurodegenerative diseases and four specific outcomes: Alzheimer's disease, vascular dementia, unspecified dementia, and Parkinson's disease. We fitted Cox proportional hazard models to obtain hazard ratios (HR) and 95% confidence intervals (CI) of the associations between one interquartile range (IQR) increment in surrounding greenness and neurodegenerative disease mortality outcomes, adjusted for census-based covariates. Furthermore, we evaluated the potential role of 2010 air pollution (PM_2.5 and NO₂) concentrations, and we explored effect modification by sociodemographic characteristics.

RESULTS

From 1,134,502 individuals included at baseline, 6.1% died from neurodegenerative diseases during follow-up. After full adjustment, one IQR (0.22) increment of surrounding greenness was associated with a 4-5% reduction in premature mortality from all neurodegenerative diseases, Alzheimer's disease, vascular and unspecified dementia [e.g., for Alzheimer's disease mortality: HR 0.95 (95%CI: 0.93, 0.98)]. No association was found with Parkinson's disease mortality. Main associations remained for all neurodegenerative disease mortality when accounting for air pollution, but not for the majority of specific mortality outcomes. Associations were strongest in the lower educated and residents from most deprived neighbourhoods.

CONCLUSIONS

Living near greener spaces may reduce the risk of neurodegenerative disease mortality among older adults, potentially independent from air pollution. Socioeconomically disadvantaged groups may experience the greatest beneficial effect.

Increased urban greenness associated with improved mental health among middle-aged and older adults of the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVES

Some studies suggest that residential surrounding greenness is associated with improved mental health. Few of these studies have focussed on middle-aged and older adults, explored the modifying effects of social determinants of health, or accounted for the extent to which individuals interact with their neighbourhood environments.

METHODS

We analysed cross-sectional data collected from 26,811 urban participants of the Canadian Longitudinal Study of Aging who were between 45 and 86 years of age. Participants provided details on socioeconomic characteristics, health behaviours, and their frequency of neighbourhood interactions. The Normalized Difference Vegetation Index (NDVI), a measure of greenness, was assigned to participants' residential addresses at a buffer distance of 500 m. Four self-reported measures of mental health were considered: The Center for Epidemiologic Studies Depression Scale (CES-D-10; short scale), past diagnosis of clinical depression, perceptions of mental health, and the Satisfaction with Life Scale (SWLS). Regression models were used to describe associations between greenness and these outcomes, and spline models were fit to characterize the exposure-response function between greenness and CES-D-10 scores. Stratified analyses evaluated whether associations varied by sociodemographic status.

RESULTS

In adjusted models, we observed a 5% (Odds Ratio (OR) = 0.95; 95% CI = 0.90, 0.99) reduced odds of depressive symptoms in relation to an interquartile range increase of NDVI (0.06) within a 500 m buffer of the participant's residence. Similarly, we found an inverse association with a self-reported clinical diagnosis of depression (OR = 0.97; 95% CI = 0.92-1.01). Increases in surrounding greenness were associated with improved perceptions of mental health, and the SWLS. Our spline analyses found that beneficial effects between greenness and the CES-D-10 were strongest among those of lower income.

CONCLUSIONS

These findings suggest that residential greenness has mental health benefits, and that interventions to increase urban greenness can help reduce social inequalities in mental health.

AJEDI in Science: Leveraging Instructor Communities to Create Antiracist Curricula

Gateway college science courses continue to exclude students from science, disproportionately discriminating against students of color. As the higher education system strives to reduce discrimination, we need a deliberate, iterative process to modify, supplement, or replace current modalities. By incorporating antiracist, just, equitable, diverse, and inclusive (AJEDI) principles throughout course design, instructors create learning environments that provide an antidote to historically oppressive systems. In this paper, we describe how a community of microbiology instructors who all teach Tiny Earth, a course-based undergraduate research experience, created and rapidly integrated antiracist content and pivoted to an online format in response to the social unrest and pandemic of 2020. The effort strengthened an existing teaching community of practice and produced collective change in classrooms across the nation. We provide a perspective on how instructor communities of practice can be leveraged to design and disseminate AJEDI curriculum.

From Childhood Residential Green space to Adult Mental Wellbeing: A Pathway Analysis among Chinese Adults

Residential green spaces, arguably the most accessible type of urban green space, may have lasting impacts on children and even change their lives later in adulthood. However, the potential pathways from childhood residential green space to adulthood mental wellbeing are not well understood. Therefore, we conducted a questionnaire survey among Chinese adults (N = 770) in September 2021 to capture data on subjective measures of residential green space and nature contact during childhood, and nature connectedness, nature contact, and mental wellbeing during adulthood. Structural equation modeling (SEM) was employed to examine theoretical pathways between childhood residential green space and adult mental wellbeing. The results suggest that childhood residential green space positively predicts childhood nature contact and also has direct and indirect positive impacts on nature contact, nature connectedness, and mental wellbeing during adulthood. These findings advance understanding of the long-term impacts of childhood residential green space. Policymakers are advised to prioritize residential greening as well as other recreational facilities for children when planning health-promoting environments in urban spaces. Due to limitations in our study design, we also advise future studies to re-examine and extend the framework documented here.

Neighbourhood walkability and mortality: Findings from a 15-year follow-up of a nationally representative cohort of Canadian adults in urban areas

BACKGROUND

Using a nationally representative cohort of Canadian adults, we assessed associations between neighbourhood walkability and cause-specific mortality and investigated whether they differed by socioeconomic status.

METHODS

The study population was drawn from the 2001 Canadian Census Health and Environment Cohort, which contains individual-level data from a random sample of 20% of Canadian households mandated to complete the long-form census. We included those aged ≥ 25 years at baseline who lived in urban and suburban areas. The national death registry was used to ascertain annual vital status. Linkages to annual income tax data provided place of residence. The Canadian Active Living Environments, a national index that summarizes walkability across Canadian neighbourhoods, was assigned to individuals' residential history. The Cox proportional hazards model was used to assess associations between walkability and cause-specific mortality.

RESULTS

A total of 1.8 million participants (52.5% female) accrued 27.3 million person-years and 265 710 deaths during the 15-year follow-up. The adjusted hazard ratio (HR) for living in a highly walkable neighbourhood relative to living in the least walkable neighbourhoods was associated with a 9% (HR: 0.91 [0.88, 0.95]) and 3% (HR: 0.97 [0.94, 0.99]) reduced risk of cardiovascular and all non-accidental mortality, respectively. The strongest benefits of walkability were found among individuals within the lowest education and household income categories, and who lived in the most deprived neighbourhoods. There were no significant associations (most [class 5] versus least [class 1] walkable HR: 0.84 [0.61-1.16]) seen for accidental traffic mortality.

CONCLUSIONS

Canadian adults who live in walkable neighbourhoods have lower rates of cardiovascular and non-accidental mortality, with the greatest benefits seen in those from the lowest socioeconomic groups.

Residential greenness and hair cortisol levels during the first trimester of pregnancy

BACKGROUND AND AIM

Studies have shown that increased maternal cortisol level is associated with child adverse health outcomes. Hair cortisol (HC) is suitable for assessing long-term circulating cortisol concentration. Only two previous studies reported beneficial associations between cortisol and residential greenness during pregnancy and no study focused on the first trimester. Our aim was to evaluate the association between residential greenness and first trimester HC levels among pregnant women in Israel.

METHODS

Women were recruited during second and third trimesters. Hair samples were collected from the scalp and retrospective HC levels during the first trimester were quantified for 217 women. HC levels were natural log transformed and outliers were excluded. Based on geocoded birth address, small area sociodemographic status (SES) and mean residential surrounding greenness were calculated using high-resolution satellite-based Normalised Difference Vegetation Index (NDVI) data at 100, 300 and 500-m buffers in a cross-sectional approach. In addition, longitudinal exposure to mean greenness during a week preconception and during the first trimester were calculated. Missing covariates were imputed and linearity of the associations were evaluated. Generalized linear models were used to estimate the crude and adjusted associations controlled for the relevant covariates.

RESULTS

After exclusion of outliers, for 211 women, crude and adjusted beneficial associations between exposure to higher mean NDVI and HC levels were observed for all the exposure measures. An increase in 1 interquartile range of greenness (100 m buffer) was associated with a statistically significant lower estimated natural log mean HC level (-0.27 95% CI: -0.44; -0.11). The associations were robust to adjustment for covariates. The findings were consistent for different buffers, for the longitudinal approach, when all observations were included in the analysis and slightly stronger associations were observed for women with addresses geocoded at the home or street level. For most of the exposure measures, stronger associations were observed among those of lower sociodemographic status.

CONCLUSION

Our findings that more greenness associated with reduced maternal cortisol levels measured in the hair during the first trimester, could have substantial implications for urban planners and public health professional. If our observations will be replicated, it may present a useful avenue for public-health intervention to promote health through the provision of greenness exposure during early pregnancy, specifically to disadvantage populations.

Racial and ethnic disparities in pregnancy complications and the protective role of greenspace: A retrospective birth cohort study

Greenspace may positively impact pregnancy health for racially and economically minoritized populations; few studies have examined local availability and accessibility of green/park space in reducing maternal morbidity. The objective of this retrospective birth cohort study was to examine the association between residential exposure to greenspace and adverse pregnancy health outcomes in a Southern US state characterized by high poverty and racial disparities in maternal health (2013-2017). National data from the Protected Area database - United States (PAD-US) and ParkServe estimated three publicly available and accessible residential greenspace measures-a more direct proxy than using remotely-sensed greenness indicators (e.g., normalized difference vegetation index (NDVI))-(a) percent area of greenspace (M1), (b) area of available greenspace per person (M2), (c) total population within a 10-minute walk (M3). Generalized Estimating Equations with logistic regression were used to examine the association between individual greenspace metrics and South Carolina hospital deliveries (n = 238,922 deliveries) for women with correlated maternal health outcomes for gestational hypertension (GHTN), gestational diabetes (GD), severe maternal morbidity (SMM), preeclampsia (PRE), mental disorders (MD), depressive disorders (DD), and preterm birth (PTB). Lowest compared to highest tertiles of all three metrics were associated with increased risk for MD, DD, and a monotonic increase in GD, particularly for black women. Women with the lowest access to M2 and M3 were more at risk for PRE, PTB, and MD. We observed that women in low-income, majority-black communities in the lowest versus highest tertile of M2 were more likely to experience a DD, MD, SMM, or PTB compared to primarily high-income majority-white communities. Available and accessible green/park space may present as an effective nature-based intervention to reduce maternal complications, particularly for gestational diabetes and other pregnancy health risks for which there are currently few known evidence-based primary prevention strategies.

Greenspace, Inflammation, Cardiovascular Health, and Cancer: A Review and Conceptual Framework for Greenspace in Cardio-Oncology Research

Cardiovascular disease (CVD) is a leading cause of global morbidity and mortality. Cancer survivors have significantly elevated risk of poor cardiovascular (CV) health outcomes due to close co-morbid linkages and shared risk factors between CVD and cancer, as well as adverse effects of cancer treatment-related cardiotoxicity. CVD and cancer-related outcomes are exacerbated by increased risk of inflammation. Results from different pharmacological interventions aimed at reducing inflammation and risk of major adverse cardiovascular events (MACEs) have been largely mixed to date. Greenspaces have been shown to reduce inflammation and have been associated with CV health benefits, including reduced CVD behavioral risk factors and overall improvement in CV outcomes. Greenspace may, thus, serve to alleviate the CVD burden among cancer survivors. To understand pathways through which greenspace can prevent or reduce adverse CV outcomes among cancer survivors, we review the state of knowledge on associations among inflammation, CVD, cancer, and existing pharmacological interventions. We then discuss greenspace benefits for CV health from ecological to multilevel studies and a few existing experimental studies. Furthermore, we review the relationship between greenspace and inflammation, and we highlight forest bathing in Asian-based studies while presenting existing research gaps in the US literature. Then, we use the socioecological model of health to present an expanded conceptual framework to help fill this US literature gap. Lastly, we present a way forward, including implications for translational science and a brief discussion on necessities for virtual nature and/or exposure to nature images due to the increasing human-nature disconnect; we also offer guidance for greenspace research in cardio-oncology to improve CV health outcomes among cancer survivors.

Nature-Based Physical Activity and Hedonic and Eudaimonic Wellbeing: The Mediating Roles of Motivational Quality and Nature Relatedness

The current study evaluated the degree to which nature-based physical activity (NPA) influenced two distinct types of psychological wellbeing: hedonic wellbeing and eudaimonic wellbeing. The type of motivation an individual experiences for physical activity, and the extent to which individuals have a sense of relatedness with nature, have been shown to influence the specific type of psychological wellbeing that is experienced as a result of NPA. However, the role of these two variables in the relationship between NPA and psychological wellbeing has not been examined. Thus, this study assessed the potential mediating influence of (1) motivational quality and (2) nature relatedness on the relationships between NPA and hedonic and eudaimonic wellbeing, respectively. Participants (N = 262) completed an online survey assessing hedonic and eudaimonic wellbeing, NPA, intrinsic motivation, autonomous extrinsic motivation, and nature relatedness. Data were analysed using Partial Least Squares Structural Equation Modelling. Results showed that motivational quality and nature relatedness both fully mediated the relationships between NPA and hedonic and eudaimonic wellbeing. Specifically, intrinsic motivation positively mediated the relationship between NPA and hedonic wellbeing. Autonomous extrinsic motivation and nature relatedness positively mediated the relationship between NPA and eudaimonic wellbeing. These findings suggest that the associations between NPA and eudaimonic wellbeing and hedonic wellbeing, respectively, are driven by different mechanisms relating to an individual's (1) underlying motivation and (2) sense of connection to nature. These findings suggest that promoting distinct types of wellbeing (hedonic vs. eudaimonic) through NPA requires distinct approaches. Emphasising enjoyment, pleasure, and positive kinaesthetic experiences within NPA may be more conducive to hedonic wellbeing, while highlighting opportunities for connecting with nature or experiencing valued outcomes of NPA may be more conducive to eudaimonic wellbeing.

Neighbourhood green space and health disparities in the global South: Evidence from Cali, Colombia

Increasing attention has been given to the role of green space in reducing health disparities. However, robust evidence to support decision making is lacking in the global South. We investigate the relationship between green space and health as well as its underlying mechanism in Cali, Colombia. Results indicate that neighbourhood greenness is associated with enhanced self-rated 'good' health and reduced physical and mental distress. The health benefits of green space appear to be stronger for people living in wealthier neighbourhoods than those in poor neighbourhoods. Results highlight the importance of considering health disparities for future green infrastructure planning in the global South context.

Estimating multiple greenspace exposure types and their associations with neighbourhood premature mortality: A socioecological study

BACKGROUND

Greenspace exposures are often measured using single exposure metrics, which can lead to conflicting results. Existing methodologies are limited in their ability to estimate greenspace exposure comprehensively. We demonstrate new methods for estimating single and combined greenspace exposure metrics, representing multiple exposure types that combine impacts at various scales. We also investigate the association between those greenspace exposure types and premature mortality.

METHODS

We used geospatial data and spatial analytics to model and map greenspace availability, accessibility and eye-level visibility exposure metrics. These were harmonised and standardised to create a novel composite greenspace exposure index (CGEI). Using these metrics, we investigated associations between greenspace exposures and years of potential life lost (YPLL) for 1673 neighbourhoods applying spatial autoregressive models. We also investigated the variations in these associations in conjunction with levels of socioeconomic deprivation based on the index of multiple deprivations.

RESULTS

Our new CGEI metric provides the opportunity to estimate spatially explicit total greenspace exposure. We found that a 1-unit increase in neighbourhood CGEI was associated with approximately a 10-year reduction in YPLL. Meaning a 0.1 increment or 10% increase in the CGEI is associated with an approximately one year lower premature mortality value. A single 1-unit increase in greenspace availability was associated with a YPLL reduction of 9.8 years, whereas greenness visibility related to a reduction of 6.14 years. We found no significant association between greenspace accessibility and YPLL. Our results further identified divergent trends in the relations between greenspace exposure types (e.g. availability vs. accessibility) and levels of socioeconomic deprivation (e.g. least vs. most).

CONCLUSION

Our methods and metrics provide a novel approach to the assessment of multiple greenspace exposure types, and can be linked to the broader exposome framework. Our results showed that a higher composite greenspace exposure is associated with lower premature mortality.

Green space and mortality in European cities: a health impact assessment study

BACKGROUND

Natural outdoor environments including green spaces play an important role in preserving population health and wellbeing in cities, but the number of deaths that could be prevented by increasing green space in European cities is not known. We aimed to estimate the number of natural-cause deaths among adult residents that could be prevented in cities in 31 European countries, if the WHO recommendation for universal access to green space was achieved.

METHODS

In this health impact assessment study we focused on adult residents (aged ≥20 years; n=169 134 322) in 978 cities and 49 greater cities, in 31 European countries. We used two green space proxies: normalised difference vegetation index (NDVI), and percentage of green area (%GA). The exposure was estimated at a fine grid-cell level (250 m × 250 m) and the preventable mortality burden for 2015 was estimated at the local city-level.

FINDINGS

For 2015 we found that meeting the WHO recommendation of access to green space could prevent 42 968 (95% CI 32 296-64 177) deaths annually using the NDVI proxy (ie, 20% [95% CI 15-30] of deaths per 100 000 inhabitants-year), which represents 2·3% (95% CI 1·7-3·4) of the total natural-cause mortality and 245 (95% CI 184-366) years of life lost per 100 000 inhabitants-year. For the %GA proxy 17 947 (95%CI 0-35 747) deaths could be prevented annually. For %GA the number of attributable deaths were half of that of the NDVI and results were non-significant due to the exposure response function considered. The distribution of NDVI and %GA varied between cities and was not equally distributed within cities. Among European capitals, Athens, Brussels, Budapest, Copenhagen, and Riga showed some of the highest mortality burdens due to the lack of green space. The main source of uncertainty for our results was the choice of the age-structures of the population for the NDVI analysis, and exposure-response function for the %GA analysis.

INTERPRETATION

A large number of premature deaths in European cities could be prevented by increasing exposure to green space, while contributing to sustainable, liveable and healthy cities.

FUNDING

GoGreenRoutes, Internal ISGlobal fund, and the United States Department of Agriculture Forest Service.

Municipality Data as a Rapid and Effective Tool to Analyse Spatial and Temporal Variations of All-Cause Mortality by Town District: The Experience in Genoa (Italy)

The main objective of this study was to analyse the space-time epidemiological differences by sex during the 2009-2020 period in the total mortality recorded among residents in each of the 25 districts of the Genoa municipality, net of the age effect. The analysis was based on official statistical data relating to total mortality and on the resident population. An estimate of the expected deaths was made to calculate the sex-specific age-standardised mortality ratio (SMR). The temporal trends and age-standardized death rates (SDRs) with respect to those of the European population specific to sex and calendar year were identified for each district. Over the entire observation period, the SMR for males ranged from 124.4 (Cornigliano) to 82.0 (Albaro); for females, the values ranged between 133.4 (Cornigliano) and 85.6 (Nervi-Quinto-S. Ilario). Between 2019 and 2020, Genoa recorded an increase in SDR of 24.5%, more pronounced in males (+26.7%) than in females (+22.4%). This epidemiological methodology is replicable and allows to quickly identify spatial, temporal, sex, and age differences in the general mortality within a municipality.

Legacies of Environmental Injustice on Neighborhood Violence, Poverty and Active Living in an African American Community

Features of the built environment such as parks and open spaces contribute to increased physical activity in populations, while living in neighborhoods with high poverty, racial/ethnic segregation, presence of neighborhood problems, and violence has been associated with less active living. Our present study examined the factors that may facilitate or hinder the long-term success of built environment interventions aimed at promoting physical activity in communities with a legacy of environmental injustice. The data for this study came from a larger assessment of the impact of a new local park in Newark, NJ. Analysis included all adults from the original study population who self-identified as African American/Black (N=95). To provide an in-depth understanding of how neighborhood social and physical features influence physical activity among African Americans living in high poverty neighborhoods, we analyzed data from two focus groups with a total of 14 participants, and six in-depth interviews held in 2009-2010. Survey results indicated high exposure to violence, and associations between neighborhood features and walking. Self-reported neighborhood walkability was associated with increased walking (P=.01), while increased perception of neighborhood safety was associated with less walking (P=.01). Qualitative results indicated that residents perceived the new park as a positive change, but also expressed concern about the presence of violence and lack of social cohesion among neighbors, with younger generations expressing less optimism than the elderly. Positive changes associated with improvements to the built environment may be limited by social conditions such as neighborhood violence. These mixed findings suggest that policies and initiatives aimed at improving the built environment should address poverty, safety, and social cohesion to ensure more active living communities.

COVID-19, the Built Environment, and Health

BACKGROUND

Since the dawn of cities, the built environment has both affected infectious disease transmission and evolved in response to infectious diseases. COVID-19 illustrates both dynamics. The pandemic presented an opportunity to implement health promotion and disease prevention strategies in numerous elements of the built environment.

OBJECTIVES

This commentary aims to identify features of the built environment that affect the risk of COVID-19 as well as to identify elements of the pandemic response with implications for the built environment (and, therefore, for long-term public health).

DISCUSSION

Built environment risk factors for COVID-19 transmission include crowding, poverty, and racism (as they manifest in housing and neighborhood features), poor indoor air circulation, and ambient air pollution. Potential long-term implications of COVID-19 for the built environment include changes in building design, increased teleworking, reconfigured streets, changing modes of travel, provision of parks and greenspace, and population shifts out of urban centers. Although it is too early to predict with confidence which of these responses may persist, identifying and monitoring them can help health professionals, architects, urban planners, and decision makers, as well as members of the public, optimize healthy built environments during and after recovery from the pandemic. https://doi.org/10.1289/EHP8888.

Sustaining planetary health through systems thinking: Public health's critical role

Understanding and responding to adverse human health impacts of global environmental change will be a major priority of 21st century public health professionals. The emerging field of planetary health aims to face this challenge by studying and promoting policies that protect the health of humans and of the Earth's natural systems that support them. Public health, drawing on its experience of guiding policies to improve population health, has contributed to planetary health's development. Yet, few public health practitioners are familiar with planetary health's systems-oriented approaches for understanding relationships between economic development, environmental degradation, and human health. In this narrative review, we present key planetary health concepts and show how systems thinking has guided its development. We discuss historical approaches to studying impacts of economic development on human health and the environment. We then review novel conceptual frameworks adopted by planetary health scientists to study and forecast impacts of policies that influence human health and Earth's natural systems at varying spatiotemporal scales. We conclude by presenting examples of how applying the "Doughnut" model (an economic framework where the needs of people are met without overshooting the world's ecological limits) could guide policies for promoting health co-benefits to humans and natural systems.

Associations between Nature Exposure and Health: A Review of the Evidence

There is extensive empirical literature on the association between exposure to nature and health. In this narrative review, we discuss the strength of evidence from recent (i.e., the last decade) experimental and observational studies on nature exposure and health, highlighting research on children and youth where possible. We found evidence for associations between nature exposure and improved cognitive function, brain activity, blood pressure, mental health, physical activity, and sleep. Results from experimental studies provide evidence of protective effects of exposure to natural environments on mental health outcomes and cognitive function. Cross-sectional observational studies provide evidence of positive associations between nature exposure and increased levels of physical activity and decreased risk of cardiovascular disease, and longitudinal observational studies are beginning to assess long-term effects of nature exposure on depression, anxiety, cognitive function, and chronic disease. Limitations of current knowledge include inconsistent measures of exposure to nature, the impacts of the type and quality of green space, and health effects of duration and frequency of exposure. Future directions include incorporation of more rigorous study designs, investigation of the underlying mechanisms of the association between green space and health, advancement of exposure assessment, and evaluation of sensitive periods in the early life-course.