The pathways linking objectively-measured greenspace exposure and mental health: A systematic review of observational studies

Co-benefits of nature-based solutions: A health impact assessment of the Barcelona Green Corridor (Eixos Verds) plan

INTRODUCTION

The Green Corridors Plan (Eixos Verds Plan), proposed by the Barcelona City Council, aims to enhance urban well-being, environmental sustainability, and resilience by transforming one in every three streets into green corridors. Although initially designed for city-wide implementation, only the first phase, focused on the centric Eixample district, has been completed, and the overall plan implementation has been postponed. Our aim is to evaluate the health co-benefits of implementing the Green Corridors plan citywide, focusing on the direct effects of increased exposure to greenness and the impact of temperature reduction on mortality.

METHODS

We conducted a comprehensive Health Impact Assessment (HIA) considering direct effects of expanding green spaces (GS) and the impact on temperature reduction. Preventable mortality at the census tract level for adult residents was estimated, and to address uncertainties, we performed Monte Carlo iterations. We computed the percentage increase in GS (land use) and tree cover and converted them into Normalized Difference Vegetation Index (NDVI) to conduct the HIA, employing a Generalized Additive Model (GAM). We used the Weather Research and Forecasting model (WRF) coupled with the urban parameterizations "Building Effect Parameterization" (BEP) and "Building Energy Model" (BEM) for temperature modelling. Hourly temperatures from 25/06/2015 to 25/07/2015 were simulated, both with and without Green Corridors Plan implementation.

RESULTS

City-wide implementation of the Green Corridors plan would increase average GS by 3.64 % (IQR: 2.17 % - 4.40 %) and NDVI by 0.286 (IQR: 0.256-0.304) per census tract. This could potentially prevent 178 premature deaths annually (95 % CI: 116-247), equating to 13 deaths per 100,000 inhabitants (95 % CI: 9-19). The average daily temperature reduction per census tract was estimated at 0.05 °C, with a maximum reduction of 0.42 °C. Temperature reduction could potentially prevent 5 deaths during the simulated month. Additionally, we estimated a mean decrease in the thermal stress of 0.11 °C, reaching up to 1.48 °C at its peak.

CONCLUSION

The Green Corridors plan can make significant contributions to a healthier urban environment. To address climate and especially heat impacts, complementary strategies to achieve more substantial temperature reduction are needed. Overall, our findings underscore the potential of nature-based solutions (NbS), exemplified by the Green Corridors Plan, in creating more sustainable and health-promoting urban environments.

Life in green: Associations between greenspace availability and mental health over the lifecourse - A 40-year prospective birth cohort study

BACKGROUND

The beneficial impacts of greenspace availability on mental health are well-documented. However, longitudinal evidence using a spatial lifecourse perspective is rare, leaving the dynamics of how greenspace influences mental health across the lifecourse unclear. This study first uses prospective birth cohort data to examine the associations between greenspace availability in childhood (0-16 years) and mental health in adolescence (16 years) and between greenspace availability and mental health across adulthood (18-40 years).

METHOD

Data were obtained from the Christchurch Health and Development Study, comprised 1,265 cohort members born in Christchurch, New Zealand, in 1977. Mental health outcomes including depressive symptoms, anxiety disorders and suicidal ideation were assessed in adolescence (16 years), and in adulthood (18-40 years). Greenspace availability from birth to age 40 years was measured as the proportion of vegetated areas within circular buffers (radius from 100m to 3000m) around members' geocoded residential addresses using a time-series impervious surfaces data from 1985 to 2015. Bayesian Relevant Lifecourse exposure models examined the associations between childhood greenspace availability and adolescent mental health and tested for critical/sensitive age periods. Generalised Estimating Equation logistic regression models assessed the associations between greenspace availability and mental health across adulthood. These analyses were adjusted for various important individual, family, and area-level covariates.

RESULTS

No associations were found between childhood greenspace availability and any adolescent mental health conditions. However, in adulthood, a one standard deviation increase in greenspace availability within 1500m and 2000m buffers was associated with a 12% and 13% reduced risk of depressive symptoms, respectively, after adjusting for various covariates.

DISCUSSION

This study supports the protective effects of greenspace on adult depressive symptoms, highlighting the significance of employing a spatial lifecourse epidemiology framework to examine the long-term effects of environmental factors on health over the lifecourse.

Exploring the pathways linking prenatal and early childhood greenness exposure to attention-deficit/hyperactivity disorder symptoms during childhood: An approach based on robust causal inference

BACKGROUND

Epidemiological studies suggest that exposure to greenness during childhood may protect children from developing attention-deficit hyperactivity disorder (ADHD).

OBJECTIVE

We analyzed the effect of both prenatal (pregnancy) and early childhood (4-5-year follow-up) residential greenness exposure and green space availability on ADHD symptoms during childhood (up to the age of 12 years) and further explored the potential mediating role of PM2.5 and physical activity in the association.

METHODS

The study population included participants from the INfancia y Medio Ambiente (INMA) prospective birth cohort (Gipuzkoa, Sabadell, and Valencia). Average Normalized Difference Vegetation Index (NDVI) in buffers of 100-, 300- and 500-m around the residential addresses was used as an indicator of greenness, while green space availability was determined based on the presence of a major green space within 150-m from the residence. Childhood ADHD symptoms were assessed at the 6-8- and 10-12-year follow-ups using Conners Parents Rating Scale-Revised: Short Form.

RESULTS

Although no association was found for the prenatal exposure period, increased early childhood NDVI inversely associated with the OR of clinically significant ADHD symptoms during the 6-8-year follow-up at the 100-m (OR 0.03, 95% CI: 0.003 to 0.44), 300-m (OR 0.04, 95% CI: 0.003 to 0.42) and 500-m (OR 0.08, 95% CI: 0.01 to 0.76) buffers, but exclusively in the context of direct effects. Additionally, the 10-12-year follow-up analysis found moderate to weak evidence of potential total and direct effects of NDVI at both 100- and 300-m buffers on inattention scores, as well as for NDVI at the 300-m buffer on ADHD index scores. The analysis did not reveal evidence of mediation through PM2.5 or physical activity.

CONCLUSIONS

The evidence suggests that early childhood greenness exposure may reduce the risk of developing ADHD symptoms later in childhood, and that this association is not mediated through PM2.5 and physical activity.

Linking joint exposures to residential greenness and air pollution with adults' social health in dense Hong Kong

Despite the growing recognition of the impact of urban environments on social health, limited research explores the combined associations of multiple urban exposures, particularly in dense cities. This study examines the interplay between greenspace, air pollution, and social health as well as the underlying pathways and population heterogeneity in Hong Kong using cross-sectional survey data from 1977 adults and residential environmental data. Social health includes social contacts, relations, and support. Greenspace used street-view greenness (SVG), park density, and the normalized difference vegetation index (NDVI). 100-m daily ground NO2 and O3, indicative of air pollution, were derived using a spatiotemporal deep learning model. Mediators involved physical activity and negative emotions. Main analyses were performed in a 1000-m buffer with multivariate logistical regressions, stratification, interaction, and Partial Lease Square - Structural Equation Modelling (PLS-SEM). Multi-exposure models revealed positive associations between park density/SVG and social contacts, as well as between SVG and social relations, while O3 was negatively associated with social relations/support. Significant moderators included age, birthplace, employment, and education. PLS-SEM indicated direct positive associations between SVG and social contacts/relations and significant indirect negative associations between NO2/O3 and social health via negative emotions. This study adds to urban health research by exploring complex relationships between greenspace, air pollution, and social health, highlighting the role of the environment in fostering social restoration.

Neighborhood Resources Associated With Psychological Trajectories and Neural Reactivity to Reward After Trauma

Importance

Research on resilience after trauma has often focused on individual-level factors (eg, ability to cope with adversity) and overlooked influential neighborhood-level factors that may help mitigate the development of posttraumatic stress disorder (PTSD).

Objective

To investigate whether an interaction between residential greenspace and self-reported individual resources was associated with a resilient PTSD trajectory (ie, low/no symptoms) and to test if the association between greenspace and PTSD trajectory was mediated by neural reactivity to reward.

Design, Setting, and Participants

As part of a longitudinal cohort study, trauma survivors were recruited from emergency departments across the US. Two weeks after trauma, a subset of participants underwent functional magnetic resonance imaging during a monetary reward task. Study data were analyzed from January to November 2023.

Exposures

Residential greenspace within a 100-m buffer of each participant's home address was derived from satellite imagery and quantified using the Normalized Difference Vegetation Index and perceived individual resources measured by the Connor-Davidson Resilience Scale (CD-RISC).

Main Outcome and Measures

PTSD symptom severity measured at 2 weeks, 8 weeks, 3 months, and 6 months after trauma. Neural responses to monetary reward in reward-related regions (ie, amygdala, nucleus accumbens, orbitofrontal cortex) was a secondary outcome. Covariates included both geocoded (eg, area deprivation index) and self-reported characteristics (eg, childhood maltreatment, income).

Results

In 2597 trauma survivors (mean [SD] age, 36.5 [13.4] years; 1637 female [63%]; 1304 non-Hispanic Black [50.2%], 289 Hispanic [11.1%], 901 non-Hispanic White [34.7%], 93 non-Hispanic other race [3.6%], and 10 missing/unreported [0.4%]), 6 PTSD trajectories (resilient, nonremitting high, nonremitting moderate, slow recovery, rapid recovery, delayed) were identified through latent-class mixed-effect modeling. Multinominal logistic regressions revealed that for individuals with higher CD-RISC scores, greenspace was associated with a greater likelihood of assignment in a resilient trajectory compared with nonremitting high (Wald z test = -3.92; P < .001), nonremitting moderate (Wald z test = -2.24; P = .03), or slow recovery (Wald z test = -2.27; P = .02) classes. Greenspace was also associated with greater neural reactivity to reward in the amygdala (n = 288; t277 = 2.83; adjusted P value = 0.02); however, reward reactivity did not differ by PTSD trajectory.

Conclusions and Relevance

In this cohort study, greenspace and self-reported individual resources were significantly associated with PTSD trajectories. These findings suggest that factors at multiple ecological levels may contribute to the likelihood of resiliency to PTSD after trauma.

The impact of place on multimorbidity: A systematic scoping review

Multimorbidity, commonly defined as the co-existence of two or more long-term conditions, is a major global public health challenge with significant impacts for health and social care systems. There is a substantial body of work identifying different individual- and household-level determinants of multimorbidity, yet the role of place-based characteristics in affecting multimorbidity remains limited. This systematic scoping review identifies place-based risk factors for multimorbidity and further synthesises the potential pathways explaining these relationships using longitudinal evidence. By systematically searching seven major databases, such as Medline, Embase, and Web of Science, using relevant search terms (e.g., MeSH) relating to place-based risk factors and multimorbidity, 76 out of 7761 studies were included for evidence synthesis. We include studies exploring the relationship between place-based risk factors and multimorbidity among the general population older than 18 years old in the setting of community-dwelling, primary, and secondary care. We identified 12 types of place-based risk factors, with the impacts of area-level deprivation/SES, pollution, and urban/rurality on multimorbidity being most frequently considered and with the most consistent findings, with people living in more deprived/low SES, highly polluted, or more urbanised areas having increased risks of multimorbidity. Further, the impact of these place-based risk factors on multimorbidity varied according to the operationalisation of the multimorbidity measure. We also identified that the impacts of other types of place-based factors on multimorbidity remain underexplored, such as social cohesion and greenspace. Finally, using these longitudinal findings, we propose a conceptual framework linking place and multimorbidity. We suggest that future studies explore a wider range of place-level environmental exposures and use more precise measures, exploit electronic health records to implement more consistent and reproducible measurements of multimorbidity, moreover, make greater use of longitudinal study designs or analytical approaches better suited to identifying causal processes.

Walking trail access, exercise behavior, and going out-of-home among older adults: Examining longitudinal associations and mediators

AIM

Although the presence of a walking trail within a neighborhood would be an important environmental determinant of health behaviors, such as exercise and going out-of-home, their longitudinal associations and mediators are still unconfirmed. This study examined the longitudinal associations of walking trail access with exercise behavior and going out-of-home and mediating roles of awareness and use of walking trails on their associations among older adults.

METHODS

A four-wave questionnaire-based longitudinal survey was conducted among Japanese older adults (Wave 1: baseline; Wave 2: after one year; Wave 3: after three years; and Wave 4: after five years). Each survey measured weekly exercise time and frequency of going out-of-home. Wave 4 survey also measured awareness and use of walking trails. This study calculated distance to nearest walking trail using geographic information systems. This study analyzed the data from all waves (n = 834) for longitudinal associations and the data from Wave 4 (n = 567) for mediated associations.

RESULTS

Latent growth modeling showed insignificant longitudinal associations of walking trail access with weekly exercise time and frequency of going out-of-home. The path analyses showed that a shorter distance to the walking trail was indirectly and significantly associated with longer weekly exercise time (standardized indirect effect=-0.03, p<.001) and a higher weekly frequency of going out-of-home (standardized indirect effect=-0.03, p<.001), mediated by awareness and use of walking trails.

CONCLUSIONS

These findings indicate that the influence of walking trail access on exercise behavior and going out-of-home would be attenuated by awareness and use of walking trails among older adults.

Extensive inequality of residential greenspace exposure within urban areas in China

Ensuring residents' equal access to high quality urban greenspace is vital for urban environmental justice and sustainable urban development. However, most previous studies have mainly focused on greenspace quantity, overlooking its quality. Moreover, the national-level spatial distribution pattern of residential greenspace exposure (RGE) within urban areas remains unclear. Here, we have improved the existing RGE assessment framework by integrating both the quality and quantity of urban greenspace to evaluate RGE and its associated inequality across 119,692 blocks in 334 Chinese cities in 2020. We find that the spatial distribution pattern of RGE varies with urban size. Large cities exhibit a distinct clustering of low RGE in their central areas, whereas small cities tend to show a pronounced clustering of high RGE in the central areas. RGE in Chinese cities indicates extensive inequality, as the average RGE of high-exposed people is nearly four times greater than that of low-exposed people. Moreover, residents in larger cities are more prone to experiencing greater inequalities compared to those in smaller cities. We also find that the landscape metrics (i.e., connectance index and mean Euclidean nearest-neighbor distance) of greenspace possess a strong explanatory power (R2 = 0.431) for the observed inequality. Our study underscores the importance of optimizing the landscape structure of urban greenspace and enhancing equality in the quality of greenspace. These findings provide novel insights for urban greenspace planning and promoting urban environmental justice.

Assessing momentary stress responses to dynamic real-time greenspace exposure: Unveiling algorithmic uncertainty and the temporality of exposure context

Mental stress issues are emerging among residents of modern cities. Among environmental factors associated with stress mitigation, greenspace has consistently been shown to have significant stress-reducing properties. However, the temporality of greenspace exposure, particularly the cumulative threshold effect in urban environments, has been largely neglected in past studies. In addition, different algorithms and their related measurements of greenspace have led to inconsistent mental health outcomes. To address both gaps, we evaluated the dynamic greenspace exposure of 221 Hong Kong residents by integrating three distinct green space measurements: the Normalized Difference Vegetation Index (NDVI), the Green Space Area Ratio (GSAR), and the Eye-level Green View Index (GVI) based on individual real-time GPS data. We subsequently gauged individual momentary stress levels via Ecological Momentary Assessment (EMA) and modeled its association with dynamic green space exposure using mixed ordinal logistic regression across diverse cumulative time frames. The results reveal great disparities in greenspace-stress association between different greenspace measurements and different cumulative time frames: (1) Among the three measurements, GVI is the most robust and effective measurement in assessing the stress-reducing effect in urban environments. (2) Within specific time frames, cumulative exposure has a more pronounced stress-reducing influence than momentary exposure. (3) The stress-reducing effects of cumulative eye-level greenspace exposure exhibit two temporal phases: A continuous exposure spanning 12-36 min leads to a progressive enhancement in the stress-mitigating effect of eye-level greenspace, peaking initially and then diminishing after 36 min. Upon extended exposure reaching 2.3 h, the stress-alleviating impact of eye-level green space peaks once again before gradually waning. Our research underscores the need for multiple measurements of environmental exposure to address the algorithmic uncertainty in environmental health research and deeper insights into the temporality of the greenspace-mental relationship.

Objective and subjective accounts of urban exposures for epidemiological research on mental health. Measurement and analysis

The interest in the impact of urban environmental exposures (UrbEEs) on mental health has greatly increased in the last two decades. Researchers have tended to measure said exposures either via objective measurement procedures (eg, air pollution campaigns and geographic information systems computations) or by self-reported techniques such as the use of scales and questionnaires. It has been suggested that studying both the objective features of the environments and people's perceptions are key to understand environmental determinants of health and might be needed to tailor effective interventions. However, there is little guidance on how to approach this matter, the comparability between objective and subjective accounts of UrbEEs and, more importantly, suitable statistical procedures to deal with the practicalities of this kind of data. In this essay, we aim to build the case for the joint use of both sets of variables in epidemiological studies and propose socioecological models as a valid theoretical framework to accommodate these. In the methodological sphere, we will also review current literature to select examples of (un)appropriate subjective accounts of urban exposures and propose a series of statistical procedures to estimate the total, direct and indirect effects of UrbEEs on mental health and the potential associations between objective and subjective UrbEEs accounts.

How Green Space Justice in urban built-up areas affects public mental health: a moderated chain mediation model

Background

Green and blue spaces, as crucial components of urban ecosystems, significantly impact the physical and mental health of residents. However, the mechanisms through which Green/Blue Space Justice influence residents' health remain unclear.

Methods

This study aims to explore the impact of green spaces on public psychological responses, physical activity, and mental health from a justice perspective, and to examine the moderating role of blue spaces in this relationship. The research was conducted in selected communities within the Chang-Zhu-Tan urban agglomeration in Hunan Province, China. A total of 801 valid questionnaires were collected through field visits and online surveys. The study uses an improved Gaussian-based two-step floating catchment area (2SFCA) method to assess green space accessibility. Data were analyzed using structural equation modeling (SEM) and moderation effect analysis to reveal the relationships between variables.

Results

The findings indicate that Green Space Justice has a significant positive impact on psychological responses, physical activity, and mental health; psychological responses and physical activity play crucial mediating roles between Green Space Justice and mental health; and Green Space Justice significantly affects mental health through a chain mediation path involving psychological responses and physical activity. Moreover, Blue Space Justice significantly moderates the impact of Green Space Justice on psychological responses and physical activity, but does not have a significant direct impact on mental health.

Conclusion

This study enriches the theory of Green Space Justice by revealing the mechanisms through which it influences mental health via psychological responses and physical activity. It provides a scientific basis for the development of healthy cities. Additionally, it recommends that urban planning should prioritize the equitable distribution and high accessibility of both green and blue spaces to comprehensively enhance residents' physical and mental well-being. Policymakers should consider prioritizing the accessibility of high-quality green spaces for vulnerable communities during urban renewal and expansion processes to reduce social health inequalities and promote broader public health outcomes.

Nature exposure and mental health during the COVID-19 pandemic: A Navigation Guide systematic review with meta-analysis

Prior reviews have highlighted that nature exposure was a valuable coping strategy enhancing mental health during the COVID-19 pandemic. However, no existing reviews have determined the quality of evidence and risk of bias of the empirical studies supporting this claim. To address this gap, we employed a Navigation Guide systematic review and meta-analysis approach to investigate associations between nature exposure and mental health during the pandemic. Searches in PubMed, Web of Science, Scopus, CINAHL, and PsycInfo retrieved relevant articles published between January 1, 2020, and March 4, 2024. We used the Navigation Guide methodology to assess the risk of bias and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessments to evaluate the overall quality of evidence. Our search retrieved 113 studies that met the inclusion criteria and reported diverse types of exposure, including nature availability, nature visit frequency, green space accessibility, and green space type, alongside associations with 12 mental health outcomes. Meta-analyses found access to gardens was associated with lower odds of depression [(Pooled odds ratio [OR] = 0.71, 95%CI = 0.61, 0.82), I2 = 0%, n = 3] and anxiety [(Pooled OR = 0.73, 95%CI = 0.63, 0.84), I2 = 0%, n = 3]. Increased time in green spaces was associated with lower level of stress [(Pooled Corr = -0.11, 95%CI = -0.17, -0.05), I2 = 0%, n = 2]. Higher frequency of visits to nature was associated with improved mental well-being [(Pooled standardized beta = 0.10, 95%CI = 0.07, 0.14), I2 = 0%, n = 2] and general mental health [(Pooled standardized beta = 0.11, 95%CI = 0.03-0.38), I2 = 82%, n = 2]. However, the number of pooled studies was small and the overall quality of evidence was "very low" for all outcomes, and high levels of bias were observed (26% of studies had high, 71% probably high). Nonetheless, given the trends in the results, nature-based solutions emphasizing exposure to gardens and green spaces near the home may have promoted psychological resilience during this public health crisis.

Mechanisms underlying the associations between different types of nature exposure and sleep duration: An 18-country analysis

Whilst green space has been linked to healthier sleep outcomes, the roles of specific types of nature exposure, potential underlying mechanisms, and between-country variations in nature-sleep associations have received little attention. Drawing on cross-sectional survey data from an 18-country sample of adults (N = 16,077) the current study examined: 1) the relative associations between six different types of nature exposure (streetscape greenery, blue view from home, green space within 1 km, coast within 1 km, green space visits, blue space visits) and insufficient sleep (<6 h vs. 7-10 h per day); 2) whether these relationships were mediated by better mental wellbeing and/or physical activity; and 3) the consistency of these pathways among the different countries. After controlling for covariates, neighbourhood nature measures (green space, coast within 1 km) were not significantly associated with insufficient sleep; but nature visible from home (streetscape greenery, blue views) and recreational visits to green and blue spaces were each associated with less insufficient sleep. Significant nature-sleep associations were mediated, to varying degrees, by better mental wellbeing, but not self-reported physical activity. Country-level heterogeneity in the strength of nature-sleep associations was observed. Increasing nature visible from the home may represent a promising strategy for promoting healthier sleep duration at the population level, whilst nature-based interventions encouraging individuals to spend time in local green/blue spaces may be an appropriate target to assist individuals affected by insufficient sleep.

Quantitative evaluation of urban green exposure and its impact on human health: A case study on the 3-30-300 green space rule

BACKGROUND AND AIMS

Urban green spaces offer various health benefits, yet the impact of comprehensive green exposure criteria on multidimensional health remains unclear. The 3-30-300 green space rule represents the green exposure indicators with specific thresholds. This study aims to quantitatively evaluate urban green exposure in cities and can support investigation of its relationship with human health.

METHODS

We conducted a cross-sectional study based on 902 investigated individuals in 261 residential locations aged 11-95 years from Xiamen City, China. 3-30-300 green exposure was calculated using field surveys, GIS, and Baidu Maps Application Programming Interface (API). Physical health data was based on Occupational Stress Indicator (OSI)-2. Mental health was from the 12-item General Health Questionnaire (GHQ-12). Social health was from a self-constructed evaluation questionnaire. Statistical analyses were conducted using Geographically Weighted Regression and Geographically Weighted Logistic Regression for global and local effects on green exposure and multidimensional health.

RESULT

Among the investigated individuals, only 3.55 % (32/902) fully meet the 3-30-300 rule in Xiamen. Global results show that individuals achieved at least 30 % vegetation coverage (Yes) is associated with better physical (β: 0.76, p < 0.01) and social (β: 0.5, p < 0.01) health. GWLR global results indicate that individuals can "see at least 3 trees from home" meeting one (OR = 0.46, 95%CI: 0.25-0.86, p < 0.05) or two (OR = 0.41, 95%CI: 0.22,0.78, p < 0.01; OR = 0.24, 95%CI: 0.07-0.77, p < 0.05) 3-30-300 rule components are significantly associated with reduced medical visits and hospitalizations refer to not met these criterias. In the GWR local analysis, achieved 30 % vegetation cover is significantly related to improved social health at all locations. Meeting any two indicators also contribute to improved social health (n = 511, β: 0.46-0.51, P < 0.05).

CONCLUSION

Green exposure indicators based on the 3-30-300 rule guiding healthy urban green space development. We observed multidimensional health benefits when 1/3 or 2/3 of the indicators were met.

Beneficial effects of short-term exposure to indoor biophilic environments on psychophysiological health: Evidence from electrophysiological activity and salivary metabolomics

BACKGROUND

The utilization of short-term natural exposure as a health intervention has great potential in the field of public health. However, previous studies have mostly focused on outdoor urban green spaces, with limited research on indoor biophilic environments, and the physiological regulatory mechanisms involved remain unclear.

OBJECTIVES

To explore the affective and physiological impact of short-term exposure to indoor biophilic environments and their potential regulatory mechanisms.

METHODS

A between-group design experiment was conducted, and the psychophysiological responses of participants to the indoor plants (Vicks Plant) were measured by a method combined the subjective survey, electrophysiological measurements, and salivary biochemical analysis. Volatile organic compounds (VOCs) from plants were also detected to analyze the main substances that caused olfactory stimuli.

RESULTS

Compared with the non-biophilic environment, short-term exposure to the indoor biophilic environment was associated with psychological and physiological relaxation, including reduced negative emotions, improved positive emotions, lower heart rate, skin conductance level, salivary cortisol and pro-inflammatory cytokines, and increased alpha brainwave power. Salivary metabolomics analysis revealed that the differential metabolites observed between the groups exhibited enrichment in two metabolic pathways related to neural function and immune response: phenylalanine, tyrosine and tryptophan biosynthesis, and ubiquinone and other terpenoid-quinone biosynthesis. These changes may be associated with the combined visual and olfactory stimuli of the biophilic environment, in which D-limonene was the dominant substance in plant-derived VOCs.

CONCLUSION

This research demonstrated the benefits of short-term exposure to indoor biophilic environments on psychophysiological health through evidence from both the nervous and endocrine systems.

Associations of the neighbourhood built and natural environment with cardiometabolic health indicators: A cross-sectional analysis of environmental moderators and behavioural mediators

BACKGROUND

Most studies examining the effects of neighbourhood urban design on cardiometabolic health focused solely on the built or natural environment. Also, they did not consider the roles of neighbourhood socio-economic status (SES) and ambient air pollution in the observed associations, and the extent to which these associations were mediated by physical activity and sedentary behaviours.

METHODS

We used data from the AusDiab3 study (N = 4141), a national cohort study of Australian adults to address the above-mentioned knowledge gaps. Spatial data were used to compute indices of neighbourhood walkability (population density, intersection density, non-commercial land use mix, commercial land use), natural environment (parkland and blue spaces) and air pollution (annual average concentrations of nitrogen dioxide (NO2) and fine particulate matter <2.5 μm in diameter (PM2.5)). Census indices were used to define neighbourhood SES. Clinical assessments collected data on adiposity, blood pressure, blood glucose and blood lipids. Generalised additive mixed models were used to estimate associations.

RESULTS

Neighbourhood walkability showed indirect beneficial associations with most indicators of cardiometabolic health via resistance training, walking and sitting for different purposes; indirect detrimental associations with the same indicators via vigorous gardening; and direct detrimental associations with blood pressure. The neighbourhood natural environment had beneficial indirect associations with most cardiometabolic health indicators via resistance training and leisure-time sitting, and beneficial direct associations with adiposity and blood lipids. Neighbourhood SES and air pollution moderated only a few associations of the neighbourhood environment with physical activity, blood lipids and blood pressure.

CONCLUSIONS

Within a low-density and low-pollution context, denser, walkable neighbourhoods with good access to nature may benefit residents' cardiometabolic health by facilitating the adoption of an active lifestyle. Possible disadvantages of living in denser neighbourhoods for older populations are having limited opportunities for gardening, higher levels of noise and less healthy dietary patterns associated with eating out.

Association between greenspace exposure and suicide-related outcomes across the lifespan: A systematic review

A growing number of studies have linked greenspace exposure to suicide, but findings are inconsistent. We conducted a systematic review on the associations between greenspace exposure and suicide-related outcomes (namely, suicide mortality, self-harm, and suicidal ideation) up until January 6, 2023. We used the Mixed Methods Appraisal Tool (or MMAT) to assess the quality of the included studies. In total, 23 studies met our inclusion criteria, consisting of 14 ecological, four cross-sectional, three longitudinal, and two experimental studies. Most studies were published in 2022 and conducted in Europe (n = 10), Asia (n = 7), and North America (n = 5), with one worldwide analysis. Various indicators were used to assess greenspace exposure including objective measures (e.g., level of surrounding greenness, quantity, structural features, tree canopy coverage), and greenspace use (e.g., duration and frequency). Suicide mortality was the most studied outcome (n = 14). Quality assessment showed that most (87 %) of the included observational studies used representative samples. Protective associations of exposure to greenspace were reported for suicide mortality (9/14 or 64 %), self-harm (n = 3/5 or 60 %) and suicidal ideation (n = 4/6 or 67 %), with nine or 36 % studies reporting no association. Most of the included studies adjusted for key covariates such as age, sex, and socioeconomic status at various aggregate levels (e.g., household, city). For greenspace exposure and suicide mortality, studies stratified by sex (n = 10) showed larger protective associations for females (n = 7) than for males (n = 4). However, the included studies showed high heterogeneity in terms of exposure indicators and greenspace definitions. Experimental studies and studies using youth samples were rare. While more research is warranted, preliminary findings suggest protective associations between greenspace exposure and suicide-related outcomes.

A Scoping Review of Urban Planning Decision Support Tools and Processes That Account for the Health, Environment, and Economic Benefits of Trees and Greenspace

Compelling evidence shows that trees and greenspaces positively impact human well-being and the environment and offer economic benefits. Nevertheless, there exists a knowledge gap regarding the extent to which this evidence is efficiently incorporated into existing urban planning decision-making processes. This scoping review identified the extent to which urban planning decision-making frameworks, models, and tools consider the health, environmental, and economic benefits of trees and greenspace. Out of 28 reviewed studies, 11 (39%) reported on frameworks, models, and tools that take into account the health, environmental, and economic dimensions of trees and greenspace. Additionally, seven studies provided comprehensive coverage of at least one of the three key dimensions. However, none of the decision support frameworks, models, or tools comprehensively integrated all three dimensions, with only two tools (7%) scoring above 50% (five or more out of nine) in terms of comprehensiveness. This review highlights the urgent need to incorporate the true economic and monetary values of the health and environmental benefits of trees and greenspace to inform urban development decision making.

Association between residential greenspace and mental health among cancer survivors in Shanghai, China

BACKGROUND

Living near and enjoying visually green landscapes is associated with better mental health, but evidence focusing on vulnerable populations (such as cancer survivors) is sparse. The purpose of this study was to explore the association between residential greenspace and anxiety and depressive symptoms among cancer survivors in Shanghai, China.

METHODS

In total, 4195 cancer survivors participated in this study from the 2022 Shanghai Cancer Patient Needs Survey. The estimation of residential greenspaces was based on Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). The presence and severity of depressive and anxiety symptoms were assessed by using the Patient Health Questionnaire-2 (PHQ-2) and Generalized Anxiety Disorder-2 (GAD-2). The relation between mental health and green space was assessed using the Generalized Additive Model (GAM) after controlling for relevant individual covariates and contextual characteristics.

RESULTS

The prevalence of anxiety and depression in cancer survivors was 36.2% and 28.3% respectively. After multivariate adjustment, each increase in inter-quartile range (IQR) for NDVI in the 250 m buffer (NDVI-250m) was associated with a decrease in PHQ-2 score (△score (95%CI): 0.018 (-0.034, -0.002)) and GAD-2 score (△score (95%CI): 0.018 (-0.034, -0.002)), respectively. We observed that an increase in IQR for NDVI-250m was associated with a 3.3% (Odds ratio (OR) (95%CI):0.967 (0.943, 0.991)) reduction in anxiety symptoms. More pronounced greenspace-mental health effects were found among young adults (18-65 years) and participants living in suburban areas, compared to young people over 65 and those living in urban areas (P-interaction < 0.05).

CONCLUSIONS

Higher levels of residential green space are associated with lower risk of depression and anxiety disorders. Our findings will fill the gap in the relationship between green space and mental health among cancer survivors in urban China, and provide new evidence for garden afforestation, community planning and policy-making. To better understand this association, more longitudinal studies are necessary to investigate the mechanisms involved.

Short-term exposure sequences and anxiety symptoms: a time series clustering of smartphone-based mobility trajectories

BACKGROUND

Short-term environmental exposures, including green space, air pollution, and noise, have been suggested to affect health. However, the evidence is limited to aggregated exposure estimates which do not allow the capture of daily spatiotemporal exposure sequences. We aimed to (1) determine individuals' sequential exposure patterns along their daily mobility paths and (2) examine whether and to what extent these exposure patterns were associated with anxiety symptoms.

METHODS

We cross-sectionally tracked 141 participants aged 18-65 using their global positioning system (GPS) enabled smartphones for up to 7 days in the Netherlands. We estimated their location-dependent exposures for green space, fine particulate matter, and noise along their moving trajectories at 10-min intervals. The resulting time-resolved exposure sequences were then partitioned using multivariate time series clustering with dynamic time warping as the similarity measure. Respondents' anxiety symptoms were assessed with the Generalized Anxiety Disorders-7 questionnaire. We fitted linear regressions to assess the associations between sequential exposure patterns and anxiety symptoms.

RESULTS

We found four distinctive daily sequential exposure patterns across the participants. Exposure patterns differed in terms of exposure levels and daily variations. Regression results revealed that participants with a "moderately health-threatening" exposure pattern were significantly associated with fewer anxiety symptoms than participants with a "strongly health-threatening" exposure pattern.

CONCLUSIONS

Our findings support that environmental exposures' daily sequence and short-term magnitudes may be associated with mental health. We urge more time-resolved mobility-based assessments in future analyses of environmental health effects in daily life.

Residential greenspace and anxiety symptoms among Australian women living in major cities: A longitudinal analysis

Despite an increasing number of studies demonstrating the potential mental health benefits of greenspace, few longitudinal studies have been reported. We aimed to assess associations between two metrics of residential greenspace exposure and anxiety symptoms in a cohort of Australian women living in major cities. Our study comprised 3,938 women, born between 1973 and 78. Anxiety symptoms in the previous month were assessed at follow-up every three years during 2003-2018, using the anxiety subscale of the Goldberg Anxiety and Depression Scale. The three-month seasonal average normalized difference vegetation index (NDVI) was estimated from 30 m Landsat satellite images in a 500 m buffer (NDVI500m) around participants' address at each survey (higher NDVI indicates more green vegetation). The annual fractional cover of non-photosynthesising vegetation was estimated (fNPV500m, with higher values indicating greater levels of dead leaf litter or dry grass). A generalised estimating equation assessed associations between greenspace measures and anxiety symptoms (as odds ratios [ORs]), adjusting for repeated outcomes and individual-level covariates. Additional analyses focused on women experiencing substantial changes in between-survey exposure due to moving, and adjusting for nitrogen dioxide (NO2) and fine particulate matter (PM2.5) exposure, among others. A standard deviation (SD) (0.12 units) increase in NDVI500m was significantly associated with lower odds of anxiety symptoms (OR: 0.96, 95% CI: 0.93-0.99) in the adjusted model. An SD (5.2%) increase in annual fNPV500m was consistent with the direction expected for that exposure, but not significant in the adjusted model (OR: 1.03, 95% CI: 0.99-1.07). NDVI500m was modestly attenuated when air pollutants were adjusted for, while fNPV500m only became significant when PM2.5 was adjusted for. Between-survey contrasts had no clear effect for NDVI500m. Moving to a higher fNPV500m area, compared with a similar fNPV500m area, was consistently associated with anxiety symptoms (OR: 1.15, 95% CI: 1.02-1.31). NDVI500m was generally associated with lower odds of anxiety symptoms, while fNPV500m was generally associated with higher odds of anxiety, depending on the covariates considered.

A Canonical Correlation Analysis Study on the Association Between Neighborhood Green Space and Residents' Mental Health

Based on survey data conducted in Guangzhou in 2021, this study employs canonical correlation analysis (CCA) to evaluate the relationship between neighborhood green space, residents' green space use behavior, and their mental health. The results show that compared with the objectively measured accessibility, residents' subjective perceived accessibility of neighborhood green space plays a greater role in promoting green space use behavior and mental health. Meanwhile, the plant diversity, safety, and the number of recreational facilities in a green space can promote the frequency of green space use, improve residents' mental health status and reduce their perceived stress. Although perceived accessibility is more related to green space use behavior than green space quality indicators, green space safety and recreational facilities have many more benefits on mental health than perceived accessibility. In addition, residents' green space use behavior, especially green space visit frequency, can promote mental health and reduce perceived stress.

Natural environments, psychosocial health, and health behaviors in a crisis - A scoping review of the literature in the COVID-19 context

The COVID-19 outbreak led to major restrictions globally, affecting people's psychosocial health and their health behaviors. Thus, the purpose of this scoping review was to summarize the available research regarding nature and health in the COVID-19 context. Keywords relating to natural environments and COVID-19 were combined to conduct a systematic online search in six major databases. Eligibility criteria were a) published since 2020 with data collected in the COVID-19 context b) peer-reviewed, c) original empirical data collected on human participants, d) investigated the association between natural environments and psychosocial health or health behaviors, and e) English, German, or Scandinavian languages. Out of 9126 articles being screened, we identified 188 relevant articles, representing 187 distinct studies. Most research focused on adults in the general population and was predominantly conducted in the USA, Europe, and China. Overall, the findings indicate that nature may mitigate the impact of COVID-19 on psychological health and physical activity. Through a systematic thematic analysis of the extracted data, three primary themes were identified: 1) type of nature assessed, 2) psychosocial health and health behaviors investigated, and 3) heterogeneity in the nature-health relationship. Research gaps in the COVID-19 context were identified regarding I) nature characteristics that promote psychosocial health and health behaviors, II) investigations of digital and virtual nature, III) psychological constructs relating to mental health promotion, IV) health-promoting behaviors other than physical activity, V) underlying mechanisms regarding heterogeneity in the nature-health relationship based on human, nature, and geographic characteristics, and VI) research focusing on vulnerable groups. Overall, natural environments demonstrate considerable potential in buffering the impact of stressful events on a population level on mental health. However, future research is warranted to fill the mentioned research gaps and to examine the long-term effects of nature exposure during COVID-19.

Clinical guidelines for the use of lifestyle-based mental health care in major depressive disorder: World Federation of Societies for Biological Psychiatry (WFSBP) and Australasian Society of Lifestyle Medicine (ASLM) taskforce

OBJECTIVES

The primary objectives of these international guidelines were to provide a global audience of clinicians with (a) a series of evidence-based recommendations for the provision of lifestyle-based mental health care in clinical practice for adults with Major Depressive Disorder (MDD) and (b) a series of implementation considerations that may be applicable across a range of settings.

METHODS

Recommendations and associated evidence-based gradings were based on a series of systematic literature searches of published research as well as the clinical expertise of taskforce members. The focus of the guidelines was eight lifestyle domains: physical activity and exercise, smoking cessation, work-directed interventions, mindfulness-based and stress management therapies, diet, sleep, loneliness and social support, and green space interaction. The following electronic bibliographic databases were searched for articles published prior to June 2020: PubMed, EMBASE, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register), CINAHL, PsycINFO. Evidence grading was based on the level of evidence specific to MDD and risk of bias, in accordance with the World Federation of Societies for Biological Psychiatry criteria.

RESULTS

Nine recommendations were formed. The recommendations with the highest ratings to improve MDD were the use of physical activity and exercise, relaxation techniques, work-directed interventions, sleep, and mindfulness-based therapies (Grade 2). Interventions related to diet and green space were recommended, but with a lower strength of evidence (Grade 3). Recommendations regarding smoking cessation and loneliness and social support were based on expert opinion. Key implementation considerations included the need for input from allied health professionals and support networks to implement this type of approach, the importance of partnering such recommendations with behaviour change support, and the need to deliver interventions using a biopsychosocial-cultural framework.

CONCLUSIONS

Lifestyle-based interventions are recommended as a foundational component of mental health care in clinical practice for adults with Major Depressive Disorder, where other evidence-based therapies can be added or used in combination. The findings and recommendations of these guidelines support the need for further research to address existing gaps in efficacy and implementation research, especially for emerging lifestyle-based approaches (e.g. green space, loneliness and social support interventions) where data are limited. Further work is also needed to develop innovative approaches for delivery and models of care, and to support the training of health professionals regarding lifestyle-based mental health care.

Green space exposure and type 2 diabetes mellitus incidence: A systematic review

INTRODUCTION

Epidemiological studies have suggested that exposure to green spaces is associated with a lower prevalence of diabetes. The aim of this systematic review was to summarize the evidence on green spaces and diabetes mellitus II (T2DM) in longitudinal studies.

METHODS

We searched PubMed, SCOPUS, Web of Science (WoS)/Core Collection, WoS/MEDLINE, and EMBASE until February 2023. We included cohort studies that assessed the incidence of T2DM according to the level of exposure to green spaces. Two authors independently performed study selection, data extraction, and analysis of risk of bias. No meta-analysis was performed due to clinical heterogeneity between studies.

RESULTS

We included 13 cohort studies with a sample size ranging from 1700 to 1 922 545 participants. Studies presented different ways of defining (quartiles, percentages) and measuring (tools, buffers) green spaces. Similarly, the definition of T2DM was heterogeneous (self-reports, medical records, clinical criteria). Twelve studies showed that individuals with higher exposure to green spaces had a decreased incidence of T2DM. Out of these 12 studies, 10 revealed statistically significant differences. All studies were of high methodological quality, except for one.

CONCLUSION

Our findings suggest that exposure to green space could be a protective factor for the development of T2DM. Promoting policies to preserve and increase green space could help to reduce T2DM at the community level. More standardization of green space exposure definition is needed in studies on green space and T2DM.

Perceived Social Support Mediates the Relationship between Use of Greenspace and Geriatric Depression: A Cross-Sectional Study in a Sample of South-Italian Older Adults

A growing body of evidence is suggestive for the beneficial role of contact with greenspace (e.g., use of greenspace, visual access to greenspace, etc.) on mental health (e.g., depression, anxiety, etc.). In addition, several studies have pointed out the benefits of social support and social interaction on psychological wellbeing. Even if evidence on the association between contact with greenspace and perceived social support were mixed, it was supposed that the use of greenspace could enhance social interactions and perceived social support, especially among older adults. The present study aims to explore the effect of use of greenspace on geriatric depression in a sample of South-Italian older adults and the mediating role of perceived social support in this association. A structural equation model was tested in a sample of 454 older adults (60-90 years old) residing in the Metropolitan Area of Bari, Apulia. The fit indices revealed the goodness of fit of the model (CFI = 0.934; TLI = 0.900; IFI = 0.911; NFI = 0.935; RMSEA = 0.074; SRMR = 0.056). Results showed that the use of greenspace was inversely associated with geriatric depression through perceived social support. These findings underlined the relevance of perceived social support on the pathway linking use of greenspace and geriatric depressive symptoms. This evidence may be useful to policymakers to plan interventions for promoting physical access to greenspace and social participation in an age-friendly city framework.

The Impact of the Coronavirus Pandemic on the Contribution of Local Green Space and Nature Connection to Mental Health

BACKGROUND

Exposure to green space and feeling connected to the natural environment have independently been associated with improved mental health outcomes. During the coronavirus pandemic, people experienced restrictions on access to the outdoors, and health data indicated a decline in mental health in the UK general population.

METHODS

Data available from two independent surveys conducted prior to and during the pandemic enabled a naturally occurring comparison of mental health and its correlates prior to and during the pandemic.

RESULTS

Survey responses from 877 UK residents were included in the analyses. Independent t-tests revealed significant declines in mental health scores during the pandemic. After controlling for age and gender, greater nature connection significantly predicted lower depression and stress and improved well-being. Percentage of green space did not significantly predict any mental health outcomes. Further, time point (pre- or during COVID) and the interaction of time point with green space and nature connection did not significantly predict any of the outcome measures. The findings indicate that nature connection may play an important role in promoting mental health. Strategies to improve mental health and reduce mental illness should consider the role of nature connection and the use of interventions that involve direct interaction with natural environments.

The Economic Value of Health Benefits Associated with Urban Park Investment

The allocation of resources towards the development and enhancement of urban parks offers an effective strategy for promoting and improving the health and well-being of urban populations. Investments in urban parks can result in a multitude of health benefits. The increased usage of greenspace by park users has been linked to positive physical and mental health outcomes. Additionally, the expansion of greenspace in urban areas can mitigate harmful impacts from air pollutants, heat, noise, and climate-related health risks. While the health benefits attributed to urban parks and greenspaces are well documented, few studies have measured the economic value of these benefits. This study applied a novel ecohealth economic valuation framework to quantify and estimate the potential economic value of health benefits attributed to the development of a proposed park in the downtown core of Peterborough, Canada. The results indicated that development of the small urban park will result in annual benefits of CAD 133,000 per year, including CAD 109,877 in the avoided economic burden of physical inactivity, CAD 23,084 in health savings associated with improved mental health, and CAD 127 in health savings attributed to better air quality. When including the economic value of higher life satisfaction, the economic benefit is more than CAD 4 million per year. The study demonstrates the value of developing and enhancing urban parks as a strategy to improve population health and well-being, and as a means of cost savings to the medical system.

Suicide and Transportation Noise: A Prospective Cohort Study from Switzerland

BACKGROUND

Although plausible from a pathophysiological point of view, robust evidence for effects of transportation noise on mental health remains scarce. Meanwhile, psychiatric diseases are among the most prevalent noncommunicable diseases worldwide, and suicide as a mortality outcome highly connected to mental disorders presents a pressing public health issue. The aim of this study was to investigate the association between source-specific transportation noise, particulate matter (PM) air pollution, residential greenness, and suicide by means of a nationwide cohort study.

METHODS

Road traffic, railway and aircraft noise exposure as well as exposure to air pollution [PM with aerodynamic diameter ≤2.5μm (PM2.5)] and greenness [normalized difference vegetation index (NDVI)] were linked to 5.1 million adults (age 15 y and older) in the Swiss National Cohort, accounting for their address history. Mean noise exposure in 5-y periods was calculated. Individuals were followed for up to 15 y (2001-2015). Time-varying Cox regression models were applied to deaths by suicide (excluding assisted suicide). Models included all three noise sources, PM2.5, and NDVI plus individual and spatial covariates, including socioeconomic status. Effect modification by sex, age, socioeconomic indicators, and degree of urbanization was explored.

RESULTS

During the follow-up, there were 11,265 suicide deaths (10.4% poisoning, 33.3% hanging, 28.7% firearms, 14.7% falls). Road traffic and railway noise were associated with total suicides [hazard ratios: 1.040; 95% confidence interval (CI): 1.015, 1.065; and 1.022 (95% CI: 1.004, 1.041) per 10 dB day-evening-night level (Lden)], whereas for aircraft noise, a risk increase starting from 50 dB was masked by an inverse association in the very low exposure range (30-40 dB). Associations were stronger for females than males. The results were robust to adjustment for residential greenness and air pollution.

CONCLUSION

In this longitudinal, nationwide cohort study, we report a robust association between exposure to road traffic and railway noise and risk of death by suicide after adjusting for exposure to air pollution and greenness. These findings add to the growing body of evidence that mental health disorders may be related to chronic transportation noise exposure. https://doi.org/10.1289/EHP11587.

Spatial Heterogeneity and Regional Clustering of Factors Influencing Chinese Adolescents' Physical Fitness

There is often significant spatial heterogeneity in the factors influencing physical fitness in adolescents, yet less attention has been paid to this in established studies. Based on the 2018 Chinese National Student Physical Fitness Standard Test data, this study uses a multi-scale, geographically weighted regression (MGWR) model combined with a K-means clustering algorithm to construct a spatial regression model of the factors influencing adolescent physical fitness, and to investigate the degree of spatial variation in the physical fitness of Chinese adolescents from a socio-ecological perspective of health promotion. The following conclusions were drawn: the performance of the youth physical fitness regression model was significantly improved after taking spatial scale and heterogeneity into account. At the provincial scale, the non-farm output, average altitude, and precipitation of each region were strongly related to youth physical fitness, and each influencing factor generally showed a banded spatial heterogeneity pattern, which can be summarized into four types: N-S, E-W, NE-SW, and SE-NW. From the perspective of youth physical fitness, China can be divided into three regions of influence: the socio-economic-influenced region, mainly including the eastern region and some of the central provinces of China; the natural-environment-influenced region, which mainly includes the northwestern part of China and some provinces in the highland region; and the multi-factor joint-influenced region, which mainly includes the provinces in the central and northeastern regions of China. Finally, this study provides syndemic suggestions for physical fitness and health promotion for youths in each region.

Examining activity-friendly neighborhoods in the Norwegian context: green space and walkability in relation to physical activity and the moderating role of perceived safety

BACKGROUND

Despite the well-known health benefits of regular physical activity, inactivity remains a major public health concern. Understanding how the built environment can encourage physical activity is therefore important to inform current policy strategies for creating activity-friendly neighborhoods. This study aimed to examine whether neighborhood walkability and greenness were associated with physical activity, and if perceived safety moderated any such relations, among adult citizens in Norway.

METHODS

This cross-sectional study included a sample of 5670 adults aged ≥ 18 years living in urban areas of Stavanger. Information on physical activity (PA) levels, perceived neighborhood safety, and socio-demography were obtained from questionnaire data collected in the Norwegian county public health survey of Rogaland. Geographic information systems were utilized to compute walkability, vegetation scores and proportion of green space within postcode areas, which subsequently were linked to the survey data. Hierarchical linear regression models were fitted to examine associations between walkability, amount of vegetation, proportion of green space and weekly minutes of PA, and to estimate main and interaction effects of perceived safety on these relationships.

RESULTS

The adults were on average physically active 148.3 min/week. The amount of green vegetation in the neighborhood was positively related to physical activity when adjusting for potential confounders. No such relations were observed for proportion of green space and walkability. Perceived neighborhood safety was significantly related to increased levels of physical activity, but no moderating role of perceived safety was observed.

CONCLUSION

Although our findings should be interpreted with caution, the results point towards the importance of policymakers, planners, and public health professionals to advocate for safe environments with green vegetation for physical activity in the neighborhood.

Green spaces for mental disorders

PURPOSE OF REVIEW

Mental illness is a global challenge, exacerbated by the coronavirus pandemic. Research suggests access to local green spaces is associated with better mental health, yet access is not always equitable. Evaluation of how nature-based interventions protect and support mental health is therefore required.

RECENT FINDINGS

Accessible local green spaces are associated with better mental health. They encourage active behaviours and social interaction, reduce loneliness and stress. Green views from the home are associated with increased self-esteem, life satisfaction and happiness and reduced depression, anxiety and loneliness. Nature-based interventions and green social prescriptions effectively target vulnerable groups, resulting in significant reductions in depression, anxiety and anger alongside positive mental health outcomes.

SUMMARY

Although existing evidence is encouraging, robust, high-quality research that strengthens the evidence base and informs future clinical practice and policy decision making is needed. Evidence of the long-term effectiveness in individuals with diagnosed mental illness is also required to ascertain the potential social and wider returns on investment. Barriers to use of green social prescriptions like mental health symptoms and geographical accessibility need to be overcome to increase accessibility and uptake of green social prescriptions for the prevention and treatment of mental illness.

Environmental stress, minority status, and local poverty: risk factors for mental health in Berlin's inner city

This study examines whether climate change-associated environmental stressors, including air and noise pollution, local heat levels, as well as a lack of surrounding greenspace, mediate the effects of local poverty on mental health, using the 28-item General Health Questionnaire. We recruited 478 adults who were representative of eleven of Berlin's inner-city neighborhoods. The relationship of individual-level variables, neighborhood-level sociodemographic and environmental data from the Berlin Senate (Department for Urban Development, Building and Housing) to mental health was assessed in a multilevel model using SPSS. We found that neither local exposure to environmental stressors, nor available greenspace as a protective factor, mediated the effects of local poverty on variance in mental health (all p values > 0.2). However, surrounding greenspace (r = -0.24, p < 0.001), nitrogen dioxide levels (r = 0.10, p < 0.05), noise pollution (rho = 0.15, p < 0.01), and particle pollution (r = 0.12, p < 0.001) were associated with local poverty, which, more strongly than individual factors, accounted for variance in mental health (β = 0.47, p < 0.001). Our analysis indicates that the effects of local poverty on mental health are not mediated by environmental factors. Instead, local poverty was associated with both an increased mental health burden and the exposure to climate-related environmental stressors.

Restorative Effects from Green Exposure: A Systematic Review and Meta-Analysis of Randomized Control Trials

Despite growing research on green space and health benefits, the body of evidence remains heterogeneous and unclear. A systematic review and meta-analysis of studies of randomized controlled trials (RCTs) with high evidence levels are deemed timely. We searched Scopus, PubMed, Embase, and Web of Science for the literature up to January 2022 and assessed bias using the Cochrane Risk of Bias tool 2.0. We calculated joint impact estimates for each green space exposure assessment technique using random and fixed effects models. Compared to non-green space situations, green space exposure was related to decreased negative feelings, such as fatigue -0.84 (95% CI: -1.15 to -0.54), and increased levels of pleasant emotions, such as vitality 0.85 (95% CI: 0.52 to 1.18). It also lowered physiological indicators, including heart rate levels, by 0.60 (95% CI: -0.90 to -0.31). Effect sizes were large and statistically significant, and the overall quality of the evidence was good. Existing RCTs on greenspace exposure pay insufficient attention to older and adolescent populations, different ethnic groups, different regions, and doses of greenspace exposure interventions. More research is needed to understand how and how much green space investment has the most restorative benefits and guide urban green space planning and renewal.

The impact of black carbon (BC) on mode-specific galvanic skin response (GSR) as a measure of stress in urban environments

Previous research has shown that walking and cycling could help alleviate stress in cities, however there is poor knowledge on how specific microenvironmental conditions encountered during daily journeys may lead to varying degrees of stress experienced at that moment. We use objectively measured data and a robust causal inference framework to address this gap. Using a Bayesian Doubly Robust (BDR) approach, we find that black carbon exposure statistically significantly increases stress, as measured by Galvanic Skin Response (GSR), while cycling and while walking. Augmented Outcome Regression (AOR) models indicate that greenspace exposure and the presence of walking or cycling infrastructure could reduce stress. None of these effects are statistically significant for people in motorized transport. These findings add to a growing evidence-base on health benefits of policies aimed at decreasing air pollution, improving active travel infrastructure and increasing greenspace in cities.

Capybara Ticks and the Urban Context of Spotted Fever in Brazil: An Overview

Spotted fever is caused by Rickettsia rickettsii and is transmitted through tick’s saliva. Humans, ticks, and capybaras (Hydrochoerus hydrochaeris) are often coexisting in environments that favor the spread of Brazilian spotted fever (BSF). Although capybaras do not transmit R. rickettsii, they can amplify these bacteria among tick vector populations, playing a significant role in the one health approach and epidemiology of the disease. Urban populations of capybaras have increased, especially in Southeast Brazil, as well as the number of cases and lethality of BSF have increased in the country since the 1980s. This expansion is mainly determined by the availability of food and the absence of predators. Thus, urban areas, including parks and university campuses, provide an abundance of food and protection against predators, ensuring the multiplication of the species and increasing the risk of transmission to humans due to the proximity of man with animals in the urban environment. Therefore, this chapter aims to address aspects of spotted fever, considering the many dimensions of the species involved, contributing to public strategies and policies.

Exploring how greenspace programmes might be effective in supporting people with problem substance use: a realist interview study

BACKGROUND

Greenspace programmes are health projects run outside in nature, typically with the aim of improving mental health. Research suggests that programmes may also be effective in supporting people with problem substance use (PSU), but there is limited understanding of the key components that make them successful for this client group. Previous work has claimed that a realist-informed intervention framework for greenspace programmes for mental health could be transferable to programmes that support people with PSU, and that this could provide insight into the causal processes within programmes. However, this claim is yet to be explored in depth. The aim of this study was to further test, refine, and consolidate the proposed framework to show how greenspace programmes could support people with PSU.

METHODS

Using a realist approach, 17 participants (8 programme staff; 9 wider stakeholders) were interviewed about contexts, mechanisms, and outcomes (CMOs) relative to greenspace programmes for mental health and PSU. Semi-structured interviews were used since they facilitated exploration of the proposed framework but were flexible enough to allow identification of new CMOs for framework refinement. Interviews were audio-recorded, fully transcribed, and analysed inductively and deductively against the proposed framework.

RESULTS

Findings supported the proposed framework and indicated that greenspace programmes support people with poor mental health and PSU due to: feelings of escape; space to reflect; physical activity; self-efficacy; feelings of purpose; relationships; and shared experiences. However, data showed that programmes must also consider: explicit intervention focus to ensure adequate support for clients; existing challenges with funding and stakeholder buy-in; and the impact of COVID-19. Findings allowed development of a refined framework that shows how greenspace programmes can support people with PSU.

CONCLUSION

The findings of this project are theoretically novel and have practical relevance for those designing greenspace programmes by providing recommendations on how to optimise, tailor, and implement future interventions. Findings could be particularly relevant for academic researchers, multidisciplinary health professionals, and for those working in the third sector, developing and delivering greenspace programmes for people to improve their mental health and to support them with PSU.

Daily space-time activities, multiple environmental exposures, and anxiety symptoms: A cross-sectional mobile phone-based sensing study

BACKGROUND

Few mobility-based studies have investigated the associations between multiple environmental exposures, including social exposures, and mental health.

OBJECTIVE

To assess how exposure to green space, blue space, noise, air pollution, and crowdedness along people's daily mobility paths are associated with anxiety symptoms.

METHODS

358 participants were cross-sectionally tracked with Global Positioning System (GPS)-enabled mobile phones. Anxiety symptoms were measured at baseline using the Generalized Anxiety Disorder-7 (GAD-7) questionnaire. Green space, blue space, noise, and air pollution were assessed based on concentric buffers of 50 m and 100 m around each GPS point. Crowdedness was measured by the number of nearby Bluetooth-enabled devices detected along the mobility paths. Multiple linear regressions with full covariate adjustment were fitted to examine anxiety-environmental exposures associations. Random forest models were applied to explore possible nonlinear associations and exposure interactions.

RESULTS

Regression results showed null linear associations between GAD-7 scores and environmental exposures. Random forest models indicated that GAD-7-environment associations varied nonlinearly with exposure levels. We found a negative association between green space and GAD-7 scores only for participants with moderate green space exposure. We observed a positive association between GAD-7 scores and noise levels above 60 dB and air pollution concentrations above 17.2 μg m^-3. Crowdedness was positively associated with GAD-7 scores, but exposure-response functions flattened out with pronounced crowdedness of >7.5. Blue space tended to be positively associated with GAD-7 scores. Random forest models ranked environmental exposures as more important to explain GAD-7 scores than linear models.

CONCLUSIONS

Our findings indicate possible nonlinear associations between mobility-based environmental exposures and anxiety symptoms. More studies are needed to obtain an in-depth understanding of underlying anxiety-environment mechanisms during daily life.

The geospatial and conceptual configuration of the natural environment impacts the association with health outcomes and behavior in children and adolescents

Background

Studies investigating associations between natural environments and health outcomes or health behaviors in children and adolescents yielded heterogenous results to date. This may be the result of different geospatial configurations of the natural environment and confounding characteristics of the study population. Thus, we investigated how the relationship between the natural environment and mental health, muscular fitness, and physical activity varies depending on the geospatial configuration of nature and children’s and adolescents’ characteristics.

Methods

Data were derived from the German Motorik-Modul (MoMo) cohort study (2018–2020) that investigates physical activity, muscular fitness, and health parameters in a national sample of children and adolescents (N = 2843) between four and 17 years (M_age = 10.46 ± 3.49 years; 48.3% girls). Mental health was assessed via questionnaire, muscular fitness via standing long jump, and physical activity with 7-day accelerometer measurement. Using geographic information systems, land cover, and land use data, three different nature definitions were applied. Both circular buffers (100–1000 m) and street-network buffers (1000–5000 m) were created for each of the nature definitions. Associations were explored with linear regression models, and interaction analysis was used to investigate how those relationships vary by gender, age, and socio-economic status.

Results

The relationship between the three outcomes and the natural environment varied considerably depending on the nature definition, buffer size, and buffer type, as well as socio-demographic characteristics. Specifically, when comparing youth with a high socio-economic status to those with a medium socio-economic status, smaller circular buffer distances were related to less physical activity, but larger street-network buffer distances were related to greater mental health problems. Distinct relationships also occurred for youth with low socio-economic status in those relationships, with the pattern being less clear.

Conclusions

For future health research studies that investigate the role of the natural environment, we argue for the development of an a-priori model that integrates both geospatial considerations (nature definition, buffer type, and buffer size) and conceptual considerations (health outcome/behavior, sample characteristics) based on potentially underlying mechanisms that link the natural environment and the health outcome or behavior under investigation to theoretically underpin the geospatial configuration of the natural environment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12942-022-00309-0.

Residential green space and mental health-related prescription medication sales: An ecological study in Belgium

BACKGROUND

Residential green space has been associated with mental health benefits, but how such associations vary with green space types is insufficiently known.

OBJECTIVE

We aimed to investigate associations between types and quantities of green space and sales of mood disorder medication in Belgium.

METHODS

We used aggregated sales data of psycholeptics and psychoanaleptics prescribed to adults from 2006 to 2014. Generalized mixed effects models were used to investigate associations between relative covers of woodland, low-green, grassland, and garden, and average annual medication sales. Models were adjusted for socio-economic background variables, urban-rural differences, and administrative region, and included random effects of latitude and longitude.

RESULTS

Urban census tracts were associated with 9-10% higher medication sales. In nationwide models, a 10% increase in relative cover of woodland, garden, and grass was associated with a 1-2% decrease in medication sales. The same association was found for low green but only for men. In stratified models, a 10% increase in relative cover of any green space type in urban census tracts was associated with a decrease of medication sales by 1-3%. In rural census tracts, no protective associations between green space and mood disorder medication sales were observed, with the exception of relative woodland cover for women (-1%), and low green was associated with higher medication sales (+6-7%).

CONCLUSIONS

Taken together, these results suggest that living in green environments may be beneficial for adult mental health. Woodland exposure seemed the most beneficial, but the amount of green space was more important than the type. Results underline the importance of conserving green space in our living environment, for the conservation of biodiversity and for human health.

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.

Urban greenspace and mental health in Chinese older adults: Associations across different greenspace measures and mediating effects of environmental perceptions

This study aimed to contrast the associations of street view-, land use- and satellite-derived greenspace measures with older adults' mental health and to examine the mediating effects of neighborhood environmental perceptions (i.e., noise, aesthetics and satisfaction with recreational opportunities) to explain potential heterogeneity in the associations. Data of 879 respondents aged 60 or older in Dalian, China were used, and multilevel regression models were conducted in Stata. Results indicated that the Normalized Difference Vegetation Index (NDVI), vegetation coverage, park coverage and streetscape grasses were positively correlated with older adults' mental health. The associations of exposure metrics measured by overhead view were stronger than those measured by the street view. Streetscape grasses had a stronger association with older adults' mental health than streetscape trees. Noise, aesthetics and satisfaction with recreational opportunities mediated these associations, but the strength of the mediating effects differed across the greenspace measures. Our findings confirm the necessity of multi-measures assessment for greenspace to examine associations with older adults' mental health in Chinese settings and can contribute to the realization of health benefits of urban greenspace.

Residential Exposure to Urban Trees and Medication Sales for Mood Disorders and Cardiovascular Disease in Brussels, Belgium: An Ecological Study

BACKGROUND

The available evidence for positive associations between urban trees and human health is mixed, partly because the assessment of exposure to trees is often imprecise because of, for instance, exclusion of trees in private areas and the lack of three-dimensional (3D) exposure indicators (e.g., crown volume).

OBJECTIVES

We aimed to quantify all trees and relevant 3D structural traits in Brussels (Belgium) and to investigate associations between the number of trees, tree traits, and sales of medication commonly prescribed for mood disorders and cardiovascular disease.

METHODS

We developed a workflow to automatically isolate all individual trees from airborne light detection and ranging (LiDAR) data collected in 2012. Trait data were subsequently extracted for 309,757 trees in 604 census tracts. We used the average annual age-standardized rate of medication sales in Brussels for the period 2006 to 2014, calculated from reimbursement information on medication prescribed to adults (19-64 years of age). The medication sales data were provided by sex at the census tract level. Generalized log-linear models were used to investigate associations between the number of trees, the crown volume, tree structural variation, and medication sales. Models were run separately for mood disorder and cardiovascular medication and for men and women. All models were adjusted for indicators of area-level socioeconomic status.

RESULTS

Single-factor models showed that higher stem densities and higher crown volumes are both associated with lower medication sales, but opposing associations emerged in multifactor models. Higher crown volume [an increase by one interquartile range (IQR) of 1.4×104 m³/ha] was associated with 34% lower mood disorder medication sales [women, β=-0.341 (95% CI: -0.379, -0.303); men, β=-0.340 (95% CI: -0.378, -0.303)] and with 21-25% lower cardiovascular medication sales [women, β=-0.214 (95% CI: -0.246, -0.182); men, β=-0.252 (95% CI: -0.285, -0.219)]. Conversely, a higher stem density (an increase by one IQR of 21.8 trees/ha) was associated with 28-32% higher mood disorder medication sales [women, β=0.322 (95% CI: 0.284, 0.361); men, β=0.281 (95% CI: 0.243, 0.319)] and with 20-24% higher cardiovascular medication sales [women, β=0.202 (95% CI: 0.169, 0.236); men, β=0.240 (95% CI: 0.206, 0.273)].

DISCUSSION

We found a trade-off between the number of trees and the crown volumes of those trees for human health benefits in an urban environment. Our results demonstrate that conserving large trees in urban environments may not only support conservation of biodiversity but also human health. https://doi.org/10.1289/EHP9924.

The influence of early-life residential exposure to different vegetation types and paved surfaces on early childhood development: A population-based birth cohort study

BACKGROUND

Growing evidence suggests that exposure to green space is associated with improved childhood health and development, but the influence of different green space types remains relatively unexplored. In the present study, we investigated the association between early-life residential exposure to vegetation and early childhood development and evaluated whether associations differed according to land cover types, including paved land.

METHODS

Early childhood development was assessed via kindergarten teacher-ratings on the Early Development Instrument (EDI) in a large population-based birth cohort (n = 27,539) in Metro Vancouver, Canada. The residential surrounding environment was characterized using a high spatial resolution land cover map that was linked to children by six-digit residential postal codes. Early-life residential exposure (from birth to time of EDI assessment, mean age = 5.6 years) was calculated as the mean of annual percentage values of different land cover classes (i.e., total vegetation, tree cover, grass cover, paved surfaces) within a 250 m buffer zone of postal code centroids. Multilevel models were used to analyze associations between respective land cover classes and early childhood development.

RESULTS

In adjusted models, one interquartile range increase in total vegetation percentage was associated with a 0.33 increase in total EDI score (95% CI: 0.21, 0.45). Similar positive associations were observed for tree cover (β-coefficient: 0.26, 95% CI: 0.15, 0.37) and grass cover (β-coefficient: 0.12, 95% CI: 0.02, 0.22), while negative associations were observed for paved surfaces (β-coefficient: -0.35, 95% CI: -0.47, -0.23).

CONCLUSIONS

Our findings indicate that increased early-life residential exposure to vegetation is positively associated with early childhood developmental outcomes, and that associations may be stronger for residential exposure to tree cover relative to grass cover. Our results further indicate that childhood development may be negatively associated with residential exposure to paved surfaces. These findings can inform urban planning to support early childhood developmental health.

Does exposure to greenness improve children's neuropsychological development and mental health? A Navigation Guide systematic review of observational evidence for associations

BACKGROUND

Contact with nature may have a key role in child brain development. Recent observational studies have reported improvements in children's neuropsychological development and mental health associated with greenness exposure. In a rapidly urbanizing word, researchers, policymakers, healthcare workers and urban planners need to work together to elaborate evidence-based policies and interventions to increase the availability of quality green space with the potential to enhance childhood development.

OBJECTIVE

To review the observational evidence assessing the effect of exposure to greenness on children's neuropsychological development and mental health.

METHODS

The protocol for the review was preregistered at PROSPERO (CRD42020213838). The Navigation Guide systematic review methodology was followed. Search strategies were formulated and adapted to each database. Searches were performed in PubMed, Scopus, Web of Science and EBSCO's GreenFILE on October 5, 2021. Additional articles were further identified by hand-searching reference lists of included papers.

RESULTS

A systematic search of 4 databases identified 621 studies, of which 34 were included in the review. The studies included investigated diverse domains within neuropsychological development and mental health, such as attention, working memory, intelligence, cognitive development, academic performance, well-being, attention-deficit/hyperactivity disorder symptoms, and behavior. Most of the studies were rated as having high or probably high risk of bias in the assessment.

DISCUSSION

Although nearly all studies showed a positive association between greenness exposure and the outcomes studied, the heterogeneity in the methods used to assess exposure and the diversity of domains within each main outcome has made it difficult to draw clear conclusions. Future studies should adopt a longitudinal design to confirm the causality of the associations and include measures to determine which characteristics of greenness have the greatest influence on each domain. Researchers should also try to explore pathways linking exposure to greenness with the neuropsychological development and mental health, by implementing mechanistic studies.

Healthy Dwelling: Design of Biophilic Interior Environments Fostering Self-Care Practices for People Living with Migraines, Chronic Pain, and Depression

The benefits of biophilic interior design have been recognized by healthcare facilities, but residential environments receive relatively less attention with respect to improving the health of people living with chronic diseases. Recent “stay-at-home” restrictions due to the COVID-19 pandemic further emphasized the importance of creating interior spaces that directly and indirectly support physical and mental health. In this viewpoint article, we discuss opportunities for combining biophilic interventions with interior design, fostering disease-specific self-care. We provide examples of designing residential spaces integrating biophilic interventions, light therapy, relaxation opportunities, mindfulness meditation, listening to music, physical activities, aromatherapy, and quality sleep. These modalities can provide the clinical benefits of reducing migraine headaches and chronic pain, as well as improving depressive symptoms. The disease-specific interior environment can be incorporated into residential homes, workplaces, assisted-living residences, hospitals and hospital at home programs. This work aims to promote a cross-disciplinary dialogue towards combining biophilic design and advances in lifestyle medicine to create therapeutic interior environments and to improve healthcare outcomes.

The relationship between greenspace exposure and psychopathology symptoms: A systematic review

Greenspace exposure is associated with psychological benefits. In this systematic review, we summarized and critically evaluated the literature on the relationship between greenspace exposure (i.e., objective and subjective assessments of interactions with nature) and psychopathology incidence and symptom severity in those with and without a clinical diagnosis. A secondary aim of our review was to examine potential interactions between greenspace exposure and urban environmental features (e.g., pollution, population density) associated with poorer mental health. We identified 40 studies published between January 1, 1981, and July 31, 2020, from PubMed and PsycINFO electronic database search. Although heterogeneous in assessments of greenspace exposure and psychopathology symptom domain, the majority of cross-sectional and longitudinal evidence found that objectively assessed greenspace exposure (e.g., satellite measures of greenery) was related to less severe symptoms and lower incidence of psychopathology in children (e.g., attention-deficit/hyperactivity disorder symptoms) and adults (e.g., depression symptoms). In addition, five studies that assessed urban environmental features suggest that greenspace exposure may show a net positive relationship with psychopathology over and above the absence of urban features. We discuss limitations of the literature and future directions, including more mechanistic work to delineate the potential cognitive, affective, and behavioral factors that may contribute to the beneficial relationship between greenspace exposure and psychological health.

Psychosocial and Biological Outcomes of Immersive, Mindfulness-Based Treks in Nature for Groups of Young Adults and Caregivers Affected by Cancer: Results from a Single Arm Program Evaluation from 2016-2021

The COVID-19 pandemic has left many individuals suffering from “connection deficit disorder” given changes to the way we work, go to school, socialize, and engage in daily activities. Young adults affected by cancer between the ages of 18–39 have known this connection deficit long before the pandemic. Being diagnosed and treated for cancer during this time can significantly disrupt engagement in important educational, career, social, and reproductive pursuits, and contribute to increased stress, anxiety, depression, and other negative outcomes. Experiencing meaningful connection—with nature, with peers who understand, and with oneself, may help assuage this adverse effect of disconnect. A single arm within-subjects program evaluation was conducted to examine outcomes following participation in immersive, multi-night, mindfulness-based treks in nature in a sample of young adults (n = 157) and caregivers (n = 50) affected by cancer from 2016–2021. Pre to post-trek changes included significant (p < 0.001) self-reported improvements in feeling connected to nature (d = 0.93–0.95), peers (d = 1.1–1.3), and oneself (d = 0.57–1.5); significant (p < 0.001) improvements on PROMIS Anxiety (d = 0.62–0.78), Depression (d = 0.87–0.89), and Sleep Disturbance (d = 0.37–0.48) short forms; and significant (p < 0.05) changes in pro-inflammatory biomarkers (d = 0.55–0.82). Connection-promoting experiences like this have the potential to improve health and wellbeing in this population and serve as a model for others.