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

Green sanctuaries: residential green and garden space and the natural environment mitigate mental disorders risk of diabetic patients

BACKGROUND

The co-occurrence of diabetes and mental disorders is an exceedingly common comorbidity with poor prognosis. We aim to investigate the impact of green space, garden space, and the natural environment on the risk of mental disorders among the population living with diabetes.

METHODS

We performed a longitudinal analysis based on 39,397 participants with diabetes from the UK Biobank. Residential green and garden space modeled from land use data and the natural environment from Land Cover Map were assigned to the residential address for each participant. Cox proportional hazards model was used to analyze the associations between nature exposures and mental disorders of diabetes. Casual mediation analysis was used to quantify indirect effect of air pollution.

RESULTS

During a mean follow-up of 7.55 years, 4513 incident mental disorders cases were identified, including 2952 depressive disorders and 1209 anxiety disorders. Participants with natural environment at 300 m buffer in the second and third tertiles had 7% (HR = 0.93, 95%CI: 0.86-0.99) and 12% (HR = 0.88, 95%CI: 0.82-0.94) lower risks of incident mental disorders compared with those in the first tertile, respectively. The risk of mental disorders incidence among diabetes patients will decrease by 13% when exposed to the third tertile of garden space at 300 m buffer. The natural environment and garden space individually prevented 6.65% and 10.18% of mental disorders incidents among diabetes patients. The risk of incident mental disorders was statistically decreased when exposed to the third tertile of green space at 1000 m buffer (HR = 0.84, 95% CI: 0.78-0.90). Protective effects of three nature exposures against depressive and anxiety disorders in diabetes patients were also observed. Air pollution, particularly nitrogen dioxide, nitrogen oxides, and fine particulate matter, significantly contributed to the associations between nature exposures and mental disorders, mediating 48.3%, 29.2%, and 62.4% of the associations, respectively.

CONCLUSIONS

Residential green and garden space and the natural environment could mitigate mental disorders risk in diabetes patients, with air pollution playing a vital mediator. This highlights the potential for local governments to enhance the sustainability of such interventions, grounded in public health and urban planning, through strategic planning initiatives.

From space to street: A systematic review of the associations between visible greenery and bluespace in street view imagery and mental health

A large body of literature shows that living near greenery supports healthy lifestyles and improves mental health. Much of this research has used greenery measured from a bird's eye perspective. Street view images (SVI) are an important alternative data source that could assess visible greenery experienced by residents in daily life. The current review is the first to systematically critique and synthesize the evidence relating to greenery and bluespace in SVI and its associations with mental health outcomes. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct this review. First, we identified relevant articles published as of April 2023 in PubMed, Web of Science, Scopus, and CINAHL. Articles meeting inclusion criteria were narratively synthesized. Quality assessments were conducted with the Newcastle-Ottawa Scale (NOS). Based on our search, we identified 35 articles on greenery and bluespace measured with SVI and mental health outcomes. Two-thirds of the included papers found positive associations between greenery in SVI and mental health. The average score for risk of bias was good. Association between visible greenery in SVI and all 10 of the mental health outcomes studied were low or very low quality of evidence and showed limited or inadequate strength of evidence. SVI is likely to be an increasingly used and a validated instrument for estimating health-promoting exposure to greenery. Future research would benefit from the standardization of SVI datasets and computational processes, and studies conducted outside of China and high-income countries. Such advancements would improve the generalizability and robustness of associations between visible greenery and mental health outcomes.

Examining the importance of neighborhood natural, and built environment factors in predicting older adults' mental well-being: An XGBoost-SHAP approach

BACKGROUND

Previous studies have shown that urban neighborhood environmental factors significantly influence the health outcomes of urban older adults. However, most cross-sectional studies exploring the health effects of these factors have failed to quantify the relative importance of each factor.

METHODS

We use XGBoost machine learning techniques and SHAPley Additive Interpretation (SHAP) to rank the importance of urban neighborhood environmental factors in shaping the mental health of urban older adults. To address self-selection bias in housing choice, we distinguish older adults living in private housing from those living in public as residents in private housing have more freedom to choose where to live.

RESULTS

The results show that both natural and built environmental factors in urban neighborhoods are important predictors of mental well-being scores. Five natural environmental factors (blue space, perceived greenery quantity, NDVI, street view greenness, aesthetic quality) and three built environmental factors (physical activity facilities quality, physical activity facilities quantity, neighborhood disorder) had considerable predictive power for mental well-being scores in two groups. Among them, blue space, perceived greenery quantity and street view greenness quantity became less important after controlling for self-selection bias, possibly because of the unequal distribution of quantity and quality, and the performance of neighborhood disorder, aesthetic quality and physical activity facilities quality was more sensitive in public housing.

CONCLUSIONS

These results highlight the nuanced and differential effects of neighborhood environmental exposures on mental well-being outcomes, depending on housing preferences. The results of this study can provide support for decision makers in urban planning, landscape design and environmental management in order to improve the mental well-being status of urban older adults.

Nature connectedness connects the visibility of trees through windows and mental wellbeing: a study on the "3 visible trees" component of the 3-30-300 rule

To examine the mediatory role of nature connectedness between tree visibility through windows and mental wellbeing, we conducted a questionnaire survey and examined the mediation effect using both cross-sectional and semi-longitudinal mediation models. We evaluated nature connectedness using the Inclusion of Nature in Self (INS) scale and the Connectedness to Nature Scale (CNS) and measured mental wellbeing using the WHO-5 wellbeing index. Our results showed that participants who could see at least three trees through their windows reported higher levels of both nature connectedness and mental wellbeing compared to those without such visibility. Nature connectedness significantly mediated the relationship between the visibility of trees through windows and mental wellbeing, albeit with a somewhat limited effect. More broadly, this study provides additional evidence in support of the "3" component of the 3-30-300 "rule" for equitable access to greenspace in cities.

The impact of urban green space on the health of middle-aged and older adults

Introduction

Urban green space is one of the most closely related ecosystem services to residents' lives, and it can be regarded as a preventive public health measure. Residents living in parks and other green environments can help improve their physical and mental health, reduce stress and even prevent crime and violence. Therefore, based on the actual situation in China, this paper analyzes the relationship between urban green space and the health of middle-aged and older adults and its mechanisms.

Methods

This study used multiple linear regression, based the data from the China Health and Retirement Longitudinal Study (CHARLS) in 2013, 2015, and 2018, to explore the relationship between urban green space and the health of middle-aged and older adults. At the same time, group regression was conducted to identify the heterogeneity of health effects of urban green space.

Results

The research shows that the increase of urban green space areas can significantly improve the health status of middle-aged and older adults. After a series of robustness tests, the results are still valid. In addition, the health effects of urban green space are different because of gender, age, education level, marital status residence, geographical location of the respondents and park quantity distribution. Further research found that reducing hot weather and optimizing air quality are the potential mechanisms of urban green space affecting the health of middle-aged and older adults, providing new evidence for the causal mechanism between urban green space and the health of middle-aged and older adults.

Discussion

This study expanded the research scope of the impact of urban green space on the health of middle-aged and older adults, covering a representative sample in China. The results show that urban green space has an important impact on the health of middle-aged and older adults. Policy suggestions are made to help cities optimize the landscape and residents to enjoy ecology.

Investigating the Association between Streetscapes and Mental Health in Zhanjiang, China: Using Baidu Street View Images and Deep Learning

Mental health is one of the main factors that significantly affect one's life. Previous studies suggest that streets are the main activity space for urban residents and have important impacts on human mental health. Existing studies, however, have not fully examined the relationships between streetscape characteristics and people's mental health on a street level. This study thus aims to explore the spatial patterns of urban streetscape features and their associations with residents' mental health by age and sex in Zhanjiang, China. Using Baidu Street View (BSV) images and deep learning, we extracted the Green View Index (GVI) and the street enclosure to represent two physical features of the streetscapes. Global Moran's I and hotspot analysis methods were used to examine the spatial distributions of streetscape features. We find that both GVI and street enclosure tend to cluster, but show almost opposite spatial distributions. The Results of Pearson's correlation analysis show that residents' mental health does not correlate with GVI, but it has a significant positive correlation with the street enclosure, especially for men aged 31 to 70 and women over 70-year-old. These findings emphasize the important effects of streetscapes on human health and provide useful information for urban planning.

The Effect of Psychological Burden on Dyslipidemia Moderated by Greenness: A Nationwide Study from China

Globally, dyslipidemia is now become a leading risk factor for many adverse health outcomes, especially in the middle-aged and elderly. Recent evidence suggests that exposure to greenness and the relief of a psychological burden may decrease the prevalence of dyslipidemia. The objective of our study was to examine whether a green space can moderate the association between mental health status and dyslipidemia. Our study selected the datasets of depression symptoms, dyslipidemia from the China Health and Retirement Longitudinal Study (CHARLS), and the satellite-based normalized difference vegetation index (NDVI) from the 30 m annual maximum NDVI dataset in China in 2018. Ultimately, a total of 10,022 middle-aged and elderly Chinese were involved in our study. Multilevel logistic regressions were performed to examine the association between symptoms of depression and dyslipidemia, as well as the moderate effect of greenness exposure on the association. Our research suggested that adults diagnosed with depression symptoms were more likely to suffer from dyslipidemia. In addition, the NDVI was shown to moderate the effect of depression on dyslipidemia significantly, though the effect was attenuated as depression increased. Regarding the moderate effect of the NDVI on the above association across age, gender, and residence, the findings presented that females, the elderly, and respondents living in urban areas were at a greater risk of having dyslipidemia, although the protective effect of the NDVI was considered. Likewise, the moderate effect of the NDVI gradually decreased as the level of depression increased in different groups. The current study conducted in China provides insights into the association between mental health, green space, and dyslipidemia. Hence, improving mental health and green spaces can be potential targets for medical interventions to decrease the prevalence of dyslipidemia.

The built environment and mental health among older adults in Dalian: The mediating role of perceived environmental attributes

The basic attributes of the urban built environment are an important factor affecting mental health. However, research has rarely distinguished objective and perceived built environment characteristics to explore the associations with older adults' mental health. Based on data of 879 respondents aged 60 or older in Dalian, China, we explored the mediating roles of perceived built environmental attributes in the relationship between objective built environmental characteristics and mental wellbeing by structural equation modelling. Furthermore, to control for residential self-selection, the model was further tested by excluding the participants who self-selected their residences. The results showed that accessibility to daily living service facilities was positively associated with older adults' mental wellbeing through an indirect role of perceived built environmental attributes. The positive direct effect of aggregation of daily living service facilities on mental wellbeing was offset by the negative indirect effects of perceived built environmental attributes. In addition, the street interface density was negatively related to mental wellbeing through indirect effects. The diverse leisure, exercise and landscape facilities, underground parking and presence of elevators within neighborhoods were all positively associated with older adults' mental wellbeing through direct and/or indirect effects. The results were verified after excluding residential self-selection samples. These findings are helpful for evidence-based planning strategies and can provide guidelines on designing neighborhood landscapes and facilities which can further contribute to aging in place policies.