The greener the better? Does neighborhood greenness buffer the effects of stressful life events on externalizing behavior in late adolescence?

Increased urban greenspace in childhood associated with lower inattention deficit among adolescents

PURPOSE

There is a growing interest in assessing the benefits of exposure to urban greenspace on mental health due to the increased urbanization of youth and concerns for their mental health. We investigated the prospective associations of residential greenspace in childhood and mental health in adolescence. Use of a well-characterized birth cohort permitted adjustment for a range of potential confounding factors including family and neighborhood characteristics in addition to prior mental health problems, and exploration of moderation effects by sex and family socioeconomic status.

METHODS

We analyzed longitudinal data collected from 742 urban-dwelling participants of the Quebec Longitudinal Study of Children Development. The Normalized Difference Vegetation Index (NDVI) within 250, 500, and 1000 m buffer zones surrounding the home residence was used to indicate childhood exposure to greenspace. Six self-reported mental health problems at 15/17 years were examined using the Mental Health and Social Inadaptation questionnaire: inattention, hyperactivity/impulsivity, conduct, depression, anxiety, and suicidal ideation.

RESULTS

Childhood urban greenspace was associated with lower inattention problems in both females and males. We observed a 0.14 reduced standard deviation (SD) (β = - 0.14, SE = 0.05, p < 0.01) in relation to an interquartile range (IQR) increase of NDVI (0.15) at the 250 m buffer zone, and similar results were found in 500 m and 1000 m buffer zones. These associations only slightly attenuated after adjustment for individual (sex, childhood mental health), family (family SES, maternal age at birth, parental mental health, family composition), and neighborhood (material and social deprivation) characteristics (β = - 0.13, SE = 0.06, p = 0.03). No association was found for other mental health problems, and no moderation associations of sex or family socioeconomic status were observed.

CONCLUSION

 These findings suggest that increasing residential greenspace in cities may be associated with modest benefits in attentional capacities in youth, necessitating further research to elucidate the underlying mechanisms.

Does the quality of street greenspace matter? Examining the associations between multiple greenspace exposures and chronic health conditions of urban residents in a rapidly urbanising Chinese city

BACKGROUND

Numerous studies have demonstrated that greenspace(GS) exposure is associated with health improvements in individuals with hypertension and diabetes. However, studies examining the associations between multiple GS exposures and chronic health conditions in developing countries are limited.

METHODS

Geospatial data and spatial analysis were employed to objectively measure the total neighbourhood vegetative cover (mean value of normalised difference vegetation index [NDVI] within specific buffer zone) and proximity to park-based GS (network distance from home to the entrance of park-based GS). Street view imagery and machine learning techniques were used to measure the subjective perceptions of street GS quality. A multiple linear regression model was applied to examine the associations between multiple GS exposures and the prevalence of hypertension and diabetes in neighbourhoods located in Qingdao, China.

RESULTS

The model explained 29.8% and 28.2% of the prevalence of hypertension and diabetes, respectively. The results suggested that: 1) the total vegetative cover of the neighbourhood was inversely correlated with the prevalence of hypertension (β = -0.272, p = 0.013, 95% confidence interval (CI): [-1.332, -0.162]) and diabetes (β = -0.230, p = 0.037, 95% CI: [-0.720, -0.008]). 2) The street GS quality was negatively correlated with the prevalence of hypertension (β = -0.303, p = 0.007, 95% CI: [-2.981, -0.491]) and diabetes (β = -0.309, p = 0.006, 95% CI: [-1.839, -0.314]). 3) Proximity to park-based GS and the prevalence of hypertension and diabetes mellitus were not significantly correlated.

CONCLUSIONS

This study used subjective and objective methods to comprehensively assess the greenspace exposure from overhead to eye level, from quantity, proximity to quality. The results demonstrated the beneficial relationships between street GS quality, total vegetative cover, and chronic health in a rapidly urbanising Chinese city. Furthermore. the effect of street GS quality was more pronounced in potentially mitigating chronic health problems, and improving the quality of street GS might be an efficient and effective intervention pathway for addressing chronic health issues in densely populated cities.

Greenspace and health outcomes in children and adolescents: A systematic review

An increasing body of evidence has linked greenspace and various health outcomes in children and adolescents, but the conclusions were inconsistent. For this review, we comprehensively summarized the measurement methods of greenspace, resultant health outcomes, and potential mechanisms from epidemiological studies in children and adolescents (aged ≤19 years). We searched for studies published and indexed in MEDLINE and EMBASE (via Ovid) up to April 11, 2022. There were a total of 9,291 studies identified with 140 articles from 28 countries finally assessed and included in this systematic review. Over 70% of the studies were conducted in highly urbanised countries/regions, but very limited research has been done in low-and middle-income countries and none in Africa. Measures of greenspace varied. Various health outcomes were reported, including protective effects of greenspace exposure on aspects of obesity/overweight, myopia, lung health, circulatory health, cognitive function, and general health in children and adolescents. The associations between greenspace exposure and other health outcomes were inconsistent, especially for respiratory health studies. We pooled odds ratios (OR) using random-effects meta-analysis for health outcomes of asthma (OR = 0.94, 95%CI: 0.84 to 1.06), allergic rhinitis (OR = 0.95; 95% CI: 0.73 to 1.25), and obesity/overweight (OR = 0.91, 95%CI: 0.84 to 0.98) with per 0.1 unit increase in normalized difference in vegetation index (NDVI). These associations have important implications for the assessment and management of urban environment and health in children and adolescents.

Growing up green: a systematic review of the influence of greenspace on youth development and health outcomes

Youth growing up in places with more greenspaces have better developmental outcomes. The literature on greenspace and youth development is largely cross-sectional, thus limited in terms of measuring development and establishing causal inference. We conducted a systematic review of prospective, longitudinal studies measuring the association between greenspace exposure and youth development outcomes measured between ages two and eighteen. We searched Cochrane, PubMed, CINAHL, Scopus, and Environment Complete, and included prospective cohort, quasi-experimental, and experimental studies on greenspace and youth development. Study quality was assessed using a 10-item checklist adapted from a previously published review on greenspace and health. Twenty-eight studies met criteria for review and were grouped into five thematic categories based on reported outcomes: cognitive and brain development, mental health and wellbeing, attention and behavior, allergy and respiratory, and obesity and weight. Seventy-nine percent of studies suggest an association between greenspace and improved youth development. Most studies were concentrated in wealthy, Western European countries, limiting generalizability of findings. Key opportunities for future research include: (1) improved uniformity of standards in measuring greenspace, (2) improved measures to account for large latency periods between greenspace exposure and developmental outcomes, and (3) more diverse study settings and populations.

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

Background

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

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.

Association between greenspace and blood pressure: A systematic review and meta-analysis

Many studies have investigated the association between greenspaces and blood pressure (BP), but the results remain mixed. We conducted a systematic review and meta-analysis to comprehensively evaluate the evidence concerning greenspaces with BP levels and prevalent hypertension. Systematic literature searches were performed in Web of Science, PubMed, and Embase up to 25 April 2021. Combined effect estimates were calculated using random-effect models for each greenspace exposure assessment method that had been examined in ≥3 studies. Sensitivity analysis, subgroup analysis, and publication bias were also conducted. Of 38 articles (including 52 analyses, 5.2 million participants in total) examining the effects of normalized difference vegetation index (NDVI) (n = 23), proportion of greenspace (n = 11), distance to greenspace (n = 9), and others (n = 9) were identified. Most studies (65%) reported beneficial associations between greenspaces and BP levels/hypertension. Our results of meta-analyses showed that higher NDVI_500m was significantly associated with lower levels of systolic blood pressure (SBP = -0.77 mmHg, 95%CI: -1.23 to -0.32) and diastolic blood pressure (DBP = -0.32 mmHg, 95%CI: -0.57 to -0.07). We also found that NDVI in different buffers and the proportion of greenspaces were significantly associated with lower odds (1-9%) of hypertension. However, no significant effect was found for distance to greenspaces. In summary, our results indicate the beneficial effects of greenspace exposure on BP and hypertension. However, future better-designed studies, preferably longitudinal, are needed to confirm and better quantify the observed benefits in BP and/or hypertension.

Urban Adolescence: The Role of Neighbourhood Greenspace in Mental Well-Being

Mental health and well-being in adolescence are associated with many short- and long-term outcomes. The evidence suggests that greenspace may play a role in adolescents' mental well-being, but we do not know much about the specifics of this link. In this paper, we investigated the role of other factors in the association. In a cross-sectional study, we investigated the role of neighbourhood greenspace in emotional and behavioural outcomes in 11-year-old urban adolescents participating in the UK Millennium Cohort Study (n = 4,534). We used linear regression models to test for an association of greenspace with self-esteem, happiness, positive mood, negative mood, and antisocial behaviour. We also investigated effect modification/moderation by garden access, physical activity, and perceived area safety. We did not find a main effect of greenspace, but we did find interaction effects. First, in adolescents without a garden, higher levels of greenspace were associated with lower levels of self-esteem and positive mood. Second, in adolescents who reported lower levels of physical activity, higher levels of greenspace were associated with lower levels of negative mood. Third, in adolescents who perceived their areas to be unsafe, higher levels of greenspace were associated with higher levels of antisocial behaviour. Our findings suggest that merely more greenspace in the neighbourhood may not be sufficient to promote the mental well-being of urban adolescents in the UK. However, greenspace does seem to have an influence under certain conditions which should be investigated further in future studies.

Relationship between stressful life events and cyberbullying perpetration: Roles of fatalism and self-compassion

Few studies have documented the relationship between stressful life events and cyberbullying perpetration, and the mechanisms connecting this link are unknown. Thus, the current study tested the association of stressful life events with cyberbullying perpetration and explored this influencing mechanism further with fatalism and self-compassion tested as a mediator and a moderator respectively. A sample of 1104 Chinese adolescents (50.72% males; mean age = 13.11) volunteered for this study. The results revealed that exposure to stressful life events was positively related to cyberbullying perpetration, and fatalism played a mediation role in this relationship. The moderated mediation model revealed that stronger self-compassion weakened and even interrupted the direct associations of stressful life events with fatalism and cyberbullying perpetration, and further weakened and even interrupted the indirect relationship between stressful life events and cyberbullying perpetration via fatalism. That is, adolescents low in self-compassion were more likely to build fatalistic beliefs and engage in cyberbullying perpetration when they experienced high levels of stressful life events; whereas, stressful life events were not related to increased risk of cyberbullying perpetration among adolescents high in self-compassion.

Home garden use during COVID-19: Associations with physical and mental wellbeing in older adults

The COVID-19 pandemic has affected many aspects of people's lives. Lockdown measures to reduce the spread of COVID-19 have been more stringent for those aged over 70, at highest risk for the disease. Here, we examine whether home garden usage is associated with self-reported mental and physical wellbeing in older adults, during COVID-19 lockdown in Scotland. This study analysed data from 171 individuals (mean age 84 ± 0.5 years) from the Lothian Birth Cohort 1936 study who completed an online survey approximately two months after lockdown commenced (May/June, 2020), and reported having access to a home garden. The survey also included items on garden activities (gardening, relaxing), frequency of garden usage during lockdown, and measures of self-rated physical health, emotional and mental health, anxiety about COVID-19, and sleep quality. Ordinal regression models were adjusted for sex, living alone, education, occupational social class, anxiety and depressive symptoms, body mass index, and history of diabetes and cardiovascular disease. Neither gardening nor relaxing in the garden were associated with health outcomes. However, higher frequency of garden usage during lockdown was associated with better self-rated physical health (P = 0.005), emotional and mental health (P = 0.04), sleep quality (P = 0.03), and a composite health score (P = 0.001), after adjusting for covariates. None of the garden measures were associated with perceived change in physical health, mental and emotional health, or sleep quality, from pre-lockdown levels. The results of the current study provide support for positive health benefits of spending time in a garden-though associations may be bidirectional-and suggest that domestic gardens could be a potential health resource during the COVID-19 pandemic.

Relative 'greenness' and not availability of public open space buffers stressful life events and longitudinal trajectories of psychological distress

Despite evidence of associations between urban green space exposure and mental health, explanatory mechanisms and the role of green space qualities remain unclear. This prospective cohort study (n = 929) examined the distinct relationships of residential public open space (POS) availability and 'greenness' with four-year trajectories of psychological distress in Montreal, Canada. Stress-buffering and main effect mechanisms were tested under the respective hypotheses that POS exposures 1) attenuate the impact of stressful events on psychological distress and 2) protect against psychological distress independently of exposure to stressful events. Results from growth mixture models indicate that residing among 'greener' POS protects against rising distress through both mechanisms. Conversely, POS availability was not associated with trajectories of distress when holding greenness constant. Findings reinforce the need to consider the quality as well as quantity of public open space in urban environments.

The Association between Green Space and Adolescents' Mental Well-Being: A Systematic Review

This systematic review summarised and evaluated the evidence for associations between green space and adolescents’ mental well-being. The PRISMA statement guidelines were followed for reporting systematic reviews. Fourteen articles met the inclusion criteria for this review. Synthesis suggests beneficial associations between green space exposure and reduced stress, positive mood, less depressive symptoms, better emotional well-being, improved mental health and behaviour, and decreased psychological distress in adolescents. Several studies found the relationship varied by demographic and socio-economic factors. The limited number of studies and the risk of bias were the main limitations, together with heterogeneity regarding green space and mental well-being assessments. Overall, this review highlights the potential contribution of green space in schoolyards. Improving the availability, accessibility and quality of green space is likely to generate positive impacts on adolescents’ mental well-being. More consistent evidence on the use of different types of green space and perceptions of features are needed in the future.

Analytical approaches to testing pathways linking greenspace to health: A scoping review of the empirical literature

BACKGROUND

Inadequate translation from theoretical to statistical models of the greenspace - health relationship may lead to incorrect conclusions about the importance of some pathways, which in turn may reduce the effectiveness of public health interventions involving urban greening. In this scoping review we aimed to: (1) summarize the general characteristics of approaches to intervening variable inference (mediation analysis) employed in epidemiological research in the field; (2) identify potential threats to the validity of findings; and (3) propose recommendations for planning, conducting, and reporting mediation analyses.

METHODS

We conducted a scoping review, searching PubMed, Scopus, and Web of Science for peer-reviewed epidemiological studies published by December 31, 2019. The list of potential studies was continuously updated through other sources until March 2020. Narrative presentation of the results was coupled with descriptive summary of study characteristics.

RESULTS

We found 106 studies, most of which were cross-sectional in design. Most studies only had a spatial measure of greenspace. Mental health/well-being was the most commonly studied outcome, and physical activity and air pollution were the most commonly tested intervening variables. Most studies only conducted single mediation analysis, even when multiple potentially intertwined mediators were measured. The analytical approaches used were causal steps, difference-of-coefficients, product-of-coefficients, counterfactual framework, and structural equation modelling (SEM). Bootstrapping was the most commonly used method to construct the 95% CI of the indirect effect. The product-of-coefficients method and SEM as used to investigate serial mediation components were more likely to yield findings of indirect effect. In some cases, the causal steps approach thwarted tests of indirect effect, even though both links in an indirect effect were supported. In most studies, sensitivity analyses and proper methodological discussion of the modelling approach were missing.

CONCLUSIONS

We found a persistent pattern of suboptimal conduct and reporting of mediation analysis in epidemiological studies investigating pathways linking greenspace to health; however, recent years have seen improvements in these respects. Better planning, conduct, and reporting of mediation analyses are warranted.