Exposure to greenspace and bluespace and cognitive functioning in children - A systematic review

Longitudinal associations between greenspace exposure, structural brain development, and mental health and academic performance during early adolescence

BACKGROUND

Greenspace exposure is associated with positive mental health and academic outcomes. This preregistered longitudinal study examines whether the influence of greenspace exposure on structural brain development partially explains these associations.

METHODS

We analyzed data from the Adolescent Brain Cognitive Development (ABCD) study (N=7102), to test the relationship between greenspace exposure at age 9-10 and brain structure two years later, as well as change over time. Additionally, we tested whether brain structural development statistically mediated the associations of greenspace exposure with mental health and academic performance.

RESULTS

Greenspace exposure was associated with greater total surface area (SA) and cortical volume (CV), greater cortical thickness (CT) in temporal regions and the insula, lower thickness in the caudal middle frontal and superior frontal gyri, greater SA across several regions, and greater volume of the caudate nucleus, putamen, and nucleus accumbens. In analyses studying change in brain structure over time, higher greenspace exposure was associated with greater growth of total SA, lower average thickness reduction, and reduced total CV growth as well as changes at the regional level. We also found significant indirect effects of the association of greenspace exposure with academic performance and mental health through both total and regional cortical structure.

CONCLUSIONS

Greenspace exposure is linked to structural neurodevelopment, which is, in turn, associated with better mental health and academic achievement. Our findings underscore the importance of greenspace in supporting brain development and positive outcomes in children and adolescents.

Urban greenspace under a changing climate: Benefit or harm for allergies and respiratory health?

An increasing proportion of the world's population lives in urban settings that have limited greenspace. Urbanization puts pressure on existing greenspace and reduces its access. Climate impacts, including increased temperature and extreme weather events, challenge the maintenance of urban vegetation, reducing its ecosystem services and benefits for human health. Although urban greenspace has been positively associated with numerous health indicators, the evidence for allergies and respiratory health is much less clear and mixed. To address these uncertainties, a workshop with 20 global participants was held in Munich, Germany, in May 2024, focusing on the impact of greenspace-related co-exposures on allergies and respiratory health. This narrative review captures key insights from the workshop, including the roles of urban greenspace in (1) climate change mitigation, (2) interactions with pollen, and (3) emissions of biogenic volatile organic compounds and their byproducts, such as ozone. Additionally, it presents research and stakeholder recommendations from the workshop. Future studies that integrate advanced greenspace exposure assessments and consider the interplay of greenspace with pollen and biogenic volatile organic compounds, along with their relevant byproducts are needed. Increased public awareness and policy actions will also be essential for developing urban greenspace that maximizes health benefits, minimizes risks, and ensures resilience amid a changing climate and rapid urbanization.

Do residents in proximity to blue spaces exhibit lower emotion-related impulsivity? The mediating role of perceived crowdedness

BACKGROUND

Emotion-related impulsivity (ERI) is a significant predisposing factor for various mental health issues and is influenced by individuals' immediate environment. Previous research has largely focused on mitigating ERI through individual-level interventions without extensively considering the role of the external environment. This study explores the impact of passive blue space exposure (PBSE) on ERI, considering both subjective and objective measures of PBSE and investigating the mediating role of perceived crowdedness.

METHODS

Two studies were conducted using online platforms to collect data from Chinese residents. Study 1 (n = 369) examined the predictive effect of objective PBSE, as assessed by the normalized difference water index (NDWI), on ERI. Study 2 (n = 374) focused on subjective PBSE and the mediating effect of perceived crowdedness on ERI. Descriptive statistics, correlational analyses, and path analyses were employed to evaluate the relationships between PBSE, perceived crowdedness, and ERI.

RESULTS

Study 1 demonstrated a negative correlation between objective PBSE and ERI, with marginal significance in predictive analysis after controlling for covariates. Study 2 revealed that subjective PBSE was significantly negatively associated with ERI, and perceived crowdedness significantly mediated this relationship. Subjective PBSE reduced perceived crowdedness, which in turn decreased ERI, accounting for 20% of the total effect. The findings suggest that PBSE, both objective and subjective, may serve as a protective factor against ERI.

CONCLUSIONS

This research highlights the negative association between PBSE and ERI, extending the understanding of environmental influences on impulsive behavior. It emphasizes the potential of utilizing blue spaces in urban planning and individual exposure to alleviate impulsivity. The study also sheds light on the importance of considering both subjective and objective environmental factors in psychological research and interventions. Future studies should consider a comprehensive approach to measuring PBSE and explore causal relationships through experimental designs.

Urban air pollution and child neurodevelopmental conditions: a systematic bibliometric review

PURPOSE OF REVIEW

Using advanced bibliometric analysis, we systematically mapped the most current literature on urban air pollution and neurodevelopmental conditions to identify key patterns and associations. Here, we review the findings from the broader literature by discussing a distilled, validated subset of 44 representative studies.

RECENT FINDINGS

Literature highlights a complex relationship between environmental toxins, neurodevelopmental disorders in children, and neurobehavioral pathways involving oxidative stress, neuroinflammation, and protein aggregation. Chronic prenatal and postnatal exposure to airborne pollutants - such as particulate matter and heavy metals - may contribute to early formation of amyloid plaques through preadolescence. These processes may compromise synaptic plasticity and neural integrity, which can progressively induce cognitive, emotional, and behavioral dysregulation, sharing some pathological features traditionally associated with adult neurodegenerative diseases.

SUMMARY

The interactions between air pollution exposure levels, developmental timing, and factors such as genetic vulnerability associated with neurodevelopmental disorders are still undetermined. However, accelerated neurodegenerative processes leading to cognitive decline and suboptimal mental health in children and adolescents seem most likely linked with pollutants penetrating the blood-brain barrier, and inducing oxidative stress and neuroinflammation. Urgent precautionary action might reduce environmental exposures during critical early developmental periods, thereby safeguarding children's cognitive function and mental health.

Environmental perceptions, self-regulation, and coping with noise mediate the associations between children's physical environment and sleep and mental health problems

BACKGROUND

Children face various challenges in their home and extended neighborhood settings. In this study, we examine the impact of the built and social environments on sleep/mental health and the potential mediating role of environmental perceptions, self-regulation, and coping with noise.

METHODS

Cross-sectional data for 1251 schoolchildren (8-12 years) were sampled in the Tyrol region of Austria/Italy. Questionnaires provided information on sociodemographic and housing factors, perceived neighborhood quality, coping with noise during homework, self-regulation, sleep, and mental health problems. A built environment score was based on modeled levels of road and rail traffic noise, nitrogen dioxide, and imperviousness density. Home garden represented availability of accessible greenspace. Associations between predictors and mental health/sleep problems were examined using quantile regressions and structural equation modeling (SEM).

RESULTS

In multivariate regressions, poor neighborhood quality, poor self-regulation, low traffic safety, and higher coping efforts were associated with more mental health and sleep problems. Good family relations acted in the opposite direction. In SEM, the built environment score was associated with lower neighborhood quality and lower traffic safety, which in turn led to higher coping efforts, and then to mental health/sleep problems. Home gardens related to less sleep problems through higher perceived neighborhood quality and lower coping efforts. Good family relations were associated with better mental health/sleep directly and via better self-regulation and lower coping efforts.

CONCLUSIONS

Children forced to engage in coping activities when disturbed by noise during homework show poorer mental health. Good family relations, good neighborhood quality, and close-by greenspace may be factors to alleviate built environment stressors. The negative association of required coping with noise during homework suggests that children, in contrast to adults, may be limited in their coping abilities. Our findings call for further inquiries, as children and their environments may vary with respect to coping efficiency.

Nurturing attention through nature

BACKGROUND

Previous research suggests an association between exposure to nature and improved attention. However, no observational studies explored the underlying mechanisms or considered bluespace, and none used Polish data. We investigated the association between exposure to nature and attention, and whether it was mediated by nature perception, physical activity and sleep duration.

METHODS

Data derived from the case-control NeuroSmog study comprised 195 participants with attention deficit hyperactivity disorder (ADHD) and 457 participants without ADHD, all aged 10 to 13. Attention was evaluated using the computerized attention network test and the continuous performance test. Lifelong and current exposure to nature, determined by percentage of grass and tree cover and water presence within 500m buffer around residences, as well as domestic garden, were examined through linear, log-linear and negative binomial regressions. Potential pathways were explored using structural equation modelling.

RESULTS

Participants with ADHD with higher exposure to tree cover tended to have improved orienting ability, shorter reaction time and fewer correct rejections, while participants without ADHD tended to show decreased alertness and improved orienting ability. Participants with ADHD with higher exposure to grass cover tended to have longer reaction time, decreased alertness, improved orienting ability, reduced target discrimination ability, fewer correct rejections and less risky response style, while participants without ADHD tended to show decreased orienting ability, more mistakes, longer reaction time, better hit rate and more risky response style. Participants without ADHD with water in their neighbourhood tended to have improved orienting ability, fewer mistakes and better hit rate. Participants without ADHD with a garden tended to show improved target discrimination ability, better hit rate and more risky response style. No mediating pathways were revealed.

CONCLUSION

Tree cover and presence of garden and water tended to be associated with improved attention in Polish adolescents while grass tended to have negative impact.

The Health-Related and Learning Performance Effects of Air Pollution and Other Urban-Related Environmental Factors on School-Age Children and Adolescents-A Scoping Review of Systematic Reviews

PURPOSE OF REVIEW

This scoping review aims to assess the impact of air pollution, traffic noise, heat, and green and blue space exposures on the physical and cognitive development of school-age children and adolescents. While existing evidence indicates adverse effects of transport-related exposures on their health, a comprehensive scoping review is necessary to consolidate findings on various urban environmental exposures' effects on children's development.

RECENT FINDINGS

There is consistent evidence on how air pollution negatively affects children's cognitive and respiratory health and learning performance, increasing their susceptibility to diseases in their adult life. Scientific evidence on heat and traffic noise, while less researched, indicates that they negatively affect children's health. On the contrary, green space exposure seems to benefit or mitigate these adverse effects, suggesting a potential strategy to promote children's cognitive and physical development in urban settings. This review underscores the substantial impact of urban exposures on the physical and mental development of children and adolescents. It highlights adverse health effects that can extend into adulthood, affecting academic opportunities and well-being beyond health. While acknowledging the necessity for more research on the mechanisms of air pollution effects and associations with heat and noise exposure, the review advocates prioritizing policy changes and urban planning interventions. This includes minimizing air pollution and traffic noise while enhancing urban vegetation, particularly in school environments, to ensure the healthy development of children and promote lifelong health.

Interplay among Anxiety, Digital Environmental Exposure, and Cognitive Control: Implications of Natural Settings

Inhibitory control performance may differ greatly as a function of individual differences such as anxiety. Nonetheless, how cognitive control proficiency might be influenced by exposure to various environments and how anxiety traits might impact these effects remain unexplored. A cohort of thirty healthy volunteers participated in the study. Participants performed a Go/No-Go task before exposure to a 'forest' and 'urban' virtual environment, in a counterbalanced design, before repeating the GNG task. The State-Trait Anxiety Inventory (STAI) was finally filled-in. Our findings unveiled an initial negative correlation between anxiety trait levels and GNG task performance, consistent with the established literature attributing difficulties in inhibitory functionality to anxiety. Additionally, different environmental exposures reported opposite trends. Exposure to the 'forest' environment distinctly improved the GNG performance in relation to anxiety traits, while the 'urban' setting demonstrated adverse effects on task performance. These results underscore the intricate relationship among cognitive control, environmental exposure, and trait anxiety. In particular, our findings highlight the potential of natural settings, such as forests, to mitigate the impact of anxiety on inhibition. This might have implications for interventions aimed at improving cognitive control.

The economics of nature's healing touch: A systematic review and conceptual framework of green space, pharmaceutical prescriptions, and healthcare expenditure associations

Green spaces play a crucial role in promoting sustainable and healthy lives. Recent evidence shows that green space also may reduce the need for healthcare, prescription medications, and associated costs. This systematic review provides the first comprehensive assessment of the available literature examining green space exposure and its associations with healthcare prescriptions and expenditures. We applied Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to search MEDLINE, Scopus, and Web of Science for observational studies published in English through May 6, 2023. A quality assessment of the included studies was conducted using the Office of Health Assessment and Translation (OHAT) tool, and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessment was used to evaluate the overall quality of evidence. Our search retrieved 26 studies that met the inclusion criteria and were included in our review. Among these, 20 studies (77 % of the total) showed beneficial associations of green space exposure with healthcare prescriptions or expenditures. However, most studies had risks of bias, and the overall strength of evidence for both outcomes was limited. Based on our findings and related bodies of literature, we present a conceptual framework to explain the possible associations and complex mechanisms underlying green space and healthcare outcomes. The framework differs from existing green space and health models by including upstream factors related to healthcare access (i.e., rurality and socioeconomic status), which may flip the direction of associations. Additional research with lower risks of bias is necessary to validate this framework and better understand the potential for green space to reduce healthcare prescriptions and expenditures.

Residential green space improves cognitive performances in primary schoolchildren independent of traffic-related air pollution exposure

BACKGROUND

Cognitive performances of schoolchildren have been adversely associated with both recent and chronic exposure to ambient air pollution at the residence. In addition, growing evidence indicates that exposure to green space is associated with a wide range of health benefits. Therefore, we aimed to investigate if surrounding green space at the residence improves cognitive performance of primary schoolchildren while taking into account air pollution exposure.

METHODS

Cognitive performance tests were administered repeatedly to a total of 307 primary schoolchildren aged 9-12y, living in Flanders, Belgium (2012-2014). These tests covered three cognitive domains: attention (Stroop and Continuous Performance Tests), short-term memory (Digit Span Forward and Backward Tests), and visual information processing speed (Digit-Symbol and Pattern Comparison Tests). Green space exposure was estimated within several radii around their current residence (50 m to 2000 m), using a aerial photo-derived high-resolution (1 m²) land cover map. Furthermore, air pollution exposure to PM_2.5 and NO₂ during the year before examination was modelled for the child's residence using a spatial-temporal interpolation method.

RESULTS

An improvement of the children's attention was found with more residential green space exposure independent of traffic-related air pollution. For an interquartile range increment (21%) of green space within 100 m of the residence, a significantly lower mean reaction time was observed independent of NO₂ for both the sustained-selective (-9.74 ms, 95% CI: -16.6 to -2.9 ms, p = 0.006) and the selective attention outcomes (-65.90 ms, 95% CI: -117.0 to -14.8 ms, p = 0.01). Moreover, green space exposure within a large radius (2000 m) around the residence was significantly associated with a better performance in short-term memory (Digit-Span Forward Test) and a higher visual information processing speed (Pattern Comparison Test), taking into account traffic-related exposure. However, all associations were attenuated after taking into account long-term residential PM_2.5 exposure.

CONCLUSIONS

Our panel study showed that exposure to residential surrounding green space was associated with better cognitive performances at 9-12 years of age, taking into account traffic-related air pollution exposure. These findings support the necessity to build attractive green spaces in the residential environment to promote healthy cognitive development in children.