Early life exposure to residential green space impacts cognitive functioning in children aged 4 to 6 years

Green-gray imbalance: Rapid urbanization reduces the probability of green space exposure in early 21st century China

Green space exposure provides greater beneficial effects on residents compared to unnatural spaces, commonly referred to as "gray spaces". However, during rapid urbanization, gray spaces expand more quickly than green spaces, often encroaching upon and overtaking these natural environments. This unchecked growth leads to detrimental impacts on the human habitat and overall environmental quality. Consequently, it is essential to meticulously assess the spatial and temporal patterns of residents' exposure levels, as well as to thoroughly investigate the underlying driving mechanisms behind these changes. This study used population-weighted exposure level measurements to assess gray and green space exposure in Chinese cities in the early 21st Century (2000-2019). Additionally, the Gray-Green space Exposure Ratio (GER) was calculated, and the spatiotemporal driving mechanism of GER by each factor was analyzed by geostatistical modeling. The results show that gray space exposure is generally increasing in China, especially in eastern parts of China. The probability of exposure to gray spaces exceeds that of green spaces in some high urbanization rate cities. This trend will continue, albeit at a slower rate. Urban sprawl, built-up area density, and increased electricity consumption were the main drivers of rising GER, whereas greenspace integrity contributed to lower GER; the driving mechanisms for GER changes were spatiotemporal heterogeneous. This study provides a reliable reference for restoring the green space exposure to promote the living environment constructing and residents' access to nature.

Pathways linking greenspace to behavioural problems in Polish children

Background

Previous cross-sectional studies have found a beneficial relationship between greenspace and children's behaviour. Nevertheless, evidence on the mechanisms underlying this association remains scant. We examined whether the availability of greenspace was related to fewer behavioural problems in Polish children and investigated potential mechanisms.

Methods

Data were obtained from the case-control NeuroSmog study, in which children with and without attention deficit hyperactivity disorder (ADHD) were tested from October 2020 to September 2022. The analytic sample comprised 679 children aged 10-13 years. Parents reported internalizing, externalizing, and total behavioural problems using the Child Behaviour Check List (CBCL), as well as information about the presence of a domestic garden and potential mediators: greenspace perception, neighbourhood social cohesion, and physical activity. Tree and grass covers were extracted in 500 m and 1 km buffers around lifelong residences. Structural equation modelling (SEM) was used to examine the psychosocial pathways linking the greenspace metrics to behavioural problems.

Results

Greenspace was only indirectly related to fewer behavioural problems. Specifically, tree cover was related to greater levels of physical activity which, in turn, was related to fewer internalizing and total behavioural problems. Tree cover and presence of garden were related to greenspace perception which, in turn, was associated with higher neighbourhood social cohesion which, in turn, was linked to fewer behavioural problems. The patterns of associations in children without ADHD were very similar to those in the full sample except that the associations from garden to greenspace perception and from physical activity to total behavioural problems were no longer significant. The only association persisted among girls was from neighbourhood social cohesion to behavioural problems and among boys were from tree cover to physical activity and tree cover and garden to greenspace perception.

Conclusion

Trees and garden, but not grass, are linked to fewer behavioural problems through greenspace perception, neighbourhood social cohesion, and physical activity in Polish children.

Maternal greenness exposure and preterm birth in Brazil: A nationwide birth cohort study

In the dynamic landscape of maternal and child health, understanding the intricate interplay between environmental factors and pregnancy outcomes is of paramount importance. This study investigates the relationship between maternal greenness exposure and preterm births in Brazil using data spanning from 2010 to 2019. Satellite-derived indices, including the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), were employed to assess greenness exposure during whole pregnancy in maternal residential area. Employing Cox proportional hazard models, we calculated the hazard ratios (HRs) with 95% confidence intervals (CIs) for changes in NDVI, while adjusting for individual and area-level covariates. In total, 24,010,250 live births were included. Prevalence of preterm birth was 11.5%, with a modest but statistically significant decreasing trend (p = 0.013) observed across the nation over the study period. The findings reveal a significant association between greenness exposure and a reduced risk of preterm birth. Specifically, for every 0.1 increase in NDVI, there was a 2.0% decrease in the risk of preterm birth (95%CI: 1.9%-2.2%). Stratified analyses based on maternal education and ethnicity indicated potential effect modifications, with stronger protective effects observed among younger mothers and those with less years of education. Sensitivity analyses using EVI yielded consistent results. In conclusion, this study suggests that higher maternal greenness exposure is linked to a decreased risk of preterm birth in Brazil. These findings imply that enhancing residential greenspaces could be a valuable public health strategy to promote maternal and child health in Brazil.

Exposure to Residential Green Space and Bone Mineral Density in Young Children

Importance

Bone mass accrual is influenced by environmental and lifestyle factors. Targeted interventions at the early stages of life might decrease fracture and/or osteoporosis risk later in life.

Objective

To investigate whether early-life exposure to residential surrounding green space is associated with a change in bone mineral density in young children.

Design, Setting, and Participants

In this prospective birth cohort study (ENVIRONAGE [Environmental Influence on Aging in Early Life]), mother-child pairs from Flanders, Belgium, were recruited at birth and followed up for 4 to 6 years, between October 1, 2014, and July 31, 2021. Data analysis was conducted between January and February 2022.

Exposures

Green space was estimated for high green (>3 m vegetation height), low green (≤3 m vegetation height ), and total green (sum of high and low) within several radii (100-3000 m) around the residence after geocoding of the addresses.

Main Outcomes and Measures

Radial bone mineral density was assessed using quantitative ultrasound measurement at follow-up, measured as the mean of the axially transmitted speed of sound in meters per second. Multiple linear and logistic regression models were used while accounting for relevant covariates and potential confounders.

Results

The study population comprised 327 children (180 [55.0%] female; mean [SD] age, 4.6 [0.4] years at the follow-up evaluation). Early-life exposure to residential green space was associated with increased childhood bone health. An IQR increment in total green (21.2%) and high green (19.9%) space within 500 m was associated with an increase of 27.38 m/s (95% CI, 9.63-45.13 m/s) and 25.30 m/s (95% CI, 7.93-42.68 m/s) in bone mineral density, respectively. Additionally, an IQR increase in total (25.2%) and high (23.2%) green space within 1000 m was associated with a 67% (odds ratio, 0.33; 95% CI, 0.17-0.61) and 61% (odds ratio, 0.39; 95% CI, 0.18-0.75) lower risk of having a bone density lower than the sex-specific 10th percentile (3567.6 m/s for girls and 3522.8 m/s for boys).

Conclusions and Relevance

In this study of children aged 4 to 6 years, higher bone mineral density and a lower risk of having low bone density were associated with higher residential green space exposure during childhood. These findings highlight the importance of early-life exposure to residential green space on bone health during critical periods of growth and development, with long-term implications.

Assessing the impact of blue and green spaces on mental health of disabled children: A scoping review

During recent decades, there has been a growing consideration of the role of blue and green spaces on mental health of children, but there is insufficient attention in the literature to the mental health of children with disabilities. This paper presents an overview of the evidence on how blue and green spaces affect the mental health of children with various disabilities. A database search found twenty studies eligible for the review, after several consecutive screening stages. Most studies used a cross-sectional design and were carried out in Europe. The results consistently indicate that blue and green space can reduce emotional, behavioral, and social problems in disabled children. A protective association was found between the level of blue or greenness and depressive and anxiety symptoms. Moreover, in most of the studies there were no significant changes in the result after adjusting for socioeconomic confounders. Generally, there is an identified need for more short-term exposure studies in this area, focusing on the impact of landscape design elements on mental health of disabled children. The findings of this scoping review call on urban planners, health care workers and decision makers to consider appropriate measures and interventions providing more blue and green space exposure to disabled children.

Availability, accessibility, and use of green spaces and cognitive development in primary school children

Green spaces may have beneficial impacts on children's cognition. However, few studies explored the exposure to green spaces beyond residential areas, and their availability, accessibility and uses at the same time. The aim of the present study was to describe patterns of availability, accessibility, and uses of green spaces among primary school children and to explore how these exposure dimensions are associated with cognitive development. Exposures to green space near home, school, commuting route, and other daily activity locations were assessed for 1607 children aged 6-11 years from six birth cohorts across Europe, and included variables related to: availability (NDVI buffers: 100, 300, 500 m), potential accessibility (proximity to a major green space: linear distance; within 300 m), and use (play time in green spaces: hours/year), and the number of visits to green spaces (times/previous week). Cognition measured as fluid intelligence, inattention, and working memory was assessed by computerized tests. We performed multiple linear regression analyses on pooled and imputed data adjusted for individual and area-level confounders. Availability, accessibility, and uses of green spaces showed a social gradient that was unfavorable in more vulnerable socioeconomic groups. NDVI was associated with more playing time in green spaces, but proximity to a major green space was not. Associations between green space exposures and cognitive function outcomes were not statistically significant in our overall study population. Stratification by socioeconomic variables showed that living within 300 m of a major green space was associated with improved working memory only in children in less deprived residential areas (β = 0.30, CI: 0.09,0.51), and that more time playing in green spaces was associated with better working memory only in children of highly educated mothers (β per IQR increase in hour/year = 0.10; 95% CI: 0.01, 0.19). However, studying within 300 m of a major green space increased inattention scores in children in more deprived areas (β = 15.45, 95% CI: 3.50, 27.40).

Diversity of Studies on Neighborhood Greenspace and Brain Health by Racialized/Ethnic Group and Geographic Region: A Rapid Review

Studies examining associations between greenspace and Alzheimer's disease and related dementia (ADRD) outcomes are rapidly on the rise, yet no known literature reviews have summarized the racialized/ethnic group and geographic variation of those published studies. This is a significant gap given the known disparities in both greenspace access and ADRD risk between racialized/ethnic groups and between developed versus developing countries. In this rapid literature review, we (1) describe the diversity of published greenspace-brain health studies with respect to racialized/ethnic groups and geographic regions; (2) determine the extent to which published studies have investigated racialized/ethnic group differences in associations; and (3) review methodological issues surrounding studies of racialized/ethnic group disparities in greenspace and brain health associations. Of the 57 papers meeting our inclusion criteria as of 4 March 2022, 21% (n = 12) explicitly identified and included individuals who were Black, Hispanic/Latinx, and/or Asian. Twenty-one percent of studies (n = 12) were conducted in developing countries (e.g., China, Dominican Republic, Mexico), and 7% (n = 4) examined racialized/ethnic group differences in greenspace-brain health associations. None of the studies were framed by health disparities, social/structural determinants of health, or related frameworks, despite the known differences in both greenspace availability/quality and dementia risk by racialized/ethnic group and geography. Studies are needed in developing countries and that directly investigate racialized/ethnic group disparities in greenspace-brain health associations to target and promote health equity.

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

BACKGROUND

The field of greenspace and bluespace research in relation to cognitive outcomes is rapidly growing. Several systematic reviews have already been published on this topic but none of them are specific to cognitive outcomes in the entire age range of children. Moreover, only a few of them have examined the effects of bluespace in addition to greenspace. Also, theses reviews are focused either only on observational studies or experimental studies. Our systematic review focuses on cognitive outcomes in relation to greenspace and bluespace in children and adolescents aged 0-18; it captures both observational and experimental studies. Cognitive outcomes are presented according to an evidence-based taxonomy of human cognitive abilities: the Cattell-Horn-Carroll (CHC) theory.

METHODS

We conducted searches in the PubMed and PsychInfo databases, from their inception dates to 17 December 2021. We used three-text terms related to outcome, exposure, and population as well as MeSH terms for outcome and population. Further, the reference lists and existing reviews were searched ("snowball" search) until 21 April 2022 to detect additional studies. For the results reporting, we followed the updated guidelines of the Preferred Reporting Items for Systematic reviews and Meta Analyses (PRISMA). We included observational and experimental studies on greenspace or bluespace exposure in relation to cognitive functioning, published in English, German, or Polish. Two reviewers independently checked study eligibility and extracted data. Two reviewers evaluated the risk of bias according to the Office of Health Assessment and Translation (OHAT) tool. At all stages, discrepancies between the two reviewers were solved via discussion with a third reviewer.

RESULTS

Records identified from PubMed (n = 2030) and PsycINFO (n = 1168) were deduplicated and screened. Twenty one reports were first selected. The "snowball" search revealed 16 additional reports. Altogether, 39 studies (17 experimental and 22 observational) published in 37 reports were qualified. The data extraction showed that the methodology used in the studies was heterogenous and the findings were inconsistent. The majority of the studies investigated attentional functioning, which we subdivided into two categories according to the CHC theory: attentional control and reaction and decision speed (12 studies) and attentional control and processing speed (10 studies). Eleven studies investigated working memory and/or short-term memory that we categorized as CHC working memory capacity. Nine studies investigated intellectual functioning, which we categorized as CHC general ability, fluid reasoning, and comprehension-knowledge. Two studies investigated visual-spatial skills, which we categorized as CHC visual processing and psychomotor speed. One study measured parent-reported attention; two studies examined early childhood/cognitive development; three studies examined decision-making and self-regulation, which can be categorized as several CHC theory abilities.

DISCUSSION

The heterogeneity of the included studies does not permit clear conclusions for our review. In accordance with previous systematic reviews, greenspace and bluespace were not more strongly related to a particular domain of cognitive functioning than other cognitive domains, and no effects of age or type of exposure assessment on the association between nature and cognition were detected. Further research is needed, including state-of-the-art of assessment of cognitive outcomes and diverse exposure assessment methods within both observational and experimental approaches. Expertise will be required in several domains, such as environmental epidemiology, cognitive psychology, and neuropsychology. Systematic review registration number (INPLASY): 202220018.

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.

Adverse Childhood Experiences (ACEs) and Environmental Exposures on Neurocognitive Outcomes in Children: Empirical Evidence, Potential Mechanisms, and Implications

The purpose of this article is to examine the current literature regarding the relationship between adverse childhood experiences (ACEs) and environmental exposures. Specifically, the paper will focus on how this relationship between ACEs and physical environmental factors impacts the neurocognitive development of children. With a comprehensive literary search focusing on ACEs, inclusive of socioeconomic status (SES), and environmental toxins common in urban environments, the paper explores how these factors contribute to cognitive outcomes that are associated with the environment and childhood nurturing. The relationship between ACEs and environmental exposures reveals adverse outcomes in children's neurocognitive development. These cognitive outcomes include learning disabilities, lowered IQ, memory and attention problems, and overall poor educational outcomes. Additionally, potential mechanisms of environmental exposures and children's neurocognitive outcomes are explored, referencing data from animal studies and evidence from brain imaging studies. This study further analyzes the current gaps in the literature, such as the lack of data focusing on exposure to environmental toxicants resulting from experiencing ACEs and discusses the research and social policy implications of ACEs and environmental exposure in the neurocognitive development of children.

Association of indoor dust microbiota with cognitive function and behavior in preschool-aged children

BACKGROUND

Childhood cognitive development depends on neuroimmune interactions. Immunomodulation by early-life microbial exposure may influence neuropsychological function. In this study, we investigate the association between residential indoor microbiota and cognition and behavior among preschoolers.

RESULTS

Indoor-settled dust bacterial and fungal characteristics were assessed using 16S and ITS amplicon sequencing (microbial diversity) and qPCR measurements (microbial loads). Child behavior was assessed using four scales: peer relationship, emotional, conduct, and hyperactivity was assessed by the Strengths and Difficulties Questionnaire (SDQ). Cognitive function was assessed using four tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB) software. The first two tasks were designed to assess attention and psychomotor speed (Motor Screening (MOT) and Big/Little Circle (BLC)) and the last two to evaluate the child's visual recognition/working memory (Spatial Span (SSP) and Delayed Matching to Sample (DMS)). Among the 172 included children (age 4-6 years), we observed a 51% (95%CI;75%;9%) lower odds of children scoring not normal for hyperactivity and a decrease of 3.20% (95%CI, -6.01%; -0.30%) in BLC response time, for every IQR increase in fungal Shannon diversity. Contrarily, microbial loads were directly associated with SDQ scales and response time. For example, a 2-fold increase in Gram-positive bacterial load was associated with 70% (95%CI 18%; 156%) higher odds of scoring not normal for hyperactivity and an increase of 5.17% (95%CI 0.87%; 9.65%) in DMS response time.

CONCLUSIONS

Our findings show that early-life exposure to diverse indoor fungal communities is associated with better behavioral and cognitive outcomes, whereas higher indoor microbial load was associated with worse outcomes. Video Abstract.

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.

The association between urban greenspace and psychological health among young adults in Addis Ababa, Ethiopia

INTRODUCTION

Psychological disorders are emerging as health priorities in Sub-Saharan Africa, specifically Ethiopia. Urban greenspace - parks, trees, and other vegetation integrated into urban form - may facilitate population psychological health, but is largely understudied outside high-income countries. We explore greenspace in relation to psychological health among young adults in Addis Ababa, Ethiopia.

METHOD

Greenspace exposure was calculated using the normalized difference vegetation index (NDVI) derived from publicly available satellite imagery (2018-2019). We used tests of spatial clustering to characterize greenspace distribution. Derived NDVI values were linked to Positive Outcomes for Orphans study participants to explore cross-sectional associations between greenspace exposure and psychological health (measured 2019-2021). Two continuous scores of psychological health were examined: total difficulties from the Strengths and Difficulties Questionnaire and depressive symptoms from the 8-item Patient Health Questionnaire. Multilevel generalized linear regression, nested by administrative units, was used to estimate the association between greenspace and psychological health. We also explored effect modification by gender and having income.

RESULTS

We found greenspace is spatially clustered in Addis Ababa, with high greenspace density in the northeast region and low greenspace density in the center of the city. Our findings suggest residing in greener areas is associated with fewer emotional and behavioral difficulties (β = -1.89; 95% CI: -3.50, -0.29), but not significantly associated with depressive symptomology (β = -0.61; 95% CI: -2.33, 1.11). We observed stronger associations between greenspace and total difficulties among those reporting any income and among males, and for the association between greenspace and depression symptomology among males.

CONCLUSION

We offer initial exploration into the role of greenspace in psychological well-being in Addis Ababa, with potential implications for urban communities across Sub-Saharan Africa. Further research should continue to explore how the built and natural environment could be leveraged in similar settings to promote population psychological health.

A multi-exposure approach to study telomere dynamics in childhood: A role for residential green space and waist circumference

BACKGROUND

Telomeres are vulnerable to various environmental exposures and lifestyle factors, encompassed in the exposome. Recent research shows that telomere length is substantially determined early in life and that exposures in childhood may have important consequences in setting later life telomere length.

OBJECTIVES

We explore in a child population the associations of 17 exposures with telomere length and longitudinal telomere change.

METHODS

Children (2.8-10.3y at baseline, 51.3% boys) were followed-up for five to seven years. Relative telomere length was measured at baseline and follow-up using quantitative real-time PCR. Exposures and lifestyle factors included: body composition (body mass index and waist circumference), dietary habits (sugar- and fat-rich food intake, vegetables and fruit intake), psychosocial stress (events, emotions, behaviour), sleep duration, physical activity, and residential environmental quality (longterm black carbon, particulate matter exposure, and residential green space). Cross-sectional (n=182) and longitudinal (n=150) analyses were assessed using linear regression models, adjusting for age, sex, socioeconomic status and multiple testing.

RESULTS

Our longitudinal analyses showed that higher residential green space at baseline was associated with (β=0.261, p=0.002) lower telomere attrition and that children with a higher waist circumference at baseline showed a higher telomere attrition (β=-0.287, p=0.001). These two predictors were confirmed via LASSO variable selection and correction for multiple testing. In addition, children with more unhealthy exposures at baseline had a significantly higher telomere attrition over the follow-up period compared to children with more healthy exposures (β=-0.200, p=0.017).

DISCUSSION

Waist circumference and residential green space were identified as predictors associated with telomere attrition in childhood. These results further support the advantages of a healthy lifestyle from early age onwards and the importance of a green environment to promote molecular longevity from childhood onwards.

Machine Learning for Prediction of Cognitive Health in Adults Using Sociodemographic, Neighbourhood Environmental, and Lifestyle Factors

The environment we live in, and our lifestyle within this environment, can shape our cognitive health. We investigated whether sociodemographic, neighbourhood environment, and lifestyle variables can be used to predict cognitive health status in adults. Cross-sectional data from the AusDiab3 study, an Australian cohort study of adults (34-97 years) (n = 4141) was used. Cognitive function was measured using processing speed and memory tests, which were categorized into distinct classes using latent profile analysis. Sociodemographic variables, measures of the built and natural environment estimated using geographic information system data, and physical activity and sedentary behaviours were used as predictors. Machine learning was performed using gradient boosting machine, support vector machine, artificial neural network, and linear models. Sociodemographic variables predicted processing speed (r2 = 0.43) and memory (r2 = 0.20) with good accuracy. Lifestyle factors also accurately predicted processing speed (r2 = 0.29) but weakly predicted memory (r2 = 0.10). Neighbourhood and built environment factors were weak predictors of cognitive function. Sociodemographic (AUC = 0.84) and lifestyle (AUC = 0.78) factors also accurately classified cognitive classes. Sociodemographic and lifestyle variables can predict cognitive function in adults. Machine learning tools are useful for population-level assessment of cognitive health status via readily available and easy-to-collect data.