Greenspace and human microbiota: A systematic review.

BACKGROUND: Potential effect of greenspace exposure on human microbiota have been explored by a number of observational and interventional studies, but the results remained mixed. We comprehensively synthesized these studies by performing a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. METHODS: Comprehensive literature searches in three international databases (PubMed, Embase, and Web of Science) and three Chinese databases (China National Knowledge Infrastructure, Wanfang, and China Biology Medicine disc) were conducted from inception to November 1, 2023. Observational and interventional studies that evaluated associations between greenspace exposure and human microbiota at different anatomical sites were included. Studies were assessed using the National Toxicology Program's office of Health Assessment and Translation risk of bias tool and certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. Two authors independently performed study selection, data extraction, and risk of bias assessment, and evidence grading. Study results were synthesized descriptively. RESULTS: Twenty studies, including 11 observational studies and 9 interventional studies, were finally included into the systematic review. The microbiota of the included studies was from gut (n = 13), skin (n = 10), oral cavity (n = 5), nasal cavity (n = 5) and eyes (n = 1). The majority of studies reported the associations of greenspace exposure with increased diversity (e.g., richness and Shannon index) and/or altered overall composition of human gut (n = 12) and skin microbiota (n = 8), with increases in the relative abundance of probiotics (e.g., Ruminococcaceae) and decreases in the relative abundance of pathogens (e.g., Streptococcus and Escherichia/Shigella). Due to limited number of studies, evidence concerning greenspace and oral, nasal, and ocular microbiota were still inconclusive. CONCLUSION: The current evidence suggests that greenspace exposure may diversify gut and skin microbiota and alter their composition to healthier profiles. These findings would be helpful in uncovering the potential mechanisms underlying greenspace and human health and in promoting a healthier profile of human microbiota.

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.

Long-term exposure to low-level air pollution and greenness and mortality in Northern Europe. The Life-GAP project.

BACKGROUND: Air pollution has been linked to mortality, but there are few studies examining the association with different exposure time windows spanning across several decades. The evidence for the effects of green space and mortality is contradictory. OBJECTIVE: We investigated all-cause mortality in relation to exposure to particulate matter (PM2.5 and PM10), black carbon (BC), nitrogen dioxide (NO2), ozone (O3) and greenness (normalized difference vegetation index - NDVI) across different exposure time windows. METHODS: The exposure assessment was based on a combination of the Danish Eulerian Hemispheric Model and the Urban Background Model for the years 1990, 2000 and 2010. The analysis included a complete case dataset with 9,135 participants from the third Respiratory Health in Northern Europe study (RHINE III), aged 40-65 years in 2010, with mortality follow-up to 2021. We performed Cox proportional hazard models, adjusting for potential confounders. RESULTS: Altogether, 327 (3.6 %) persons died in the period 2010-2021. Increased exposures in 1990 of PM2.5, PM10, BC and NO2 were associated with increased all-cause mortality hazard ratios of 1.40 (95 % CI1.04-1.87 per 5 µg/m3), 1.33 (95 % CI: 1.02-1.74 per 10 µg/m3), 1.16 (95 % CI: 0.98-1.38 per 0.4 µg/m3) and 1.17 (95 % CI: 0.92-1.50 per 10 µg/m3), respectively. No statistically significant associations were observed between air pollution and mortality in other time windows. O3 showed an inverse association with mortality, while no association was observed between greenness and mortality. Adjusting for NDVI increased the hazard ratios for PM2.5, PM10, BC and NO2 exposures in 1990. We did not find significant interactions between greenness and air pollution metrics. CONCLUSION: Long term exposure to even low levels of air pollution is associated with mortality. Opening up for a long latency period, our findings indicate that air pollution exposures over time may be even more harmful than anticipated.

Impact of long-term exposure to ambient ozone on lung function over a course of 20 years (The ECRHS study): a prospective cohort study in adults.

Background: While the adverse effects of short-term ambient ozone exposure on lung function are well-documented, the impact of long-term exposure remains poorly understood, especially in adults. Methods: We aimed to investigate the association between long-term ozone exposure and lung function decline. The 3014 participants were drawn from 17 centers across eight countries, all of which were from the European Community Respiratory Health Survey (ECRHS). Spirometry was conducted to measure pre-bronchodilation forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) at approximately 35, 44, and 55 years of age. We assigned annual mean values of daily maximum running 8-h average ozone concentrations to individual residential addresses. Adjustments were made for PM2.5, NO2, and greenness. To capture the ozone-related change in spirometric parameters, our linear mixed effects regression models included an interaction term between long-term ozone exposure and age. Findings: Mean ambient ozone concentrations were approximately 65 µg/m³. A one interquartile range increase of 7 µg/m³ in ozone was associated with a faster decline in FEV1 of -2.08 mL/year (95% confidence interval: -2.79, -1.36) and in FVC of -2.86 mL/year (-3.73, -1.99) mL/year over the study period. Associations were robust after adjusting for PM2.5, NO2, and greenness. The associations were more pronounced in residents of northern Europe and individuals who were older at baseline. No consistent associations were detected with the FEV1/FVC ratio. Interpretation: Long-term exposure to elevated ambient ozone concentrations was associated with a faster decline of spirometric lung function among middle-aged European adults over a 20-year period. Funding: German Research Foundation.

Does exposure to nature make children more intelligent? Analysis in Polish children with and without ADHD.

Previous studies have shown that exposure to nature and physical activity (PA) may be associated with higher intelligence in children. We examined whether there is an association between lifelong exposure to greenspace and bluespace and intelligence in children aged 10-13 with and without attention deficit hyperactivity disorder (ADHD), and whether PA mediates this association. The sample (N = 714) was collected within the NeuroSmog case-control study, where children with (N = 206) and without ADHD (N = 508) were recruited from 18 towns in Southern Poland. Nature exposure was estimated as the sum of the z-scores of the objective and perceived measures. Objective greenspace exposure was defined as the percentage of grass and tree cover in 500 m and 1 km buffers around lifelong residential addresses, respectively. Objective bluespace exposure was defined as the percentage of water cover in 500 m and 1 km buffers. Perceived greenspace/bluespace was measured as the parent-rated availability, quality, and use of greenspace/bluespace. Intelligence was assessed using the Polish version of the Stanford-Binet Intelligence Scales, 5th edition (SB5). SB5 Full Scale Intelligence Quotient (IQ), Nonverbal IQ, Verbal IQ, five factor and ten subtest scores were analysed as outcomes. The associations between nature and IQ scores were assessed by linear regressions separately for cases and controls, adjusting the models for sex, parental education, and urbanicity. Structural equation modeling was implemented to test whether PA mediated the association between nature and intelligence. None of the greenspace or bluespace measures were consistently associated with intelligence. PA was not found to be a mediator. We did not find evidence that higher lifelong nature exposure is associated with higher intelligence in Polish schoolchildren with or without ADHD. This casts doubts on whether exposure to nature has relevant influence on IQ.

Air pollution and attention in Polish schoolchildren with and without ADHD.

BACKGROUND: Development and functioning of attention-a key component of human cognition-can be affected by environmental factors. We investigated whether long- and short-term exposure to particulate matter with aerodynamic diameter < 10 µm (PM10) and nitrogen dioxide (NO2) are related to attention in 10- to 13-year-old children living in Polish towns recruited in the NeuroSmog case-control study. METHODS: We investigated associations between air pollution and attention separately in children with attention deficit hyperactivity disorder (ADHD, n = 187), a sensitive, at-risk population with impaired attention and in population-based typically developing children (TD, n = 465). Alerting, orienting, and executive aspects of attention were measured using the attention network test (ANT), while inhibitory control was measured with the continuous performance test (CPT). We assessed long-term exposure to NO2 and PM10 using novel hybrid land use regression (LUR) models. Short-term exposures to NO2 and PM10 were assigned to each subject using measurements taken at the air pollution monitoring station nearest to their home address. We tested associations for each exposure-outcome pair using adjusted linear and negative binomial regressions. RESULTS: We found that long-term exposures to both NO2 and PM10 were associated with worse visual attention in children with ADHD. Short-term exposure to NO2 was associated with less efficient executive attention in TD children and more errors in children with ADHD. It was also associated with shorter CPT response times in TD children; however, this effect was accompanied by a trend towards more CPT commission errors, suggestive of more impulsive performance in these subjects. Finally, we found that short-term PM10 exposure was associated with fewer omission errors in CPT in TD children. CONCLUSIONS: Exposure to air pollution, especially short-term exposure to NO2, may have a negative impact on attention in children. In sensitive populations, this impact might be different than in the general population.

Residential greenspace and lung function decline over 20 years in a prospective cohort: The ECRHS study.

BACKGROUND: The few studies that have examined associations between greenspace and lung function in adulthood have yielded conflicting results and none have examined whether the rate of lung function decline is affected. OBJECTIVE: We explored the association between residential greenspace and change in lung function over 20 years in 5559 adults from 22 centers in 11 countries participating in the population-based, international European Community Respiratory Health Survey. METHODS: Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were measured by spirometry when participants were approximately 35 (1990-1994), 44 (1999-2003), and 55 (2010-2014) years old. Greenness was assessed as the mean Normalized Difference Vegetation Index (NDVI) in 500 m, 300 m, and 100 m circular buffers around the residential addresses at the time of lung function measurement. Green spaces were defined as the presence of agricultural, natural, or urban green spaces in a circular 300 m buffer. Associations of these greenspace parameters with the rate of lung function change were assessed using adjusted linear mixed effects regression models with random intercepts for subjects nested within centers. Sensitivity analyses considered air pollution exposures. RESULTS: A 0.2-increase (average interquartile range) in NDVI in the 500 m buffer was consistently associated with a faster decline in FVC (-1.25 mL/year [95% confidence interval: -2.18 to -0.33]). These associations were especially pronounced in females and those living in areas with low PM10 levels. We found no consistent associations with FEV1 and the FEV1/FVC ratio. Residing near forests or urban green spaces was associated with a faster decline in FEV1, while agricultural land and forests were related to a greater decline in FVC. CONCLUSIONS: More residential greenspace was not associated with better lung function in middle-aged European adults. Instead, we observed slight but consistent declines in lung function parameters. The potentially detrimental association requires verification in future studies.

Family Functioning Style as a Predictor of the Quality of Cognitive Functioning of Primary School Students With ADHD.

OBJECTIVE: This study aimed to specify whether family communication and satisfaction are predictors of a child's executive functions and whether attention deficit hyperactivity disorder (ADHD) severity lies in the pathway between these variables. METHOD: Two hundred Polish children with ADHD, aged 10 to 13, were tested using Conners 3, the PU1 Battery of Cognitive Tests and Stanford-Binet Intelligence Scale, Fifth Edition (SB5). Parents filled out the FACES IV-SOR questionnaire. Structural equation modeling (SEM) was used to test the hypotheses. RESULTS: The quality of family communication and satisfaction did not predict executive functioning in children with ADHD, and ADHD severity did not play a mediating role neither in boys or in girls. Intelligent quotient was the only predictor of executive functioning in the group of boys. CONCLUSION: These results contrast with those of previous studies that have shown the existence of similar associations in other cultural contexts.

Gene-environment interaction in the association of residential greenness and 25(OH) vitamin D.

There is increasing awareness for beneficial health effects of green space surrounding the home, but the underlying mechanisms are not yet fully understood and challenging to study given the correlation with other exposures. Here, the association of residential greenness and vitamin D including a gene-environment interaction is investigated. 25-hydroxyvitamin D (25(OH)D) was measured by electrochemiluminescence at ages 10 and 15 years in participants of two German birth cohorts GINIplus and LISA. Greenness was measured using the Landsat-derived Normalized Difference Vegetation Index (NDVI) in a 500 m buffer surrounding the home. Linear and logistic regression models were applied at both time points adjusted for several covariates (N10Y = 2,504, N15Y = 2,613). In additional analyses vitamin D-related genes, physical activity, time spent outdoors, supplements, and measurement season were investigated as potential confounders or effect modifiers. A 1.5-SD increase in NDVI was significantly associated with increased 25(OH)D values at ages 10 and 15 years (ß10y = 2.41 nmol/l, p=<0.01; ß15y = 2.03 nmol/l, p = 0.02). In stratified analyses, the associations were not seen in participants spending more than 5 h/day outside in summer, having a high physical activity level, taking supplements, or being examined during the winter season. In a subset (n = 1,732) with genetic data, a significant gene-environment interaction of NDVI with CYP2R1, an upstream gene in 25(OH)D synthesis, was observed at age 10 years. When investigating 25(OH)D sufficiency, defined as values above 50 nmol/l, a 1.5-SD increase in NDVI was associated with significantly higher odds of having sufficient 25 (OH)D levels at age 10 years (OR = 1.48, 1.19-1.83). In conclusion, robust associations between residential greenness and 25 (OH)D levels were observed in children and adolescents independent of other confounders and additionally supported by the presence of a gene-environment interaction. Effects of NDVI were stronger in those having lower vitamin D levels at age 10 years due to their covariate profile or genetically lower 25(OH)D synthesis.

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.

Association of residential and school green- and bluespace with academic performance in 10-13-year-old Polish schoolchildren with and without attention deficit hyperactivity disorder.

BACKGROUND: Several studies, mostly based on the USA data, have reported that school greenspace was associated with better academic performance. However, nearly all of them were conducted on aggregated data. We are among the first individual data-based studies worldwide to examine whether exposure to school and residential green- and bluespace can boost academic performance. METHODS: NeuroSmog is an ongoing case-control study investigating the impact of air pollution on brain development in children with and without attention deficit hyperactivity disorder (ADHD). 658 children aged 10 to 13 years from 18 large and small towns in southern Poland constituted the analytical sample. Information about latest end-of-year school grades in Polish and maths was collected by the parent report while perceived academic performance in these subjects was collected by the Youth Self-Report. Tree, grass, and water cover, as well as overall vegetation, were abstracted in Euclidean buffers of 500 and 1000 m around concurrent school and residential addresses. Perceived green- and bluespace data were also collected. Adjusted for age, sex, parent education, financial situation, and urbanicity, logistic models were fitted to assess the associations between each exposure-outcome pair. RESULT: We found no consistent associations between academic performance and school or residential green- and bluespace. This held true for children with and without ADHD. CONCLUSIONS: Higher residential and school green- and bluespace do not seem to be sufficient for better academic performance.

When green enters a room: A scoping review of epidemiological studies on indoor plants and mental health.

BACKGROUND: Increasing numbers of epidemiological studies are investigating the association between outdoor greenery and various health outcomes. However, in the case of indoor plants, although experimental studies seem relatively abundant, epidemiological studies remain scarce, and research considering the mental health effects is even more limited. Thus, we aim to identify and summarise the relevant epidemiological studies on indoor plant exposure and mental health via this scoping review, thereby presenting the current state of knowledge and research niches. METHODS: PubMed and PsycINFO were systematically searched for epidemiological studies on indoor plant exposure and mental health, including mental and behavioural disorders, quality of life, and cognitive function. The publication period was from the inception of these two databases to 22nd June 2022. We extracted information on exposure to indoor plants and mental health-related outcomes from the relevant studies. RESULTS: The systematic search yielded 1186 unique results. Six studies met the inclusion criteria and were finally included in this scoping review. All included studies were Europe-based cross-sectional studies on mental and behavioural disorders. One study was conducted in 2015 and investigated the office environment, whereas the other five were conducted during the COVID-19 pandemic and focused on the home environment. Despite considerable heterogeneity in outcome assessments and indoor plant exposure metrics, all six studies generally reported beneficial associations between having indoor plants and mental health, such as reducing stress, depressive symptoms, and negative emotions. CONCLUSIONS: Epidemiological evidence on exposure to indoor plants and mental health is currently limited. In general, favourable effects of indoor plants are supported, although most relevant studies were conducted in the context of COVID-19. Before conducting more studies to explore the associations, data collection methods must be refined with more elaborate designs that allow for the measurement of more comprehensive metrics of indoor plants. REGISTRATION: Open Science Framework, osf.io/5xr6b.

Long-term air pollution exposure, greenspace and health-related quality of life in the ECRHS study.

BACKGROUND: Associations of long-term exposure to air pollution and greenspace with health-related quality of life (HRQOL) are poorly studied and few studies have accounted for asthma-rhinitis status. OBJECTIVE: To assess the associations of air pollution and greenspace with HRQOL and whether asthma and/or rhinitis modify these associations. METHODS: The study was based on the participants in the second (2000-2002, n = 6542) and third (2011-2013, n = 3686) waves of the European Community Respiratory Health Survey (ECRHS) including 19 centres. The mean follow-up time was 11.3 years. HRQOL was assessed by the SF-36 Physical and Mental Component Summary scores (PCS and MCS). NO2, PM2.5 and PM10 annual concentrations were estimated at the residential address from existing land-use regression models. Greenspace around the residential address was estimated by the (i) mean of the Normalized Difference Vegetation Index (NDVI) and by the (ii) presence of green spaces within a 300 m buffer. Associations of each exposure variable with PCS and MCS were assessed by mixed linear regression models, accounting for the multicentre design and repeated data, and adjusting for potential confounders. Analyses were stratified by asthma-rhinitis status. RESULTS: The mean (SD) age of the ECRHS-II and III participants was 43 (7.1) and 54 (7.2) years, respectively, and 48 % were men. Higher NO2, PM2.5 and PM10 concentrations were associated with lower MCS (regression coefficients [95%CI] for one unit increase in the inter-quartile range of exposures were -0.69 [-1.23; -0.15], -1.79 [-2.88; -0.70], -1.80 [-2.98; -0.62] respectively). Higher NDVI and presence of forests were associated with higher MCS. No consistent associations were observed for PCS. Similar association patterns were observed regardless of asthma-rhinitis status. CONCLUSION: European adults who resided at places with higher air pollution and lower greenspace were more likely to have lower mental component of HRQOL. Asthma or rhinitis status did not modify these associations.

Ambient ozone exposure and bone turnover markers in children: Results from the GINIplus and LISA birth cohorts.

BACKGROUND: Multiple environmental factors can regulate bone metabolism, and it is hypothesized that air pollution may be deleteriously involved in this regulation. However, only a few studies considered bone turnover markers (BTMs) - sensitive and specific markers of bone metabolism - as outcomes, and no study investigated the exposure to ambient ozone. Here, we intended to explore the associations between long-term exposure to ambient ozone and concentrations of two BTMs, osteocalcin and ß-isomer of C-terminal telopeptide of type I collagen (CTx), amongst 10-year-old children. METHODS: Based on the GINIplus and LISA birth cohorts, our cross-sectional analysis included 1848 children aged 10 years from Munich and Wesel. Serum osteocalcin and CTx concentrations were measured. We estimated ozone exposures by optimal interpolation, assessed nitrogen dioxide and particulate matter with an aerodynamic diameter <10 µm concentrations by land use regression models, and assigned the exposures to home addresses. Linear regression models were built and adjusted for covariates as well as co-pollutants. RESULTS: The mean concentrations were 93.09 ng/mL and 663.66 ng/L for osteocalcin and CTx, respectively. In general, higher levels of ozone were associated with decreased concentrations of both BTMs. This held true for the two areas and different exposure metrics. The number of days per year with a maximum 8-h average concentration exceeding 120 µg/m³ showed consistent results across different models. Specifically, models adjusted for co-pollutants illustrated that the beta estimates and 95% confidence intervals on osteocalcin and CTx were -2.51 (-3.78, -1.14) and -44.53 (-57.12, -31.93), respectively, for an increase of 10 days. CONCLUSIONS: We found that long-term exposure to ambient ozone was associated with decreased concentrations of BTMs in German children. This association might potentially affect bone metabolism. Nevertheless, unless other prospective studies confirm our results, the detrimental effects of ambient ozone on bone development in children should be interpreted cautiously.

Home gardens and distances to nature associated with behavior problems in alpine schoolchildren: Role of secondhand smoke exposure and biomarkers.

BACKGROUND: Behavior problems in children are shaped by a complex intertwining of environmental, social, and biological factors. This study investigated whether more nature exposure was associated with less behavior problems and whether these associations were mediated by differences in secondhand smoke in the home, sleep problems, adiposity, and inflammation. METHODS: We used cross-sectional data collected from 1251 schoolchildren (8-12 years old) in the Tyrol region of Austria and Italy. Information on sociodemographics, lifestyle, perinatal data, and housing conditions was obtained by questionnaire. Behavior problems in the past school year were rated by teachers using the Needleman questionnaire for classroom performance. We estimated nature exposure using a comprehensive naturalness index called "distance to nature" (D2N). This was calculated in several buffer sizes around the child's home and school. Presence of a home garden was assessed by self-report. Data on potential mediators including parental smoking in the home, child's urinary cotinine concentrations, sleep problems, body mass index, and urinary neopterin concentrations were also collected. Structural equation modeling was used to examine the multiple pathways between nature exposure and behavior problems. RESULTS: Children who lived in a home with a garden and those whose school was closer to nature exhibited less school behavior problems. The effect of proximity to nature from the school was directly associated with less behavior problems, and the effect of a home garden on behavior problems acted indirectly through a lower likelihood of secondhand smoke exposure. Associations were in unexpected directions between behavior problems and residential proximity to nature and depended on the outcome and context. CONCLUSIONS: Natural environments in school and home surroundings might be beneficial for school conduct and performance. Lower secondhand smoke exposure at home might be a pathway between home gardens and children's behavioral problems. Associations with residential proximity to nature in this study were in unexpected directions and warrant further investigation. These findings serve as a point of departure for investigating how proximal nature might activate health supportive pathways in children and simultaneously confer childhood health benefits via positive behavioral changes in their parents.

Residential green space and age at menarche in German and Australian adolescent girls: A longitudinal study.

BACKGROUND: A large multicentre European study reported later onset of menopause among women residing in greener areas. This influence on the timing of a reproductive event like menopause, raises the question whether similar associations can be observed with timing of menarche. We investigated whether exposure to residential green space was related to the age at menarche in German and Australian adolescent girls. METHODS: The analytic samples comprised of 1706 German and 1474 Australian adolescent girls. Percentage of green space was calculated in 1000 m buffers around a residential address or its surrogate at the previous follow-up. Mixed effects Cox proportional hazard models were used to explore the associations. The survival object was the occurrence of menarche at the time of follow-up (15-year follow-up of the German cohorts and the study wave at 14-15 years in the Australian cohort) and number of years since baseline (10-year follow-up in the German cohort and the study wave at 10-11 years in the Australian cohort). Participants who did not reach menarche were included as censored observations. RESULTS: A greener residence was not associated with the age at menarche. Null findings were consistent in the general population and in analyses stratified by socioeconomic status or urbanicity in both countries. Urban residents were more likely to have earlier menarche, and this association was consistent across Germany and Australia. CONCLUSION: The results of our analysis do not support the hypothesis that residing in places with more green space can influence timing of menarche. However, given the limitations of our study, researchers should not be discouraged to further explore environmental risk factors of early menarche.

Associations of greenness surrounding schools with blood pressure and hypertension: A nationwide cross-sectional study of 61,229 children and adolescents in China.

BACKGROUND: Greenness exposure may lower blood pressure. However, few studies of this relationship have been conducted with children and adolescents, especially in low and middle-income countries. OBJECTIVES: To evaluate associations between greenness around schools and blood pressure among children and adolescents across China. METHODS: We recruited 61,229 Chinese citizens aged 6-18 years from 94 schools in a nationwide cross-sectional study in seven Chinese provinces/province-level municipalities. Participants' blood pressures and hypertension were assessed with standardized protocols. Greenness levels within 500 m and 1,000 m of each school were estimated with three satellite-based indices: vegetation continuous fields (VCF), normalized difference vegetation index (NDVI), and soil adjusted vegetation index (SAVI). Generalized linear mixed models were used to evaluate associations between greenness and blood pressure, greenness and prevalent hypertension, using coefficient and odds ratio respectively. Stratified analyses and mediation analyses were also performed. RESULTS: One interquartile range increase in greenness was associated with a 17%-20% reduced prevalence of hypertension for all measures of greenness (odds ratios for VCF500m = 20% (95% CI:18%, 23%); for NDVI500m = 17% (95% CI:13%, 21%); and for SAVI500m = 17% (95% CI: 13%, 20%). Increases in greenness were also associated with reductions in systolic blood pressure (0.48-0.58 mmHg) and diastolic blood pressure (0.26-0.52 mmHg). Older participants, boys, and urban dwellers showed stronger associations than their counterparts. No evidence of mediation was observed for air pollution (i.e., NO2 and PM2.5) and body mass index. CONCLUSION: Higher greenness around schools may lower blood pressure levels and prevalent hypertension among Chinese children and adolescents, particularly in older subjects, boys, and those living in urban districts. Further studies, preferably longitudinal, are needed to examine causality.

Natural and built environments and blood pressure of Alpine schoolchildren.

BACKGROUND: Early life environments may influence children's blood pressure (BP), but evidence on the combined effects of natural and built environment exposures is scarce. The present study investigates the associations of natural and built environment indicators, traffic noise, and air pollution with BP in children living in Alpine valleys. METHODS: In 2004/2005, 1251 school children (8-12 years old) were sampled for a cross-sectional survey in several Austrian and Italian mountain valleys. Children's mothers completed a questionnaire. The outcomes of interest were systolic and diastolic BP measured with a calibrated oscillometric device. Indicators of land cover assigned to the residential and school coordinates within 100 and 1000 m included normalized difference vegetation index (NDVI), tree canopy cover, and a broader naturalness indicator titled distance to nature (D2N). The presence of a home garden was also measured via self-report. Imperviousness density served as a proxy for the built environment. Residential air pollution (NO2) and noise (Lden) from traffic were calculated using bespoke modeling. NO2, Lden, physical activity, and body mass index (BMI) were treated as mediating pathways. RESULTS: Higher NDVI and tree cover levels in residential and school surroundings and home gardens were consistently associated with lower BP. The built environment was associated with higher BP. Counterintuitive inverse associations between NO2 and Lden and BP were also found. Structural equation modeling showed that higher levels of greenspace and presence of a home garden were weakly associated with more outdoor play spaces, and in turn with lower BMI, and ultimately with lower BP. CONCLUSIONS: Exposure to natural environments may help maintain normal BP in children, while built environment may increase children's BP. Outdoor play and less adiposity in greener areas may mediate some of these associations. Evidence on air pollution and noise remains controversial and difficult to explain.

Green space quality and adolescent mental health: do personality traits matter?

INTRODUCTION: Adolescents, especially females, tend to experience poorer mental health if they are higher in introversion and neuroticism. As a result, they also may have more to gain from having quality green space (e.g. parks) nearby to enable restoration, but this remains tested. METHOD: Cross-sectional data on 2946 adolescents aged 16-17y were extracted from the Longitudinal Study of Australian Children. Multilevel linear regressions assessed association between parent/caregiver green space quality perception with self-reported Strengths and Difficulties Questionnaire Total Difficulties Scores (TDS) and internalising (e.g. anxiety) and externalising (e.g. fidgetiness) subscales. Models were weighted for representativeness, accounted for spatial clustering within postcodes, and adjusted for geographic stratum and socioeconomic confounders. This was followed by adjustment for introversion and neuroticism, and then three-way interaction terms between each trait, green space quality and sex to assess for potential effect modification. RESULTS: Quality green spaces was associated with higher TDS (ß = 1.506; SE = 0.371), internalising (ß = 0.982; SE = 0.220) and externalising (ß = 0.518; SE = 0.234) scores (i.e. poorer mental health). Introversion was associated with higher TDS (ß = 1.416; SE = 0.089), higher internalising (ß = 1.233; SE = 0.050) and higher externalising scores (ß = 0.181; SE = 0.056). Similar associations were observed for neuroticism and TDS (ß = 2.283; SE = 0.084), internalising (ß = 1.627; SE = 0.046) and externalising scores (ß = 0.656; SE = 0.056). Mean levels of introversion were similar for girls and boys (1.73 vs 1.76, p = 0.6573), but mean levels of neuroticism were notably higher in girls than boys (2.42 and 1.67, p < 0.0001). Likelihood ratio tests indicated three-way interactions improved models analysing the internalising subscale outcome only. Green space quality made no difference to associations between introversion or neuroticism and internalising scores in males. Quality green space was associated with 3.2 and 2.1 reductions in mean internalising scores among females with the highest levels of introversion or neuroticism, respectively. CONCLUSIONS: Individual differences in psychological traits may predispose some adolescents, and females especially, to restoration from green space.