A Systematic Review and Meta-Analysis of Associations between Green and Blue Spaces and Birth Outcomes

Contributions of neighborhood physical and social environments to racial and ethnic disparities in birth outcomes in California: a mediation analysis

BACKGROUND

Racially minoritized populations experience higher rates of adverse birth outcomes than White populations in the U.S. We estimated the mediating effect of neighborhood social and physical environments on disparities in adverse birth outcomes in California.

METHOD

We used birthing parent's residential address for California live birth records from 2019 to estimate census block group Area Deprivation Index and census tract level measures of ambient fine particulate matter (PM2.5), drinking water contamination, tree canopy coverage, as a measure of greenspace, potential heat vulnerability, and noise. We performed mediation analysis to assess whether neighborhood factors explain racial/ethnic disparities in preterm birth (PTB) and term-birth low birth weight (TLBW) comparing Black, Latinx, and Asian with White births after controlling for individual-level factors.

RESULTS

Black, Latinx, and Asian parents had PTB rates that were 67%, 36%, and 11% higher, and TLBW rates that were 150%, 38%, and 81% higher than Whites. Neighborhood deprivation contributed 7% (95% CI: 3%, 11%) to the Black-White and 9% (95% CI: 6%, 12%) to the Latinx-White disparity in PTB, and 8% (95% CI: 3%, 12%) of the Black-White and 9% (95% CI: 5%, 15%) of the Latinx-White disparity in TLBW. Drinking water contamination contributed 2% (95% CI: 1%, 4%) to the Latinx-White disparity in PTB. Lack of greenspace accounted for 7% (95% CI: 2%, 10%) of the Latinx-White PTB disparity and 7% (95% CI: 3%, 12%) of the Asian-White PTB disparity. PM2.5 contributed 11% (95% CI: 5%, 18%), drinking water contamination contributed 3% (95% CI: 1%, 7%), and potential heat vulnerability contributed 2% (95% CI: 1%, 3%) to the Latinx-White TLBW disparity. Lack of green space contributed 3% (95% CI: 1%, 6%) to the Asian-White TLBW disparity.

CONCLUSIONS

Our study suggests social environments explain portions of Black/Latinx-White disparities while physical environments explain Latinx/Asian-White disparities in PTB and TLBW.

Visiting natural open spaces in urban areas during pregnancy and its association with daily physical activity

We examined the association between visiting natural open spaces (NOS) and physical activity (PA) at different trimesters of pregnancy. We used GPS and accelerometer data from women residing in Donostia-San Sebastian and Barcelona. Daily visits to NOS were associated with an increase of circa 8 min of moderate to vigorous physical activity (MVPA) in the first and second trimesters of pregnancy. Women who visited NOS were more likely to meet the WHO daily PA guidelines during the first trimester. Visiting NOS can promote PA consistently during pregnancy, improving maternal health and well-being in urban settings.

A cohort study of the multipollutant effects of PM2.5, NO2, and O3 on C-reactive protein levels during pregnancy

Background

PM2.5, NO2, and O3 contribute to the development of adverse pregnancy complications. While studies have investigated the independent effects of these exposures, literature on their combined effects is limited. Our objective was to study the multipollutant effects of PM2.5, NO2, and O3 on maternal systemic C-reactive protein (CRP) levels.

Methods

We used data from 1170 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals Study (MIREC) study in Canada. Air pollution exposures were assigned to each participant based on residential location. CRP was measured in third-trimester blood samples. We fit multipollutant linear regression models and evaluated the effects of air pollutant mixtures (14-day averages) using repeated-holdout Weighted Quantile Sum (WQS) regression and by calculating the Air Quality Health Index (AQHI).

Results

In multipollutant models adjusting for NO2, O3, and green space, each interquartile range (IQR) increase in 14-day average PM2.5 (IQR: 6.9 µg/m3) was associated with 27.1% (95% confidence interval [CI] = 6.2, 50.7) higher CRP. In air pollution mixture models adjusting for green space, each IQR increase in AQHI was associated with 37.7% (95% CI = 13.9, 66.5) higher CRP; and an IQR increase in the WQS index was associated with 78.6% (95% CI = 29.7, 146.0) higher CRP.

Conclusion

PM2.5 has the strongest relationship of the individual pollutants examined with maternal blood CRP concentrations. Mixtures incorporating all three pollutants, assessed using the AQHI and WQS index, showed stronger relationships with CRP compared with individual pollutants and illustrate the importance of conducting multipollutant analyses.

Greenspaces and Health: Scoping Review of studies in Europe

Objectives

Access to greenspaces and contact with nature can promote physical activity and have positive effects on physical and mental health. This scoping literature review aims to examine current evidence linking greenspaces and (a) behaviour change, (b) health outcomes and (c) co-benefits.

Methods

This review was conducted in accordance with the PRISMA scoping review guidelines. Searches were conducted through PubMed and EMBASE databases for studies published between 2000 and March 2023 with a focus on Europe.

Results

122 scientific articles and grey literature reports were identified. Access to greenspaces is positively associated with physical and mental health, and reduced risk of all-cause mortality and some non-communicable diseases. Greenspace quality is associated with increased physical activity and reduced risk of obesity. Nature-based therapies or green prescription are effective in improving mental health outcomes and overall health. Importantly, numerous co-benefits of greenspaces are identified.

Conclusion

Increasing access to greenspaces for populations with particular attention to greenspace quality is important for co-benefits. Responsible governance and use of greenspaces are crucial to minimize public health risks and human disturbance of nature.

Measuring Greenspace in Rural Areas for Studies of Birth Outcomes: A Comparison of Street View Data and Satellite Data

Using street view data, in replace of remotely sensed (RS) data, to study the health impact of greenspace has become popular. However, direct comparisons of these two methods of measuring greenspace are still limited, and their findings are inconsistent. On the other hand, almost all studies of greenspace focus on urban areas. The effectiveness of greenspace in rural areas remains to be investigated. In this study, we compared measures of greenspace based on the Google Street View data with those based on RS data by calculating the correlation between the two and evaluating their associations with birth outcomes. Besides the direct measures of greenness, we also compared the measures of environmental diversity, calculated with the two types of data. Our study area consists of the States of New Hampshire and Vermont, USA, which are largely rural. Our results show that the correlations between the two types of greenness measures were weak to moderate, and the greenness at an eye-level view largely reflects the immediate surroundings. Neither the street view data- nor the RS data-based measures identify the influence of greenspace on birth outcomes in our rural study area. Interestingly, the environmental diversity was largely negatively associated with birth outcomes, particularly gestational age. Our study revealed that in rural areas, the effectiveness of greenspace and environmental diversity may be considerably different from that in urban areas.

Effects of land cover and air pollution on the risk of preterm births

OBJECTIVE

To evaluate the association between gestational age and green areas, urban built areas, and the concentration of particulate matter 2.5 (PM2.5) in the city of São Paulo, analyzing the irregular distribution of these areas and pollution levels above the recommended level.

METHODS

The study population consisted of a cohort of live births from 2012, and data from the Live Birth Information System (Sinasc) of the city of São Paulo were used. Using satellite images and supervised classification, the distribution and quantity of green areas and built areas in the city of São Paulo was obtained, as well as the concentrations of PM2.5. Logistic regressions were used to obtain possible associations.

RESULTS

The results of the study show that a lower percentage of green areas is significantly associated with a higher chance of preterm births. A higher building density was positively associated with the odds ratio for preterm birth. We did not find any significant associations between air pollution (PM2.5) and preterm births.

CONCLUSIONS

The results of this study show that greener areas are less associated with preterm births when compared with less green areas.

Association between residential green spaces and pregnancy outcomes: a systematic review and meta-analysis

Residential exposure to greenness has shown positive influences on pregnancy outcomes like birth weight, preterm births, and small to gestational age (SGA) deliveries. We aimed to comprehensively review and investigate these associations by conducting a systematic review with meta-analysis. Relevant studies were retrieved from PubMed, EMBASE, ScienceDirect, and Google Scholar databases before June 2023. Summary effect estimates included birth weight, low birth weight (LBW), preterm births, and SGA which were calculated for 0.1 unit increase in residential greenness exposure. Overall quality of the evidence was examined through Joanna Briggs Institute (JBI) critical appraisal tool. The review included 31 articles and found a statistically significant increase in birth weight measured at 250 m buffer distance (β = 8.95, 95% CI = 1.63-16.27). Green spaces were also associated with lower odds of LBW (OR = 0.97, 95% CI = 0.96-0.98). Residential greenness had positive impacts on pregnancy outcomes that calls for emphasis on urban planning, especially in developing countries.

More than greening: Using a novel index to assess restorative nature and vulnerability relationships

Urban living limits access to nature yet spending time in nature is crucial for human health and well-being. To overcome this, urban planners and policymakers are actively looking for different ways to conserve and create more urban nature through parks, street trees, and other greening strategies. However, research shows that in most cities, these greening efforts are not equitably distributed, nor are they equal in terms of their quality or benefits they provide. Creating more equitable access to urban nature is a challenge and a priority in the next decade, and so is improving the quality of urban nature and associated benefits for urbanites. To address this challenge and contribute at both practical and conceptual levels, we propose a new Local Restorative Nature (LRN) index for geospatially assessing the "restorative quality" of urban nature that can support mental well-being. To contextualize the LRN index, we map the distribution of restorative nature in relation to social vulnerability in Vancouver, Canada. The novel LRN index provides critical insights showing that many neighborhoods with vulnerable populations in Vancouver have less exposure to restorative nature to support mental health and highlights where to strategically prioritize urban greening investment in areas that need it the most. The LRN index is scalable and can be used by urban planners in other cities and contexts to improve equitable distribution of restorative nature and better support urbanites' well-being.

Associations of green and blue space exposure in pregnancy with epigenetic gestational age acceleration

Early life is seen as a particularly sensitive period for environmental exposures. Natural space exposure during pregnancy has been associated with offspring health. Epigenetic gestational age acceleration, a discrepancy between clinical and DNA methylation-based gestational age, may underlie these associations. In 1359 mother-newborn pairs from the population-based Generation R Study, we examined the associations of natural space exposure, defined as surrounding greenness, distance to major green and blue (water) space, and size of the blue space during pregnancy with offspring epigenetic gestational age acceleration. Natural space exposure was based on participants' geocoded addresses, and epigenetic gestational age acceleration was calculated from cord blood DNA methylation using Bohlin's and Knight's epigenetic clocks. Sensitivity analyses were conducted in a subgroup of newborns with optimal pregnancy dating, based on last menstrual period. Surrounding greenness, measured in normalized difference vegetation index values, was intermediate (median 0.4, IQR 0.2), and 84% and 56% of the participants had a major green or blue space near their home address, respectively. We did not observe associations of natural space availability during pregnancy with offspring epigenetic gestational age acceleration. This could imply that epigenetic gestational age acceleration in cord blood does not underlie the effects of residential natural space availability in pregnancy on offspring health. Future studies could investigate whether residential natural space availability during pregnancy is associated with offspring differential DNA methylation at other CpGs than those included in the epigenetic gestational clocks.

Nature-based biopsychosocial resilience: An integrative theoretical framework for research on nature and health

Nature-based solutions including urban forests and wetlands can help communities cope better with climate change and other environmental stressors by enhancing social-ecological resilience. Natural ecosystems, settings, elements and affordances can also help individuals become more personally resilient to a variety of stressors, although the mechanisms underpinning individual-level nature-based resilience, and their relations to social-ecological resilience, are not well articulated. We propose 'nature-based biopsychosocial resilience theory' (NBRT) to address these gaps. Our framework begins by suggesting that individual-level resilience can refer to both: a) a person's set of adaptive resources; and b) the processes by which these resources are deployed. Drawing on existing nature-health perspectives, we argue that nature contact can support individuals build and maintain biological, psychological, and social (i.e. biopsychosocial) resilience-related resources. Together with nature-based social-ecological resilience, these biopsychosocial resilience resources can: i) reduce the risk of various stressors (preventive resilience); ii) enhance adaptive reactions to stressful circumstances (response resilience), and/or iii) facilitate more rapid and/or complete recovery from stress (recovery resilience). Reference to these three resilience processes supports integration across more familiar pathways involving harm reduction, capacity building, and restoration. Evidence in support of the theory, potential interventions to promote nature-based biopsychosocial resilience, and issues that require further consideration are discussed.

Place-Based Strategies Addressing Neighborhood Environments to Improve Perinatal and Preterm Infant Outcomes

Preterm birth (defined as birth <37 weeks of gestation) is a significant health concern globally, with lasting implications for individuals, families, and society. In the United States, high preterm birth rates among Black and low-income populations likely result from differences in environmental exposures. Structural racism and economic disadvantage have led to unequal distribution of polluting industrial sites and roadways across society as well as differential access to health-promoting resources which contribute to preterm birth risk. Once born, preterm infants remain at risk for numerous environmentally responsive adverse health outcomes that affect growth and development throughout childhood and adulthood. In this commentary, we describe associations of neighborhood environments with pregnancy and preterm infant health outcomes and propose strategies to address harmful exposures that affect families across the lifespan.

The impact of place-based contextual social and environmental determinants on preterm birth: A systematic review of the empirical evidence

The objective of this study was to systematically review the available empirical evidence examining associations between preterm birth (PTB) and five domains of place-based contextual social and environmental determinants, including (1) physical environment, (2) residential greenness, (3) neighborhood violence/crime, (4) food accessibility and availability, and (5) health services accessibility, among adult mothers in high-income countries. The evidence in this review suggests an adverse association between damaged physical environment, neighborhood violence/crime, lack of health services accessibility, and PTB. The existing evidence also suggests a beneficial effect of residential greenness on PTB. Further studies are needed to investigate these associations for more understanding of the direction and magnitude of these association and for potential heterogeneity by factors such as race/ethnicity, urban vs rural residence, immigration status, and social class.

A spatial indicator of environmental and climatic vulnerability in Rome

BACKGROUND

Urban areas are disproportionately affected by multiple pressures from overbuilding, traffic, air pollution, and heat waves that often interact and are interconnected in producing health effects. A new synthetic tool to summarize environmental and climatic vulnerability has been introduced for the city of Rome, Italy, to provide the basis for environmental and health policies.

METHODS

From a literature overview and based on the availability of data, several macro-dimensions were identified on 1,461 grid cells with a width of 1 km² in Rome: land use, roads and traffic-related exposure, green space data, soil sealing, air pollution (PM_2.5, PM₁₀, NO₂, C₆H₆, SO₂), urban heat island intensity. The Geographically Weighted Principal Component Analysis (GWPCA) method was performed to produce a composite spatial indicator to describe and interpret each spatial feature by integrating all environmental dimensions. The method of natural breaks was used to define the risk classes. A bivariate map of environmental and social vulnerability was described.

RESULTS

The first three components explained most of the variation in the data structure with an average of 78.2% of the total percentage of variance (PTV) explained by the GWPCA, with air pollution and soil sealing contributing most in the first component; green space in the second component; road and traffic density and SO₂ in the third component. 56% of the population lives in areas with high or very high levels of environmental and climatic vulnerability, showing a periphery-centre trend, inverse to the deprivation index.

CONCLUSIONS

A new environmental and climatic vulnerability indicator for the city of Rome was able to identify the areas and population at risk in the city, and can be integrated with other vulnerability dimensions, such as social deprivation, providing the basis for risk stratification of the population and for the design of policies to address environmental, climatic and social injustice.

Associations between Residential Greenspace and Fecundability in a North American Preconception Cohort Study

BACKGROUND

Residential green space can have positive physiological effects on human health through various mechanisms, including reducing stress and/or depression or facilitating physical activity. Although green space has been consistently associated with improved birth outcomes in several studies, there has been limited study of its effect on other reproductive outcomes, including fertility.

OBJECTIVE

We examined associations between residential green space and fecundability, the per-cycle probability of conception.

METHODS

We analyzed data from 8,563 female participants enrolled between 2013 and 2019 in Pregnancy Study Online (PRESTO), a prospective preconception cohort study of North American couples attempting conception. Participants completed a baseline questionnaire on sociodemographic, behavioral, and reproductive factors, and bimonthly follow-up questionnaires for up to 12 months to ascertain pregnancies. Using geocoded addresses, we calculated residential green space exposure using the Normalized Difference Vegetation Index (NDVI) within 50-, 100-, 250-, and 500 -m buffers across multiple temporal scales: annual maximum, seasonal maximum, and seasonal mean. We used proportional probabilities regression models to estimate fecundability ratios (FRs), adjusting for sociodemographic, behavioral, and neighborhood characteristics. We also evaluated the extent to which associations were mediated by reductions in perceived stress or depressive symptoms and increased physical activity.

RESULTS

When comparing the highest (≥ 0.8 ) with the lowest (< 0.2 ) NDVI exposures within 50 m , we observed positive associations in the annual maximum NDVI [FR: 1.33; 95% confidence interval (CI): 1.06, 1.67] and seasonal maximum NDVI (FR: 1.19; 95% CI: 1.00, 1.41) models, but little association in the seasonal mean NDVI models (FR: 0.98; 95% CI: 0.73, 1.30). Restricted cubic splines showed evidence of nonlinearity in this association. Results were similar across buffer distances. Perceived stress, depressive symptoms, and physical activity explained ≤ 5 : 0 % of mediation across all NDVI metrics.

DISCUSSION

In this cohort, greater residential green space was associated with a modest increase in fecundability. https://doi.org/10.1289/EHP10648.

Effect of nature prescriptions on cardiometabolic and mental health, and physical activity: a systematic review

Nature prescriptions are gaining popularity as a form of social prescribing in support of sustainable health care. This systematic review and meta-analysis aims to synthesise evidence on the effectiveness of nature prescriptions and determine the factors important for their success. We searched five databases from inception up to July 25, 2021. Randomised and non-randomised controlled studies featuring a nature prescription (ie, a referral or an organised programme, by a health or social professional, to encourage spending time in nature) were included. Two reviewers independently conducted all steps of study selection; one reviewer collected summary data from published reports and conducted the risk of bias assessment. Random-effect DerSimonian-Laird meta-analyses were conducted for five key outcomes. We identified 92 unique studies (122 reports), of which 28 studies contributed data to meta-analyses. Compared with control conditions, nature prescription programmes resulted in a greater reduction in systolic blood pressure (mean difference -4·82 mm Hg [-8·92 to -0·72]) and diastolic blood pressure (mean difference -3·82 mm Hg [-6·47 to -1·16). Nature prescriptions also had a moderate to large effect on depression scores (post-intervention standardised mean difference -0·50 [-0·84 to -0·16]; change from baseline standardised mean difference -0·42 [-0·82 to -0·03]) and anxiety scores (post-intervention standardised mean difference -0·57 [-1·12 to -0·03]; change from baseline standardised mean difference -1·27 [-2·20 to -0·33]). Nature prescriptions resulted in a greater increase in daily step counts than control conditions (mean difference 900 steps [790 to 1010]) but did not improve weekly time of moderate physical activity (mean difference 25·90 min [-10·26 to 62·06]). A subgroup analysis restricted to studies featuring a referring institution showed stronger effects on depression scores, daily step counts, and weekly time of moderate physical activity than the general analysis. Beneficial effects on anxiety and depression scores were mainly provided by interventions involving social professionals whereas beneficial effects on blood pressures and daily step counts were provided mainly by interventions involving health professionals. Most studies have a moderate to high risk of bias. Nature prescription programmes showed evidence of cardiometabolic and mental health benefits and increases in walking. Effective nature prescription programmes can involve a range of natural settings and activities and can be implemented via social and community channels, in addition to health professionals.

The association of green space, tree canopy and parks with life expectancy in neighborhoods of Los Angeles

Substantial evidence suggests that access to urban green spaces and parks is associated with positive health outcomes, including decreased mortality. Few existing studies have investigated the association between green spaces and life expectancy (LE), and none have used small-area data in the U.S. Here we used the recently released U.S. Small-Area Life Expectancy Estimates Project data to quantify the relationship between LE and green space in Los Angeles County, a large diverse region with inequities in park access. We developed a model to quantify the association between green space and LE at the census tract level. We evaluated three green space metrics: normalized difference vegetation index (NDVI, 0.6-meter scale), percent tree canopy cover, and accessible park acres. We statistically adjusted for 15 other determinants of LE. We also developed conditional autoregressive models to account for spatial dependence. Tree canopy and NDVI were both significantly associated with higher LE. For an interquartile range (IQR) increase in each metric respectively, the spatial models demonstrated a 0.24 to 0.33-year increase in LE. Tree canopy and NDVI also modified the effect of park acreage on LE. ln areas with tree canopy levels below the county median, an IQR increase in park acreage was associated with an increase of 0.12 years. Although on an individual level these effects were modest, we predicted 155,300 years of LE gains across the population in LA County if all areas below median tree canopy were brought to the county median of park acres. If tree canopy or NDVI were brought to median levels, between 570,300 and 908,800 years of LE could be gained. The majority of potential gains are in areas with predominantly Hispanic/Latinx and Black populations. These findings suggest that equitable access to green spaces could result in substantial population health benefits.

The association of park use and park perception with quality of life using structural equation modeling

Introduction

The literature is limited on the impact of neighborhood parks on quality of life (QoL) and the mechanism linking them.

Methods

In this paper, we applied the structural equation model to data from a cross-sectional sample of 650 participants in low-income communities of New York City, we examined the associations of neighborhood park use vs. park perception and QoL, and whether these associations were mediated through self-reported perceived stress. We also examined whether park use mediated the relationship between park perception and QoL.

Results

We found that park use had a significant but weak association with QoL (standardized β = 0.08, 95% confidence interval (CI): 0.02, 0.15, p = 0.02), but this relationship was not mediated by self-reported stress. Park perception was more strongly associated with QoL than park use (standardized β = 0.23, 95% CI: 0.16, 0.30, p < 0.01), and this was partly mediated by self-reported stress (indirect effect- standardized β = 0.08, 95% CI: 0.03, 0.13, p < 0.01) and, to a lesser extent, by park use (indirect effect- standardized β = 0.01, 95% CI: 0.00, 0.02, p = 0.01).

Discussion

Having well-perceived parks appears to be an important factor for QoL independent of park use, suggesting that quality parks may benefit everyone in a community beyond park users. This strengthens the argument in favor of increasing park investment as a strategy to improve population wellbeing.

Epigenome-wide analysis of maternal exposure to green space during gestation and cord blood DNA methylation in the ENVIRONAGE cohort

BACKGROUND

DNA methylation programming is sensitive to prenatal life environmental influences, but the impact of maternal exposure to green space on newborns DNA methylation has not been studied yet.

METHODS

We conducted a meta-epigenome-wide association study (EWAS) of maternal exposure to green space during gestation with cord blood DNA methylation in two subsets of the ENVIRONAGE cohort (N = 538). Cord blood DNA methylation was measured by Illumina HumanMethylation 450K in one subset (N = 189) and EPICarray in another (N = 349). High (vegetation height>3 m (m)), low (vegetation height<3 m) and total (including both) high-resolution green space exposures during pregnancy were estimated within 100 m and 1000 m distance around maternal residence. In each subset, we sought cytosine-phosphate-guanine (CpG) sites via linear mixed models adjusted on newborns' sex, ethnicity, gestational age, season at delivery, sampling day, maternal parity, age, smoking, education, and estimated blood cell proportions. EWASs results were meta-analysed via fixed-effects meta-analyses. Differentially methylated regions (DMRs) were identified via ENmix-combp and DMRcate algorithms. Sensitivity analyses were additionally adjusted on PM_2.5, distance to major roads, urbanicity and neighborhood income. In the 450K subset, cord blood expression of differentially methylated genes was measured by Agilent microarrays and associated with green space.

RESULTS

147 DMRs were identified, 85 of which were still significant upon adjustment for PM_2.5, distance to major roads, urbanicity and neighborhood income, including HLA-DRB5, RPTOR, KCNQ1DN, A1BG-AS1, HTR2A, ZNF274, COL11A1 and PRSS36 DMRs. One CpG reached genome-wide significance, while 54 CpGs were suggestive significant (p-values<1e-05). Among them, a CpG, hypermethylated with 100 m buffer total green space, was annotated to PAQR9, whose expression decreased with 1000 m buffer low green space (p-value = 1.45e-05).

CONCLUSIONS

Our results demonstrate that maternal exposure to green space during pregnancy is associated with cord blood DNA methylation, mainly at loci organized in regions, in genes playing important roles in neurological development (e.g., HTR2A).

Exposure to outdoor residential noise during pregnancy, embryonic size, fetal growth, and birth outcomes

INTRODUCTION

Previous literature suggested that noise exposure during pregnancy was not associated with adverse birth outcomes. However, no studies evaluated the association between noise exposure and embryonic and fetal growth, or mutually assessed other urban environmental exposures such as traffic-related air pollution or natural spaces.

METHODS

We included 7947 pregnant women from the Generation R Study, the Netherlands. We estimated total (road traffic, aircraft, railway, and industry), road traffic, and railway noise at the participants' home addresses during pregnancy using environmental noise maps. We estimated traffic-related air pollution using land-use regression models, greenness within a 300 m buffer using the normalized difference vegetation index, and distance to blue spaces using topographical maps at the home addresses. Embryonic size (crown-rump length) and fetal growth parameters (head circumference, femur length, and estimated fetal weight) were measured by ultrasound at several gestational ages. Information on neonatal anthropometrics at birth (head circumference, length, and weight) and adverse birth outcomes (preterm birth, low birth weight, and small for gestational age) were retrieved from medical records.

RESULTS

Higher total noise exposure during pregnancy was associated with larger crown-rump length (0.07 SDS [95%CI 0.00 to 0.14]). No association was found with fetal growth parameters, neonatal anthropometrics, and adverse birth outcomes. Similar results were observed for road traffic noise exposure, while railway noise exposure was not associated with any of the outcomes. Traffic-related air pollution was not associated with crown-rump length. Total noise exposure mediated 15% of the association between exposure to greenness and smaller crown-rump length. No association was observed between distance to blue spaces and total noise exposure.

CONCLUSION

Exposure to outdoor residential noise during pregnancy was associated with larger embryonic size. Moreover, a reduction of total noise exposure during pregnancy partially mediated the association between exposure to greenness and smaller embryonic size. Additional research is warranted to confirm and further understand these novel findings.

Exposure to natural environments during pregnancy and birth outcomes in 11 European birth cohorts

Research suggests that maternal exposure to natural environments (i.e., green and blue spaces) promotes healthy fetal growth. However, the available evidence is heterogeneous across regions, with very few studies on the effects of blue spaces. This study evaluated associations between maternal exposure to natural environments and birth outcomes in 11 birth cohorts across nine European countries. This study, part of the LifeCycle project, was based on a total sample size of 69,683 newborns with harmonised data. For each participant, we calculated seven indicators of residential exposure to natural environments: surrounding greenspace in 100m, 300m, and 500m using Normalised Difference Vegetation Index (NDVI) buffers, distance to the nearest green space, accessibility to green space, distance to the nearest blue space, and accessibility to blue space. Measures of birth weight and small for gestational age (SGA) were extracted from hospital records. We used pooled linear and logistic regression models to estimate associations between exposure to the natural environment and birth outcomes, controlling for the relevant covariates. We evaluated the potential effect modification by socioeconomic status (SES) and region of Europe and the influence of ambient air pollution on the associations. In the pooled analyses, residential surrounding greenspace in 100m, 300m, and 500m buffer was associated with increased birth weight and lower odds for SGA. Higher residential distance to green space was associated with lower birth weight and higher odds for SGA. We observed close to null associations for accessibility to green space and exposure to blue space. We found stronger estimated magnitudes for those participants with lower educational levels, from more deprived areas, and living in the northern European region. Our associations did not change notably after adjustment for air pollution. These findings may support implementing policies to promote natural environments in our cities, starting in more deprived areas.

Determining Gentrification's Relationship to Birth Outcomes in Metropolitan California

There is inconsistent evidence as to whether gentrification, the increase of affluent residents into low-income neighborhoods, is detrimental to health. To date, there is no systematic evidence on how gentrification may matter for a range of birth outcomes across cities with varying characteristics. We utilize California's Birth Cohort File (2009-2012), Decennial Census data, and the American Community Survey (2008-2012) to investigate the relationship of gentrification to: preterm birth, low birthweight, and small-for-gestational-age across California. We find that socioeconomic gentrification is uniformly associated with better birth outcomes. Notably, however, we find that only places specifically experiencing increases in non-White gentrification had this positive impact. These associations vary somewhat by maternal characteristics and by type of gentrification measure utilized; discrepancies between alternative measurement strategies are explored. This study provides evidence that socioeconomic gentrification is positively related to birth outcomes and the race-ethnic character of gentrification matters, emphasizing the continued need to examine how gentrification may impact a range of health and social outcomes.

Do sex and gender modify the association between green space and physical health? A systematic review

A growing literature shows that green space can have protective effects on human health. As a marginalized group, women often have worse life outcomes than men, including disparities in some health outcomes. Given their marginalization, women might have "more to gain" than men from living near green spaces. Yet, limited research has deliberately studied whether green space-health associations are stronger for women or men. We conducted a systematic review to synthesize empirical evidence on whether sex or gender modifies the protective associations between green space and seven physical health outcomes (cardiovascular disease, cancer, diabetes, general physical health, non-malignant respiratory disease, mortality, and obesity-related health outcomes). After searching five databases, we identified 62 articles (including 81 relevant analyses) examining whether such effect modification existed. We classified analyses based on whether green space-health were stronger for women, no sex/gender differences were detected, or such associations were stronger for men. Most analyses found that green space-physical health associations were stronger for women than for men when considering study results across all selected health outcomes. Also, women showed stronger protective associations with green space than men for obesity-related outcomes and mortality. Additionally, the protective green space-health associations were slightly stronger among women for green land cover (greenness, NDVI) than for public green space (parks), and women were also favored over men when green space was measured very close to one's home (0-500 m). Further, the green space-health associations were stronger for women than for men in Europe and North America, but not in other continents. As many government agencies and nongovernmental organizations worldwide work to advance gender equity, our review shows that green space could help reduce some gender-based health disparities. More robust empirical studies (e.g., experimental) are needed to contribute to this body of evidence.

Effects of greenness on preterm birth: A national longitudinal study of 3.7 million singleton births

Exposure to greenness may lead to a wide range of beneficial health outcomes. However, the effects of greenness on preterm birth (PTB) are inconsistent, and limited studies have focused on the subcategories of PTB. A total of 3,751,672 singleton births from a national birth cohort in mainland China were included in this study. Greenness was estimated using the satellite-based Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index with 500-m and 1,000-m buffers around participants’ addresses. The subcategories of PTB (20–36 weeks) included extremely PTB (EPTB, 20–27 weeks), very PTB (VPTB, 28–31 week), and moderate-to-late PTB (MPTB, 32–36 weeks). Gestational age (GA) was included as another birth outcome. We used logistic regression models and multiple linear regression models to analyze these associations throughout the entire pregnancy. We found inverse associations between greenness and PTB and positive associations between greenness and GA. Specifically, an increase of 0.1 NDVI exposure within a 500-m buffer throughout the entire pregnancy was significantly associated with decreases in PTB (odds ratio [OR], 0.930; 95% confidence interval [CI], 0.927–0.932), EPTB (OR, 0.820; 95% CI, 0.801–0.839), VPTB (OR, 0.913; 95% CI, 0.908–0.919), MPTB (OR, 0.934; 95% CI, 0.931–0.936), and an increase in GA (β = 0.050; 95% CI, 0.049–0.051 weeks). These results suggest the potential protective effects of greenness on PTB and its subcategories: MPTB, VPTB, and EPTB in China.

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A national study with 3.7 million births on greenness-PTB in China

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Higher greenness was associated with lower risks of PTB and its subcategories

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PTB of shorter gestational weeks may benefit more from greenness exposure

Residential proximity to greenness and adverse birth outcomes in urban areas: Findings from a national Canadian population-based study

BACKGROUND

Over the last decade, several studies have reported that residential proximity to vegetation, or 'greenness', is associated with improved birth outcomes, including for term birth weight (TBW), preterm birth (PTB), and small for gestational age (SGA). However, there remain several uncertainties about these possible benefits including the role of air pollution, and the extent to they are influenced socioeconomic status.

METHODS

We addressed these gaps using a national population-based study of 2.2 million singleton live births in Canadian metropolitan areas between 1999 and 2008. Exposures to greenness, fine particulate matter (PM_2.5), and nitrogen dioxide (NO₂) were assigned to infants using the postal code of their mother's residence at the time of birth. The Normalized Difference Vegetation Index (NDVI) was used to characterize greenness, while estimates of ambient PM_2.5 and NO₂ were estimated using remote sensing, and a national land-use regression surface, respectively. Multivariable regression analysis was performed to describe associations between residential greenness and the birth outcomes. Stratified analyses explored whether these associations were modified by neighbourhood measures of socioeconomic status.

RESULTS

Mothers who lived in greener areas had a lower risk of low TBW, PTB, and SGA babies. These associations persisted after adjustment for ambient NO₂ and PM_2.5. Specifically, in fully adjusted models, an interquartile range (IQR = 0.16) increase in the NDVI within a residential buffer of 250 m yielded odds ratios of 0.93 (95% confidence interval (CI): 0.92, 0.94), 0.94 (95% CI: 0.92, 0.95), and 0.94 (95% CI: 0.93, 0.95) for the outcomes of PTB, low TBW, and SGA, respectively. Similarly, an IQR increase in greenness was associated with a 16.3 g (95% CI: 15.3, 17.4) increase in TBW. We found inverse associations between greenness and the occurrence of adverse birth outcomes regardless of the socioeconomic status of the neighbourhood.

INTERPRETATION

Our findings support the hypothesis that residential greenness contributes to healthier pregnancies, that these associations are independent from exposure to air pollution. , and that proximity to greenness benefits all mothers regardless of socioeconomic status.

Residential greenness and hair cortisol levels during the first trimester of pregnancy

BACKGROUND AND AIM

Studies have shown that increased maternal cortisol level is associated with child adverse health outcomes. Hair cortisol (HC) is suitable for assessing long-term circulating cortisol concentration. Only two previous studies reported beneficial associations between cortisol and residential greenness during pregnancy and no study focused on the first trimester. Our aim was to evaluate the association between residential greenness and first trimester HC levels among pregnant women in Israel.

METHODS

Women were recruited during second and third trimesters. Hair samples were collected from the scalp and retrospective HC levels during the first trimester were quantified for 217 women. HC levels were natural log transformed and outliers were excluded. Based on geocoded birth address, small area sociodemographic status (SES) and mean residential surrounding greenness were calculated using high-resolution satellite-based Normalised Difference Vegetation Index (NDVI) data at 100, 300 and 500-m buffers in a cross-sectional approach. In addition, longitudinal exposure to mean greenness during a week preconception and during the first trimester were calculated. Missing covariates were imputed and linearity of the associations were evaluated. Generalized linear models were used to estimate the crude and adjusted associations controlled for the relevant covariates.

RESULTS

After exclusion of outliers, for 211 women, crude and adjusted beneficial associations between exposure to higher mean NDVI and HC levels were observed for all the exposure measures. An increase in 1 interquartile range of greenness (100 m buffer) was associated with a statistically significant lower estimated natural log mean HC level (-0.27 95% CI: -0.44; -0.11). The associations were robust to adjustment for covariates. The findings were consistent for different buffers, for the longitudinal approach, when all observations were included in the analysis and slightly stronger associations were observed for women with addresses geocoded at the home or street level. For most of the exposure measures, stronger associations were observed among those of lower sociodemographic status.

CONCLUSION

Our findings that more greenness associated with reduced maternal cortisol levels measured in the hair during the first trimester, could have substantial implications for urban planners and public health professional. If our observations will be replicated, it may present a useful avenue for public-health intervention to promote health through the provision of greenness exposure during early pregnancy, specifically to disadvantage populations.

The association between environmental greenness and the risk of food allergy: A population-based study in Melbourne, Australia

BACKGROUND

While exposure to environmental greenness in childhood has shown mixed associations with the development of allergic disease, the relationship with food allergy has not been explored. We investigated the association between exposure to environmental greenness and challenge-confirmed food allergy in a large population-based cohort.

METHODS

The HealthNuts study recruited 5276 12-month-old infants in Melbourne, Australia, who underwent skin prick testing to peanut, egg, and sesame; infants with a detectable wheal underwent food challenges to determine food allergy status. Environmental greenness was estimated using the normalized difference vegetation index (NDVI) for five buffer zones around the infant's home address: at the home, 100 m, 500 m, 800 m, and 1600 m radial distances. Environmental greenness was categorized into 3 tertiles and mixed effects logistic regression models quantified the association between greenness and the risk of food allergy, adjusting for confounding and accounting for clustering at the neighborhood level.

RESULTS

NDVI data were available for n = 5097. For most buffer zones, medium and high greenness, compared to low greenness, was associated with an increased risk of peanut allergy (eg, 100 m tertile 2 aOR 1.89 95% CI 1.22-2.95, tertile 3 aOR 1.78 95% CI 1.13-2.82). For egg allergy, the effect sizes were smaller (100 m tertile 2 aOR 1.52 95% CI 1.16-1.97, tertile 3 aOR 1.38 95% CI 1.05-1.82). Socioeconomic status (SES) modified the association between greenness and peanut allergy, but not egg allergy; associations were apparent in the low SES group but not in the high SES group (p for interaction 0.08 at 100 m). Air pollution (PM2.5) also modified the associations between environmental greenness and food allergy, with associations present in high air pollution areas but not low (p for interaction at 100 m 0.05 for peanut and 0.06 for egg allergy.) CONCLUSION: Increased exposure to environmental greenness in the first year of life was associated with an increased risk of food allergy. Increased greenness may correlate with higher pollen levels which may trigger innate immune responses skewing the immune system to the Th2-dependent allergic phenotype; additionally, some pollen and food allergens are cross-reactive. Given the mixed data on greenness and other allergies, the relationship appears complex and may also be influenced by confounding variables outside those that were measured in this study.

Green CURIOCITY: a study protocol for a European birth cohort study analysing childhood heat-related health impacts and protective effects of urban natural environments

INTRODUCTION

The European climate is getting warmer and the impact on childhood health and development is insufficiently understood. Equally, how heat-related health risks can be reduced through nature-based solutions, such as exposure to urban natural environments, is unknown. Green CURe In Outdoor CITY spaces (Green CURIOCITY) will analyse how heat exposure during pregnancy affects birth outcomes and how long-term heat exposure may influence children's neurodevelopment. We will also investigate if adverse effects can be mitigated by urban natural environments. A final goal is to visualise intraurban patterns of heat vulnerability and assist planning towards healthier cities.

METHODS AND ANALYSIS

We will use existing data from the Human Early-Life Exposure cohort, which includes information on birth outcomes and neurodevelopment from six European birth cohorts. The cohort is linked to data on prenatal heat exposure and impact on birth outcomes will be analysed with logistic regression models, adjusting for air pollution and noise and sociobehavioural covariates. Similarly, impact of cumulative and immediate heat exposure on neurodevelopmental outcomes at age 5 will be assessed. For both analyses, the potentially moderating impact of natural environments will be quantified. For visualisation, Geographical information systems data will be combined to develop vulnerability maps, demonstrating urban 'hot spots' where the risk of negative impacts of heat is aggravated due to sociodemographic and land use patterns. Finally, geospatial and meteorological data will be used for informing GreenUr, an existing software prototype developed by the WHO Regional Office for Europe to quantify health impacts and augment policy tools for urban green space planning.

ETHICS AND DISSEMINATION

The protocol was approved by the Comité Ético de Investigación Clínica Parc de Salut MAR, Spain. Findings will be published in peer-reviewed journals and presented at policy events. Through stakeholder engagement, the results will also reach user groups and practitioners.

Developing an Approach for Assessing Urban Blue-Green Spaces Towards Sustainable Urban Growth Through Retrospective Cyber Metrics Analysis of Operational Estimations Approaches

Urban blue-green spaces provide us abundant social, environmental, and economic benefits, but the disparities often exist in their distribution and accessibility. Traditionally urban blue-green spaces are a consolidation of “blue-green infrastructure” within urban areas. Several urban features like parks, forests, gardens, visible water, such as parks, rivers, canals, reservoirs, ponds, lakes, fountains, etc. are categorized or considered under the blue-green spaces and these are very much crucial for various urban ecosystem services. These play a significant role for all stakeholders of the urban community. Thus, everyone must ensure the equitable number of blue-green spaces for all. Recently, several rules and regulations towards the safeguarding of urban blue-green spaces have been outlined. The work presents a methodological framework to develop an approach towards sustainable urban growth with the help of urban blue-green spaces assessments. The current work has attempted to examine the linkage between issues of the urban blue-green spaces for restoring the required infrastructures. It can be utilised for all sustainable urban development for urban planning and design projects to play a pivotal role. The work emphasizes more to develop a methodological framework to analyze the urban blue-green spaces for augmentation with a theoretical framework. It is expected that the advancement of a problem cum objectives-driven approach will help to design an impact-driven approach for planned and concrete action.

An Overview of Environmental Risk Factors for Food Allergy

IgE-mediated food allergy is an increasing public health concern in many regions around the world. Although genetics play a role in the development of food allergy, the reported increase has occurred largely within a single generation and therefore it is unlikely that this can be accounted for by changes in the human genome. Environmental factors must play a key role. While there is strong evidence to support the early introduction of allergenic solids to prevent food allergy, this is unlikely to be sufficient to prevent all food allergy. The purpose of this review is to summarize the evidence on risk factors for food allergy with a focus the outdoor physical environment. We discuss emerging evidence of mechanisms that could explain a role for vitamin D, air pollution, environmental greenness, and pollen exposure in the development of food allergy. We also describe the recent extension of the dual allergen exposure hypothesis to potentially include the respiratory epithelial barrier in addition to the skin. Few existing studies have examined the relationship between these environmental factors with objective measures of IgE-mediated food allergy and further research in this area is needed. Future research also needs to consider the complex interplay between multiple environmental factors.

Greenspace and human health: An umbrella review

Multiple systematic reviews on greenspace and health outcomes exist, but the overall evidence base remains unclear. Therefore, we performed an umbrella review to collect and appraise all relevant systematic reviews of epidemiological studies on greenness exposure and health. We searched PubMed, Embase, and Web of Science from inception to June 28, 2021, and screened references of relevant articles. Systematic reviews with or without meta-analyses of epidemiological studies that examined the associations of greenness with any health outcome were included. Two independent investigators performed study selection and data extraction. We also evaluated the methodological quality of the included systematic reviews using the “Assessing the Methodological Quality of Systematic Reviews 2” checklist. A total of 40 systematic reviews and meta-analyses were included, of which most were cross-sectional studies conducted in high-income countries. Greenspace exposure was estimated with various objective and subjective parameters. Beneficial associations of greenspace with all-cause and stroke-specific mortality, CVD morbidity, cardiometabolic factors, mental health, low birth weight, physical activity, sleep quality, and urban crime were observed. No consistent associations between greenspace and other health outcomes (e.g., cancers) were observed. Most of the included systematic reviews and meta-analyses had one or more limitations in methodology. Our findings provide supportive evidence regarding the beneficial effects of greenspace exposure on some aspects of human health. However, the credibility of such evidence was compromised by methodological limitations. Better performed systematic reviews and meta-analyses as well as longitudinal designed primary studies are needed to validate this conclusion.

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The evidence concerning greenspace and health outcomes remains unclear

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We performed an umbrella review of 40 systematic reviews on greenspace and health

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Greenspace exposure was estimated with various objective and subjective parameters

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Greenspace was beneficially associated with several aspects of human health

Green Space Quality and Health: A Systematic Review

(1) Background: As cities densify, researcher and policy focus is intensifying on which green space types and qualities are important for health. We conducted a systematic review to examine whether particular green space types and qualities have been shown to provide health benefits and if so, which specific types and qualities, and which health outcomes. (2) Methods: We searched five databases from inception up to June 30, 2021. We included all studies examining a wide range of green space characteristics on various health outcomes. (3) Results: 68 articles from 59 studies were found, with a high degree of heterogeneity in study designs, definitions of quality and outcomes. Most studies were cross-sectional, ecological or cohort studies. Environment types, vegetation types, and the size and connectivity of green spaces were associated with improved health outcomes, though with contingencies by age and gender. Health benefits were more consistently observed in areas with greater tree canopy, but not grassland. The main outcomes with evidence of health benefits included allergic respiratory conditions, cardiovascular conditions and psychological wellbeing. Both objectively and subjectively measured qualities demonstrated associations with health outcomes. (4) Conclusion: Experimental studies and longitudinal cohort studies will strengthen current evidence. Evidence was lacking for needs-specific or culturally-appropriate amenities and soundscape characteristics. Qualities that need more in-depth investigation include indices that account for forms, patterns, and networks of objectively and subjectively measured green space qualities.

Urban residential tree canopy and perceived stress among pregnant women

OBJECTIVE

To examine the association of urban residential tree canopy cover with perceived stress in a cohort of pregnant women in Philadelphia, PA, and explore whether this association differed among participants with a history of anxiety and depression.

STUDY DESIGN

We performed a secondary analysis of 1294 participants of the Motherhood & Microbiome (M&M) pregnancy cohort who lived in Philadelphia, with first visit perceived stress (Cohen's Perceived Stress Scale, PSS-14), and key covariate data. Tree canopy cover was calculated as percent cover within 100 and 500 m radii buffers around participants' homes. We performed multilevel mixed effects linear regression models, with perceived stress as the dependent variable. The main independent variable was tree canopy coverage. Individual-level covariates included season of last menstrual period, history of depression or anxiety, race/ethnicity, insurance, parity, and age. Census tract neighborhood deprivation index was used to account for area-level socioeconomic confounding variables. We also examined whether a history of anxiety or depression, modified the association between tree canopy coverage and perceived stress.

RESULTS

Most participants were non-Hispanic Black (70.6%, n = 913), on Medicaid or uninsured (60.4%, n = 781), and 15.8% (n = 204) of participants had a prior history of depression or anxiety. We did not detect associations between tree canopy coverage and perceived stress overall. However, we detected effect modification; among participants with a history of depression or anxiety, each standard deviation increase in tree canopy cover was associated with lower PSS-14 in 100 m buffers (β -1.0, 95% CI -1.8, -0.2), but not among participants with no histories of depression or anxiety (β 0.2, 95% CI -0.3, 0.7) (interaction P = 0.007). Results were similar in directionality but not statistically significant within 500 m buffers.

CONCLUSION

Residential tree canopy coverage was associated with reduced perceived stress among urban-dwelling pregnant women with history of anxiety or depression. Future studies of the effects of greenness and other stress-reducing efforts should consider underlying mental health conditions as effect modifiers.

Green Space and Health in Mainland China: A Systematic Review

Non-communicable diseases (NCDs) have become a major cause of premature mortality and disabilities in China due to factors concomitant with rapid economic growth and urbanisation over three decades. Promoting green space might be a valuable strategy to help improve population health in China, as well as a range of co-benefits (e.g., increasing resilience to climate change). No systematic review has so far determined the degree of association between green space and health outcomes in China. This review was conducted to address this gap. Five electronic databases were searched using search terms on green space, health, and China. The review of 83 publications that met eligibility criteria reports associations indicative of various health benefits from more green space, including mental health, general health, healthier weight status and anthropometry, and more favorable cardiometabolic and cerebrovascular outcomes. There was insufficient evidence to draw firm conclusions on mortality, birth outcomes, and cognitive function, and findings on respiratory and infectious outcomes were inconsistent and limited. Future work needs to examine the health benefits of particular types and qualities of green spaces, as well as to take advantage of (quasi-)experimental designs to test greening interventions within the context of China's rapid urbanization and economic growth.

Identifying urban built environment factors in pregnancy care and maternal mental health outcomes

Backgrounds

Risk factors related to the built environment have been associated with women’s mental health and preventive care. This study sought to identify built environment factors that are associated with variations in prenatal care and subsequent pregnancy-related outcomes in an urban setting.

Methods

In a retrospective observational study, we characterized the types and frequency of prenatal care events that are associated with the various built environment factors of the patients’ residing neighborhoods. In comparison to women living in higher-quality built environments, we hypothesize that women who reside in lower-quality built environments experience different patterns of clinical events that may increase the risk for adverse outcomes. Using machine learning, we performed pattern detection to characterize the variability in prenatal care concerning encounter types, clinical problems, and medication prescriptions. Structural equation modeling was used to test the associations among built environment, prenatal care variation, and pregnancy outcome. The main outcome is postpartum depression (PPD) diagnosis within 1 year following childbirth. The exposures were the quality of the built environment in the patients’ residing neighborhoods. Electronic health records (EHR) data of pregnant women (n = 8,949) who had live delivery at an urban academic medical center from 2015 to 2017 were included in the study.

Results

We discovered prenatal care patterns that were summarized into three common types. Women who experienced the prenatal care pattern with the highest rates of PPD were more likely to reside in neighborhoods with homogeneous land use, lower walkability, lower air pollutant concentration, and lower retail floor ratios after adjusting for age, neighborhood average education level, marital status, and income inequality.

Conclusions

In an urban setting, multi-purpose and walkable communities were found to be associated with a lower risk of PPD. Findings may inform urban design policies and provide awareness for care providers on the association of patients’ residing neighborhoods and healthy pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04056-1.

A multi-scalar perspective on health and urban housing: an umbrella review

With more than half the world's population living in cities, understanding how the built environment impacts human health at different urban scales is crucial. To be able to shape cities for health, an understanding is needed of planetary health impacts, which encompass the human health impacts of human-caused disruptions on the Earth's natural ecosystems. This umbrella review maps health evidence across the spatial scales of the built environment (building; neighbourhood; and wider system, including city, regional and planetary levels), with a specific focus on urban housing. Systematic reviews published in English between January 2011 and December 2020 were searched across 20 databases, with 1176 articles identified and 124 articles screened for inclusion. Findings suggests that most evidence reports on health determinants at the neighbourhood level, such as greenspace, physical and socio-economic conditions, transport infrastructure and access to local services. Physical health outcomes are also primarily reported, with an emerging interest in mental health outcomes. There is little evidence on planetary health outcomes and significant gaps in the research literature are identified. Based on these findings, three potential directions are identified for future research.

Is greener better? Associations between greenness and birth outcomes in both urban and non-urban settings

BACKGROUND

Beneficial effects of greenness on birth outcomes have been reported, but few studies have investigated the associations in both urban and non-urban settings. We aimed to evaluate and compare linear and nonlinear associations between greenness and birth outcomes in urban and non-urban settings.

METHODS

From October 2015 to December 2018, participants were recruited into the Maoming Birth Cohort Study. A total of 11 258 live birth records were obtained. Greenness exposure was assessed using the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Linear regression and nonlinear restricted cubic spline models were implemented to investigate the associations between greenness and birthweight, birth length, gestational age, preterm birth, low birthweight, small for gestational age and the potential for effect variation under urban or non-urban settings, after adjusting for covariates.

RESULTS

A 0.1-unit increase in NDVI-500m was significantly associated with an increase of 35.4 g in birthweight [95% confidence interval (CI): 13.2, 57.7], 0.15 cm in birth length (95% CI: 0.03, 0.26), 0.88 days in gestational age (95% CI: 0.05, 1.71) and lower odds of low birthweight [odds ratio (OR) = 0.69, 95% CI: 0.56, 0.85] and preterm birth (OR = 0.70, 95% CI: 0.58, 0.85). No association with head circumference was observed. For all outcomes, no significant linear associations were observed among non-urban dwellers. Inversed 'U-shaped' associations between greenness exposure and birth outcomes were observed in the total study population.

CONCLUSIONS

Greenness exposure was associated with increased gestational age, birthweight and birth length in urban dwellers. Nonlinear associations assessed by restricted cubic splines suggested that health benefits could be larger when increasing greenness levels from low to medium compared with increasing greenness from medium to high levels. Further studies adopting nonlinear methods are warranted to verify our findings.

Associations between Nature Exposure and Health: A Review of the Evidence

There is extensive empirical literature on the association between exposure to nature and health. In this narrative review, we discuss the strength of evidence from recent (i.e., the last decade) experimental and observational studies on nature exposure and health, highlighting research on children and youth where possible. We found evidence for associations between nature exposure and improved cognitive function, brain activity, blood pressure, mental health, physical activity, and sleep. Results from experimental studies provide evidence of protective effects of exposure to natural environments on mental health outcomes and cognitive function. Cross-sectional observational studies provide evidence of positive associations between nature exposure and increased levels of physical activity and decreased risk of cardiovascular disease, and longitudinal observational studies are beginning to assess long-term effects of nature exposure on depression, anxiety, cognitive function, and chronic disease. Limitations of current knowledge include inconsistent measures of exposure to nature, the impacts of the type and quality of green space, and health effects of duration and frequency of exposure. Future directions include incorporation of more rigorous study designs, investigation of the underlying mechanisms of the association between green space and health, advancement of exposure assessment, and evaluation of sensitive periods in the early life-course.

The association of fractional cover, foliage projective cover and biodiversity with birthweight

INTRODUCTION

Environmental exposures can contribute both benefits and risks to human health. Maternal exposure to green space has been associated with improvements in birthweight, among other birth outcomes. Newer measures of green space have been developed, which allows for an exploration of the effect of different ground covers (green, dry and bare earth), as well as measures of biodiversity. This study explores the association of these novel green space measures with birthweight in a large birth cohort in Queensland, Australia.

METHODS

Birthweight was acquired from the routine health records. Records were allocated green space values for fractional cover, biodiversity and foliage projective cover. Directed acyclic graphs were developed to guide variable selection. Mixed-effects linear regression and generalised linear mixed-effects models were developed, with random intercepts for maternal residential locality and year of birth. Results are presented as standardised beta coefficients or odds ratios, with 95% confidence intervals.

RESULTS

An IQR increase of green cover (29.6 g, 95% CI 13.8-45.5) and foliage projective cover (26.0 g, 95% CI 10.8-41.3) are associated with birthweight in urban areas. An IQR increase in dry cover -34.4 g, 95% CI -60.4 to -8.4) and bare earth (-17.7 g, 95% CI -32.8 to -2.6) are associated with lower birthweight. Mothers living in rural areas had similar results, with an IQR increase in green cover (17.8 g, 95% CI 2.9-32.7) associated with higher birthweight, and bare earth (-27.7 g, 95% CI -45.7 to -9.7) was associated with lower birthweight. The biodiversity measure used in this study was not associated with any birthweight outcomes.

CONCLUSION

This study finds that the types of ground cover within the maternal residential locality are associated with small, but significant, changes in estimated birthweight, and these effects are not limited to urban areas.

Green Space and Health Equity: A Systematic Review on the Potential of Green Space to Reduce Health Disparities

Disadvantaged groups worldwide, such as low-income and racially/ethnically minoritized people, experience worse health outcomes than more privileged groups, including wealthier and white people. Such health disparities are a major public health issue in several countries around the world. In this systematic review, we examine whether green space shows stronger associations with physical health for disadvantaged groups than for privileged groups. We hypothesize that disadvantaged groups have stronger protective effects from green space because of their greater dependency on proximate green space, as they tend to lack access to other health-promoting resources. We use the preferred reporting items for systematic reviews and meta-analyses (PRISMA) method and search five databases (CINAHL, Cochrane, PubMed, Scopus, and Web of Science) to look for articles that examine whether socioeconomic status (SES) or race/ethnicity modify the green space-health associations. Based on this search, we identify 90 articles meeting our inclusion criteria. We find lower-SES people show more beneficial effects than affluent people, particularly when concerning public green spaces/parks rather than green land covers/greenness. Studies in Europe show stronger protective effects for lower-SES people versus higher-SES people than do studies in North America. We find no notable differences in the protective effects of green space between racial/ethnic groups. Collectively, these results suggest green space might be a tool to advance health equity and provide ways forward for urban planners, parks managers, and public health professionals to address health disparities.

Residential greenness and birth outcomes: A systematic review and meta-analysis of observational studies

BACKGROUND

The amount of natural vegetation surrounding homes (residential greenness) has been proposed as a mitigation measure to buffer the adverse health effects of urban living, associated with promoting health and wellbeing including birth outcomes. This study aimed to systematically review the epidemiological evidence on the association of residential greenness with birth outcomes and quantitatively provide summary effect estimates of the current literature.

METHODS

We extensively searched epidemiological studies related to residential greenness and birth outcomes in three electronic databases (EMBASE, Web of Science, and PubMed) using terms related to residential greenness and birth outcomes before July 10, 2020. Summary effect estimates of residential greenness on birth outcomes including SGA (small for gestational age), PTB (preterm birth), LBW (low birth weight), and birth weight were calculated for each 0.1 unit increase in residential greenness exposure, as well as comparing the highest to the lowest categories using random-effects meta-analyses. We assessed the risk of bias of each individual study, and the overall quality of the body of evidence and level of evidence for each exposure-outcome were also evaluated.

RESULTS

The initial search identified 161 studies, of which 29 studies were finally included. Meta-analysis for continuous exposure suggested that an increase in residential greenness, measured by NDVI (normalized difference vegetation index) with different buffer sizes, was generally associated with higher birth weights ranging from 7.99 g [95% confidence interval (CI) = 4.29-11.70] to 15.35 g (95% CI = 11.41-19.29) and lower odds of LBW ranging from 0.79 (95% CI = 0.65-0.96) to 0.93 (95% CI = 0.86-1.00), but associations between residential greenness and PTB or SGA were not significant. When introducing the exposure as high versus low categories, similar results were found. The overall evidence for each exposure-outcome combination was considered to be of "moderate" certainty.

CONCLUSIONS

This study indicated a potential positive association between residential greenness and several birth outcomes. However, because of the moderate to high between-study heterogeneity, further studies with better adjustment of covariates, improved residential greenness assessment in a longitudinal approach throughout pregnancy rather than a cross-sectional approach at time of delivery, and accounting thoroughly for socioeconomic status, are warranted to replicate these findings as well as to explore in greater detail in their implications.

Ambient Air Pollution, Extreme Temperatures and Birth Outcomes: A Protocol for an Umbrella Review, Systematic Review and Meta-Analysis

Prenatal exposure to ambient air pollution and extreme temperatures are among the major risk factors of adverse birth outcomes and with potential long-term effects during the life course. Although low- and middle-income countries (LMICs) are most vulnerable, there is limited synthesis of evidence in such settings. This document describes a protocol for both an umbrella review (Systematic Review 1) and a focused systematic review and meta-analysis of studies from LMICs (Systematic Review 2). We will search from start date of each database to present, six major academic databases (PubMed, CINAHL, Scopus, MEDLINE/Ovid, EMBASE/Ovid and Web of Science Core Collection), systematic reviews repositories and references of eligible studies. Additional searches in grey literature will also be conducted. Eligibility criteria include studies of pregnant women exposed to ambient air pollutants and/or extreme temperatures during pregnancy with and without adverse birth outcomes. The umbrella review (Systematic Review 1) will include only previous systematic reviews while Systematic Review 2 will include quantitative observational studies in LMICs. Searches will be restricted to English language using comprehensive search terms to consecutively screen the titles, abstracts and full-texts to select eligible studies. Two independent authors will conduct the study screening and selection, risk of bias assessment and data extraction using JBI SUMARI web-based software. Narrative and semi-quantitative syntheses will be employed for the Systematic Review 1. For Systematic Review 2, we will perform meta-analysis with two alternative meta-analytical methods (quality effect and inverse variance heterogeneity) as well as the classic random effect model. If meta-analysis is infeasible, narrative synthesis will be presented. Confidence in cumulative evidence and the strength of the evidence will be assessed. This protocol is registered with PROSPERO (CRD42020200387).

Urban-Related Environmental Exposures during Pregnancy and Placental Development and Preeclampsia: a Review

PURPOSE OF REVIEW

To summarize the current knowledge of the pathophysiological implications and the clinical role of urban-related environmental exposures in pregnancy.

RECENT FINDINGS

The ongoing urbanization worldwide is leading to an increasing number of pregnant women being exposed to higher levels of urban-related environmental hazards such as air pollution and noise and, at the same time, having less contact with natural environments. Pregnancy represents a particular and vulnerable life period both for women and their children. Extensive physiological and metabolic changes, as well as changes to the cardiovascular and respiratory systems during pregnancy, could result in increased sensitivity to damage by environmental factors. Exposure to air pollution and noise is associated with placental dysfunction and damage, which, in turn, could lead to maternal complications such as preeclampsia. In contrast, more contact with greenspace during pregnancy seems to mitigate these adverse impacts. These findings open up new challenges for our understanding of the potential effect of urban living on placental function and preeclampsia, and offer new clinical and research opportunities.

[Research on Healthy Neighborhood Evaluation System Based on the Combined Perspectives of Urban Planning and Public Health]

Neighborhoods are places where people spend the most time in their lives. Neighborhoods have a decisive impact on the residents' health. With several important tasks, including the transformation of old neighborhoods, the maintenance of existing neighborhoods, and the construction of new neighborhoods in the future, a scientific and reasonable evaluation standard is urgently needed to guide the development of healthy neighborhoods. To build the evaluation system, this paper first clarifies the principles for selecting evaluation indicators, which include: 1) the indicators are selected from a humanistic perspective; 2) the pathways between neighborhoods environment and health outcomes are deeply considered; 3) the indicators are selected from multiple scales. Secondly, based on the combined perspectives of urban planning and public health, it identifies the indicators that affect the residents' health in neighborhoods and searches the literature through the quality assessment to provide evidence to support the accuracy and effectiveness of the indicators. Finally, it proposes prospect to the evaluation, including 1) it is urgent to improve and utilize the healthy neighborhoods based on the Chinese condition; 2) advanced technologies need to be widely applied in neighborhoods in the future; 3) the transitions in cities should be considered in the future development of neighborhoods. It hopes that relevant researchers and government leaders to realize the importance and urgency of healthy neighborhoods to build more healthy neighborhoods in China.