Racial and ethnic disparities in pregnancy complications and the protective role of greenspace: A retrospective birth cohort study

Sensitive months for green spaces' impact on macrosomia and interaction with air pollutants: A birth cohort study

Macrosomia poses significant health risks to mother and fetuses, yet the protective sensitive window for the effects of green space resources on the risk of macrosomia remains unexplored. This study identified sensitive windows of green space exposure and examined the interactions with air pollutants. In a study of 221,380 full-term newborns delivered at the Hospital, from 2017 to 2021, Normalized Difference Vegetation Index (NDVI) and atmospheric pollutant concentrations were matched to participants based on their residences in the Ningxia region. A Cox proportional hazards model was utilized to estimate the association between green space exposure and macrosomia and analyze the differences between the macrosomia (<4500 g) and macrosomia (≥4500 g) groups. Green space exposure for each month of pregnancy was employed to identify possible sensitive windows. Possible interactions between green spaces and air pollutants were tested on additive and multiplicative scales. Across 250, 500, 1000, and 2000-m buffers, increased NDVI exposure and range throughout the pregnancy were linked to a lower macrosomia risk, with the strongest association in the macrosomia (≥4500 g) group. The key window for the protective effect of green spaces was in late pregnancy, with the most pronounced protective effect noted in the 9th month of pregnancy. We also found a consistent combined effect between low green space and the air pollutants (NO2 and SO2). The research highlights the beneficial impact of increased green space during late pregnancy and the combined effect of low green space and elevated air pollutant levels on macrosomia risk, which can support government initiatives in urban green space development and public health protection.

Structural Stigma, Racism, and Sexism Studies on Substance Use and Mental Health: A Review of Measures and Designs

PURPOSE

Most research on the structural determinants of substance use and mental health has centered around widely studied factors such as alcohol taxes, tobacco control policies, essential/precursor chemical regulations, neighborhood/city characteristics, and immigration policies. Other structural determinants exist, however, many of which are being identified in the emerging fields of structural stigma, structural racism, and structural sexism. This narrative review surveys the measures and designs used in substance use and mental health studies from these three fields.

SEARCH METHODS

The PubMed, PsycINFO, and Scopus databases were searched on May 11, 2023. A focused search approach used terminology for structural racism, stigma, or sexism combined with terminology for substance use or mental health. Peer-reviewed studies were included if they were written in English and assessed associations between objective structural measures and substance use and mental health outcomes.

SEARCH RESULTS

Of 2,536 studies identified, 2,487 were excluded. Forty-nine studies (30 related to stigma, 16 related to racism, and three related to sexism) met the inclusion criteria. Information was abstracted about the structural measures, outcome measures, research design, sample, and findings of each study.

DISCUSSION AND CONCLUSIONS

The structural determinant measures used in the studies reviewed were diverse. They addressed, for example, community opinions, the gender of legislators, economic vulnerability, financial loan discrimination, college policies, law enforcement, historical trauma, and legislative protections for sexual and gender minorities and for reproductive rights. Most of the structural determinant measures were constructed by combining multiple indicators into indexes or by merging indexes into composite indexes, although some studies relied on single indicators alone. The substance use and mental health outcome measures most frequently examined were related to alcohol and depression, respectively. The studies were conducted in numerous nations and drew samples from an array of groups, including, for example, patients who experienced overdoses from substance use, sexual and gender minorities, racial and ethnic minority groups, women, youth, migrants, and patients subject to involuntary psychiatric hospitalization. Most of the studies used passive-observational (correlational) research designs and, as a result, did not assess whether their structural determinant variables were causally related to substance use and mental health. Nevertheless, the studies reviewed can be used by public health proponents to foster awareness that a wide range of structural determinants correlate with the substance use and mental health of many groups within and across nations.

Greenspace Morphology and Preterm Birth: A State-Wide Study in Georgia, United States (2001-2016)

BACKGROUND

Residential greenness is linked to birth outcomes. However, the role of greenspace morphology remains poorly understood. Additionally, evidence is lacking regarding whether these relationships vary by subpopulation.

OBJECTIVE

We examined the association between preterm birth and residential greenspace morphology, including percentage, shape, connectedness, aggregation, closeness, and fragmentation.

METHODS

We analyzed 2,063,444 singleton live births between 2001 to 2016 in Georgia, USA. Thirty-meter resolution landcover data from National Land Cover Databased (2001-2016) were obtained to calculate greenspace morphology metrics for 1,953 census tracts in Georgia. A two-stage logistic regression examined associations between each greenspace morphology metric and preterm birth at individual level. Stratified analysis was conducted by maternal race, ethnicity, education, urbanicity, poverty rate, and greenspace percentage.

RESULTS

Higher greenspace percentage, aggregation, closeness, shape complexity, connectedness, and lower fragmentation were linked to a lower risk of preterm birth. After adjusting for poverty rate, associations with morphology attenuated, except for fragmentation [odds ratio (OR) = 1.014; 95% confidence interval (CI): 1.0001, 1.026] across the entire population. Strongest associations were found among black mothers and in high-poverty areas. Specifically, the odds of preterm birth in the highest quartile of greenspace percentage were 0.962 (95% CI: 0.933, 0.991) times the odds in the lowest quartile. Additionally, a lower risk of preterm birth was associated with higher greenspace aggregation (OR = 0.969; 95% CI: 0.947, 0.992), and a higher risk of preterm birth was associated with higher fragmentation (OR = 1.028; 95% CI: 1.009, 1.047), both in the black mothers group. In tracts with a high poverty rate, a lower risk of preterm birth associate with higher greenspace percentage (OR = 0.953; 95% CI: 0.910, 0.999), aggregation (OR = 0.976; 95% CI: 0.955, 0.997), and lower fragmentation (OR = 0.976; 95% CI: 0.958, 0.994). The association with greenspace morphology was most pronounced in census tracts with a medium level of greenspace percentage.

DISCUSSION

Our study complements other studies by showing the importance and protective effects of greenspace morphology. The observed effects are particularly prominent in census tracts characterized by a moderate level of greenspace percentage, high poverty rates, and among black women. Our findings suggest the need for tailored greenspace planning strategies based on varying levels of greenness in different areas. For locations with low greenness, increasing the greenspace percentage may be prioritized. In areas with a medium level of greenness, strategic enhancement of greenspace morphology is recommended. For areas with high greenness, the focus should be on improving spatial closeness of greenspace. https://doi.org/10.1289/EHP14571.

Systematic Review of Nature-Based Interventions for Perinatal Depression, Anxiety, and Loneliness

BACKGROUND

Perinatal mood and anxiety disorders and social isolation are prevalent and associated with adverse maternal and child health outcomes. We conducted a systematic review to assess the evidence for nature-based interventions (NBIs) to address depression, anxiety, and loneliness among pregnant and postpartum women.

METHODS

Studies were identified through MEDLINE, Embase, CINAHL, APA PsycINFO, ClinicalTrials.org, Web of Science, and Cochrane Reviews in February 2023. Included studies were original, peer-reviewed studies published in or translated into English that evaluated an intervention which engaged pregnant or postpartum women directly with nature and used a quantitative outcome measure for anxiety, depression, or loneliness.

RESULTS

Three studies, including 68 pregnant or postpartum women and their family or friends, met our inclusion criteria. Results were synthesized narratively in text and tables. All studies had early-stage designs and relatively small sample sizes. A variety of intervention content and delivery platforms were utilized. Studies were not adequately powered to test or detect statistically significant changes in depression, anxiety, or loneliness. Measurement of nature engagement varied. Using the Downs and Black checklist, we found study quality varied from good to poor.

DISCUSSION

More research is needed to understand the potential benefits of NBIs for perinatal mental health and social wellbeing. Additional study rigor is needed, including the consistent use of validated and well-rationalized measures of nature engagement. Intervention design should consider the varying needs perinatal populations, including barriers to and facilitators of engagement for diverse communities.

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.

Place-Based Differences in the Association Between Greenspace and Suicide-Related Outcomes Among Young People

PURPOSE

This study investigated place-based differences in the association between greenspace and suicide-related outcomes (SROs) among young people, guided by the following two objectives: (1) Contextualize place-based differences in the association between greenspace and SRO prevalence among young people at the community level in five different urbanities (urban, suburban, micropolitan, small towns, and rural/isolated communities) and (2) identify which greenspace metrics (quantity, quality, or accessibility) are most protective for SROs at the community level.

METHODS

Publicly available greenspace datasets were used to derive greenspace quantity, quality, and accessibility metrics. SRO emergency department visits for young people were identified from 2016-2019 in North Carolina, USA. Generalized linear models investigated the association between greenspace metrics and community-level drivers of SRO prevalence. Shapely additive explanations confirmed the most important greenspace variables in accurately predicting community-level SRO prevalence.

RESULTS

The prevalence of SROs was highest in communities with the least amount of public greenspace; this association was most pronounced in suburban communities, with SROs 27% higher in suburban communities with low quantities of greenspace (PRRUrban: 1.11, confidence interval [CI]: 1.08-1.13; PRRSuburban: 1.27, CI: 1.10-1.46; PRRSmallTowns: 1.21, CI: 1.05-1.39), and in communities with the worst greenspace accessibility (i.e., furthest distance to nearest greenspace) (PRRUrban: 1.07, CI: 1.04-1.10; PRRRural&Isolated: 1.95, CI: 1.54-2.49).

DISCUSSION

Our analysis provides place-based, community-specific findings to guide targeted greenspace interventions aimed at addressing the rising prevalence of SROs among young people. Our findings suggest that greenspace quantity interventions may be most effective in urban, suburban, and small-town communities, and greenspace accessibility interventions may be most useful in urban and rural/isolated communities.

Examining modification of the associations between air pollution and birth outcomes by neighborhood deprivation in a North Carolina birth cohort, 2011-2015

Background

Evidence from studies of air pollutants and birth outcomes suggests an association, but uncertainties around geographical variability and modifying factors still remain. As neighborhood-level social characteristics are associated with birth outcomes, we assess whether neighborhood deprivation level is an effect measure modifier on the association between air pollution and birth outcomes in a North Carolina birth cohort.

Methods

Using birth certificate data, all North Carolina residential singleton live births from 1 January 2011 to 31 December 2015 with gestational ages of 20-44 weeks (n = 566,799) were examined for birth defect diagnoses and preterm birth. Exposures were daily average fine particulate matter (PM2.5), daily 8-h maximum nitrogen dioxide (NO2), and daily 8-h maximum ozone (O3) modeled concentrations, and the modifier of interest was the neighborhood deprivation index (NDI). Linear binomial models were used to estimate the prevalence differences and 95% confidence intervals (CI) for the association between ambient air pollution and birth defect diagnoses. Modified Poisson regression models were used to estimate risk differences (RDs) and 95% CIs for air pollution and preterm birth. Models were stratified by the neighborhood deprivation index group (low, medium, or high) to assess potential modification by NDI.

Results

Approximately 3.1% of the study population had at least one birth defect and 8.18% were born preterm. For preterm birth, associations with PM2.5 and O3 did not follow a conclusive pattern and there was no evidence of modification by NDI. The associations between NO2 and preterm birth were generally negative across exposure windows except for a positive association with NO2 and preterm birth for high NDI [RD: 34.70 (95% CI 4.84-64.56)] for entire pregnancy exposure. There was no evidence of associations between pollutants examined and birth defects.

Conclusions

There may be differences in the association between NO2 exposure and preterm birth by NDI but we did not observe any evidence of associations for birth defects. Our results support the public health protection afforded by reductions in air pollution, even in areas of neighborhood deprivation, but future research conducted in areas with higher levels of air pollution and evaluating the potential for modification by neighborhood deprivation level would be informative.

Association of Psychiatric Emergency Visits and Warm Ambient Temperature during Pregnancy: A Time-Stratified Case-Crossover Study

BACKGROUND

Acute exposure to high ambient temperature and heat waves during the warm season has been linked with psychiatric disorders. Emerging research has shown that pregnant people, due to physiological and psychological changes, may be more sensitive to extreme heat, and acute exposure has been linked to increased risk of pregnancy complications; however, few studies have examined psychiatric complications.

OBJECTIVE

Our objective was to examine the association between acute exposure to warm ambient temperatures and emergency department (ED) visits for mental disorders during pregnancy.

METHODS

A time-stratified case-crossover design with conditional logistic regression was performed on ∼ 206,000 psychiatric ED visits for pregnant patients in North Carolina, from May to September 2016 to 2019. Daily average ambient temperature was the main exposure and was linked to daily visits by maternal zip code of residence for prenatal mood and anxiety disorders (PMAD), severe mental illness (SMI), mental disorder of pregnancy (MDP), suicidal thoughts (SUIC), and any psychiatric disorder (Any). Effect modification by trimester, residential segregation, economic segregation, urbanicity, and availability of greenspace was also investigated.

RESULTS

Each 5 ° C increase in same-day exposure to warm ambient temperature on case days was associated with an increase in incidence rate ratio (IRR) for any psychiatric disorder [IRR = 1.07; 95% confidence interval (CI): 1.01, 1.14] including anxiety (IRR = 1.14; 95% CI: 1.00, 1.30), bipolar disorder (IRR = 1.28; 95% CI: 0.98, 1.67), and suicidal thoughts (IRR = 1.28; 95% CI: 1.00, 1.65) compared to control days. In general, the associations were strongest for warm season temperatures on the same day of exposure or for temperatures averaged over the 3 or 6 d preceding the ED visit. The greatest risk of an incident ED admission for PMAD (RR = 1.20; 95% CI: 1.04, 1.39), particularly for anxiety (RR = 1.30; 95% CI: 1.07, 1.59), and any psychiatric disorder (RR = 1.17; 95% CI: 1.07, 1.28) occurred following cumulative exposure to hot temperatures the week before admission. Higher psychiatric burden from temperature was observed in urban areas and on extreme heat days.

CONCLUSIONS

For this pregnant population in the southeastern United States, short-term exposure to high ambient temperatures during the warm season was associated with a greater risk of ED visits for an array of psychiatric disorders. Findings show that climate-related increases in ambient temperature may contribute to psychiatric morbidity in pregnant people. https://doi.org/10.1289/EHP13293.

Urban Green Space and Perinatal Health Inequities in the United States: A Literature Review

Access to urban green space has been linked to positive health outcomes including enhanced perinatal health. The purpose of this article was to review, summarize, and synthesize what is known about the relationship between urban green space and perinatal health and outline implications for practice, policy, education, and research. Nineteen articles were included in this state-of-the-science review. Overall, it was found that limited access to green space is significantly related to adverse birth outcomes. These findings present an important opportunity for childbirth educators and other clinicians involved in the provision of prenatal and reproductive health care. Through education and intervention, poor perinatal outcomes may be mitigated. Clinical screening and education about the importance of access to and use of urban green space during pregnancy should be an essential component of preconception counseling and antenatal screening for at-risk populations. Policy makers should be made aware of these findings so that impactful change can be made in order to reduce disparities and promote health equity.

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.

Advancing Understanding on Greenspace and Mental Health in Young People

Mental distress among young people has increased in recent years. Research suggests that greenspace may benefit mental health. The objective of this exploratory study is to further understanding of place-based differences (i.e., urbanity) in the greenspace-mental health association. We leverage publicly available greenspace data sets to operationalize greenspace quantity, quality, and accessibility metrics at the community-level. Emergency department visits for young people (ages 24 and under) were coded for: anxiety, depression, mood disorders, mental and behavioral disorders, and substance use disorders. Generalized linear models investigated the association between greenspace metrics and community-level mental health burden; results are reported as prevalence rate ratios (PRR). Urban and suburban communities with the lowest quantities of greenspace had the highest prevalence of poor mental health outcomes, particularly for mood disorders in urban areas (PRR: 1.19, 95% CI: 1.16-1.21), and substance use disorders in suburban areas (PRR: 1.35, 95% CI: 1.28-1.43). In urban, micropolitan, and rural/isolated areas further distance to greenspace was associated with a higher prevalence of poor mental health outcomes; this association was most pronounced for substance use disorders (PRRUrban: 1.31, 95% CI: 1.29-1.32; PRRMicropolitan: 1.47, 95% CI: 1.43-1.51; PRRRural 2.38: 95% CI: 2.19-2.58). In small towns and rural/isolated communities, poor mental health outcomes were more prevalent in communities with the worst greenspace quality; this association was most pronounced for mental and behavioral disorders in small towns (PRR: 1.29, 95% CI: 1.24-1.35), and for anxiety disorders in rural/isolated communities (PRR: 1.61, 95% CI: 1.43-1.82). The association between greenspace metrics and mental health outcomes among young people is place-based with variations across the rural-urban continuum.

Impacts of compounding drought and heatwave events on child mental health: insights from a spatial clustering analysis

BACKGROUND

Concurrent heatwave and drought events may have larger health impacts than each event separately; however, no US-based studies have examined differential mental health impacts of compound drought and heatwave events in pediatric populations.

OBJECTIVE

To examine the spatial patterns of mood disorders and suicide-related emergency department (ED) visits in children during heatwave, drought, and compound heatwave and drought events. We tested whether the occurrence of compound heatwave and drought events have a synergistic (multiplicative) effect on the risk of mental health related outcomes in children as compared to the additive effect of each individual climate hazard. Lastly, we identified household and community-level determinants of geographic variability of high psychiatric burden.

METHODS

Daily counts of psychiatric ED visits in North Carolina from 2016 to 2019 (May to Sept) for pediatric populations were aggregated at the county scale. Bernoulli cluster analyses identified high-risk spatial clusters of psychiatric morbidity during heatwave, drought, or compound heatwave and drought periods. Multivariate adaptive regression models examined the individual importance of household and community-level determinants in predicting high-risk clustering of mood disorders or suicidality across the three climate threats.

RESULTS

Results showed significant spatial clustering of suicide and mood disorder risks in children during heatwave, drought, and compound event periods. Periods of drought were associated with the highest likelihood of spatial clustering for suicide and mood disorders, where the risk of an ED visit was 4.48 and 6.32 times higher, respectively, compared to non-drought periods. Compounding events were associated with a threefold increase in both suicide and mood disorder-related ED visits. Community and household vulnerability factors that most contributed to spatial clustering varied across climate hazards, but consistent determinants included residential segregation, green space availability, low English proficiency, overcrowding, no broadband access, no vehicle access, housing vacancy, and availability of housing units.

CONCLUSION

Findings advance understanding on the locations of vulnerable pediatric populations who are disproportionately exposed to compounding climate stressors and identify community resilience factors to target in public health adaptation strategies.

Mapping high-risk clusters and identifying place-based risk factors of mental health burden in pregnancy

Purpose

Despite affecting up to 20% of women and being the leading cause of preventable deaths during the perinatal and postpartum period, maternal mental health conditions are chronically understudied. This study is the first to identify spatial patterns in perinatal mental health conditions, and relate these patterns to place-based social and environmental factors that drive cluster development.

Methods

We performed spatial clustering analysis of emergency department (ED) visits for perinatal mood and anxiety disorders (PMAD), severe mental illness (SMI), and maternal mental disorders of pregnancy (MDP) using the Poisson model in SatScan from 2016 to 2019 in North Carolina. Logistic regression was used to examine the association between patient and community-level factors and high-risk clusters.

Results

The most significant spatial clustering for all three outcomes was concentrated in smaller urban areas in the western, central piedmont, and coastal plains regions of the state, with odds ratios greater than 3 for some cluster locations. Individual factors (e.g., age, race, ethnicity) and contextual factors (e.g., racial and socioeconomic segregation, urbanity) were associated with high risk clusters.

Conclusions

Results provide important contextual and spatial information concerning at-risk populations with a high burden of maternal mental health disorders and can better inform targeted locations for the expansion of maternal mental health services.

Ambient cold exposure amplifies the effect of ambient PM1 on blood pressure and hypertensive disorders of pregnancy among Chinese pregnant women: A nationwide cohort study

BACKGROUND

Little evidence exists regarding the combined effect between ambient temperature and air pollution exposure on maternal blood pressure (BP) and hypertensive disorders of pregnancy (HDP).

OBJECTIVES

To assess effect modification by temperature exposure on the PM1-BP/HDP associations among Chinese pregnant women based on a nationwide study.

METHODS

We conducted a cross-sectional country-based population study in China, enrolling 86,005 participants from November 2017 to December 2021. BP was measured with standardized sphygmomanometers. HDP was defined according to the American College of Obstetricians and Gynecologists' recommendations. Daily temperature data were obtained from the European Centre for Medium-Range Weather Forecasts. PM1 concentrations were evaluated using generalized additive model. Generalized linear mixed models were used to examine the health effects, controlling for multiple covariates. We also performed a series of stratified and sensitivity analyses.

RESULTS

The pro-hypertensive effect of PM1 was observed in the first trimester. Cold exposure amplifies the first-trimester PM1-BP/HDP associations, with adjusted estimate (aβ) for systolic blood pressure (SBP) of 3.038 (95 % CI: 2.320-3.755), aβ for diastolic blood pressure (DBP) of 2.189 (95 % CI: 1.503-2.875), and aOR for HDP of 1.392 (95 % CI: 1.160-1.670). Pregnant women who were educated longer than 17 years or living in urban areas appeared to be more vulnerable to the modification in the first trimester. These findings remained robust after sensitivity analyses.

CONCLUSIONS

First trimester maybe the critical exposure window for the PM1-BP/HDP associations among Chinese pregnant women. Cold exposure amplifies the associations, and those with higher education level or living in urban areas appeared to be more vulnerable.

A Difference-In Difference Analysis of the South Carolina 2015 Extreme Floods and the Association with Maternal Health

Research documenting the public health impacts of natural disasters often focuses on adults and children. Little research has examined the influence of extreme events, like floods, on maternal health, and less has examined the effect of disasters on maternal indicators like severe maternal morbidity (SMM) or unexpected outcomes of labor and delivery that result in significant short-or long-term consequences to a woman's health. The aim of this study is to identify the impacts of the 2015 flood events on maternal health outcomes in South Carolina, USA. We employ a quasi-experimental design using a difference-in-difference analysis with log-binomial regressions to evaluate maternal outcomes for impacted and control locations during the disaster event. Unlike previous studies, we extended our difference-in-difference analysis to include a trimester of exposure to assess the timing of flood exposure. We did not find evidence of statistically significant main effects on maternal health from the 2015 flood events related to preterm birth, gestational diabetes, mental disorders of pregnancy, depression, and generalized anxiety. However, we did find a statistically significant increase in SMM and low birth weight during the flood event for women in select trimester periods who were directly exposed. Our work provides new evidence on the effects of extreme flood events, like the 2015 floods, which can impact maternal health during specific exposure periods of pregnancy. Additional research is needed across other extreme weather events, as the unique context of the 2015 floods limits the generalizability of our findings.

Changes in Residential Greenspace and Birth Outcomes among Siblings: Differences by Maternal Race

Growing research investigates the perinatal health benefits of greenspace in a mother's prenatal environment. However, evidence of associations between residential greenspace and birth outcomes remains mixed, limiting the relevance this work holds for urban policy and greening interventions. Past research relies predominantly on cross-sectional designs that are vulnerable to residential selection bias, and rarely tests effect modification by maternal race/ethnicity, which may contribute to heterogeneous findings. This study uses a rigorous, longitudinal sibling comparison design and maternal fixed effect analyses to test whether increases in maternal exposure to residential greenspace between pregnancies precede improved birth outcomes among non-Hispanic (NH) white (n = 247,285) and Black (n = 54,995) mothers (mean age = 28 years) who had at least two consecutive live births in California between 2005 and 2015. Results show that increases in residential greenspace correspond with higher birthweight (coef. = 75.49, 95% CI: 23.48, 127.50) among Black, but not white (coef. = -0.51, 95% CI: -22.90, 21.90), infants. Additional analyses suggest that prior evidence of perinatal benefits associated with residential greenspace among white mothers may arise from residential selection; no such bias is observed for Black mothers. Taken together, these findings support urban greening initiatives in historically under-resourced neighborhoods. Efforts to evenly distribute residential greenspace may reduce persistent racial disparities in birth outcomes, an important step towards promoting health equity across the life course.

Methods in Public Health Environmental Justice Research: a Scoping Review from 2018 to 2021

PURPOSE OF REVIEW

The volume of public health environmental justice (EJ) research produced by academic institutions increased through 2022. However, the methods used for evaluating EJ in exposure science and epidemiologic studies have not been catalogued. Here, we completed a scoping review of EJ studies published in 19 environmental science and epidemiologic journals from 2018 to 2021 to summarize research types, frameworks, and methods.

RECENT FINDINGS

We identified 402 articles that included populations with health disparities as a part of EJ research question and met other inclusion criteria. Most studies (60%) evaluated EJ questions related to socioeconomic status (SES) or race/ethnicity. EJ studies took place in 69 countries, led by the US (n = 246 [61%]). Only 50% of studies explicitly described a theoretical EJ framework in the background, methods, or discussion and just 10% explicitly stated a framework in all three sections. Among exposure studies, the most common area-level exposure was air pollution (40%), whereas chemicals predominated personal exposure studies (35%). Overall, the most common method used for exposure-only EJ analyses was main effect regression modeling (50%); for epidemiologic studies the most common method was effect modification (58%), where an analysis evaluated a health disparity variable as an effect modifier. Based on the results of this scoping review, current methods in public health EJ studies could be bolstered by integrating expertise from other fields (e.g., sociology), conducting community-based participatory research and intervention studies, and using more rigorous, theory-based, and solution-oriented statistical research methods.

Association between greenspace and cancer: evidence from a systematic review and meta-analysis of multiple large cohort studies

Cancer is a chronic disease that seriously endangers human health, and studies on its association with greenspace have been published. We aimed to systematically review the epidemiological evidence and obtain the best available evidence. PubMed, Web of Science, Embase, and Cochrane Library were used as search databases, the time limit was September 12, 2022, and the cited articles were manually supplemented. Two researchers independently performed literature screening and data extraction. We performed a meta-analysis of data using a normalized difference vegetation index (NDVI) as the greenspace measure, providing hazard ratio (HR) and corresponding 95% CI. After standardization of the data, we used a random effects model for pooling. We also assessed the risk of bias for each study and the quality of each evidence body. We identified 10,108 items and included 14 studies from 11 institutions in eight countries. All studies had a low risk of bias. Quantitative analysis of 13 studies found a beneficial association of greenspace with the mortality of lung cancer (pooled HR [95% CI]=0.965 [0.947, 0.983]) and prostate cancer (HR [95% CI]=0.939 [0.898, 0.980]) based on 0.1-unit NDVI increment and a potential beneficial association with the incidence of prostate, lung, and breast cancer. Greenspace had opposite associations with cancer mortality for urban and rural populations. Indirect comparisons did not find statistically significant differences in the effects of greenspace on different cancer outcomes. The evidence body assessment was considered to be "very low." This review indicated potential beneficial associations between greenspace for lung, prostate, and breast cancer outcomes. However, there was a lack of mediation analysis to explore the underlying mechanism of a causal association. Meanwhile, the interstudy heterogeneity was large. Therefore, future studies should consider more accurate exposure assessment and more comprehensive covariate coverage, while focusing on mediating analysis. PROSPERO: CRD42022361068.

Spatial Analysis of Greenspace and Mental Health in North Carolina: Consideration of Rural and Urban Communities

Greenspace positively impacts mental health. Previous research has focused on the greenspace-mental health relationship in urban areas. Yet, little work has looked at rural areas despite rural communities reporting similar rates of poor mental health outcomes and higher rates of suicide mortality compared with urban areas. This ecological research study examined the following research questions: (1) Do public and/or private greenspaces affect the spatial distribution of mental health outcomes in North Carolina? (2) Does this relationship change with rurality? Emergency department data for 6 mental health conditions and suicide mortality data from 2009 to 2018 were included in this analysis. Spatial error and ordinary least squares regressions were used to examine the influence of public and private greenspace quantity on mental health in rural and urban communities. Results suggest greenspace benefits mental health in rural and urban communities. The strength of this relationship varies with urbanity and between public and private greenspaces, suggesting a more complex causal relationship. Given the high case counts and often lower density of mental health care facilities in rural areas, focusing attention on low-cost mental health interventions, such as greenspace, is important when considering rural mental health care.

Neighborhood Deprivation and Racial Disparities in Early Pregnancy Impaired Glucose Tolerance

OBJECTIVE

There is mounting evidence that neighborhoods contribute to perinatal health inequity. We aimed (1) to determine whether neighborhood deprivation (a composite marker of area-level poverty, education, and housing) is associated with early pregnancy impaired glucose intolerance (IGT) and pre-pregnancy obesity and (2) to quantify the extent to which neighborhood deprivation may explain racial disparities in IGT and obesity.

STUDY DESIGN

This was a retrospective cohort study of non-diabetic patients with singleton births ≥ 20 weeks' gestation from 1 January 2017-31 December 2019 in two Philadelphia hospitals. The primary outcome was IGT (HbA1c 5.7-6.4%) at <20 weeks' gestation. Addresses were geocoded and census tract neighborhood deprivation index (range 0-1, higher indicating more deprivation) was calculated. Mixed-effects logistic regression and causal mediation models adjusted for covariates were used.

RESULTS

Of the 10,642 patients who met the inclusion criteria, 49% self-identified as Black, 49% were Medicaid insured, 32% were obese, and 11% had IGT. There were large racial disparities in IGT (16% vs. 3%) and obesity (45% vs. 16%) among Black vs. White patients, respectively (p < 0.0001). Mean (SD) neighborhood deprivation was higher among Black (0.55 (0.10)) compared with White patients (0.36 (0.11)) (p < 0.0001). Neighborhood deprivation was associated with IGT and obesity in models adjusted for age, insurance, parity, and race (aOR 1.15, 95%CI: 1.07, 1.24 and aOR 1.39, 95%CI: 1.28, 1.52, respectively). Mediation analysis revealed that 6.7% (95%CI: 1.6%, 11.7%) of the Black-White disparity in IGT might be explained by neighborhood deprivation and 13.3% (95%CI: 10.7%, 16.7%) by obesity. Mediation analysis also suggested that 17.4% (95%CI: 12.0%, 22.4%) of the Black-White disparity in obesity may be explained by neighborhood deprivation.

CONCLUSION

Neighborhood deprivation may contribute to early pregnancy IGT and obesity-surrogate markers of periconceptional metabolic health in which there are large racial disparities. Investing in neighborhoods where Black patients live may improve perinatal health equity.

Potential impact of ambient temperature on maternal blood pressure and hypertensive disorders of pregnancy: A nationwide multicenter study based on the China birth cohort

Limited evidence exists regarding the association between ambient temperature and blood pressure (BP) level of pregnant women. To investigate the associations of ambient temperature with maternal BP and hypertensive disorders of pregnancy (HDP), we studied 105,063 participants in 38 centers of 17 provinces from November 2017 to December 2021. BP was measured with standardized automated digital sphygmomanometers. Ambient temperature was classified into five classes as very hot, moderate hot, mild, moderate cold, and very cold. Generalized linear mixed models were used to investigate the ambient temperature-BP/HDP associations, controlling for multiple covariates. No significant associations of first-trimester ambient temperature with maternal BP and HDP prevalence were observed. Compared with mild temperature, second-trimester very cold and second-trimester moderate cold were statistically associated with the increase of 1.239 mmHg (95% CI: 0.908, 1.569) and 0.428 mmHg (95% CI: 0.099, 0.757) for second-trimester systolic blood pressure (SBP), respectively. Similar trends were also observed in the association between second-trimester cold exposure and second-trimester diastolic blood pressure (DBP), in the association between second-trimester cold exposure and third-trimester SBP/DBP as well as in the association between third-trimester cold exposure and third-trimester SBP/DBP although some estimates were not statistically significant. Furthermore, in the second and third trimester, very cold [second trimester: adjusted odds ratio (aOR) = 1.298; third trimester: aOR = 1.236) and moderate cold (second trimester: aOR = 1.208; third trimester: aOR = 1.146) exposures also increased the odds of HDP, and these associations were stronger among participants aged ≥35 years or from North China. The second and third trimesters are the critical exposure windows for ambient temperature exposure-BP/HDP associations. During this period, exposure to cold ambient temperature was associated with elevated BP as well as increased HDP prevalence among most Chinese pregnant women, those aged ≥35 years or from North China being more vulnerable.

Association between urban green space and postpartum depression, and the role of physical activity: a retrospective cohort study in Southern California

Background

Little research exists regarding the relationships between green space and postpartum depression (PPD). We aimed to investigate the relationships between PPD and green space exposure, and the mediating role of physical activity (PA).

Methods

Clinical data were obtained from Kaiser Permanente Southern California electronic health records in 2008-2018. PPD ascertainment was based on both diagnostic codes and prescription medications. Maternal residential green space exposures were assessed using street view-based measures and vegetation types (i.e., street tree, low-lying vegetation, and grass), satellite-based measures [i.e., Normalized Difference Vegetation Index (NDVI), land-cover green space, and tree canopy cover], and proximity to the nearest park. Multilevel logistic regression was applied to estimate the association between green space and PPD. A causal mediation analysis was performed to estimate the proportion mediated by PA during pregnancy in the total effects of green space on PPD.

Findings

In total, we included 415,020 participants (30.2 ± 5.8 years) with 43,399 (10.5%) PPD cases. Hispanic mothers accounted for about half of the total population. A reduced risk for PPD was associated with total green space exposure based on street-view measure [500 m buffer, adjusted odds ratio (OR) per interquartile range: 0.98, 95% CI: 0.97-0.99], but not NDVI, land-cover greenness, or proximity to a park. Compared to other types of green space, tree coverage showed stronger protective effects (500 m buffer, OR = 0.98, 95% CI: 0.97-0.99). The proportions of mediation effects attributable to PA during pregnancy ranged from 2.7% to 7.2% across green space indicators.

Interpretation

Street view-based green space and tree coverage were associated with a decreased risk of PPD. The observed association was primarily due to increased tree coverage, rather than low-lying vegetation or grass. Increased PA was a plausible pathway linking green space to lower risk for PPD.

Funding

National Institute of Environmental Health Sciences (NIEHS; R01ES030353).

Environmental justice and allergic disease: A Work Group Report of the AAAAI Environmental Exposure and Respiratory Health Committee and the Diversity, Equity and Inclusion Committee

Environmental justice is the concept that all people have the right to live in a healthy environment, to be protected against environmental hazards, and to participate in decisions affecting their communities. Communities of color and low-income populations live, work, and play in environments with disproportionate exposure to hazards associated with allergic disease. This unequal distribution of hazards has contributed to health disparities and is largely the result of systemic racism that promotes segregation of neighborhoods, disinvestment in predominantly racial/ethnic minority neighborhoods, and discriminatory housing, employment, and lending practices. The AAAAI Environmental Exposure and Respiratory Health Committee and Diversity, Equity and Inclusion Committee jointly developed this report to improve allergy/immunology specialists' awareness of environmental injustice, its roots in systemic racism, and its impact on health disparities in allergic disease. We present evidence supporting the relationship between exposure to environmental hazards, particularly at the neighborhood level, and the disproportionately high incidence and poor outcomes from allergic diseases in marginalized populations. Achieving environmental justice requires investment in at-risk communities to increase access to safe housing, clean air and water, employment opportunities, education, nutrition, and health care. Through policies that promote environmental justice, we can achieve greater health equity in allergic disease.

Green space, air pollution and gestational diabetes mellitus: A retrospective cohort study in central China

Emerging evidence suggests residential surrounding green space is beneficial for human health. The association between green space and GDM showed inconsistent results, and potential effect modification of green space with air pollution is still unclear. This study aims to evaluate the association between green space and GDM, and further explore potential interaction and medication effects. Participants were recruited from a retrospective cohort study between 2015 and 2020 in Henan, China. Residential green space based on normalized difference vegetation index (NDVI) and air pollution exposure were estimated using spatial-statistical models. Multivariate logistic regression was applied to evaluate the association between per 0.1 unit increase in NDVI with 4 buffer sizes (250 m, 500 m, 1000 m, 2000 m) and GDM. We examined potential interaction of green space and air pollutants on GDM. Mediating effects of air pollution associated with green space exposure on GDM were also investigated by causal mediation analyses. A total of 46,665 eligible pregnant women were identified. There were 4092 (8.8 %) women diagnosed with GDM according to the IADPSG criteria. We found that per 0.1-unit increment in NDVI250 m, NDVI500 m, NDVI1000 m and NDVI2000 m in second trimester were associated with the decreased risk of GDM, with adjusted OR of 0.921(95 %CI: 0.890-0.953), 0.922 (95 %CI: 0.891-0.953), 0.921 (95 %CI: 0.892-0.952) and 0.921 (95 %CI: 0.892-0.951), respectively. We identified significant interactions between second trimester PM2.5 and O3 exposure and NDVI for GDM (Pinteraction < 0.001). The causal mediation analysis showed that PM2.5 mediated approximately 2.5-5.5 % of the association between green space and GDM, while the estimated mediating effect of O3 was approximately 30.1-38.5 %. In conclusion, our study indicates that residential green space was associated with a reduced risk of GDM, particularly second trimester. Green space may benefit to GDM partly mediated by a reduction in PM2.5 and O3.

Built and Social Environments, Environmental Justice, and Maternal Pregnancy Complications

Purpose of Review

The Environmental Justice Movement centers on addressing inequitable distribution of environmental harms in marginalized communities. It has been commonly understood as the disproportionate concentration of environmental pollutants or hazards. As such, much of the work on environmental harms and maternal pregnancy complications have focused on environmental toxins. This scoping review surveyed the literature exploring the built and social environment factors and maternal pregnancy complications among racially marginalized women and highlights how an environmental justice framework can inform policy interventions for maternal health inequities caused by structural racism in built and social environments.

Recent Findings

The literature examining the association between neighborhood level built and social environment factors and maternal pregnancy complications in the last five years is sparse. When excluding environmental toxins, we identified 16 studies that fit our criteria of neighborhood-level environmental exposure, with the majority focused on built environment factors, specifically proximity to greenspace and food environment.

Summary

We identified a few important gaps and opportunities for future research in this area. First is a need to explore additional built environment elements. Secondly, extensive research is needed on the social environment. Third is a critical understanding to incorporate structural racism and cultural perspectives to better understand these relationships in minoritized populations and highlight the intersection between environmental hazards concentration and their structural causes. Finally, an environmental justice framework is critically needed in the interpretation and translation of this literature to inform policy solutions that can counteract the harms in racially marginalized communities and improve health.