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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

[Environmental exposures and epigenome changes within the first 1000 days of life]

Early environmental exposures can have long-term effects on child's development and health. Epigenetic modifications may partly explain these effects, and studying them could lead to significant advances in our understanding of the underlying mechanisms. This review summarises recent data on epigenetic and environmental epidemiology during the first 1000 days of life for several common exposures, including tobacco, phenols and phthalates, air pollutants, ambient temperature and vegetation.

How Green Space Justice in urban built-up areas affects public mental health: a moderated chain mediation model

Background

Green and blue spaces, as crucial components of urban ecosystems, significantly impact the physical and mental health of residents. However, the mechanisms through which Green/Blue Space Justice influence residents' health remain unclear.

Methods

This study aims to explore the impact of green spaces on public psychological responses, physical activity, and mental health from a justice perspective, and to examine the moderating role of blue spaces in this relationship. The research was conducted in selected communities within the Chang-Zhu-Tan urban agglomeration in Hunan Province, China. A total of 801 valid questionnaires were collected through field visits and online surveys. The study uses an improved Gaussian-based two-step floating catchment area (2SFCA) method to assess green space accessibility. Data were analyzed using structural equation modeling (SEM) and moderation effect analysis to reveal the relationships between variables.

Results

The findings indicate that Green Space Justice has a significant positive impact on psychological responses, physical activity, and mental health; psychological responses and physical activity play crucial mediating roles between Green Space Justice and mental health; and Green Space Justice significantly affects mental health through a chain mediation path involving psychological responses and physical activity. Moreover, Blue Space Justice significantly moderates the impact of Green Space Justice on psychological responses and physical activity, but does not have a significant direct impact on mental health.

Conclusion

This study enriches the theory of Green Space Justice by revealing the mechanisms through which it influences mental health via psychological responses and physical activity. It provides a scientific basis for the development of healthy cities. Additionally, it recommends that urban planning should prioritize the equitable distribution and high accessibility of both green and blue spaces to comprehensively enhance residents' physical and mental well-being. Policymakers should consider prioritizing the accessibility of high-quality green spaces for vulnerable communities during urban renewal and expansion processes to reduce social health inequalities and promote broader public health outcomes.

Maternal perceived stress and green spaces during pregnancy are associated with adult offspring gene (NR3C1 and IGF2/H19) methylation patterns in adulthood: A pilot study

BACKGROUND

Changes in NR3C1 and IGF2/H19 methylation patterns have been associated with behavioural and psychiatric outcomes. Maternal mental state has been associated with offspring NR3C1 promotor and IGF2/H19 imprinting control region (ICR) methylation patterns. However, there is a lack of prospective studies with long-term follow-up.

METHODS

52 mother-offspring pairs were studied from 12 to 22 weeks of pregnancy and offspring was followed-up until 28-29 years-of-age. During pregnancy, mothers filled in a Life Event Scale and a Daily Hassles Scale measuring perceived stress; i.e., appraisal or subjectively experienced severity of impact of important life events and of daily hassles in several life domains during pregnancy, respectively. Green space was quantified around the residence, using high-resolution (1 m2) map data. Saliva and blood samples were obtained from the adult offspring. Absolute DNA methylation levels were determined in blood and saliva on four NR3C1 amplicons, and one IGF2/H19 ICR amplicon using a bisulfite PCR and sequencing method. Linear mixed effect models were used to test the associations between perceived stress and green spaces during pregnancy, and adult offspring methylation patterns.

RESULTS

We found associations between maternal perceived stress during pregnancy and methylation patterns on two out of the four NR3C1 amplicons, measured in blood, from offspring in adulthood, but not with IGF2/H19 methylation. For an interquartile-range (IQR) increase in maternal perceived life event or daily hassles stress scores, absolute methylation levels on several NR3C1 CpG sites were significantly changed (-1.62 % to +5.89 %, p<0.05). Maternal perceived stress scores were not associated with IGF2/H19 methylation, neither in blood nor in saliva. Maternal exposure to green spaces surrounding the residence during the pregnancy was associated with IGF2/H19 ICR methylation (-0.80 % to -1.04 %, p<0.05) in saliva, but not with NR3C1 promotor methylation.

CONCLUSION

We observed significant long-term effects of maternal perceived stress during pregnancy on the methylation patterns of the NR3C1 promotor in offspring well into adulthood. This may imply that maternal psychological distress during pregnancy may influence the regulation of the HPA-axis well into adulthood. Additionally, maternal proximity to green spaces was associated with IGF2/H19 ICR methylation patterns, which is a novel finding.

Heterogeneous associations of multiplexed environmental factors and multidimensional aging metrics

Complicated associations between multiplexed environmental factors and aging are poorly understood. We manipulated aging using multidimensional metrics such as phenotypic age, brain age, and brain volumes in the UK Biobank. Weighted quantile sum regression was used to examine the relative individual contributions of multiplexed environmental factors to aging, and self-organizing maps (SOMs) were used to examine joint effects. Air pollution presented a relatively large contribution in most cases. We also found fair heterogeneities in which the same environmental factor contributed inconsistently to different aging metrics. Particulate matter contributed the most to variance in aging, while noise and green space showed considerable contribution to brain volumes. SOM identified five subpopulations with distinct environmental exposure patterns and the air pollution subpopulation had the worst aging status. This study reveals the heterogeneous associations of multiplexed environmental factors with multidimensional aging metrics and serves as a proof of concept when analyzing multifactors and multiple outcomes.

Consistent cord blood DNA methylation signatures of gestational age between South Asian and white European cohorts

BACKGROUND

Epigenetic modifications, particularly DNA methylation (DNAm) in cord blood, are an important biological marker of how external exposures during gestation can influence the in-utero environment and subsequent offspring development. Despite the recognized importance of DNAm during gestation, comparative studies to determine the consistency of these epigenetic signals across different ethnic groups are largely absent. To address this gap, we first performed epigenome-wide association studies (EWAS) of gestational age (GA) using newborn cord blood DNAm comparatively in a white European (n = 342) and a South Asian (n = 490) birth cohort living in Canada. Then, we capitalized on established cord blood epigenetic GA clocks to examine the associations between maternal exposures, offspring characteristics and epigenetic GA, as well as GA acceleration, defined as the residual difference between epigenetic and chronological GA at birth.

RESULTS

Individual EWASs confirmed 1,211 and 1,543 differentially methylated CpGs previously reported to be associated with GA, in white European and South Asian cohorts, respectively, with a similar distribution of effects. We confirmed that Bohlin's cord blood GA clock was robustly correlated with GA in white Europeans (r = 0.71; p = 6.0 × 10-54) and South Asians (r = 0.66; p = 6.9 × 10-64). In both cohorts, Bohlin's clock was positively associated with newborn weight and length and negatively associated with parity, newborn female sex, and gestational diabetes. Exclusive to South Asians, the GA clock was positively associated with the newborn ponderal index, while pre-pregnancy weight and gestational weight gain were strongly predictive of increased epigenetic GA in white Europeans. Important predictors of GA acceleration included gestational diabetes mellitus, newborn sex, and parity in both cohorts.

CONCLUSIONS

These results demonstrate the consistent DNAm signatures of GA and the utility of Bohlin's GA clock across the two populations. Although the overall pattern of DNAm is similar, its connections with the mother's environment and the baby's anthropometrics can differ between the two groups. Further research is needed to understand these unique relationships.

Current perspectives on perinatal mental health and neurobehavioral development: focus on regulation, coregulation and self-regulation

PURPOSE OF REVIEW

Perinatal mental health research provides an important perspective on neurobehavioral development. Here, we aim to review the association of maternal perinatal health with offspring neurodevelopment, providing an update on (self-)regulation problems, hypothesized mechanistic pathways, progress and challenges, and implications for mental health.

RECENT FINDINGS

(1) Meta-analyses confirm that maternal perinatal mental distress is associated with (self-)regulation problems which constitute cognitive, behavioral, and affective social-emotional problems, while exposure to positive parental mental health has a positive impact. However, effect sizes are small. (2) Hypothesized mechanistic pathways underlying this association are complex. Interactive and compensatory mechanisms across developmental time are neglected topics. (3) Progress has been made in multiexposure studies. However, challenges remain and these are shared by clinical, translational and public health sciences. (4) From a mental healthcare perspective, a multidisciplinary and system level approach employing developmentally-sensitive measures and timely treatment of (self-)regulation and coregulation problems in a dyadic caregiver-child and family level approach seems needed. The existing evidence-base is sparse.

SUMMARY

During the perinatal period, addressing vulnerable contexts and building resilient systems may promote neurobehavioral development. A pluralistic approach to research, taking a multidisciplinary approach to theoretical models and empirical investigation needs to be fostered.