Ambient Air Pollution and Newborn Size and Adiposity at Birth: Differences by Maternal Ethnicity (the Born in Bradford Study Cohort)

Air and Noise Pollution Exposure in Early Life and Mental Health From Adolescence to Young Adulthood

Importance

Growing evidence associates air pollution exposure with various psychiatric disorders. However, the importance of early-life (eg, prenatal) air pollution exposure to mental health during youth is poorly understood, and few longitudinal studies have investigated the association of noise pollution with youth mental health.

Objectives

To examine the longitudinal associations of air and noise pollution exposure in pregnancy, childhood, and adolescence with psychotic experiences, depression, and anxiety in youths from ages 13 to 24 years.

Design, Setting, and Participants

This cohort study used data from the Avon Longitudinal Study of Parents and Children, an ongoing longitudinal birth cohort founded in 1991 through 1993 in Southwest England, United Kingdom. The cohort includes over 14 000 infants with due dates between April 1, 1991, and December 31, 1992, who were subsequently followed up into adulthood. Data were analyzed October 29, 2021, to March 11, 2024.

Exposures

A novel linkage (completed in 2020) was performed to link high-resolution (100 m2) estimates of nitrogen dioxide (NO2), fine particulate matter under 2.5 μm (PM2.5), and noise pollution to home addresses from pregnancy to 12 years of age.

Main outcomes and measures

Psychotic experiences, depression, and anxiety were measured at ages 13, 18, and 24 years. Logistic regression models controlled for key individual-, family-, and area-level confounders.

Results

This cohort study included 9065 participants who had any mental health data, of whom (with sample size varying by parameter) 51.4% (4657 of 9051) were female, 19.5% (1544 of 7910) reported psychotic experiences, 11.4% (947 of 8344) reported depression, and 9.7% (811 of 8398) reported anxiety. Mean (SD) age at follow-up was 24.5 (0.8) years. After covariate adjustment, IQR increases (0.72 μg/m3) in PM2.5 levels during pregnancy (adjusted odds ratio [AOR], 1.11 [95% CI, 1.04-1.19]; P = .002) and during childhood (AOR, 1.09 [95% CI, 1.00-1.10]; P = .04) were associated with elevated odds for psychotic experiences. Pregnancy PM2.5 exposure was also associated with depression (AOR, 1.10 [95% CI, 1.02-1.18]; P = .01). Higher noise pollution exposure in childhood (AOR, 1.19 [95% CI, 1.03-1.38]; P = .02) and adolescence (AOR, 1.22 [95% CI, 1.02-1.45]; P = .03) was associated with elevated odds for anxiety.

Conclusions and Relevance

In this longitudinal cohort study, early-life air and noise pollution exposure were prospectively associated with 3 common mental health problems from adolescence to young adulthood. There was a degree of specificity in terms of pollutant-timing-outcome associations. Interventions to reduce air and noise pollution exposure (eg, clean air zones) could potentially improve population mental health. Replication using quasi-experimental designs is now needed to shed further light on the underlying causes of these associations.

Maternal urban particulate matter (SRM 1648a) exposure disrupted the cellular immune homeostasis during early life: The potential attribution of altered placental transcriptome profile

Ambient fine particular matter (PM2.5) exposure has been associated with numerous adverse effects including triggering functional disorders of the placenta and inducing immune imbalance in offspring. However, how maternal PM2.5 exposure impacts immune development during early life is not fully understood. In the current study, we exposed mice with low-, middle-, and high-dose PM2.5 during pregnancy to investigate the potential link between the transcriptional changes in the placenta and immune imbalance in mice offspring induced by PM2.5 exposures. Using flow cytometry, we found that the proportions of B cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and macrophage (Mφ) cells were altered in the blood of PM2.5-exposed mice pups but not dendritic cells (DCs) and natural killer cells (NKs). Using bulk RNA sequencing, we found that PM2.5 exposure altered the transcriptional profile which indicated an inhibition of the complement and coagulation cascades in the placenta. Weighted gene co-expression network analysis (WGCNA) revealed the potential crosstalk between the perturbation of placental gene expression and the changes of immune cell subsets in pups on postnatal day 10 (PND10). Specifically, WGCNA identified a cluster of genes including Defb15, Defb20, Defb25, Cst8, Cst12, and Adam7 that might regulate the core immune cell types in PND10 pups. Although the underlying mechanisms of how maternal PM2.5 exposure induces peripheral lymphocyte disturbance in offspring still remain much unknown, our findings here shed light on the potential role of placental dysfunction in these adverse effects.

Effects of in-utero personal exposure to PM2.5 sources and components on birthweight

In-utero exposure to fine particulate matter (PM2.5) and specific sources and components of PM2.5 have been linked with lower birthweight. However, previous results have been mixed, likely due to heterogeneity in sources impacting PM2.5 and due to measurement error from using ambient data. Therefore, we investigated the effect of PM2.5 sources and their high-loading components on birthweight using data from 198 women in the 3rd trimester from the MADRES cohort 48-h personal PM2.5 exposure monitoring sub-study. The mass contributions of six major sources of personal PM2.5 exposure were estimated for 198 pregnant women in the 3rd trimester using the EPA Positive Matrix Factorization v5.0 model, along with their 17 high-loading chemical components using optical carbon and X-ray fluorescence approaches. Single- and multi-pollutant linear regressions evaluated the association between personal PM2.5 sources/components and birthweight, adjusting for gestational age, maternal age, race, infant sex, parity, diabetes status, temperature, maternal education, and smoking history. Participants were predominately Hispanic (81%), with a mean (SD) gestational age of 39.1 (1.5) weeks and age of 28.2 (6.0) years. Mean birthweight was 3295.8 g (484.1) and mean PM2.5 exposure was 21.3 (14.4) µg/m3. A 1 SD increase in the mass contribution of the fresh sea salt source was associated with a 99.2 g decrease in birthweight (95% CI - 197.7, - 0.6), and aged sea salt was associated with a 70.1 g decrease in birthweight (95% CI - 141.7, 1.4). Magnesium, sodium, and chlorine were associated with lower birthweight, which remained after adjusting for PM2.5 mass. This study found evidence that major sources of personal PM2.5 including fresh and aged sea salt were negatively associated with birthweight, with the strongest effect on birthweight from Na and Mg. The effect of crustal and fuel oil sources differed by infant sex with negative associations seen in boys compared to positive associations in girls.

Genome-Wide Profiling of Transcriptome and DNA Methylome in Human Embryonic Stem Cells Exposed to Extractable Organic Matter from PM2.5

Increasing evidence indicates that PM2.5 exposure disrupts early embryonic development, but the mechanisms remain unclear. We hypothesized that PM2.5 cause abnormal embryonic development by interfering with DNA methylation and mRNA expression. In this study, we observed that human embryonic stem cells (hESCs) treated with extractable organic matters (EOM) from PM2.5 concentrations above 100 μg/mL exhibited reduced viability. While EOM within non-cytotoxicity concentrations did not affect the expression levels of pluripotency genes, it did enhance cellular proliferation, as indicated by increased Edu incorporation and the upregulation of cell cycle genes (Cdk2, Mdm2). Additionally, EOM significantly influenced the transcriptome patterns in hESCs. Notably, the differentially expressed genes were found to be significantly enriched in processes such as extracellular matrix organization, cell-cell junction organization, chromatin organization, and DNA methylation. Furthermore, we observed whole genomic-wide DNA methylation changes. Through a cross-analysis of changes in DNA methylation and mRNA expression, we identified an enrichment of terms related to the VEGFR signaling pathway and extracellular matrix. The gene signal transduction networks revealed that crucial hubs were implicated in cell growth and division. In conclusion, our findings demonstrate that PM2.5 induce significant alterations in transcriptome and DNA methylome in hESCs, leading to aberrant cell proliferation. This research provides novel insights into the molecular mechanisms underlying the developmental toxicity of PM2.5.

Prenatal PM2.5 exposure increases the risk of adverse pregnancy outcomes: evidence from meta-analysis of cohort studies

Adverse pregnancy outcomes (APOs) are a significant cause of fetal death. A wide range of maternal psychological, social, and environmental factors may contribute to these outcomes. Mounting epidemiological studies have indicated that PM2.5 may result in these unfavorable consequences. Previously published meta-analyses have been updated and extended. Cohort studies were searched from three databases (up to July 24, 2023), and their quality was assessed by Newcastle-Ottawa Scale (NOS). Publication bias was examined by Egger's test and funnel plot. Despite a large number of studies showing similar results, the inconsistencies between these findings require careful generalization before concluding. This meta-analysis included 67 cohort studies from 20 countries, and the findings revealed that maternal PM2.5 exposure and five APOs were correlated significantly throughout pregnancy: preterm birth (PTB) (RR = 1.05; 95% CI: 1.03, 1.07); low birth weight (LBW) (RR = 1.02; 95% CI: 1.01, 1.04); small for gestational age (SGA) (RR = 1.03; 95% CI: 1.01, 1.04); stillbirth (RR = 1.24; 95% CI: 1.06, 1.45); and change in birthweight (weight change = -6.82 g; 95% CI: -11.39, -2.25). A positive association was found between APOs and PM2.5 exposure in this meta-analysis, and the degree of increased risk of APOs varied due to different gestation periods. Therefore, it is necessary to protect pregnant women at specific times.

Effects of In-Utero Personal Exposure to PM2.5 Sources and Components on Birthweight

Background

In-utero exposure to fine particulate matter (PM2.5) and specific sources and components of PM2.5 have been linked with lower birthweight. However, previous results have been mixed, likely due to heterogeneity in sources impacting PM2.5 and due to measurement error from using ambient data. Therefore, we investigated the effect of PM2.5 sources and their high-loading components on birthweight using data from 198 women in the 3rd trimester from the MADRES cohort 48-hour personal PM2.5 exposure monitoring sub-study.

Methods

The mass contributions of six major sources of personal PM2.5 exposure were estimated for 198 pregnant women in the 3rd trimester using the EPA Positive Matrix Factorization v5.0 model, along with their 17 high-loading chemical components using optical carbon and X-ray fluorescence approaches. Single- and multi-pollutant linear regressions were used to evaluate the association between personal PM2.5 sources and birthweight. Additionally, high-loading components were evaluated with birthweight individually and in models further adjusted for PM2.5 mass.

Results

Participants were predominately Hispanic (81%), with a mean (SD) gestational age of 39.1 (1.5) weeks and age of 28.2 (6.0) years. Mean birthweight was 3,295.8g (484.1) and mean PM2.5 exposure was 21.3 (14.4) μg/m3. A 1 SD increase in the mass contribution of the fresh sea salt source was associated with a 99.2g decrease in birthweight (95% CI: -197.7, -0.6), while aged sea salt was associated with lower birthweight (β =-70.1; 95% CI: -141.7, 1.4). Magnesium sodium, and chlorine were associated with lower birthweight, which remained after adjusting for PM2.5 mass.

Conclusions

This study found evidence that major sources of personal PM2.5 including fresh and aged sea salt were negatively associated with birthweight, with the strongest effect on birthweight from Na and Mg. The effect of crustal and fuel oil sources differed by infant sex with negative associations seen in boys compared to positive associations in girls.

Effects of maternal urban particulate matter SRM 1648a exposure on birth outcomes and offspring growth in mice

The association between exposure to particulate matter (PM) during pregnancy and abnormal birth outcomes is still inconclusive. This study aims to provide more evidence for this public health concern by investigating birth outcomes and the growth of offspring in mice exposed to PM during pregnancy. C57BL/6 J pregnant mice were exposed to PM via nasal drip at three doses or solvent control. The dam weight gain was recorded during pregnancy. The number of pups, pup weight, and placental weight were recorded at embryonic day 18.5 (E18.5) necropsy. For mice that gave birth naturally, we calculated the gestation length and measured the body weight of offspring once a week from the 1st to the 6th week after birth. The results showed that there were no significant differences in maternal body weight gain, conception rate, pregnancy duration, and litter size among different groups. There were no significant differences in fetal weight, placental weight, and fetal/placental weight ratio at E18.5. Weight gain in offspring was reduced after birth. The average body weight of offspring in the high-dose group was significantly lower than that in the control group at weeks 5 in female pups. There were no significant differences in the body weight of male offspring among groups from 1st to the 6th. Together, our study indicated that maternal exposure to PM did not significantly impact birth outcomes of C57BL/6 J mice but affected growth trajectories in offspring after birth in a dose- and fetal sex-dependent manner.

Prenatal exposure to fine particulate matter and newborn anogenital distance: a prospective cohort study

BACKGROUND

Considerable attention has been paid to reproductive toxicity of fine particulate matter (PM_2.5). However, the relationship between prenatal PM_2.5 exposure and anogenital distance (AGD) has not been well studied. We aim to investigate the potential effects of prenatal exposure to PM_2.5 on newborn AGD.

METHODS

Prenatal PM_2.5 exposure of 2332 participates in Shanghai (2013-2016) was estimated using high-performance machine learning models. Anoscrotal distance (AGDas) in male infants and anofourchette distance (AGDaf) in female infants were measured by well-trained examiners within 3 days after birth. We applied multiple linear regression models and multiple informant models to estimate the association between prenatal PM_2.5 exposure and AGD.

RESULTS

Multiple linear regression models showed that a 10 μg/m³ increase in PM_2.5 exposure during full pregnancy, the second and third trimesters was inversely associated with AGDas (adjusted beta = - 1.76, 95% CI: - 2.21, - 1.31; - 0.73, 95% CI: - 1.06, - 0.40; and - 0.52; 95% CI: - 0.87, - 0.18, respectively) in males. A 10 μg/m³ increase in PM_2.5 exposure during the full pregnancy, the first, second, and third trimesters was inversely associated with AGDaf (adjusted beta = - 4.55; 95% CI: - 5.18, - 3.92; - 0.78; 95% CI: - 1.10, - 0.46; - 1.11; 95% CI: - 1.46, - 0.77; - 1.45; 95% CI: - 1.78, - 1.12, respectively) in females after adjusting for potential confounders. Multiple informant models showed consistent but slightly attenuated associations.

CONCLUSION

Our study observed a significant association between gestational PM_2.5 exposure during pregnancy and shortened AGD in newborns, and provided new evidence on potential reproductive toxicity of prenatal PM_2.5 exposure.

Using non-parametric Bayes shrinkage to assess relationships between multiple environmental and social stressors and neonatal size and body composition in the Healthy Start cohort

BACKGROUND

Both environmental and social factors have been linked to birth weight and adiposity at birth, but few studies consider the effects of exposure mixtures. Our objective was to identify which components of a mixture of neighborhood-level environmental and social exposures were driving associations with birth weight and adiposity at birth in the Healthy Start cohort.

METHODS

Exposures were assessed at the census tract level and included air pollution, built environment characteristics, and socioeconomic status. Prenatal exposures were assigned based on address at enrollment. Birth weight was measured at delivery and adiposity was measured using air displacement plethysmography within three days. We used non-parametric Bayes shrinkage (NPB) to identify exposures that were associated with our outcomes of interest. NPB models were compared to single-predictor linear regression. We also included generalized additive models (GAM) to assess nonlinear relationships. All regression models were adjusted for individual-level covariates, including maternal age, pre-pregnancy BMI, and smoking.

RESULTS

Results from NPB models showed most exposures were negatively associated with birth weight, though credible intervals were wide and generally contained zero. However, the NPB model identified an interaction between ozone and temperature on birth weight, and the GAM suggested potential non-linear relationships. For associations between ozone or temperature with birth weight, we observed effect modification by maternal race/ethnicity, where effects were stronger for mothers who identified as a race or ethnicity other than non-Hispanic White. No associations with adiposity at birth were observed.

CONCLUSIONS

NPB identified prenatal exposures to ozone and temperature as predictors of birth weight, and mothers who identify as a race or ethnicity other than non-Hispanic White might be disproportionately impacted. However, NPB models may have limited applicability when non-linear effects are present. Future work should consider a two-stage approach where NPB is used to reduce dimensionality and alternative approaches examine non-linear effects.

In-utero personal exposure to PM2.5 impacted by indoor and outdoor sources and birthweight in the MADRES cohort

BACKGROUND

In-utero exposure to outdoor particulate matter with aerodynamic diameter less than 2.5 μm (PM_2.5) is linked with low birthweight. However, previous results are mixed, likely due to measurement error introduced by estimating personal exposure from ambient data. This study investigated the effect of total personal PM_2.5 exposure on birthweight and whether it differed when it was more heavily impacted by sources of indoor vs outdoor origin in the MADRES cohort study.

METHODS

Personal PM_2.5 exposure was measured in 205 pregnant women in the 3rd trimester using 48 h integrated, filter-based sampling. Linear regression was used to test the association between personal PM_2.5 exposure and birthweight, adjusting for key covariates. Interactions of PM_2.5 with variables representing indoor sources of PM_2.5, home ventilation, or time spent indoors tested whether the effect of total PM_2.5 on birthweight varied when it was more impacted by sources of indoor vs outdoor origin.

RESULTS

In a sample of largely Hispanic (81%) pregnant women, total personal PM_2.5 was not significantly associated with birthweight (β = 38.6 per 1SD increase in PM_2.5; 95% CI:-21.1, 98.2). This association however, differed by home type (single family home: 156.9 (26.9, 287.0), 2-4 attached units:-16.6 (-111.9, 78.7), 5+ units:-62.6 (-184.9, 59.6), missing: 145.4 (-4.1, 294.9), interaction p = 0.028) and by household air conditioner use (none of the time: -27.6 (-101.5, 46.3) vs. some of the time: 139.9 (42.9, 237.0), interaction p = 0.008) Additionally, the effect of personal PM_2.5 on birthweight varied by time spent indoors (none or little of the time: - 45.1 (-208.3, 118.1) vs. most or all of the time: 57.1 (-7.3, 121.6), interaction p = 0.255).

CONCLUSIONS

While no significant association between total personal PM_2.5 exposure and birthweight was found, there was evidence that multi-unit housing (vs. single-family homes), candle and/or incense smoke, and greater outdoor source contributions to personal PM_2.5 were more strongly associated with lower birthweight.

Mother-level random effect in the association between PM2.5 and fetal growth: A population-based pregnancy cohort

BACKGROUND

A growing body of literature reports associations between exposure to particulate matter with diameter ≤2.5 μm (PM_2.5) during pregnancy and birth outcomes. However, findings are inconsistent across studies.

OBJECTIVES

To assess the association between PM_2.5 and birth outcomes of fetal growth in a cohort with high prevalence of siblings by multilevel models accounting for geographical- and mother-level correlations.

METHODS

In Israel, we used Maccabi Healthcare Services data to establish a population-based cohort of 381,265 singleton births reaching 24-42 weeks' gestation and birth weight of 500-5000 g (2004-2015). Daily PM_2.5 predictions from a satellite-based spatiotemporal model were linked to the date of birth and maternal residence. We generated mean PM_2.5 values for the entire pregnancy and for exposure periods during pregnancy. Associations between exposure and birth outcomes were modeled by using multilevel logistic regression with random effects for maternal locality of residence, administrative census area (ACA) and mother.

RESULTS

In fully adjusted models with a mother-level random intercept only, a 10-μg/m³ increase in PM_2.5 over the entire pregnancy was positively associated with term low birth weight (TLBW) (Odds ratio, OR = 1.25, 95% confidence interval, CI: 1.09,1.43) and small for gestational age (SGA) (OR = 1.15, 95% CI: 1.06,1.26). Locality- and ACA-level effects accounted for <0.4% of the variance while mother-level effects explained ∼50% of the variability. Associations varied by exposure period, infants' sex, birth order, and maternal pre-pregnancy BMI.

CONCLUSIONS

Consideration of mother-level variability in a region with high fertility rates provides new insights on the strength of associations between PM_2.5 and birth outcomes.

Effect on the health of newborns caused by extreme temperature in Guangzhou

By using 64,270 daily observations from a large hospital in Guangzhou between 2017 and 2019, we analyzed the impact of extreme temperature on the health of newborns via OLS regression with time fixed effect. Given that the short-term temperature change can be regarded as exogenous and random, solving the potential endogenous problem is critical. We find that extreme temperature negatively affects the health of newborns. The Apgar score, an index for evaluating neonatal health, decreases by 0.008 (0.029%) when the duration of extreme temperature events increases by a day. A series of robustness checks verify the reliability of this negative effect. Extreme temperature also has a particularly serious effect on the health of newborns whose mothers have poor education. By gradually extending the observation period, we find that the effect of extreme temperature on neonatal health is mainly concentrated 1-6 weeks before delivery, whereas the effect of extreme temperature on hospitalization cost is mainly concentrated 4-8 weeks before delivery. This paper provides a valuable reference for evaluating the health and social costs of extreme weather, and our findings are conducive to the construction of climate-resilient health systems, especially in Guangzhou.

Maternal exposure to ambient PM2.5 and term birth weight: A systematic review and meta-analysis of effect estimates

Effect estimates of prenatal exposure to ambient PM_2.5 on change in grams (β) of birth weight among term births (≥37 weeks of gestation; term birth weight, TBW) vary widely across studies. We present the first systematic review and meta-analysis of evidence regarding these associations. Sixty-two studies met the eligibility criteria for this review, and 31 studies were included in the meta-analysis. Random-effects meta-analysis was used to assess the quantitative relationships. Subgroup analyses were performed to gain insight into heterogeneity derived from exposure assessment methods (grouped by land use regression [LUR]-models, aerosol optical depth [AOD]-based models, interpolation/dispersion/Bayesian models, and data from monitoring stations), study regions, and concentrations of PM_2.5 exposure. The overall pooled estimate involving 23,925,941 newborns showed that TBW was negatively associated with PM_2.5 exposure (per 10 μg/m³ increment) during the entire pregnancy (β = -16.54 g), but with high heterogeneity (I² = 95.6%). The effect estimate in the LUR-models subgroup (β = -16.77 g) was the closest to the overall estimate and with less heterogeneity (I² = 18.3%) than in the other subgroups of AOD-based models (β = -41.58 g; I² = 95.6%), interpolation/dispersion models (β = -10.78 g; I² = 86.6%), and data from monitoring stations (β = -11.53 g; I² = 97.3%). Even PM_2.5 exposure levels of lower than 10 μg/m³ (the WHO air quality guideline value) had adverse effects on TBW. The LUR-models subgroup was the only subgroup that obtained similar significant of negative associations during the three trimesters as the overall trimester-specific analyses. In conclusion, TBW was negatively associated with maternal PM_2.5 exposures during the entire pregnancy and each trimester. More studies based on relatively standardized exposure assessment methods need to be conducted to further understand the precise susceptible exposure time windows and potential mechanisms.

Urban environment and cognitive and motor function in children from four European birth cohorts

BACKGROUND

The urban environment may influence neurodevelopment from conception onwards, but there is no evaluation of the impact of multiple groups of exposures simultaneously. We investigated the association between early-life urban environment and cognitive and motor function in children.

METHODS

We used data from 5403 mother-child pairs from four population-based birth-cohorts (UK, France, Spain, and Greece). We estimated thirteen urban home exposures during pregnancy and childhood, including: built environment, natural spaces, and air pollution. Verbal, non-verbal, gross motor, and fine motor functions were assessed using validated tests at five years old. We ran adjusted multi-exposure models using the Deletion-Substitution-Addition algorithm.

RESULTS

Higher greenness exposure within 300 m during pregnancy was associated with higher verbal abilities (1.5 points (95% confidence interval 0.4, 2.7) per 0.20 unit increase in greenness). Higher connectivity density within 100 m and land use diversity during pregnancy were related to lower verbal abilities. Childhood exposure to PM2.5 mediated 74% of the association between greenness during childhood and verbal abilities. Higher exposure to PM2.5 during pregnancy was related to lower fine motor function (-1.2 points (-2.1, -0.4) per 3.2 μg/m3 increase in PM2.5). No associations were found with non-verbal abilities and gross motor function.

DISCUSSION

This study suggests that built environment, greenness, and air pollution may impact child cognitive and motor function at five years old. This study adds evidence that well-designed urban planning may benefit children's cognitive and motor development.

Placental gene networks at the interface between maternal PM2.5 exposure early in gestation and reduced infant birthweight

BACKGROUND

A growing body of evidence links maternal exposure to particulate matter <2.5 μM in diameter (PM2.5) and deviations in fetal growth. Several studies suggest that the placenta plays a critical role in conveying the effects of maternal PM2.5 exposure to the developing fetus. These include observed associations between air pollutants and candidate placental features, such as mitochondrial DNA content, DNA methylation and telomere length. However, gaps remain in delineating the pathways linking the placenta to air pollution-related health effects, including a comprehensive profiling of placental processes impacted by maternal PM2.5 exposure. In this study, we examined alterations in a placental transcriptome-wide network in relation to maternal PM2.5 exposure prior to and during pregnancy and infant birthweight.

METHODS

We evaluated PM2.5 exposure and placental RNA-sequencing data among study participants enrolled in the Rhode Island Child Health Study (RICHS). Daily residential PM2.5 levels were estimated using a hybrid model incorporating land-use regression and satellite remote sensing data. Distributed lag models were implemented to assess the impact on infant birthweight due to PM2.5 weekly averages ranging from 12 weeks prior to gestation until birth. Correlations were assessed between PM2.5 levels averaged across the identified window of susceptibility and a placental transcriptome-wide gene coexpression network previously generated using the WGCNA R package.

RESULTS

We identified a sensitive window spanning 12 weeks prior to and 13 weeks into gestation during which maternal PM2.5 exposure is significantly associated with reduced infant birthweight. Two placental coexpression modules enriched for genes involved in amino acid transport and cellular respiration were correlated with infant birthweight as well as maternal PM2.5 exposure levels averaged across the identified growth restriction window.

CONCLUSION

Our findings suggest that maternal PM2.5 exposure may alter placental programming of fetal growth, with potential implications for downstream health effects, including susceptibility to cardiometabolic health outcomes and viral infections.

Telehealth rehabilitation for adults with cochlear implants in response to the Covid-19 pandemic: platform selection and case studies

BACKGROUND

Effective information giving and goal setting before cochlear implantation and individualised rehabilitation following implantation are both crucial for shaping patients' expectations and optimising outcomes. The Covid-19 pandemic led to temporary cessation of face to face clinic appointments. This created a need for telehealth rehabilitation for adults whose hearing loss presents unique communication challenges.

AIMS

We describe the piloting and implementation of telehealth rehabilitation within an adult cochlear implant service.

METHOD

Video conferencing and telehealth tools were assessed in terms of security, accessibility and functionality. Written support materials were developed. Telehealth sessions were piloted with lay volunteers. During service implementation, feedback was collected from patients and staff.

OUTCOMES & RESULTS

A video call platform was identified that was supported by the host Trust and also met the rehabilitation service's needs. A telehealth service was successfully implemented, ensuring continuity of care during lockdown. We share the platform selection framework used, practical lessons learned and patient support materials.

CONCLUSION

.Telehealth rehabilitation facilitated a well-received, effective service for adult cochlear implant patients. It is predicted that the benefits of telehealth rehabilitation will last beyond the lockdown restrictions posed by Covid-19.

Prenatal and childhood exposure to air pollution and traffic and the risk of liver injury in European children

Nonalcoholic fatty liver disease is the most prevalent pediatric chronic liver disease. Experimental studies suggest effects of air pollution and traffic exposure on liver injury. We present the first large-scale human study to evaluate associations of prenatal and childhood air pollution and traffic exposure with liver injury.

METHODS

Study population included 1,102 children from the Human Early Life Exposome project. Established liver injury biomarkers, including alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and cytokeratin-18, were measured in serum between ages 6-10 years. Air pollutant exposures included nitrogen dioxide, particulate matter <10 μm (PM10), and <2.5 μm. Traffic measures included traffic density on nearest road, traffic load in 100-m buffer, and inverse distance to nearest road. Exposure assignments were made to residential address during pregnancy (prenatal) and residential and school addresses in year preceding follow-up (childhood). Childhood indoor air pollutant exposures were also examined. Generalized additive models were fitted adjusting for confounders. Interactions by sex and overweight/obese status were examined.

RESULTS

Prenatal and childhood exposures to air pollution and traffic were not associated with child liver injury biomarkers. There was a significant interaction between prenatal ambient PM10 and overweight/obese status for alanine aminotransferase, with stronger associations among children who were overweight/obese. There was no evidence of interaction with sex.

CONCLUSION

This study found no evidence for associations between prenatal or childhood air pollution or traffic exposure with liver injury biomarkers in children. Findings suggest PM10 associations maybe higher in children who are overweight/obese, consistent with the multiple-hits hypothesis for nonalcoholic fatty liver disease pathogenesis.

Progress Towards Using Linked Population-Based Data For Geohealth Research: Comparisons Of Aotearoa New Zealand And The United Kingdom

Globally, geospatial concepts are becoming increasingly important in epidemiological and public health research. Individual level linked population-based data afford researchers with opportunities to undertake complex analyses unrivalled by other sources. However, there are significant challenges associated with using such data for impactful geohealth research. Issues range from extracting, linking and anonymising data, to the translation of findings into policy whilst working to often conflicting agendas of government and academia. Innovative organisational partnerships are therefore central to effective data use. To extend and develop existing collaborations between the institutions, in June 2019, authors from the Leeds Institute for Data Analytics and the Alan Turing Institute, London, visited the Geohealth Laboratory based at the University of Canterbury, New Zealand. This paper provides an overview of insight shared during a two-day workshop considering aspects of linked population-based data for impactful geohealth research. Specifically, we discuss both the collaborative partnership between New Zealand's Ministry of Health (MoH) and the University of Canterbury's GeoHealth Lab and novel infrastructure, and commercial partnerships enabled through the Leeds Institute for Data Analytics and the Alan Turing Institute in the UK. We consider the New Zealand Integrated Data Infrastructure as a case study approach to population-based linked health data and compare similar approaches taken by the UK towards integrated data infrastructures, including the ESRC Big Data Network centres, the UK Biobank, and longitudinal cohorts. We reflect on and compare the geohealth landscapes in New Zealand and the UK to set out recommendations and considerations for this rapidly evolving discipline.

Air pollution and pregnancy outcomes based on exposure evaluation using a land use regression model: A systematic review

This review systematically assessed those studies investigating the association between air pollution and birth outcomes using land use regression (LUR) models for exposure assessment. Fifty-four studies were identified which were published between 2007 and 2019. Most of these were conducted in America, Spain and Canada, while only five were conducted in China. One hundred and ninety-seven LUR models were developed for different pollutants. The main pollutants that these studies assessed were NO₂ and PM_2.5, and the main pregnancy outcomes investigated were preterm birth (PTB), small for gestational age (SGA) and birth weight. Studies consistently found that NO₂ exposure during pregnancy was associated with reduced fetal growth and development. The effect of NO₂ on other adverse pregnancy outcomes is unclear. In addition, it was found that increased PM_2.5 (aerodynamic equivalent diameter ≤ 2.5 um) exposure during pregnancy reduced birth weight. The effect of PM_2.5 on other adverse pregnancy outcomes is also unclear. The relationship between other pollutants and adverse pregnancy outcomes is uncertain based on the existing research. Exposure assessment with LUR modeling has been widely used in Europe and North America, but used less in China. Future studies are recommended to use LUR modeling for individual exposure evaluation in China to better characterize the relationship between air pollution and adverse pregnancy outcomes. In addition, further research is required given that a lot of the associations looked at in the review were inconclusive.

Application of the navigation guide systematic review methodology to evaluate prenatal exposure to particulate matter air pollution and infant birth weight

Low birth weight is an important risk factor for many co-morbidities both in early life as well as in adulthood. Numerous studies report associations between prenatal exposure to particulate matter (PM) air pollution and low birth weight. Previous systematic reviews and meta-analyses report varying effect sizes and significant heterogeneity between studies, but did not systematically evaluate the quality of individual studies or the overall body of evidence. We conducted a new systematic review to determine how prenatal exposure to PM2.5, PM10, and coarse PM (PM2.5-10) by trimester and across pregnancy affects infant birth weight. Using the Navigation Guide methodology, we developed and applied a systematic review protocol [CRD42017058805] that included a comprehensive search of the epidemiological literature, risk of bias (ROB) determination, meta-analysis, and evidence evaluation, all using pre-established criteria. In total, 53 studies met our inclusion criteria, which included evaluation of birth weight as a continuous variable. For PM2.5 and PM10, we restricted meta-analyses to studies determined overall as "low" or "probably low" ROB; none of the studies evaluating coarse PM were rated as "low" or "probably low" risk of bias, so all studies were used. For PM2.5, we observed that for every 10 µg/m3 increase in exposure to PM2.5 in the 2nd or 3rd trimester, respectively, there was an associated 5.69 g decrease (I2: 68%, 95% CI: -10.58, -0.79) or 10.67 g decrease in birth weight (I2: 84%, 95% CI: -20.91, -0.43). Over the entire pregnancy, for every 10 µg/m3 increase in PM2.5 exposure, there was an associated 27.55 g decrease in birth weight (I2: 94%, 95% CI: -48.45, -6.65). However, the quality of evidence for PM2.5 was rated as "low" due to imprecision and/or unexplained heterogeneity among different studies. For PM10, we observed that for every 10 µg/m3 increase in exposure in the 3rd trimester or the entire pregnancy, there was a 6.57 g decrease (I2: 0%, 95% CI: -10.66, -2.48) or 8.65 g decrease in birth weight (I2: 84%, 95% CI: -16.83, -0.48), respectively. The quality of evidence for PM10 was rated as "moderate," as heterogeneity was either absent or could be explained. The quality of evidence for coarse PM was rated as very low/low (for risk of bias and imprecision). Overall, while evidence for PM2.5 and course PM was inadequate primarily due to heterogeneity and risk of bias, respectively, our results support the existence of an inverse association between prenatal PM10 exposure and low birth weight.

Association between exposure to air pollution during intrauterine life and cephalic circumference of the newborn

It has been observed that air pollution can affect newborn health due to the negative effects of pollutants on pregnancy development. However, few studies have evaluated the impact of maternal exposure to urban air pollution on head circumference (HC) at birth. Reduced head growth during pregnancy may be associated with neurocognitive deficits in childhood. The objectives of this study were to evaluate the association between maternal exposure to air pollution and HC at birth and to provide context with a systematic review to investigate this association. This was a prospective study of low-risk pregnant women living in São Paulo, Brazil. Exposure to pollutants, namely, nitrogen dioxide (NO₂) and ozone (O₃), was measured during each trimester using passive personal samplers. We measured newborn HC until 24 h after birth. We used multiple linear regression models to evaluate the association between pollutants and HC while controlling for known determinants of pregnancy. To perform the systematic review, four different electronic databases were searched through November 2018: CENTRAL, EMBASE, LILACS, and MEDLINE. We selected longitudinal or transversal designs associating air pollution and HC at birth. Two reviewers evaluated the inclusion criteria and risk of bias and extracted data from the included papers. Thirteen studies were selected for the systematic review. We evaluated 391 patients, and we did not observe a significant association between air pollution and HC. Regarding the systematic review, 13 studies were selected for the systematic review, 8 studies showed an inverse association between maternal exposure to pollutants and HC, 4 showed no association, and one observed a direct association. In the city of São Paulo, maternal exposure to pollutants was not significantly associated with HC at birth. The systematic review suggested an inverse association between air pollution and HC at birth.

Adverse Birth Outcomes Related to NO2 and PM Exposure: European Systematic Review and Meta-Analysis

There is a growing number of international studies on the association between ambient air pollution and adverse pregnancy outcomes, and this systematic review and meta-analysis has been conducted focusing on European countries, to assess the crucial public health issue of this suspected association on this geographical area. A systematic literature search (based on Preferred Reporting Items for Systematic reviews and Meta-Analyses, PRISMA, guidelines) has been performed on all European epidemiological studies published up until 1 April 2020, on the association between maternal exposure during pregnancy to nitrogen dioxide (NO₂) or particular matter (PM) and the risk of adverse birth outcomes, including: low birth weight (LBW) and preterm birth (PTB). Fourteen articles were included in the systematic review and nine of them were included in the meta-analysis. Our meta-analysis was conducted for 2 combinations of NO₂ exposure related to birth weight and PTB. Our systematic review revealed that risk of LBW increases with the increase of air pollution exposure (including PM₁₀, PM_2.5 and NO₂) during the whole pregnancy. Our meta-analysis found that birth weight decreases with NO₂ increase (pooled beta = −13.63, 95% confidence interval (CI) (−28.03, 0.77)) and the risk of PTB increase for 10 µg/m3 increase in NO₂ (pooled odds ratio (OR) = 1.07, 95% CI (0.90, 1.28)). However, the results were not statistically significant. Our finding support the main international results, suggesting that increased air pollution exposure during pregnancy might contribute to adverse birth outcomes, especially LBW. This body of evidence has limitations that impede the formulation of firm conclusions. Further studies, well-focused on European countries, are called to resolve the limitations which could affect the strength of association such as: the exposure assessment, the critical windows of exposure during pregnancy, and the definition of adverse birth outcomes. This analysis of limitations of the current body of research could be used as a baseline for further studies and may serve as basis for reflection for research agenda improvements.

Early-Life Environmental Exposures and Childhood Obesity: An Exposome-Wide Approach

BACKGROUND

Chemical and nonchemical environmental exposures are increasingly suspected to influence the development of obesity, especially during early life, but studies mostly consider single exposure groups.

OBJECTIVES

Our study aimed to systematically assess the association between a wide array of early-life environmental exposures and childhood obesity, using an exposome-wide approach.

METHODS

The HELIX (Human Early Life Exposome) study measured child body mass index (BMI), waist circumference, skinfold thickness, and body fat mass in 1,301 children from six European birth cohorts age 6-11 y. We estimated 77 prenatal exposures and 96 childhood exposures (cross-sectionally), including indoor and outdoor air pollutants, built environment, green spaces, tobacco smoking, and biomarkers of chemical pollutants (persistent organic pollutants, metals, phthalates, phenols, and pesticides). We used an exposure-wide association study (ExWAS) to screen all exposure-outcome associations independently and used the deletion-substitution-addition (DSA) variable selection algorithm to build a final multiexposure model.

RESULTS

The prevalence of overweight and obesity combined was 28.8%. Maternal smoking was the only prenatal exposure variable associated with higher child BMI (z-score increase of 0.28, 95% confidence interval: 0.09, 0.48, for active vs. no smoking). For childhood exposures, the multiexposure model identified particulate and nitrogen dioxide air pollution inside the home, urine cotinine levels indicative of secondhand smoke exposure, and residence in more densely populated areas and in areas with fewer facilities to be associated with increased child BMI. Child blood levels of copper and cesium were associated with higher BMI, and levels of organochlorine pollutants, cobalt, and molybdenum were associated with lower BMI. Similar results were found for the other adiposity outcomes.

DISCUSSION

This first comprehensive and systematic analysis of many suspected environmental obesogens strengthens evidence for an association of smoking, air pollution exposure, and characteristics of the built environment with childhood obesity risk. Cross-sectional biomarker results may suffer from reverse causality bias, whereby obesity status influenced the biomarker concentration. https://doi.org/10.1289/EHP5975.

Effects of air pollution on the nervous system and its possible role in neurodevelopmental and neurodegenerative disorders

Recent extensive evidence indicates that air pollution, in addition to causing respiratory and cardiovascular diseases, may also negatively affect the brain and contribute to central nervous system diseases. Air pollution is comprised of ambient particulate matter (PM) of different sizes, gases, organic compounds, and metals. An important contributor to PM is represented by traffic-related air pollution, mostly ascribed to diesel exhaust (DE). Epidemiological and animal studies have shown that exposure to air pollution may be associated with multiple adverse effects on the central nervous system. In addition to a variety of behavioral abnormalities, the most prominent effects caused by air pollution are oxidative stress and neuro-inflammation, which are seen in both humans and animals, and are supported by in vitro studies. Among factors which can affect neurotoxic outcomes, age is considered most relevant. Human and animal studies suggest that air pollution may cause developmental neurotoxicity, and may contribute to the etiology of neurodevelopmental disorders, including autism spectrum disorder. In addition, air pollution exposure has been associated with increased expression of markers of neurodegenerative disease pathologies, such as alpha-synuclein or beta-amyloid, and may thus contribute to the etiopathogenesis of neurodegenerative diseases, particularly Alzheimer's disease and Parkinson's disease.

Prenatal exposure to traffic and ambient air pollution and infant weight and adiposity: The Healthy Start study

BACKGROUND

Prenatal exposures to ambient air pollution and traffic have been associated with adverse birth outcomes, and may also lead to an increased risk of obesity. Obesity risk may be reflected in changes in body composition in infancy.

OBJECTIVE

To estimate associations between prenatal ambient air pollution and traffic exposure, and infant weight and adiposity in a Colorado-based prospective cohort study.

METHODS

Participants were 1125 mother-infant pairs with term births. Birth weight was recorded from medical records and body composition measures (fat mass, fat-free mass, and adiposity [percent fat mass]) were evaluated via air displacement plethysmography at birth (n = 951) and at ~5 months (n = 574). Maternal residential address was used to calculate distance to nearest roadway, traffic density, and ambient concentrations of fine particulate matter (PM_2.5) and ozone (O₃) via inverse-distance weighted interpolation of stationary monitoring data, averaged by trimester and throughout pregnancy. Adjusted linear regression models estimated associations between exposures and infant weight and body composition.

RESULTS

Participants were urban residents and diverse in race/ethnicity and socioeconomic status. Average ambient air pollutant concentrations were generally low; the median, interquartile range (IQR), and range of third trimester concentrations were 7.3 μg/m³ (IQR: 1.3, range: 3.3-12.7) for PM_2.5 and 46.3 ppb (IQR: 18.4, range: 21.7-63.2) for 8-h maximum O_3. Overall there were few associations between traffic and air pollution exposures and infant outcomes. Third trimester O₃ was associated with greater adiposity at follow-up (2.2% per IQR, 95% CI 0.1, 4.3), and with greater rates of change in fat mass (1.8 g/day, 95% CI 0.5, 3.2) and adiposity (2.1%/100 days, 95% CI 0.4, 3.7) from birth to follow-up.

CONCLUSIONS

We found limited evidence of an association between prenatal traffic and ambient air pollution exposure and infant body composition. Suggestive associations between prenatal ozone exposure and early postnatal changes in body composition merit further investigation.

Critical windows for maternal fine particulate matter exposure and adverse birth outcomes: The Shanghai birth cohort study

BACKGROUND

Prenatal exposure to ambient levels of air pollution has been reported to adversely affect birth outcomes, yet few studies have investigated refined susceptible windows for adverse birth outcomes.

OBJECTIVES

The study aimed at estimating associations between maternal exposure to ambient fine particulate matter (PM_2.5; particles with an aerodynamic diameter ≤ 2.5 μm) and birth outcomes, including birth weight, low birth weight (LBW) and preterm birth (PTB), and identify specific susceptible windows.

METHODS

A total of 3692 singleton live births were enrolled between 2013 and 2016 in Shanghai Birth Cohort, China. Based on mothers' residential addresses, weekly mean concentrations of PM_2.5 over gestation were estimated based on an incorporated evaluating approach combining satellite-based estimates and ground-level measurements. Distributed lag non-liner models (DLNMs) were fitted by incorporating with multiple liner models and Cox proportional hazard models to evaluate weekly-as well as trimester-exposure-lag-response associations between average PM_2.5 level and birth weight, LBW and PTB, and to identify critical windows.

RESULTS

In this study, gestational exposure to PM_2.5 was associated with adverse birth outcomes in infants, and critical windows were identified as 31st-34th gestational weeks for reduced birth weight, 38th-42 nd weeks for LBW and 27th-30th weeks for PTB, respectively. Trimester-specific associations were found for all birth outcomes during the third trimester.

CONCLUSIONS

Ambient PM_2.5 exposure exhibited adverse impacts on multiple outcomes including reduced birth weight, LBW and PTB in the late pregnancy. The study provides further evidence supporting harmful effects of maternal PM_2.5 exposure on birth outcomes and identifying critical windows.

Risk of particulate matter on birth outcomes in relation to maternal socio-economic factors: a systematic review

A growing number of studies provide evidence of an association between exposure to maternal air pollution during pregnancy and adverse birth outcomes including low birth weight and preterm birth. Prevention of these health effects of air pollution is critical to reducing the adverse infant outcomes, which can have impacts throughout the life course. However, there is no consensus on whether the association between air pollution exposure and birth outcomes varies by maternal risk factors including demographic characteristics and socio-economic status. Such information is vital to understand potential environmental health disparities. Our search found 859 unique studies, of which 45 studies met our inclusion criteria (Jan. 2000- July. 2019). We systematically reviewed the 45 identified epidemiologic studies and summarized the results on effect modifications by maternal race/ethnicity, educational attainment, income, and area-level socio-economic status. We considered adverse birth outcomes of preterm birth, low birth weight, small for gestational age (SGA), and stillbirth. Suggestive evidence of higher risk of particulate matter in infants of African-American/black mothers than infants of other women was found for preterm birth and low birth weight. We found weak evidence that particulate matter risk was higher for infants of mothers with lower educational attainment for preterm birth and low birth weight. Due to the small study numbers, we were unable to conclude whether effect modification is present for income, occupation, and area-level socio-economic status, and additional research is needed. Furthermore, adverse birth outcomes such as SGA and stillbirth need more study to understand potential environmental justice issues regarding the impact of particulate matter exposure during pregnancy on birth outcomes.

Characteristics of cohort studies of long-term exposure to PM2.5: a systematic review

This study systematically reviewed all the cohort studies investigating the relationship between long-term exposure to PM_2.5 and any health outcome until February 2018. We searched ISI Web of Knowledge, Pubmed, and Scopus databases for peer-reviewed journal research articles published in English. We only extracted the results of the single-pollutant main analysis of each study, excluding the effect modifications and sensitivity analyses. Out of the initial 9523 articles, 203 articles were ultimately included for analysis. Based on the different characteristics of studies such as study design, outcome, exposure assessment method, and statistical model, we calculated the number and relative frequency of analyses with statistically significant and insignificant results. Most of the studies were prospective (84.8%), assessed both genders (66.5%), and focused on a specific age range (86.8%). Most of the articles (78.1%) had used modeling techniques for exposure assessment of cohorts' participants. Among the total of 317 health outcomes, the most investigated outcomes include mortality due to cardiovascular disease (6.19%), all causes (5.48%), lung cancer (4.00%), ischemic heart disease (3.50%), and non-accidental causes (3.50%). The percentage of analyses with statistically significant results were higher among studies that used prospective design, mortality as the outcome, fixed stations as exposure assessment method, hazard ratio as risk measure, and no covariate adjustment. We can somehow conclude that the choice of right characteristics for cohort studies can make a difference in their results.

Prenatal and Childhood Traffic-Related Air Pollution Exposure and Telomere Length in European Children: The HELIX Project

BACKGROUND

Telomere length is a molecular marker of biological aging.

OBJECTIVE

Here we investigated whether early-life exposure to residential air pollution was associated with leukocyte telomere length (LTL) at 8 y of age.

METHODS

In a multicenter European birth cohort study, HELIX (Human Early Life Exposome) ([Formula: see text]), we estimated prenatal and 1-y childhood exposure to nitrogen dioxide ([Formula: see text]), particulate matter with aerodynamic diameter [Formula: see text] ([Formula: see text]), and proximity to major roads. Average relative LTL was measured using quantitative real-time polymerase chain reaction (qPCR). Effect estimates of the association between LTL and prenatal, 1-y childhood air pollution, and proximity to major roads were calculated using multiple linear mixed models with a random cohort effect and adjusted for relevant covariates.

RESULTS

LTL was inversely associated with prenatal and 1-y childhood [Formula: see text] and [Formula: see text] exposures levels. Each standard deviation (SD) increase in prenatal [Formula: see text] was associated with a [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]) change in LTL. Prenatal [Formula: see text] was nonsignificantly associated with LTL ([Formula: see text] per SD increase; 95% CI: [Formula: see text], 0.6). For each SD increment in 1-y childhood [Formula: see text] and [Formula: see text] exposure, LTL shortened by [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]) and [Formula: see text] (95% CI: [Formula: see text], 0.1), respectively. Each doubling in residential distance to nearest major road during childhood was associated with a 1.6% (95% CI: 0.02, 3.1) lengthening in LTL.

CONCLUSION

Lower exposures to air pollution during pregnancy and childhood were associated with longer telomeres in European children at 8 y of age. These results suggest that reductions in traffic-related air pollution may promote molecular longevity, as exemplified by telomere length, from early life onward. https://doi.org/10.1289/EHP4148.

The association of early-life exposure to ambient PM2.5 and later-childhood height-for-age in India: an observational study

BACKGROUND

Children in India are exposed to high levels of ambient fine particulate matter (PM2.5). However, population-level evidence of associations with adverse health outcomes from within the country is limited. The aim of our study is to estimate the association of early-life exposure to ambient PM2.5 with child health outcomes (height-for-age) in India.

METHODS

We linked nationally-representative anthropometric data from India's 2015-2016 Demographic and Health Survey (n = 218,152 children under five across 640 districts of India) with satellite-based PM2.5 exposure (concentration) data. We then applied fixed effects regression to assess the association between early-life ambient PM2.5 and subsequent height-for-age, analyzing whether deviations in air pollution from the seasonal average for a particular place are associated with deviations in child height from the average for that season in that place, controlling for trends over time, temperature, and birth, mother, and household characteristics. We also explored the timing of exposure and potential non-linearities in the concentration-response relationship.

RESULTS

Children in the sample were exposed to an average of 55 μ g/m3 of PM2.5 in their birth month. After controlling for potential confounders, a 100 μg/m3 increase in PM2.5 in the month of birth was associated with a 0.05 [0.01-0.09] standard deviation reduction in child height. For an average 5 year old girl, this represents a height deficit of 0.24 [0.05-0.43] cm. We also found that exposure to PM2.5 in the last trimester in utero and in the first few months of life are significantly (p < 0.05) associated with child height deficits. We did not observe a decreasing marginal risk at high levels of exposure.

CONCLUSIONS

India experiences some of the worst air pollution in the world. To our knowledge, this is the first study to estimate the association of early-life exposure to ambient PM2.5 on child height-for-age at the range of ambient pollution exposures observed in India. Because average exposure to ambient PM2.5 is high in India, where child height-for-age is a critical challenge in human development, our results highlight ambient air pollution as a public health policy priority.

Developmental programming of obesity by maternal exposure to concentrated ambient PM2.5 is maternally transmitted into the third generation in a mouse model

BACKGROUND

Obesity is an uncontrolled global epidemic and one of the leading global public health challenges. Maternal exposure to ambient fine particulate matter (PM2.5) may adversely program offspring's adiposity, suggesting a specialized role of PM2.5 pollution in the global obesity epidemic. However, the vulnerable window for this adverse programming and how it is cross-generationally transmitted have not been determined. Therefore, in the present study, female C57Bl/6 J mice were exposed to filtered air (FA) or concentrated ambient PM2.5 (CAP) during different periods, and the development and adulthood adiposity of their four-generational offspring were assessed.

RESULTS

Our data show that the pre-conceptional but not gestational exposure to CAP was sufficient to cause male but not female offspring's low birth weight, accelerated postnatal weight gain, and increased adulthood adiposity. These adverse developmental traits were transmitted into the F2 offspring born by the female but not male F1 offspring of CAP-exposed dams. In contrast, no adverse development was noted in the F3 offspring.

CONCLUSIONS

The present study identified a pre-conceptional window for the adverse programming of adiposity by maternal exposure to PM2.5, and showed that it was maternally transmitted into the third generation. These data not only call special attention to the protection of women from exposure to PM2.5, but also may facilitate the development of intervention to prevent this adverse programming.

The associations of air pollution exposure during pregnancy with fetal growth and anthropometric measurements at birth: a systematic review and meta-analysis

Fetal growth has been demonstrated to be an important predictor of perinatal and postnatal health. Although the effects of maternal exposure to air pollution during pregnancy on fetal growth have been investigated using ultrasound in many previous studies, the results were inconsistent and disputable. We aimed to qualitatively and quantitatively investigate the associations of air pollution exposure during different periods of pregnancy with fetal growth and anthropometric measurements at birth. We searched for all studies investigating the associations of air pollution exposure during pregnancy with fetal growth and birth anthropometric measurements in English and Chinese databases published before July 31, 2017. A random-effects model was employed in the meta-analysis to estimate the pooled effects of each 10 μg/m³ increment in air pollutant exposure. The ACROBAT-NRSI tool was applied to assess the quality of each included study, and the GRADE tool was employed to assess the overall quality of the meta-analysis. Maternal PM_2.5 exposure (10 μg/m³) during the entire pregnancy was negatively associated with head circumference at birth (β = - 0.30 cm, 95% CI - 0.49, - 0.10), and NO₂ exposure during the entire pregnancy was significantly linked to shorter length at birth (β = - 0.03 cm, 95% CI - 0.05, - 0.02). Maternal exposure to higher NO₂ and PM_2.5 during pregnancy may impair neonatal head circumference and length development, respectively. More studies are needed to confirm the effects of NO₂ and PM_2.5 and to identify the sources and major toxic components of PMs.

N-acetylcysteine attenuates PM2.5-induced apoptosis by ROS-mediated Nrf2 pathway in human embryonic stem cells

While the effects of fine particulate matter (PM_2.5) on embryonic toxicity are widely accepted, its exact mechanisms have not yet been fully elucidated, which partially attribute to lack of ideal research model. Embryonic stem cells (ESCs) have the capacity to differentiate into all cell types of three germ layers. Thus, they are ideal resources for the reproductive toxicity assessment in vitro. In the present study, we investigated the effects of PM_2.5 exposure on the oxidative stress and apoptosis of human ESCs (hESCs) and its possible mechanism. Our results showed that strong cytotoxicity high reactive oxygen species (ROS) level and fragmentation of nuclei were observed in the PM_2.5-treated hESCs. Meanwhile, up-regulation of apoptosis as well as down-regulation of Nrf2 signaling pathway were also observed after PM_2.5 treatment. However, we did not detect significant expression change or phosphorylation of Akt and Erk in PM_2.5-treated hESCs. Interestingly, scavenging of PM_2.5-induced ROS by N-acetylcysteine (NAC) could block cell apoptosis and rescue the activity of Nrf2 signaling pathway. In conclusion, we demonstrate that PM_2.5 is toxic to hESCs by inhibition of ROS-mediated Nrf2 pathway activity. Our findings suggest activation of Nrf2 pathway will help develop new strategies for the prevention and treatment of PM_2.5-associated disease.

Ambient PM2.5 and clinically recognized early pregnancy loss: A case-control study with spatiotemporal exposure predictions

BACKGROUND

Experimental research suggests that fine particulate matter (PM_2.5) exposure might affect embryonic development. However, only few population-based studies have investigated the impact of maternal exposure to PM_2.5 on the early pregnancy loss.

OBJECTIVES

To estimate associations between clinically recognized early pregnancy loss (CREPL) and exposure to ambient PM_2.5 at individual residences during peri-conception periods, with the aim to identify susceptible exposure time windows.

METHODS

CREPL cases and normal early pregnancy controls (of similar age and gravidity presenting within one week, a total of 364 pairs) were recruited between July 2017 and July 2018 among women residing in Tianjin, China. Average ambient PM_2.5 concentrations of ten exposure windows (4 weeks, 2 weeks and 1 week before conception; the first, second, third and fourth single week, the first and second 2-week periods, and the entire 4-week period after conception) at the women's residential addresses were estimated using temporally-adjusted land use regression models. Associations between PM_2.5 exposures at specific peri-conception time windows and CREPL were examined using conditional logistic regression models, adjusted for covariates.

RESULTS

Based on adjusted models, CREPL was significantly associated with a 10 μg/m³ increase in PM_2.5 exposure during the second week after conception (OR = 1.15; 95% CI: 1.04, 1.27; p = 0.005), independent of effects at other time windows. There was also an association of CREPL with PM_2.5 during the entire 4-week period after conception (OR = 1.22; 95% CI: 1.02, 1.46; p = 0.027). There was little evidence for associations with exposure during pre-conception exposure windows.

CONCLUSIONS

Maternal exposures to ambient PM_2.5 during a critical time window following conception are associated with CREPL, with the second week after conception possibly being the exposure window of most vulnerability. Future studies should focus on replicating these findings and on pathogenic mechanisms.

Maternal fine particulate matter (PM2.5) exposure and adverse birth outcomes: an updated systematic review based on cohort studies

Exposure to ambient air pollutants during pregnancy may be associated with numerous side health effects and adverse birth outcomes. Growing numbers of studies have explored a possible linkage between prenatal exposure to PM_2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm) and impacts on fetal development. We aimed to conduct a systematic review based on published cohort studies to summarize evidence regarding the association between maternal PM_2.5 exposure and birth outcomes, including birth weight, low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Eligible studies meeting the following criterion were selected: PM_2.5 exposure during pregnancy and live birth singletons, certain presentation of sample sizes, and quantitative evaluation of the associations between exposure and outcomes. Among the 42 selected studies, 23 evaluated the impact of prenatal PM_2.5 exposure on birth weight of infants while 12 of them provided a significantly negative association for exposure and birth weight. Twenty-one studies aimed to identify the possible relationship between maternal exposure and LBW and 8 studies proved significant associations. Among 18 studies that explored the correlation between prenatal exposure and PTB, 9 reached a consistent conclusion that gestational exposure would add to the risk of PTB. Nine studies assessed the impact of PM_2.5 on SGA and 5 of them demonstrated a significant effect. So far, linkages between maternal PM_2.5 exposure during varied gestational stages and multiple adverse birth outcomes have been observed in many studies. A summary of them will be meaningful for further research on maternal exposure and adverse birth outcomes.

Influence of the Urban Exposome on Birth Weight

BACKGROUND

The exposome is defined as the totality of environmental exposures from conception onwards. It calls for providing a holistic view of environmental exposures and their effects on human health by evaluating multiple environmental exposures simultaneously during critical periods of life.

OBJECTIVE

We evaluated the association of the urban exposome with birth weight.

METHODS

We estimated exposure to the urban exposome, including the built environment, air pollution, road traffic noise, meteorology, natural space, and road traffic (corresponding to 24 environmental indicators and 60 exposures) for nearly 32,000 pregnant women from six European birth cohorts. To evaluate associations with either continuous birth weight or term low birth weight (TLBW) risk, we primarily relied on the Deletion-Substitution-Addition (DSA) algorithm, which is an extension of the stepwise variable selection method. Second, we used an exposure-by-exposure exposome-wide association studies (ExWAS) method accounting for multiple hypotheses testing to report associations not adjusted for coexposures.

RESULTS

The most consistent statistically significant associations were observed between increasing green space exposure estimated as Normalized Difference Vegetation Index (NDVI) and increased birth weight and decreased TLBW risk. Furthermore, we observed statistically significant associations among presence of public bus line, land use Shannon's Evenness Index, and traffic density and birth weight in our DSA analysis.

CONCLUSION

This investigation is the first large urban exposome study of birth weight that tests many environmental urban exposures. It confirmed previously reported associations for NDVI and generated new hypotheses for a number of built-environment exposures. https://doi.org/10.1289/EHP3971.

Combined environmental and social exposures during pregnancy and associations with neonatal size and body composition: the Healthy Start study

BACKGROUND

Prenatal environmental and social exposures have been associated with decreased birth weight. However, the effects of combined exposures in these domains are not fully understood. Here we assessed multi-domain exposures for participants in the Healthy Start study (Denver, CO) and tested associations with neonatal size and body composition.

METHODS

In separate linear regression models, we tested associations between neonatal outcomes and three indices for exposures. Two indices were developed to describe exposures to environmental hazards (ENV) and social determinants of health (SOC). A third index combined exposures in both domains (CE = ENV/10 × SOC/10). Index scores were assigned to mothers based on address at enrollment. Birth weight and length were measured at delivery, and weight-for-length z-scores were calculated using a reference distribution. Percent fat mass was obtained by air displacement plethysmography.

RESULTS

Complete data were available for 897 (64%) participants. Median (range) ENV, SOC, and CE values were 31.9 (7.1-63.2), 36.0 (2.8-75.0), and 10.9 (0.4-45.7), respectively. After adjusting for potential confounders, 10-point increases in SOC and CE were associated with 27.7 g (95%CI: 12.4 - 42.9 g) and 56.3 g (19.4 - 93.2 g) decreases in birth weight, respectively. SOC and CE were also associated with decreases in % fat mass.

CONCLUSIONS

Combined exposures during pregnancy were associated with lower birth weight and % fat mass. Evidence of a potential synergistic effect between ENV and SOC suggests a need to more fully consider neighborhood exposures when assessing neonatal outcomes.

Ambient air pollution and pregnancy outcomes: A comprehensive review and identification of environmental public health challenges

There is a growing number of studies on the association between ambient air pollution and adverse pregnancy outcomes, but their results have been inconsistent. Consequently, a comprehensive review of this research area is needed. There was a wide variability in studied pregnancy outcomes, observed gestational windows of exposure, observed ambient air pollutants, applied exposure assessment methods and statistical analysis methods Gestational duration, preterm birth, (low) birth weight, and small for gestational age/intrauterine growth restriction were most commonly investigated pregnancy outcomes. Gestational windows of exposure typically included were whole pregnancy period, 1st, 2nd, 3rd trimester, first and last gestational months. Preterm birth was the outcome most extensively studied across various gestational windows, especially at the beginning and at the end of pregnancy. Particulate matter, nitrogen dioxide, ozone, and carbon monoxide were the most commonly used markers of ambient air pollution. Continuous monitoring data were frequently combined with spatially more precisely modelled estimates of exposure. Exposure to particulate matter and ozone over the entire pregnancy was significantly associated with higher risk for preterm birth: the pooled effect estimates were 1.09 (1.03-1.16) per 10 μg/m³ increase in particulate matter with an aerodynamic diameter of 10 µm or less (PM₁₀)_,1.24 (1.08-1.41) per 10 μg/m³ increase in particulate matter with an aerodynamic diameter of 2.5 µm or less (PM_2.5), and 1.03 (1.01-1.04) per 10 ppb increase in ozone. For pregnancy outcomes other than PTB, ranges of observed effect estimates were reported due to smaller number of studies included in each gestational window of exposure. Further research is needed to link the routine pregnancy outcome data with spatially and temporally resolved ambient air pollution data, while adjusting for commonly defined confounders. Methods for assessing exposure to mixtures of pollutants, indoor air pollution exposure, and various other environmental exposures, need to be developed.

Developmental Origins of Disease: Emerging Prenatal Risk Factors and Future Disease Risk

Purpose of review

Many of the diseases and dysfunctions described in the paradigm of the developmental origins of health and disease have been studied in relation to prenatal nutrition or environmental toxicant exposures. Here, we selectively review the current research on four exposures-two nutritional and two environmental-that have recently emerged as prenatal risk factors for long-term health outcomes.

Recent findings

Recent studies have provided strong evidence that prenatal exposure to (1) excessive intake of sugar-sweetened beverages, (2) unhealthy dietary patterns, (3) perfluoroalkyl substances, and (4) fine particulate matter, may increase risk of adverse health outcomes, such as obesity, cardiometabolic dysfunction, and allergy/asthma.

Summary

Emerging prenatal nutritional factors and environmental toxicants influence offspring long-term health. More work is needed to identify the role of paternal exposures and maternal exposures during the preconception period and to further elucidate causality through intervention studies. The ubiquity of these emerging nutritional and environmental exposures makes this area of inquiry of considerable public health importance.

The Urban Exposome during Pregnancy and Its Socioeconomic Determinants

BACKGROUND

The urban exposome is the set of environmental factors that are experienced in the outdoor urban environment and that may influence child development.

OBJECTIVE

The authors' goal was to describe the urban exposome among European pregnant women and understand its socioeconomic determinants.

METHODS

Using geographic information systems, remote sensing and spatio-temporal modeling we estimated exposure during pregnancy to 28 environmental indicators in almost 30,000 women from six population-based birth cohorts, in nine urban areas from across Europe. Exposures included meteorological factors, air pollutants, traffic noise, traffic indicators, natural space, the built environment, public transport, facilities, and walkability. Socioeconomic position (SEP), assessed at both the area and individual level, was related to the exposome through an exposome-wide association study and principal component (PC) analysis.

RESULTS

Mean±standard deviation (SD) NO2 levels ranged from 13.6±5.1 μg/m3 (in Heraklion, Crete) to 43.2±11 μg/m3 (in Sabadell, Spain), mean±SD walkability score ranged from 0.22±0.04 (Kaunas, Lithuania) to 0.32±0.07 (Valencia, Spain) and mean±SD Normalized Difference Vegetation Index ranged from 0.21±0.05 in Heraklion to 0.51±0.1 in Oslo, Norway. Four PCs explained more than half of variation in the urban exposome. There was considerable heterogeneity in social patterning of the urban exposome across cities. For example, high-SEP (based on family education) women lived in greener, less noisy, and less polluted areas in Bradford, UK (0.39 higher PC1 score, 95% confidence interval (CI): 0.31, 0.47), but the reverse was observed in Oslo (-0.57 PC1 score, 95% CI: -0.73, -0.41). For most cities, effects were stronger when SEP was assessed at the area level: In Bradford, women living in high SEP areas had a 1.34 higher average PC1 score (95% CI: 1.21, 1.48).

CONCLUSIONS

The urban exposome showed considerable variability across Europe. Pregnant women of low SEP were exposed to higher levels of environmental hazards in some cities, but not others, which may contribute to inequities in child health and development. https://doi.org/10.1289/EHP2862.

Prenatal exposure to diesel exhaust PM2.5 causes offspring β cell dysfunction in adulthood

Environmental stressors that encounter in early-life and cause abnormal fetal and/or neonatal development may increase susceptibility to non-communicable diseases such as diabetes. Maternal exposure to ambient fine particulate matter (PM_2.5) is associated with various fetal abnormalities, suggesting that it may program offspring's susceptibility to diabetes. In the present study, we therefore examined whether maternal exposure to diesel exhaust PM_2.5 (DEP), one of the major sources of ambient PM_2.5 in urban areas, programs adult offspring's glucose metabolism. Female C57Bl/6J mice were intratracheally instilled with DEP or vehicle throughout a 7-wk preconceptional period, gestation, and lactation, and the glucose homeostasis of their adult male offspring was assessed. Intraperitoneal glucose tolerance test (IPGTT) revealed that the maternal exposure to DEP significantly impaired adult male offspring's glucose tolerance. Unexpectedly, it did not influence their insulin sensitivity, whereas it significantly decreased their glucose-induced insulin secretion (GIIS). This deficit in insulin secretion was corroborated by their significant decrease in arginine-induced insulin secretion. Histological analysis demonstrated that the deficit in insulin secretion was accompanied by the decrease in pancreatic islet and β cell sizes. To differentiate the effects of maternal exposure to DEP before birth and during lactation, some offspring were cross-fostered once born. We did not observe any significant effect of cross-fostering on the glucose homeostasis of adult male offspring and the function and morphology of their β cells. Prenatal exposure to DEP programs the morphology and function of β cells and thus homeostatic regulation of glucose metabolism in adult male offspring.

DNA Methylome Marks of Exposure to Particulate Matter at Three Time Points in Early Life

Maternal exposure to airborne particulate matter (PM) has been associated with restricted fetal growth and reduced birthweight. Here, we performed methylome-wide analyses of cord and children's blood DNA in relation to residential exposure to PM smaller than 10 μm (PM10). This study included participants of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC, cord blood, n = 780; blood at age 7, n = 757 and age 15-17, n = 850) and the EXPOsOMICS birth cohort consortium including cord blood from ENVIR ONAGE ( n = 197), INMA ( n = 84), Piccolipiù ( n = 99) and Rhea ( n = 75). We could not identify significant CpG sites, by meta-analyzing associations between maternal PM10 exposure during pregnancy and DNA methylation in cord blood, nor by studying DNA methylation and concordant annual exposure at 7 and 15-17 years. The CpG cg21785536 was inversely associated with PM10 exposure using a longitudinal model integrating the three studied age groups (-1.2% per 10 μg/m3; raw p-value = 3.82 × 10-8). Pathway analyses on the corresponding genes of the 100 strongest associated CpG sites of the longitudinal model revealed enriched pathways relating to the GABAergic synapse, p53 signaling and NOTCH1. We provided evidence that residential PM10 exposure in early life affects methylation of the CpG cg21785536 located on the EGF Domain Specific O-Linked N-Acetylglucosamine Transferase gene.

Effects of ambient air pollution from municipal solid waste landfill on children's non-specific immunity and respiratory health

This cross-sectional study investigated the association between air pollutant (AP) and respiratory health of 951 children residing near a municipal solid waste (MSW) landfill in Northern China. Results showed that students in non-exposure areas had significantly higher levels of lysozyme, secretory immunoglobulin A (SIgA), and better lung capacity than students in exposure areas (p < .05). Multiple regression model analysis indicated that lysozyme levels exhibited a consistent negative association with methane (CH₄: β = -76.3, 95% CI -105 to -47.7) and sulfuretted hydrogen (H₂S: β = -11.7, 95% CI -20.2 to -3.19). In addition, SIgA levels were negatively associated with H₂S (β = -68.9, 95% CI -97.9 to -39.9) and ammonia (NH₃: β = -30.3, 95% CI -51.7 to -8.96). Among all AP, H₂S and sulfur dioxide (SO₂) were the most robustly related with reduced lung function. H₂S exposure was negatively associated with six lung function indices, 1-s forced expiratory volume (FEV1%), mean forced expiratory flow between 25% and 75% (MMF), maximum voluntary ventilation (MVV), and forced expiratory flow at 25%, 50%, and 75% of the pulmonary volume (FEF25, FEF50, FEF75); and SO₂ was negatively associated with FEV1%, MVV, FEF25, FEF50 and FEF75. Our results suggested that AP exposure was negatively associated with more lung function parameters in boys than in girls. In conclusion, our findings suggested that children living adjacent to landfill sites were more likely to have deficient non-specific immunity and impaired lung function.

Impact of London's road traffic air and noise pollution on birth weight: retrospective population based cohort study

Objective To investigate the relation between exposure to both air and noise pollution from road traffic and birth weight outcomes.Design Retrospective population based cohort study.Setting Greater London and surrounding counties up to the M25 motorway (2317 km²), UK, from 2006 to 2010.Participants 540 365 singleton term live births.Main outcome measures Term low birth weight (LBW), small for gestational age (SGA) at term, and term birth weight.Results Average air pollutant exposures across pregnancy were 41 μg/m³ nitrogen dioxide (NO₂), 73 μg/m³ nitrogen oxides (NO_x), 14 μg/m³ particulate matter with aerodynamic diameter <2.5 μm (PM_2.5), 23 μg/m³ particulate matter with aerodynamic diameter <10 μm (PM₁₀), and 32 μg/m³ ozone (O₃). Average daytime (L_Aeq,16hr) and night-time (L_night) road traffic A-weighted noise levels were 58 dB and 53 dB respectively. Interquartile range increases in NO₂, NO_x, PM_2.5, PM₁₀, and source specific PM_2.5 from traffic exhaust (PM_{2.5 traffic exhaust}) and traffic non-exhaust (brake or tyre wear and resuspension) (PM_{2.5 traffic non-exhaust}) were associated with 2% to 6% increased odds of term LBW, and 1% to 3% increased odds of term SGA. Air pollutant associations were robust to adjustment for road traffic noise. Trends of decreasing birth weight across increasing road traffic noise categories were observed, but were strongly attenuated when adjusted for primary traffic related air pollutants. Only PM_{2.5 traffic exhaust} and PM_2.5 were consistently associated with increased risk of term LBW after adjustment for each of the other air pollutants. It was estimated that 3% of term LBW cases in London are directly attributable to residential exposure to PM_2.5>13.8 μg/m³during pregnancy.Conclusions The findings suggest that air pollution from road traffic in London is adversely affecting fetal growth. The results suggest little evidence for an independent exposure-response effect of traffic related noise on birth weight outcomes.

Exposure to fine particulate matter during pregnancy and risk of term low birth weight in Jinan, China, 2014-2016

BACKGROUND

Existing studies exploring the association between low birth weight (LBW) and maternal fine particulate matter (aerodynamic diameter<2.5μm, PM_2.5) exposure have presented equivocal results, and one of the possible reasons for this finding might be due to relatively low maternal exposures. In addition, relatively narrow maternal exposure windows to PM_2.5 have not been well established for LBW.

METHODS

We employed a nested matched case-control design among 43,855 term births in a large maternity and child care hospital in Jinan, China. A total of 369 cases were identified, and four controls per case matched by maternal age were randomly selected among those with normal birth weight (n=1,476) from 2014 to 2016. Ambient air monitoring data on continuous measures of PM_2.5, nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) (24-h average concentrations) from 2013 to 2016 were collected from thirteen local monitoring stations. An inverse distance weighting method based on both home and work addresses was adopted to estimate the individual daily exposures to these air pollutants during pregnancy by weighting the average of the twelve nearest monitoring stations within 30km of each 100m×100m grid cell by an inverse squared distance, and then the average exposure concentrations for gestational months, trimesters and the entire pregnancy were calculated. Adjusted conditional logistic regression models were used to estimate the odds ratios (ORs) per 10μg/m³ increment in PM_2.5 and by PM_2.5 quartiles during different gestational periods.

RESULTS

In this study, the estimated mean values of PM_2.5, NO₂, and SO₂ exposure during the entire pregnancy were 88.0, 54.6, and 63.1μg/m³, respectively. Term low birth weight (TLBW) increased in association with per 10μg/m³ increment in PM_2.5 for the 8th month [OR=1.13, 95% confidence interval (CI): 1.04, 1.22], the 9th month (OR=1.06, 95% CI: 0.99, 1.15), the third trimester (OR=1.17, 95% CI: 1.05, 1.29), and the entire pregnancy (OR=1.38, 95% CI: 1.07, 1.77) in models adjusted for one pollutant (PM_2.5). In models categorizing the PM_2.5 exposure by quartiles, comparing the second, third, and highest with the lowest PM_2.5 exposure quartile, the PM_2.5 was positively associated with TLBW during the 8th month (OR: 1.77, 95% CI: 1.09, 2.88; OR: 1.77, 95% CI: 1.03, 3.04; OR: 1.92, 95% CI: 1.04, 3.55, respectively) and for the 9th month, only association for exposure in the third versus the lowest quartile was significant (OR: 1.91, 95% CI: 1.02, 3.58).

CONCLUSIONS

The study provides evidence that exposure to PM_2.5 during pregnancy might be associated with the risk of TLBW in the context of very high pollution level of PM_2.5, and the 8th and 9th months were identified as potentially relevant exposure windows.

Early-life exposure to air pollutants and adverse pregnancy outcomes: protocol for a prospective cohort study in Beijing

INTRODUCTION

The association between early exposure to ambient air pollution and adverse pregnancy outcomes in China is unclear. This study will assess the risk of early-life exposure to air pollutants in Beijing and explore the viability of 8-hydroxydeoxyguanosine (8-OHdG) as a biological indicator to assess oxidative stress induced by early-life exposure to air pollution.

METHODS AND ANALYSIS

Here, 2500 women with singleton pregnancies and their infants will be recruited from the Beijing Obstetrics and Gynecology Hospital. We will collect nine types of biological samples, including maternal serum, urine, placental tissue, umbilical cord tissue and umbilical cord blood during all three trimesters. The air pollution data (particulate matter (PM)2.5, PM10 and similar factors) will be recorded at official fixed-site monitoring stations closest to where the pregnant women live. We plan to assess the effect of air pollutants on adverse pregnancy outcomes and infant respiratory and circulatory disease using Cox regression and competitive risk analysis and explore possible critical windows of exposure during pregnancy using daily pollutant concentrations averaged over various periods of pregnancy combined with individual activity and physiological parameters. Maternal and umbilical cord blood samples (1000 samples) will be randomly selected for 8-OHdG assays to assess the correlation between exposures to air pollutants and oxidative stress. We will determine whether air pollutant exposure or 8-OHdG levels are associated with adverse pregnancy outcomes. SPSS and SAS statistical software will be used for data analysis. Cox regression and competing risk analysis will be used to compute the HR and population attributable risk.

ETHICS AND DISSEMINATION

This research protocol has already been approved by the Medical Ethics Committee of Beijing Obstetrics and Gynecology Hospital. Written informed consent will be obtained from all study participants prior to enrolment. The results will be published in peer-reviewed journals or disseminated through conference presentations.

TRIAL REGISTRATION NUMBER

This study has been registered in WHO International Clinical Trial Register-Chinese Clinical Trial Registry under registrationnumber ChiCTR-ROC-16010181 (http :// www.chictr.org.cn / showproj.aspx ?proj=17328).

Fine-particulate matter (PM2.5), a risk factor for rat gestational diabetes with altered blood glucose and pancreatic GLUT2 expression

Recent studies have shown an intriguing association between air pollution and diabetic risk. This study was to investigate the impact of fine particulate matter (PM2.5) on glucose consequences and pancreas glucose transporter2 (GLUT2) expression in a gestational diabetes mellitus (GDM) rat model. GDM rats were exposed to a low PM2.5 dose during pregnancy. After exposure, interleukin-6 (IL-6) and blood routine tests (BRT) were detected. Pancreas underwent pathologic examination. The levels of pancreatic homogenate glutathione peroxidase (GSH-Px), methane dicarboxylic aldehyde (MDA) and GLUT2 were detected. There were lower maternal body weight gain and fetal weight in the PM2.5 group. Exposure to PM2.5 caused increased absorbed blastocyst number, higher blood mono-nuclear cells (PBMC), platelets and IL-6 levels. The postprandial blood glucose (PBG) was elevated at most time points after exposure. The pancreas of PM2.5 exposed rats revealed periductal inflammation under pathological examination. The pancreatic GSH-Px significantly reduced and MDA increased in exposed group. The pancreatic GLUT2 expression was decreased after PM2.5 exposure. Our study provides direct evidence that PM2.5 exposure can result in pancreatic pathological changes and glycemic consequences in GDM rats. The oxidative response and inflammation are involved in PM2.5 increased risk of pancreatic impairment and glycemic consequences.

Programming of mouse obesity by maternal exposure to concentrated ambient fine particles

BACKGROUND

Many diseases including obesity may originate through alterations in the early-life environment that interrupts fetal development. Increasing evidence has shown that exposure to ambient fine particles (PM2.5) is associated with abnormal fetal development. However, its long-term metabolic effects on offspring have not been systematically investigated.

RESULTS

To determine if maternal exposure to PM2.5 programs offspring obesity, female C57Bl/6j mice were exposed to filtered air (FA) or concentrated ambient PM2.5 (CAP) during pre-conception, pregnancy, and lactation, and the developmental and metabolic responses of offspring were assessed. The growth trajectory of offspring revealed that maternal exposure to CAP significantly decreased offspring birth weight but increased body weight of adult male but not female offspring, and the latter was expressed as increased adiposity. These adult male offspring had increased food intake, but were sensitive to exogenous leptin. Their hypothalamic expression of Socs3 and Pomc, two target genes of leptin, was not changed, and the hypothalamic expression of NPY, an orexigenic peptide that is inhibited by leptin, was significantly increased. These decreases in central anorexigenic signaling were accompanied by reduced plasma leptin and its expression in adipose tissues, the primary source of circulating leptin. In contrast, maternal exposure did not significantly change any of these indexes in adult female offspring. Pyrosequencing demonstrated that the leptin promoter methylation of adipocytes was significantly increased in CAP-exposed male but not female offspring.

CONCLUSIONS

Our data indicate that maternal exposure to ambient PM2.5 programs obesity in male offspring probably through alterations in the methylation of the promoter region of the leptin gene.

Developmental Neurotoxicity of Traffic-Related Air Pollution: Focus on Autism

PURPOSE OF REVIEW

Epidemiological and animal studies suggest that air pollution may negatively affect the central nervous system (CNS) and contribute to CNS diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component.

RECENT FINDINGS

Several studies suggest that young individuals may be particularly susceptible to air pollution-induced neurotoxicity and that perinatal exposure may cause or contribute to developmental disabilities and behavioral abnormalities. In particular, a number of recent studies have found associations between exposures to traffic-related air pollution and autism spectrum disorders (ASD), which are characterized by impairment in socialization and in communication and by the presence of repetitive and unusual behaviors. The cause(s) of ASD are unknown, and while it may have a hereditary component, environmental factors are increasingly suspected as playing a pivotal role in its etiology, particularly in genetically susceptible individuals. Autistic children present higher levels of neuroinflammation and systemic inflammation, which are also hallmarks of exposure to traffic-related air pollution. Gene-environment interactions may play a relevant role in determining individual susceptibility to air pollution developmental neurotoxicity. Given the worldwide presence of elevated air pollution, studies on its effects and mechanisms on the developing brain, genetic susceptibility, role in neurodevelopmental disorders, and possible therapeutic interventions are certainly warranted.

Fine particulate matter (PM2.5), a risk factor of rat gestational diabetes with altered blood glucose and pancreatic GLUT2 expression

Recent studies have shown an association between air pollution and diabetic risk. This study was to investigate the impact of fine particulate matter (PM2.5) on glucose consequences and pancreas glucose transporter 2 (GLUT2) expression and its related mechanisms in a gestational diabetes mellitus (GDM) rat model. GDM rats were exposed to a low PM2.5 dose while the controls received saline. Interleukin-6 (IL-6) and blood routine tests (BRT) were detected for analyzing coagulation and inflammation. Pancreas tissues underwent pathologic examination, the levels of homogenate glutathione peroxidase (GSH-Px), and methane dicarboxylic aldehyde (MDA) were detected for oxidative stress estimation, and the degree of GLUT2 expression of pancreas was analyzed. There were lower maternal body weight gain and fetal weight in the PM2.5 group. Exposure to PM2.5 caused increased absorbed blastocyst number and postprandial blood glucose (PBG) blood mono-nuclear cells (PBMC), platelets, and IL-6 levels. The pancreas of PM2.5 exposed rats revealed inflammation under pathological examination. The pancreatic GSH-Px significantly reduced and MDA increased and GLUT2 protein expression decreased after exposure. Our study provides direct evidence that PM2.5 exposure can result in glycemic consequences in GDM rats. The oxidative response and inflammation are involved in PM2.5 increased risk of adverse maternal and fetal consequences.