Association between particulate air pollution exposure during pregnancy and postpartum maternal psychological functioning

Joint effects of traffic-related air pollution and hypertensive disorders of pregnancy on maternal postpartum depressive and anxiety symptoms

BACKGROUND

Ambient air pollution has been linked to postpartum depression. However, few studies have investigated the effects of traffic-related NOx on postpartum depression and whether any pregnancy-related factors might increase susceptibility.

OBJECTIVES

To evaluate the association between traffic-related NOx and postpartum depressive and anxiety symptoms, and effect modification by pregnancy-related hypertension.

METHODS

This study included 453 predominantly low-income Hispanic/Latina women in the MADRES cohort. Daily traffic-related NOx concentrations by road class were estimated using the California LINE-source dispersion model (CALINE4) at participants' residential locations and averaged across pregnancy. Postpartum depressive and anxiety symptoms were evaluated by a validated questionnaire (Postpartum Distress Measure, PDM) at 1, 3, 6 and 12 months postpartum. Multivariate linear regressions were performed to estimate the associations at each timepoint. Interaction terms were added to the linear models to assess effect modification by hypertensive disorders of pregnancy (HDPs). Repeated measurement analyses were conducted by using mixed effect models.

RESULTS

We found prenatal traffic-related NOx was associated with increased PDM scores. Specifically, mothers exposed to an IQR (0.22 ppb) increase in NOx from major roads had 3.78% (95% CI: 0.53-7.14%) and 5.27% (95% CI: 0.33-10.45%) significantly higher 3-month and 12-month PDM scores, respectively. Similarly, in repeated measurement analyses, higher NOx from major roads was associated with 3.06% (95% CI: 0.43-5.76%) significantly higher PDM scores across the first year postpartum. Effect modification by HDPs was observed: higher freeway/highway and total NOx among mothers with HDPs were associated with significantly higher PDM scores at 12 months postpartum compared to those without HDPs.

IMPACT

This study shows that prenatal traffic-related air pollution was associated with postpartum depressive and anxiety symptoms. The study also found novel evidence of greater susceptibility among women with HDPs, which advances the understanding of the relationships between air pollution, maternal cardiometabolic health during pregnancy and postpartum mental health. Our study has potential implications for clinical intervention to mitigate the effects of traffic-related pollution on postpartum mental health disorders. The findings can also offer valuable insights into urban planning strategies concerning the implementation of emission control measures and the creation of green spaces.

Urban environment in pregnancy and postpartum depression: An individual participant data meta-analysis of 12 European birth cohorts

BACKGROUND

Urban environmental exposures associate with adult depression, but it is unclear whether they are associated to postpartum depression (PPD).

OBJECTIVES

We investigated associations between urban environment exposures during pregnancy and PPD.

METHODS

We included women with singleton deliveries to liveborn children from 12 European birth cohorts (N with minimum one exposure = 30,772, analysis N range 17,686-30,716 depending on exposure; representing 26-46 % of the 66,825 eligible women). We estimated maternal exposure during pregnancy to ambient air pollution with nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10), road traffic noise (Lden), natural spaces (Normalised Difference Vegetation Index; NDVI, proximity to major green or blue spaces) and built environment (population density, facility richness and walkability). Maternal PPD was assessed 3-18 months after birth using self-completed questionnaires. We used adjusted logistic regression models to estimate cohort-specific associations between each exposure and PPD and combined results via meta-analysis using DataSHIELD.

RESULTS

Of the 30,772 women included, 3,078 (10 %) reported having PPD. Exposure to PM10 was associated with slightly increased odds of PPD (adjusted odd ratios (OR) of 1.08 [95 % Confidence Intervals (CI): 0.99, 1.17] per inter quartile range increment of PM10) whilst associations for exposure to NO2 and PM2.5 were close to null. Exposure to high levels of road traffic noise (≥65 dB vs. < 65 dB) was associated with an OR of 1.12 [CI: 0.95, 1.32]. Associations between green spaces and PPD were close to null; whilst proximity to major blue spaces was associated with increased risk of PPD (OR 1.12, 95 %CI: 1.00, 1.26). All associations between built environment and PPD were close to null. Multiple exposure models showed similar results.

DISCUSSION

The study findings suggest that exposure to PM10, road traffic noise and blue spaces in pregnancy may increase PPD risk, however future studies should explore this causally.

Association between prenatal and childhood PM2.5 exposure and preadolescent anxiety and depressive symptoms

Background

Fine particulate matter (PM2.5) exposure has been linked to anxiety and depression in adults; however, there is limited research in the younger populations, in which symptoms often first arise.

Methods

We examined the association between early-life PM2.5 exposure and symptoms of anxiety and depression in a cohort of 8-11-year-olds in Mexico City. Anxiety and depressive symptoms were assessed using the Spanish versions of the Revised Children's Manifest Anxiety Scale and Children's Depression Inventory. Daily PM2.5 was estimated using a satellite-based exposure model and averaged over several early and recent exposure windows. Linear and logistic regression models were used to estimate the change in symptoms with each 5-µg/m3 increase in PM2.5. Models were adjusted for child's age, child's sex, maternal age, maternal socioeconomic status, season of conception, and temperature.

Results

Average anxiety and depressive symptom T-scores were 51.0 (range 33-73) and 53.4 (range 44-90), respectively. We observed consistent findings for exposures around the fourth year of life, as this was present for both continuous and dichotomized anxiety symptoms, in both independent exposure models and distributed lag modeling approaches. This window was also observed for elevated depressive symptoms. An additional consistent finding was for PM2.5 exposure during early pregnancy in relation to both clinically elevated anxiety and depressive symptoms, this was seen in both traditional and distributed lag modeling approaches.

Conclusion

Both early life and recent PM2.5 exposure were associated with higher mental health symptoms in the child highlighting the role of PM2.5 in the etiology of these conditions.

Association between prenatal period exposure to ambient air pollutants and development of postpartum depression: a systematic review and meta-analysis

There is body of evidence supporting a role for maternal exposure to ambient air pollutants and postpartum depression (PPD). We attempted to review the literature systematically to assess the association between exposure to both ambient air particulate matters within pregnancy and PPD. The effect estimates extracting across each study were standardized to a 10 μg/m3 change. The random-effects model was applied to pool odds ratios. According to the three included cohort articles, exposure to PM10 within second trimester (OR = 1.26, 95% CI = 1.15-1.37) was significantly associated with higher odds of PPD. However, there was no significant association between having exposure to other ambient air pollutants and PPD. This meta-analysis showed that air pollutants could be associated with an increased risk of PPD.

Association between ambient particulate matters and anhedonia among patients with depression

Recent studies have linked ambient air pollution to depression. Anhedonia is a core symptom of depression which severely impacts on prognosis. The present study aims to investigate the association of PM2.5 and PM10 exposure with anhedonia in depressed patients. A total of 538 patients with depression who were hospitalized at the Fourth People's Hospital of Hefei between June 2017 and December 2021 were included. We estimated ambient particulate matters exposure, including PM2.5 and PM10, using a satellite-based spatiotemporal model at a resolution of 1 km2. The revised Physical Anhedonia Scale (RPAS) and the revised Social Anhedonia Scale (RSAS) were evaluated. The association of ambient particulate matters and anhedonia was examined using multiple linear regression models, adjusted for potential confounders. We observed that exposure to PM2.5 were significantly associated with increased RSAS score and RPAS score, with the major effect in the 12-month exposure window (β = 1.238; 95%CI, 0.353, 2.123) and 18-month exposure window (β = 1.888; 95%CI, 0.699, 3.078), respectively. Meanwhile, PM10 levels were also significantly associated with increased RSAS score and RPAS score, with the major effect in the 18-month exposure window (β = 1.220; 95%CI, 0.439, 2) and 3-month exposure window (β = 1.602; 95%CI, 0.062, 3.143), respectively. Subgroup analysis showed that both PM2.5 and PM10 were significantly associated with anhedonia in females, patients < 40 years old, low family income group, and those who had a higher educational level. Our study suggests that long-term PM2.5 and PM10 exposure are associated with more severe anhedonia in patients with depression. These associations were different in subgroup by age, gender, family income, and educational level.

Sleep, circadian activity patterns and postpartum depression: A systematic review and meta-analysis of actigraphy studies

Transition to motherhood is a period full of challenges and demands. In this review, we focused on the associations of sleep and circadian activity patterns during and after pregnancy with postpartum mental health factors. A systematic review and meta-analysis were conducted (PROSPERO reference 316,505). A search for articles was performed using PsycARTICLES, PsycINFO, PubMed, MEDLINE, Scopus, Cochrane, DARE, hand search, and citation tracking. The search was meant to identify peer-reviewed, experimental and observational studies reporting on women over 18 years old that assessed sleep and circadian activity patterns during pregnancy or postpartum using actigraphy, and investigated postpartum mental health factors. Nineteen relevant publications were selected. Postpartum total sleep at night was the indicator that was most closely related to the psychological functioning of women after childbirth. The results of the systematic review indicated that postpartum total sleep at night was related to postpartum fatigue, and the results of the meta-analysis suggested that total sleep at night was most strongly linked with postpartum depression. More studies are needed to estimate the associations of sleep-wake rhythm during pregnancy and in the postpartum period with postpartum mental health factors.

Association of Antepartum and Postpartum Air Pollution Exposure With Postpartum Depression in Southern California

Importance

Women are especially vulnerable to mental health matters post partum because of biological, emotional, and social changes during this period. However, epidemiologic evidence of an association between air pollution exposure and postpartum depression (PPD) is limited.

Objective

To examine the associations between antepartum and postpartum maternal air pollution exposure and PPD.

Design, Setting, and Participants

This retrospective cohort study used data from Kaiser Permanente Southern California (KPSC) electronic health records and included women who had singleton live births at KPSC facilities between January 1, 2008, and December 31, 2016. Data were analyzed between January 1 and May 10, 2023.

Exposures

Ambient air pollution exposures were assessed based on maternal residential addresses using monthly averages of particulate matter less than or equal to 2.5 μm (PM2.5), particulate matter less than or equal to 10 μm (PM10), nitrogen dioxide (NO2), and ozone (O3) from spatial interpolation of monitoring station measurements. Constituents of PM2.5 (sulfate, nitrate, ammonium, organic matter, and black carbon) were obtained from fine-resolution geoscience-derived models based on satellite, ground-based monitor, and chemical transport modeling data.

Main Outcomes and Measures

Participants with an Edinburgh Postnatal Depression Scale score of 10 or higher during the 6 months after giving birth were referred to a clinical interview for further assessment and diagnosis. Ascertainment of PPD was defined using a combination of diagnostic codes and prescription medications.

Results

The study included 340 679 participants (mean [SD] age, 30.05 [5.81] years), with 25 674 having PPD (7.54%). Increased risks for PPD were observed to be associated with per-IQR increases in antepartum and postpartum exposures to O3 (adjusted odds ratio [AOR], 1.09; 95% CI, 1.06-1.12), PM10 (AOR, 1.02; 95% CI, 1.00-1.04), and PM2.5 (AOR, 1.02; 95% CI, 1. 00-1.03) but not with NO2; PPD risks were mainly associated with PM2.5 organic matter and black carbon. Overall, a higher risk of PPD was associated with O3 during the entire pregnancy and postpartum periods and with PM exposure during the late pregnancy and postpartum periods.

Conclusions and Relevance

The study findings suggest that long-term exposure to antepartum and postpartum air pollution was associated with higher PPD risks. Identifying the modifiable environmental risk factors and developing interventions are important public health issues to improve maternal mental health and alleviate the disease burden of PPD.

Climate and Environmental Change: A Generation at Risk

ABSTRACT

Climate and environmental changes have been described as the biggest global health threat of the 21st century, with the potential to cause immediate harm in early life with important lifelong effects, and important consequences for future generations. Pregnant women and children are increasingly being recognized as vulnerable populations in the context of climate change. The effects can be direct or indirect through heat stress, extreme weather events, and air pollution, potentially affecting both the immediate and long-term health of pregnant women and newborns through a broad range of mechanisms. Climate and environmental changes have wide-ranging effects on a woman's reproductive life including sexual maturation and fertility, pregnancy outcomes, lactation, breastfeeding, and menopause. A comprehensive overview of these impacts is presented as well as opportunities for interventions for nurses practicing in perinatal, neonatal, midwifery, and pediatric specialties.

Air Pollution and Perinatal Mental Health: A Comprehensive Overview

BACKGROUND

The aim of the present study was to summarise the available data about the link between air pollution exposure and the new-onset and severity of psychiatric disorders in pregnant women during the perinatal period.

MATERIALS AND METHODS

We selected articles published until June 2022 on PubMed and the Web of Science. Pollutants included were PM_2.5 (particulate matter 2.5 micrometres and smaller), PM₁₀ (particulate matter 10 micrometres and smaller), NO₂ (nitrogen dioxide), O₃ (ozone), SO₂ (sulphur dioxide), CO (carbon monoxide), PBDEs (polybrominated diphenyl ethers), PFAS (per- and polyfluoroalkyl substances), lead, and cadmium. The perinatal period was considered as the time of pregnancy until one year after childbirth.

RESULTS

Nine studies were included; most of them evaluated the association between exposure to air pollutants and the onset of Postpartum Depression (PPD). Two studies showed an association between, respectively, only PM_2.5 and both PM_2.5 and NO₂ exposure and PPD onset 12 months after childbirth, while another study found a significant association between NO₂ exposure and PPD occurrence 6 months after childbirth. PBDE blood levels were associated with more severe depressive symptoms. Lastly, one study observed a link between stressful symptoms and exposure to PM_2.5, PM₁₀ during pregnancy.

CONCLUSION

More comprehensive and uniform studies are required to make a roadmap for future interventions, given the growing relevance of issues such pollution and mental health, particularly during the perinatal period.

The mental health of women and climate change: Direct neuropsychiatric impacts and associated psychological concerns

Climate change brings exposures to heat, air pollution, poorer quality food, and infectious disease that have significant direct effects on women and their mental health. These environmental impacts are multifaceted in their consequences and raise risks of depression, suicide, violent victimization, post-traumatic stress disorder, and various other neuropsychiatric symptoms. Women also suffer increased climate psychological risks from higher rates of stillbirth, preterm birth, and developmental problems in their children. Here we review what is known about the overlap of women's individual mental health and climate change, and highlight areas where more research is needed.

Air pollution, depressive and anxiety disorders, and brain effects: A systematic review

Accumulating data suggest that air pollution increases the risk of internalizing psychopathology, including anxiety and depressive disorders. Moreover, the link between air pollution and poor mental health may relate to neurostructural and neurofunctional changes. We systematically reviewed the MEDLINE database in September 2021 for original articles reporting effects of air pollution on 1) internalizing symptoms and behaviors (anxiety or depression) and 2) frontolimbic brain regions (i.e., hippocampus, amygdala, prefrontal cortex). One hundred and eleven articles on mental health (76% human, 24% animals) and 92 on brain structure and function (11% human, 86% animals) were identified. For literature search 1, the most common pollutants examined were PM2.5 (64.9%), NO2 (37.8%), and PM10 (33.3%). For literature search 2, the most common pollutants examined were PM2.5 (32.6%), O3 (26.1%) and Diesel Exhaust Particles (DEP) (26.1%). The majority of studies (73%) reported higher internalizing symptoms and behaviors with higher air pollution exposure. Air pollution was consistently associated (95% of articles reported significant findings) with neurostructural and neurofunctional effects (e.g., increased inflammation and oxidative stress, changes to neurotransmitters and neuromodulators and their metabolites) within multiple brain regions (24% of articles), or within the hippocampus (66%), PFC (7%), and amygdala (1%). For both literature searches, the most studied exposure time frames were adulthood (48% and 59% for literature searches 1 and 2, respectively) and the prenatal period (26% and 27% for literature searches 1 and 2, respectively). Forty-three percent and 29% of studies assessed more than one exposure window in literature search 1 and 2, respectively. The extant literature suggests that air pollution is associated with increased depressive and anxiety symptoms and behaviors, and alterations in brain regions implicated in risk of psychopathology. However, there are several gaps in the literature, including: limited studies examining the neural consequences of air pollution in humans. Further, a comprehensive developmental approach is needed to examine windows of susceptibility to exposure and track the emergence of psychopathology following air pollution exposure.

Association between prenatal exposure to ambient air pollutants and postpartum depressive symptoms: A multi-city cohort study

BACKGROUND

Women are vulnerable to depression during postpartum period. While several studies have shown associations between ambient air pollution exposure and depression in general population, there was few studies focused on the effect of various air pollutants on postpartum depression (PPD).

OBJECTIVE

This study is designed to explore the association between prenatal exposure to air pollutants and PPD, and to reveal the potential vulnerable exposure time point.

METHODS

The study enrolled 10,209 pregnant women who delivered between October 2019 and February 2021 in 5 participating hospitals from 3 cities in China. Edinburgh Postnatal Depression Scale (EPDS) was administered at 6 weeks postpartum to identify PPD symptoms. Associations between PPD symptoms and exposure levels in PM_2.5, PM_10, SO₂, CO, NO₂, and O₃ averaged over the whole pregnancy and each trimester were estimated using logistic regression models after adjusting for potential confounding factors. Distributed lag models (DLMs) were used to determine the relevant associations in each gestational week.

RESULTS

The risk for developing PPD symptoms was significant following a 10 μg/m³ increase in PM₁₀ (aOR = 1.47, 95%CI:1.36-1.59), NO₂ (aOR = 1.63, 95%CI:1.44-1.85), and 0.1 mg/m³ increase in CO (aOR = 2.31, 95%CI: 1.99-2.69) during the whole pregnancy. Similar results were also found in exposure during each trimester of pregnancy. Besides, SO₂ exposure during the second trimester was a major risk factor for developing PPD symptoms (aOR = 1.10, 95%CI:1.03-1.18). Consistent effects were also observed in DLMs, except for PM_2.5 and O₃, which showed no significant sensitive windows throughout pregnancy period.

CONCLUSION

Exposure to PM₁₀, CO, NO₂, and SO₂ in pregnancy is associated with increased risks of developing depression at 6 weeks postpartum. Our findings reveal the importance of air pollution control for preventing maternal mental health disorders among the public.

Understanding the Sources of Ambient Fine Particulate Matter (PM2.5) in Jeddah, Saudi Arabia

Urban air pollution is rapidly becoming a major environmental problem of public concern in several developing countries of the world. Jeddah, the second-largest city in Saudi Arabia, is subject to high air pollution that has severe implications for the health of the exposed population. Fine particulate matter (PM2.5) samples were collected for 24 h daily, during a 1-year campaign from 2013 to 2014. This study presents a detailed investigation of PM2.5 mass, chemical composition, and sources covering all four seasons of the year. Samples were analyzed for black carbon (BC), trace elements (TEs), and water-soluble ionic species (IS). The chemical compositions were statistically examined, and the temporal and seasonal patterns were characterized using descriptive analysis, correlation matrices, and elemental enrichment factor (EF). Source apportionment and source locations were performed on PM2.5 samples using the positive matrix factorization (PMF) model, elemental enrichment factor, and air-mass back trajectory analysis. The 24-h mean PM2.5 and BC concentrations ranged from 33.9 ± 9.1–58.8 ± 25 µg/m3 and 1.8 ± 0.4–2.4 ± 0.6 µg/m3, respectively. Atmospheric PM2.5 concentrations were well above the 24-h WHO guideline of 15 µg/m3, with overall results showing significant temporal and seasonal variability. EF defined two broad categories of TEs: anthropogenic (Ni, V, Cu, Zn, Cl, Pb, S, Lu, and Br), and earth-crust derived (Al, Si, Mg, K, Ca, Ti, Cr, Mn, Fe, and Sr). The five identified factors resulting from PMF were (1) fossil-fuels/oil combustion (45.3%), (2) vehicular emissions (19.1%), (3) soil/dust resuspension (15.6%), (4) industrial mixed dust (13.5%), and (5) sea-spray (6.5%). This study highlights the importance of focusing control strategies, not only on reducing PM concentration but also on the reduction of components of the PM as well, to effectively protect human health and the environment.

Effects of ambient air pollution on psychological stress and anxiety disorder: a systematic review and meta-analysis of epidemiological evidence

OBJECTIVES

Ambient air pollution (AAP) is an important risk factor for increased mental health morbidity. Studies have highlighted the effect of AAP on psychological stress and anxiety disorder. However, existing evidence regarding this is largely equivocal. This systematic review with meta-analysis aims to synthesize published evidence to calculate the pooled estimate of the effect of AAP on psychological stress and anxiety disorder.

CONTENT

A systematic bibliographic search was undertaken using PubMed, JGateplus, Google Scholar, and Cochrane Library for observational human studies published in English till 31st March 2020 reporting the effect of AAP on psychological stress and anxiety disorder. Study quality was assessed using the Joanna Briggs Institute critical appraisal tools. Meta-analysis was performed adopting a random-effects model using Meta-XL. Of 412 articles retrieved, a total of 30 articles [AAP and anxiety disorders, (n=17, 57%); AAP and psychological stress, (n=9, 30%) and AAP and both psychological stress and anxiety disorders, (n=4, 13%)] fulfilled the inclusion criteria covering a total population of 973,725 individuals. The pooled estimate (OR) of the effects of PM₁₀ on psychological stress was 1.03 [(95% CI: 1.00, 1.05) (p=0.17, I ²=41%)]. The pooled estimate of the effects of NO₂ and PM₁₀ on anxiety disorder was 0.93 [(95% CI: 0.89, 0.97) (p=0.91, I ²=0%)] and 0.88 [(95% CI: 0.78, 0.98) (p=0.01, I ²=59%)] respectively. The pooled estimate of the effects of PM_2.5 on anxiety Disorder was 0.88 [(95% CI: 0.72, 1.06) (p=0.00, I ²=80%)].

SUMMARY AND OUTLOOK

The present study provides the most updated pooled estimate of the effect of AAP on psychological stress and anxiety disorder. Future studies should focus on longitudinal studies conducted in LIC and LMIC countries using uniform and standardized criteria for exposure and outcome assessment as well as robust adjustment for confounders to minimize methodological heterogeneity resulting in reliable and comparable estimation of environmental mental health burden.

Association between ambient air pollution and perceived stress in pregnant women

Air pollution may influence prenatal maternal stress, but research evidence is scarce. Using data from a prospective cohort study conducted on pregnant women (n = 2153), we explored the association between air pollution and perceived stress, which was assessed using the 14-item Perceived Stress Scale (PSS), among pregnant women. Average exposures to particulate matter with an aerodynamic diameter of < 2.5 µm (PM_2.5) or < 10 µm (PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) for each trimester and the entire pregnancy were estimated at maternal residential addresses using land-use regression models. Linear regression models were applied to estimate associations between PSS scores and exposures to each air pollutant. After adjustment for potential confounders, interquartile-range (IQR) increases in whole pregnancy exposures to PM_2.5, PM₁₀, and O₃ in the third trimester were associated with 0.37 (95% confidence interval [CI] 0.01, 0.74), 0.54 (95% CI 0.11, 0.97), and 0.30 (95% CI 0.07, 0.54) point increases in prenatal PSS scores, respectively. Furthermore, these associations were more evident in women with child-bearing age and a lower level of education. Also, the association between PSS scores and PM₁₀ was stronger in the spring. Our findings support the relationship between air pollution and prenatal maternal stress.

Prenatal ambient air pollution and maternal depression at 12 months postpartum in the MADRES pregnancy cohort

BACKGROUND

Depression is the leading cause of mental health-related morbidity and affects twice as many women as men. Hispanic/Latina women in the US have unique risk factors for depression and they have lower utilization of mental health care services. Identifying modifiable risk factors for maternal depression, such as ambient air pollution, is an urgent public health priority. We aimed to determine whether prenatal exposure to ambient air pollutants was associated with maternal depression at 12 months after childbirth.

METHODS

One hundred eighty predominantly low-income Hispanic/Latina women participating in the ongoing MADRES cohort study in Los Angeles, CA were followed from early pregnancy through 12 months postpartum through a series of phone questionnaires and in-person study visits. Daily prenatal ambient pollutant estimates of nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM10 and PM2.5) were assigned to participant residences using inverse-distance squared spatial interpolation from ambient monitoring data. Exposures were averaged for each trimester and across pregnancy. The primary outcome measure was maternal depression at 12 months postpartum, as reported on the 20-item Center for Epidemiologic Studies-Depression (CES-D) scale. We classified each participant as depressed (n = 29) or not depressed (n = 151) based on the suggested cutoff of 16 or above (possible scores range from 0 to 60) and fitted logistic regression models, adjusting for potential confounders.

RESULTS

We found over a two-fold increased odds of depression at 12 months postpartum associated with second trimester NO2 exposure (OR = 2.63, 95% CI: 1.41-4.89) and pregnancy average NO2 (OR = 2.04, 95% CI: 1.13-3.69). Higher second trimester PM2.5 exposure also was associated with increased depression at 12 months postpartum (OR = 1.56, 95% CI: 1.01-2.42). The effect for second trimester PM10 was similar and was borderline significant (OR = 1.58, 95% CI: 0.97-2.56).

CONCLUSIONS

In a low-income cohort consisting of primarily Hispanic/Latina women in urban Los Angeles, we found that prenatal ambient air pollution, especially mid-pregnancy NO2 and PM2.5, increased the risk of depression at 12 months after childbirth. These results underscore the need to better understand the contribution of modifiable environmental risk factors during potentially critical exposure periods.

Exposure and perception of PM2.5 pollution on the mental stress of pregnant women

Prenatal exposure to ambient PM_2.5 has been proved to be related to pregnant women's physical health and birth outcomes. However, the damage from air pollution on pregnant women's mental health has not been fully discussed. A case-control study was conducted to evaluate the effects of PM_2.5 exposure and risk perception on the mental stress of pregnant women. A total of 605 pregnant women, including 403 high symptoms of stress cases and 202 matched controls, were recruited from January 2018 to December 2018 in Nanjing, among which 313 high symptoms of stress cases and 144 matched controls were included in the analysis. Meaningfully high symptoms of anxiety were defined with a score of 6 points or greater on the phobic anxiety subscale of the Crown-Crisp index. We found that the PM_2.5 effect perceived by the case group was significantly higher than the control group, and the PM_2.5 exposure of the case group was also significantly higher than that of the control group. Binary logistic regression showed that for each increase in unit of PM_2.5 exposure, the risk of pregnant women suffering from high mental stress increased by 13.76% (95 %CI: 8.26-19.53%). Through path analysis modeling, we found that in the case group, perceived indoor attributions not only had a direct impact on mental stress (p < 0.001), but also played a key mediating role in the impact of average daily dose of PM_2.5 on mental stress (p < 0.001). The high level of mental stress is not only affected by objective exposure, but also by subjective perceptions in the case group. Considering the significant effect of PM_2.5 exposure on mental stress, pregnant women are recommended to spend appropriate amounts of time outdoors during clean air days. In addition, the mediating role of risk perception cannot be ignored. It is necessary to reassure pregnant women not to become overly concerned about the risk of PM_2.5 pollution and reduce their psychological burden.

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

Backgrounds

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Association of ambient air pollution with depressive and anxiety symptoms in pregnant women: A prospective cohort study

BACKGROUND

Air pollution is associated with depressive and anxiety symptoms in the general population. However, this relationship among pregnant women remains largely unknown.

OBJECTIVE

To evaluate the association between pregnancy air pollution exposure and maternal depressive and anxiety symptoms during the third trimester assessed using the Center for Epidemiologic Studies-Depression and State-Trait Anxiety Inventory scales, respectively.

METHODS

We analyzed 1481 pregnant women from a cohort study in Seoul. Maternal exposure to particulate matter with an aerodynamic diameter <2.5 μm (PM_2.5) and <10 μm (PM₁₀), as well as to nitrogen dioxide (NO₂) and ozone (O₃) for each trimester and the entire pregnancy was assessed at participant's residential address by land use regression models. We estimated the relative risk (RR) and corresponding confidence interval (CI) of the depressive and anxiety symptoms associated with an interquartile range (IQR) increase in PM_2.5, PM₁₀, NO₂, and O₃ using modified Poisson regression.

RESULTS

In single-pollutant models, an IQR increase in PM_2.5, PM₁₀, and NO₂ during the second trimester was associated with an increased risk of depressive symptoms (PM_2.5 RR = 1.15, 95% CI: 1.04, 1.27; PM₁₀ RR = 1.13, 95% CI: 1.04, 1.23; NO₂ RR = 1.15, 95% CI: 1.03, 1.29) after adjusting for relevant covariates. Similarly, an IQR increase in O₃ during the third trimester was associated with an increased risk of depressive symptoms (RR = 1.09, 95% CI: 1.01, 1.18), while the IQR increase in O₃ during the first trimester was associated with a decreased risk (RR = 0.89, 95% CI: 0.82, 0.96). Exposure to PM_2.5, PM₁₀, and NO₂ during the second trimester was significantly associated with anxiety symptoms. The associations with PM_2.5 and O₃ in single-and multi-pollutant models were consistent.

CONCLUSIONS

Our findings indicate that increased levels of particulate matter, NO₂, and O₃ during pregnancy may elevate the risk of depression or anxiety in pregnant women.

A survey of PM2.5 preventive behavioral intention and related factors among community elderly in Northern Taiwan

Population aging and air pollution are global concerns. The purpose of this study is to explore the relationship among particulate matter with a diameter of 2.5 μm or less (PM2.5) knowledge, PM2.5 preventive attitude, and PM2.5 preventive behavioral intention in the elderly.A cross-sectional survey design was applied in this study, including usage intention and snowball sampling. A total of 617 elderly people aged over 65 participated, and the collected data were quantitatively analyzed.The results showed that the mean score of PM2.5 knowledge of the elderly was 10.34 (79.53%) with the standard deviation (SD) of 3.42, the mean score of PM2.5 preventive attitude was 4.58 (91.60%) with SD of 0.49, and the mean score of PM2.5 preventive behavioral intention was 4.72 (94.40%) with SD of 0.40. Elderly people's characteristics regarding PM2.5 knowledge and PM2.5 preventive attitude explained 22% (adjusted R2 = 0.22, F = 30.44, P < .001) of the variance in PM2.5 preventive behavioral intention.It is concluded that we found no difference in PM2.5 knowledge, PM2.5 preventive attitude, or PM2.5 preventive behavioral intention among the elderly with or without chronic diseases. In our opinion, health education regarding the threat of PM2.5 to the health of the elderly should be strengthened, to enhance their knowledge, preventive attitude, and preventive behavioral intention of PM2.5.

Exposure to particulate matter, prenatal depressive symptoms and HPA axis dysregulation

BACKGROUND

The prevalence of depression during pregnancy is on the rise, affecting women's well-being and their children's health outcomes. Preliminary studies suggest that exposure to air pollution during pregnancy may play a role in development of depressive symptoms. In addition, pollution has been linked to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, our brain's primary stress response system. The purpose of this study was to examine the association of air pollution exposure during pregnancy to prenatal depressive symptoms. We also evaluated whether cortisol, the hormonal endpoint of HPA activation, mediated the relationship between exposure to pollution and prenatal depression.

METHODS

Women were recruited in obstetric clinics during their third trimester of pregnancy. They completed the Patient Health Questionnaire-9 to assess depression and provided salivary samples at 4 times during the day for 2 days. Four measures of cortisol were calculated from salivary assays: average cortisol level, cortisol awakening response (CAR), diurnal cortisol slope (DCS), and area under the curve (AUCG). We acquired data on particulate matter with a diameter of 2.5 μm (PM2.5) or less within each woman's residential area from public records of the air quality control district. Structural equation modeling was used to analyze the aims.

RESULTS

Increased prenatal exposure to PM2.5 across pregnancy was associated with more severe depressive symptoms during the 3rd trimester (β = 0.14, p = 0.02). Greater PM2.5 exposure also had significant relationships with both higher cortisol AUCG (β = 15.933, p = 0.005) and average cortisol levels (β = 0.018, p = 0.023) among women. However, no cortisol parameter appeared to mediate the relationship between PM2.5 exposure and depressive symptoms.

CONCLUSIONS

Findings suggest pregnancy may be a critical window of sensitivity to PM2.5 exposure that escalates depression risk and induces activation of the HPA axis, evidenced in greater overall cortisol concentration. Further research is needed to identify mechanisms underlying the effects of particulate matter, especially potential methylation of glucocorticoid or serotonin transporter genes that may elicit changes in both depression and the stress response system. In addition, assessment of depression appears warranted for pregnant women in regions known for high pollution.

Chronic exposure to air pollution and risk of mental health disorders complicating pregnancy

BACKGROUND

Air pollution is associated with mental health in the general population, but its influence on maternal mental health during pregnancy has not been assessed.

OBJECTIVE

We evaluated the relationship between unspecified mental disorders complicating pregnancy and depression with average air pollution exposure during 3-months preconception, first trimester and whole pregnancy.

METHODS

Ambient air pollution was derived from a modified Community Multiscale Air Quality model and mental health diagnoses were based on electronic intrapartum medical records. Logistic regression models assessed the odds of unspecified mental disorder complicating pregnancy (n = 11,577) and depression (n = 9793) associated with an interquartile range increase in particulate matter (PM) less than 2.5 μm (PM_2.5), PM₁₀, carbon monoxide (CO), nitrogen dioxide (NO₂), nitrogen oxide (NO_x), sulfur dioxide (SO₂), and ozone (O₃). Pregnancies without mental health disorders were the reference group (n = 211,645). Models were adjusted for maternal characteristics and study site; analyses were repeated using cases with no additional mental health co-morbidity.

RESULTS

Whole pregnancy exposure to PM₁₀, PM_2.5, NO₂, and NO_x was associated with a 29%-74% increased odds of unspecified mental disorders complicating pregnancy while CO was associated with 31% decreased odds. Results were similar for depression: whole pregnancy exposure to PM₁₀, PM_2.5, NO₂, and NO_x was associated with 11%-21% increased odds and CO and O₃ were associated with 16%-20% decreased odds. SO₂ results were inconsistent, with increased odds for unspecified mental disorders complicating pregnancy and decreased odds for depression. While most findings were similar or stronger among cases with no co-morbidity, PM_2.5 and NO_x were associated with reduced risk and SO₂ with increased risk for depression only.

DISCUSSION

Whole pregnancy exposure to PM₁₀, PM_2.5, NO₂, and NO_x were associated with unspecified mental disorder complicating pregnancy and depression, but some results varied for depression only. These risks merit further investigation.

The self-reported behaviour of Iiyiyiu Aschii Cree and the worry about pollution from industrial and hydroelectric development in northern Quebec, Canada

Worry is influenced by environmental pollution and affects individual health and well-being; however, little is known about this association in Indigenous communities. Using logistic regression models, we examined self-reported responses among Cree adults to the question "Are you worried about the pollution of the environment (land, water or air) in Iiyiyiu Aschii?" to assess if increased worry was associated with proximity to industrial and hydroelectric development, whether increased worry was associated with self-reported behavioural changes of water consumption type in the community or bush, and days spent on-the-land. Proximity to multiple industrial and hydroelectric development sites was associated with increased worry about pollution. Notably, the decreased consumption of tap water in the community was significantly associated with increased worry, but time-on-the land was not. Overall, our study provides new findings concerning development in a Cree territory in northern Quebec, Canada, and the worry about pollution's association with self-reported behavioural changes.

B-vitamin supplementation ameliorates anxiety- and depression-like behavior induced by gestational urban PM2.5 exposure through suppressing neuroinflammation in mice offspring

PM_2.5 exposure is an emerging environmental concern and severe health insult closely related to psychological conditions such as anxiety and depression in adolescence. Adolescence is a critical period for neural system development characterized by continuous brain maturation, especially in the prefrontal cortex. The etiology of these adolescent conditions may derive from fetal origin, probably attributed to the adverse effects induced by intrauterine environmental exposure. Anxiety- and depression-like behavior can be induced by gestational exposure to PM_2.5 in mice offspring which act as a useful model system. Recent studies show that B-vitamin may alleviate PM_2.5-induced hippocampal neuroinflammation- and function-related spatial memory impairment in adolescent mice offspring. However, cortical damage and related neurobehavioral defects induced by gestational PM_2.5 exposure, as well as the potential reversibility by interventions in mice offspring require to be elucidated. Here, we aimed to investigate whether B-vitamin would protect mice offspring from the adverse effects derived from gestational exposure to urban PM_2.5 on cortical areas to which anxiety and depression are closely related. Pregnant mice were divided into three groups: control group (treated with PBS alone), model group (treated with both PM_2.5 and PBS), and intervention group (treated with both PM_2.5 and B-vitamin), respectively. The mice offspring were then applied to comprehensive neurobehavioral, ultrastructural, biochemical, and molecular biological analyses. Interestingly, we observed that gestational PM_2.5 exposure led to neurobehavioral defects including anxiety- and depression-like behavior. In addition, neuroinflammation, oxidative damage, increased apoptosis, and caspase-1-mediated inflammasome activation in the prefrontal cortex were observed. Notably, both behavioral and molecular changes could be significantly alleviated by B-vitamin treatment. In summary, our results suggest that the anxiety- and depression-like behavior induced by gestational PM_2.5 exposure in mice offspring can be ameliorated by B-vitamin supplementation, probably through the suppression of apoptosis, oxidative damage, neuroinflammation, and caspase-1-mediated inflammasome activation.

Earth Observation Data Supporting Non-Communicable Disease Research: A Review

A disease is non-communicable when it is not transferred from one person to another. Typical examples include all types of cancer, diabetes, stroke, or allergies, as well as mental diseases. Non-communicable diseases have at least two things in common—environmental impact and chronicity. These diseases are often associated with reduced quality of life, a higher rate of premature deaths, and negative impacts on a countries’ economy due to healthcare costs and missing work force. Additionally, they affect the individual’s immune system, which increases susceptibility toward communicable diseases, such as the flu or other viral and bacterial infections. Thus, mitigating the effects of non-communicable diseases is one of the most pressing issues of modern medicine, healthcare, and governments in general. Apart from the predisposition toward such diseases (the genome), their occurrence is associated with environmental parameters that people are exposed to (the exposome). Exposure to stressors such as bad air or water quality, noise, extreme heat, or an overall unnatural surrounding all impact the susceptibility to non-communicable diseases. In the identification of such environmental parameters, geoinformation products derived from Earth Observation data acquired by satellites play an increasingly important role. In this paper, we present a review on the joint use of Earth Observation data and public health data for research on non-communicable diseases. We analyzed 146 articles from peer-reviewed journals (Impact Factor ≥ 2) from all over the world that included Earth Observation data and public health data for their assessments. Our results show that this field of synergistic geohealth analyses is still relatively young, with most studies published within the last five years and within national boundaries. While the contribution of Earth Observation, and especially remote sensing-derived geoinformation products on land surface dynamics is on the rise, there is still a huge potential for transdisciplinary integration into studies. We see the necessity for future research and advocate for the increased incorporation of thematically profound remote sensing products with high spatial and temporal resolution into the mapping of exposomes and thus the vulnerability and resilience assessment of a population regarding non-communicable diseases.

Ambient air pollution and depression: A systematic review with meta-analysis up to 2019

Although epidemiological studies have evaluated the associations of ambient air pollution with depression, the results remained mixed. To clarify the nature of the association, we performed a comprehensive systematic review and meta-analysis with the Inverse Variance Heterogeneity (IVhet) model to estimate the effect of ambient air pollution on depression. Three English and four Chinese databases were searched for epidemiologic studies investigating associations of ambient particulate (diameter ≤ 2.5 μm (PM_2.5), ≤10 μm (PM₁₀)) and gaseous (nitric oxide (NO), nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂) and ozone (O₃)) air pollutants with depression. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated to evaluate the strength of the associations. We identified 22 eligible studies from 10 countries of the world. Under the IVhet model, per 10 µg/m³ increase in long-term exposure to PM_2.5 (OR: 1.12, 95% CI: 0.97-1.29, I²: 51.6), PM₁₀ (OR: 1.04, 95% CI: 0.88-1.25, I²: 85.7), and NO₂ (OR: 1.05, 95% CI: 0.83-1.34, I²: 83.6), as well as short-term exposure to PM_2.5 (OR: 1.01, 95% CI: 0.99-1.04, I²: 51.6), PM₁₀ (OR: 1.01, 95% CI: 0.98-1.04, I²: 86.7), SO₂ (OR: 1.03, 95% CI: 0.99-1.07, I²: 71.2), and O₃ (OR: 1.01, 95% CI: 0.99-1.03, I²: 82.2) was not significantly associated with depression. However, we observed significant association between short-term NO₂ exposure (per 10 µg/m³ increase) and depression (OR: 1.02, 95% CI: 1.00-1.04, I²: 65.4). However, the heterogeneity was high for all of the pooled estimates, which reduced credibility of the cumulative evidence. Additionally, publication bias was detected for six of eight meta-estimates. In conclusion, short-term exposure to NO₂, but not other air pollutants, was significantly associated with depression. Given the limitations, a larger meta-analysis incorporating future well-designed longitudinal studies, and investigations into potential biologic mechanisms, will be necessary for a more definitive result.

Particulate air pollution exposure during pregnancy and postpartum depression symptoms in women in Mexico City

BACKGROUND

Postpartum depression (PPD), which affects up to 1 in 5 mothers globally, negatively impacts the health of both mothers and children. Exposure to ambient air pollution has been linked to depressive symptoms in animal models and human studies, but the relationship between air pollution and PPD has not been widely studied.

METHODS

In a birth cohort in Mexico City (509 mothers with available data), we examined the association between exposure to particulate matter ≤2.5 μm in diameter (PM_2.5) with symptoms of psychological dysfunction at 1 and 6 months postpartum. Daily PM_2.5 estimates were derived from a hybrid satellite-based spatio-temporally resolved model and averaged over pregnancy and the first year postpartum. Edinburgh Postnatal Depression Scale (EPDS) scores at 1 and 6 months were used to assess the relationship between PM_2.5 exposure and probable PPD (EPDS score ≥13) using relative risk regression and symptoms of anhedonia, depression, and anxiety (derived from EPDS subscales) using negative binomial regression.

RESULTS

A 5-μg/m³ increase in average PM_2.5 exposure during pregnancy was associated with an increased risk of PPD at 6 months (RR = 1.59; 95% CI: 1.11 to 2.28) and of late-onset PPD (no PPD at 1 month, PPD at 6 months) (RR = 2.58; 95% CI: 1.40 to 4.73) in covariate-adjusted models. No association was observed between PM_2.5 exposure in the first year postpartum and PPD. Average PM_2.5 exposure during pregnancy was also associated with increased 6-month EPDS subscale symptom scores for anhedonia (p = 0.03) and depression (p = 0.04).

CONCLUSION

Our results suggest that in women in Mexico City, particulate matter exposure during pregnancy is positively associated with PPD and symptoms of anhedonia and depression at 6 months postpartum. Future studies should examine mechanisms linking air pollution and other environmental exposures during pregnancy with postpartum psychological functioning.

Effects of early postnatal exposure to fine particulate matter on emotional and cognitive development and structural synaptic plasticity in immature and mature rats

INTRODUCTION

Fine particulate matter (PM2.5) is closely associated with many neurological disorders including neurodegenerative disease, stroke, and brain tumors. However, the toxic effects of PM2.5 on neurodevelopment remain unclear. In this study, we aimed to determine the neurotoxic effects of early postnatal exposure to PM2.5 in immature and mature rats.

METHODS

We exposed neonatal rats to PM2.5 (2 or 10 mg/kg body weight) through intranasal instillation from postnatal day (PND) 3-15, once a day. Emotional and cognitive development were evaluated using the elevated plus maze, forced swimming, and Morris water maze tests. Hippocampal tissue was collected and subjected to transmission electron microscopy observation and western blot analysis.

RESULTS

Rats had lower body weight after exposure to high dose of PM2.5. The behavioral test results indicated that high-dose PM2.5 exposure led to increased anxiety-like symptoms in immature and mature rats, apparent depressive-like behaviors in mature rats, and impaired spatial learning and memory abilities in immature rats, and low-dose PM2.5 exposure increased anxiety-like behaviors in immature rats. Further, high-dose PM2.5 exposure contributed to fewer synapses, thinner postsynaptic density, and shorter active zone in immature and mature rats, and also decreased expressions of synaptophysin (SYP), growth associated protein-43 (GAP43), and postsynaptic density-95 (PSD95) in immature rats, SYP and PSD95 in mature rats. Moreover, low-dose PM2.5 exposure diminished the expression of PSD95 in immature rats. In addition, high-dose PM2.5 exposure reduced brain-derived neurotrophic factor (BDNF) expression and cAMP response element binding protein (CREB) phosphorylation in both immature and mature rats, and low-dose PM2.5 exposure lessened BDNF expression and CREB phosphorylation in immature rats.

CONCLUSIONS

Our findings indicate that PM2.5 impairs emotional and cognitive development by disrupting structural synaptic plasticity, possibly via the CREB/BDNF signaling pathway.

Unconventional natural gas development and adverse birth outcomes in Pennsylvania: The potential mediating role of antenatal anxiety and depression

BACKGROUND

Studies have reported associations between unconventional natural gas development (UNGD) and adverse birth outcomes. None have evaluated potential mediating mechanisms.

OBJECTIVES

To evaluate associations between (1) UNGD and antenatal anxiety and depression and (2) antenatal anxiety and depression and preterm birth (<37 weeks gestation) and reduced term birth weight, (3) stochastic direct and indirect effects of UNGD on preterm birth and term birth weight operating through antenatal anxiety and depression, and (4) effect modification by family-level socioeconomic status.

METHODS

This retrospective cohort study included mothers without prevalent anxiety or depression at time of conception, who delivered at Geisinger in Pennsylvania between January 2009-January 2013. We assembled phase-specific UNGD activity data from public sources. Mothers were categorized as exposed (quartile 4) or unexposed (quartiles 1-3) based on average daily inverse distance-squared UNGD activity metric between conception and the week prior to anxiety or depression (cases) or the pregnancy-average daily metric (non-cases). We estimated associations with a doubly robust estimator (targeted minimum loss-based estimation) and adjusted for potential individual- and community-level confounding variables.

RESULTS

Analyses included 8,371 births to 7,715 mothers, 12.2% of whom had antenatal anxiety or depression. We found 4.3 additional cases of antenatal anxiety or depression per 100 women (95% CI: 1.5, 7.0) under the scenario where all mothers lived in the highest quartile of UNGD activity versus quartiles 1-3. The risk difference appeared larger among mothers receiving Medical Assistance (indicator of low family income) compared to those who did not, 5.6 (95% CI: 0.5, 10.6) versus 2.9 (95% CI: -0.7, 6.5) additional cases of antenatal anxiety or depression per 100 women. We found no relationship between antenatal anxiety or depression and adverse birth outcomes and no mediation effect either overall or when stratifying by Medical Assistance.

CONCLUSION

We observed a relationship between UNGD activity and antenatal anxiety and depression, which did not mediate the overall association between UNGD activity and adverse birth outcomes.

Trimester specific PM2.5 exposure and fetal growth in Ohio, 2007-2010

BACKGROUND

Exposure to particulate matter, particularly with aerodynamic diameter < 2.5 µm (PM_2.5), may increase inflammation and oxidative stress in pregnant women and affect fetal growth. We examined trimester specific PM_2.5 exposure levels and small for gestational age (SGA) using the statewide birth registry of Ohio from 2007 to 2010.

METHODS

Exposure to PM_2.5 in each trimester and for each gestational week was determined using data from 57 Environmental Protection Agency network monitoring stations across the state of Ohio. We restricted the data to 224,921 singleton live births, with a gestational age of 20-42 weeks, no genetic disorders or congenital abnormalities, and who had home addresses within a 10 km radius of any PM_2.5 monitoring station. We estimated odds ratios of SGA using Generalized Linear Models (GLMs) and Distributed Lag Models (DLMs), and adjustment for maternal age, race, education, parity, body mass index, insurance type, tobacco use, prenatal care initiation, birth year, season of birth, and sex of the baby.

RESULTS

Mean PM_2.5 levels during the entire pregnancy were 13.03 µg/m³ with a standard deviation of 1.57 µg/m³. Covariates adjusted odds ratios and 95% confidence intervals of a 10 µg/m³ increase in PM_2.5 levels with a 10 km buffer radius for SGA and trimesters modeled separately were 0.94 (0.88, 1.00) for the first trimester, 0.93 (0.86, 1.00) for the second trimester, 1.07 (1.00, 1.15) for the third trimester, and 0.92 (0.81, 1.06) for the entire pregnancy. When a 5 km buffer radius was used, adjusted odds ratios and 95% confidence intervals for SGA were 0.97 (0.89, 1.05) for the first trimester, 0.96 (0.88, 1.05) for the second trimester, 1.09 (1.02, 1.17) for the third trimester, and 0.99 (0.85, 1.14) for the overall pregnancy, indicating sensitivity to buffer choice. DLMs showed gestational weeks 30-35 to be a particular window of vulnerability.

CONCLUSION

Increasing exposure to PM_2.5 during the third trimester of pregnancy was associated with a small increase in risk of SGA in this population-based study. Selection of a buffer radius significantly impacted our results in the first trimester, but not in the third trimester.