Prenatal exposure to fine particulate matter air pollution (PM2.5) is an important, under-studied risk factor for neurodevelopmental dysfunction. We describe the relationships between prenatal PM2.5 exposure and vigilance and inhibitory control, executive functions related to multiple health outcomes in Mexico City children. We studied 320 children enrolled in Programming Research in Obesity, GRowth, Environment and Social Stressors, a longitudinal birth cohort study in Mexico City. We used a spatio-temporal model to estimate daily prenatal PM2.5 exposure at each participant's residential address. At age 9-10 years, children performed three Go/No-Go tasks, which measure vigilance and inhibitory control ability. We used Latent class analysis (LCA) to classify performance into subgroups that reflected neurocognitive performance and applied multivariate regression and distributed lag regression modeling (DLM) to test overall and time-dependent associations between prenatal PM2.5 exposure and Go/No-Go performance. LCA detected two Go/No-Go phenotypes: high performers (Class 1) and low performers (Class 2). Predicting odds of Class 1 vs Class 2 membership based on prenatal PM2.5 exposure timing, logistic regression modeling showed that average prenatal PM2.5 exposure in the second and third trimesters correlated with increased odds of membership in low-performance Class 2 (OR = 1.59 (1.16, 2.17), p = 0.004). Additionally, DLM analysis identified a critical window consisting of gestational days 103-268 (second and third trimesters) in which prenatal PM2.5 exposure predicted poorer Go/No-Go performance. Increased prenatal PM2.5 exposure predicted decreased vigilance and inhibitory control at age 9-10 years. These findings highlight the second and third trimesters of gestation as critical windows of PM2.5 exposure for the development of vigilance and inhibitory control in preadolescent children. Because childhood development of vigilance and inhibitory control informs behavior, academic performance, and self-regulation into adulthood, these results may help to describe the relationship of prenatal PM2.5 exposure to long-term health and psychosocial outcomes. The integrative methodology of this study also contributes to a shift towards more holistic analysis.

The aim of this study was to examine changes in depression, stress and social support levels before and during the COVID-19 pandemic in women living in Mexico City. We studied 466 women enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study who completed the Edinburgh Depression Scale (EDS) questionnaire prior (2018–2019) and during the lockdown period of the pandemic (May–November 2020). Psychosocial stress and social support for both time periods were ascertained using the Crisis in Family Systems (CRISYS) questionnaire and the Social Support Network (SSN) Scale, respectively. Associations between stress, social support and change in EDS score/depression were analyzed using generalized linear models adjusting for covariates. Higher stress (>median) during the pandemic was associated with an increase in EDS score (β: 2.13; 95% CI (1.06, 3.19), p < 0.001), and higher odds of depression (OR: 3.75; 95% CI (2.17, 6.50), p < 0.001), while social support was associated with lower odds of depression (OR: 0.56, 95% CI (0.32, 0.97), p = 0.037). Higher levels of stress during the pandemic were associated with depression. Social support may act as a buffer for the effects of psychosocial stress. Future studies should examine the long-term effects of stress associated with the pandemic on mental and overall health.

Lead exposure is neurotoxic during pregnancy and early childhood. Quantifying the expected effects of potential lead reductions on neurologic outcomes is valuable for decision makers. We estimated associations between integrated lead levels during pregnancy and early childhood on children's intellectual performance framed as hypothetical interventions to decrease lead levels. Our data source was the Programming Research in Obesity, Growth, Environment, and Social Stressors (PROGRESS) longitudinal birth cohort in Mexico City. Data included information on multiple biomarkers in the pre-and postnatal periods. We assessed the child's intellectual functioning at 48 months of age with McCarthy Scales of Children's Abilities including specific domains and the composite of these scales called the General Cognitive Index (GCI). We generated multi-media biomarkers (MMBs) combining lead biomarkers across biologic matrix and developmental period, using Weighted Quantile Sum Regression (WQS), and g-computation to estimate mean differences in cognitive scores (95%CIs) under hypothetical lead-reduction interventions. We estimated a mean difference of 0.60 points [95%CI: -0.25, 1.46] for the GCI and 0.77 [95%CI: 0.24, 1.30] for the perceptual scale following a 40% hypothetical reduction. When examined separately, prenatal exposure showed the strongest association with the perceptual domain and postnatal exposure with the quantitative domain. A sensitivity analysis using principal component analysis, agnostic to exposure directionality, yielded mostly null but directionally inconsistent results. Our results suggest that potentially 40% reductions of lead levels during pregnancy and early childhood in Mexico City may be associated with modest improvements in specific cognitive domains, although results were sensitive to the method used to construct MMBs.