Does air pollution affect the rates of stillbirths, congenital malformations and neonatal mortality? This study aims to answer this question by merging the child health data collected within Cidacs’s 100 Million Brazilian Cohort with high-resolved satellite-derived data on air pollution to establish critical ambient air pollution thresholds for preventing adverse birth outcomes and malformations based on concentrations of fine particles, PM 2.5.
The study was divided into three main phases. In the first phase, two primary databases were collected and merged using administrative identifiers. In the second phase, spatial relationships were analyzed to predict the exposure levels of mothers and children in the cohort, taking into account each baby’s time spent in the womb. In the final phase, associations between air pollution and birth outcomes were evaluated using multivariable logistic regression models.
Based on the SINASC and CIDACS datasets from 2007 to 2016, approximately 29 million births across 5,570 Brazilian municipalities were evaluated. The project team analyzed these datasets and found an increased risk of adverse birth outcomes associated with PM2.5 exposure at levels of 5. This indicates that significant correlations between exposure and negative birth outcomes occur even at levels below the WHO-recommended limits. The study also highlighted that more vulnerable families, particularly those benefiting from Bolsa Família, are more susceptible to the harmful effects of environmental pollutants. This heightened risk may be due to their residence in peripheral areas near major highways or sources of fire.
High-quality and high-resolution air pollution data were often unavailable in many locations, as they were typically collected from a limited number of monitoring stations. Due to the scarcity of pollution data and relatively small sample sizes, research groups frequently encountered difficulties in obtaining enough statistical power to accurately estimate pollution effects.
This study was innovative because it linked the data from a cohort of 100 million Brazilians, compiled by the Center for Data and Knowledge Integration for Health (CIDACS), with the latest spatial air pollution data covering the entire Brazilian territory. This integration ensured strong statistical power for the model used in the research.
Lack of substantial scientific evidence linking environmental exposures to birth-related health issues.
The findings of this project can guide the adoption of measures aimed at reducing the impact of pollution on child health.
The next steps include estimating critical air pollution limits based on the development of exposure-response curves for the studied child health outcomes (from birth to age 5). In the final phase, the project will focus on forest fires as one of the most prominent threats, not only to global biodiversity but also to local air quality in many areas of Brazil. The team will identify the largest forest fires during the sample period from 2000-2019 using a combination of time series analysis and case-crossover techniques to estimate the effects of these fires on local air quality, as well as on maternal and child health outcomes.