Abstract for the 2018 HEI Annual Conference
Air Pollution, Autism spectrum disorders, and brain imaging in CHildren among Europe – the APACHE project
1 ISGlobal, Barcelona, Spain; 2 Pompeu Fabra University, Barcelona, Spain; 3 Spanish Consortium for Research on Epidemiology and Public Health, Madrid, Spain; 4 Erasmus University Medical Centre–Sophia Children’s Hospital, Rotterdam, The Netherlands
Background. We aim to investigate i) the association between prenatal air pollution exposure at different time windows and the development of autism spectrum disorders (ASD) and ii) the association between prenatal and postnatal air pollution exposure at different time windows and brain structural and functional changes in children.
Methods. We use data from 2 epidemiological studies: i) a population-based case-cohort study of ASD in Catalunya (Spain), where children diagnosed with ASD identified through the Catalan mental health network are linked to the Catalan birth registry and ii) a population-based birth cohort study, the Generation R (the Netherlands), with existing longitudinal data on brain imaging in children at 6-10 years and at 8-12 years. For both study regions we compile existing land use regression models for a large number of pollutants. For the study of Catalunya, we also combine land use variables and satellite data remote sensing of aerosol optical depth to develop new PM2.5 and PM10 models. We estimate air pollution levels at participants’ home addresses at different time-windows during pregnancy (entire pregnancy, monthly, and weekly) and childhood (entire childhood, yearly, and monthly). We apply methods for measurement error and multi-pollutant models. We assess the association between air pollution exposure at different time windows during pregnancy and the development of ASD. We also assess the association between air pollution exposure at different time windows during pregnancy and childhood and structural and functional brain changes at 6-10 years old and at 8-12 years old.
Results. We are setting up the case-cohort study on ASD and developing new air pollution models for Catalunya. There are no results from that study yet. Regarding the imaging study, in the preliminary analysis we found that prenatal PM2.5 exposure was associated with a thinner cortex in several brain regions in 6-10 years old children and these alterations partially mediated the association between prenatal PM2.5 exposure and impaired child inhibitory control. We are currently working on the association between prenatal and postnatal exposure to several traffic-related air pollutants and white matter microstructure in 8-12 years old children. In single pollutant analysis, higher prenatal and postnatal exposure to several air pollutants was associated with a decrease in fractional anisotropy and an increase in mean diffusivity. When we mutually-adjusted those pollutants that showed an association in the single pollutant analysis, higher postnatal levels of zinc content in PM2.5, which reflects tire wear and brake linings, were associated with an increase in mean diffusivity (0.03 increase in mean diffusivity [95%CI 0.01; 0.04] for each 10 ng/m3 increase of airborne zinc). Further steps will include measurement error correction methods and advanced multipollutant modeling.
Poster by Guxens et al., 2018 Annual Conference