Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies: The ESCAPE project

BackgroundPrenatal exposure to air pollutants has been suggested as a possible etiologic factor for the occurrence of autism spectrum disorder.ObjectivesWe aimed to assess whether prenatal air pollution exposure is associated with childhood autistic traits in the general population.MethodsOurs was a collaborative study of four European population-based birth/child cohorts—CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen oxides (NO2, NOx) and particulate matter (PM) with diameters of ≤ 2.5 μm (PM2.5), ≤ 10 μm (PM10), and between 2.5 and 10 μm (PMcoarse), and PM2.5 absorbance were estimated for birth addresses by land-use regression models based on monitoring campaigns performed between 2008 and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively assessed autistic traits when the child was between 4 and 10 years of age. Children were classified with autistic traits within the borderline/clinical range and within the clinical ran...