The physical, social and intellectual development of children from conception to the end of adolescence requires an environment that is both protected and protective of their health. A growing number of diseases in children are linked to unsafe environments. Pre-natal and early life exposures are associated with child development and health and predispose to late adult effects.

Accumulating evidence from laboratory animal and human studies suggests that air pollution exposure during pregnancy affects cognitive and psychomotor development in childhood. We analyzed data from 6 European population-based birth cohorts-GENERATION R (The Netherlands), DUISBURG (Germany), EDEN (France), GASPII (Italy), RHEA (Greece), and INMA (Spain)-that recruited mother-infant pairs from 1997 to 2008. Air pollution levels-nitrogen oxides (NO2, NOx) in all regions and particulate matter (PM) with diameters of <2.5, <10, and 2.5-10 μm (PM2.5, PM10, and PMcoarse, respectively) and PM2.5 absorbance in a subgroup-at birth addresses were estimated by land-use regression models, based on monitoring campaigns performed primarily between 2008 and 2011. Levels were back-extrapolated to exact pregnancy periods using background monitoring sites. Cognitive and psychomotor development was assessed between 1 and 6 years of age. Adjusted region-specific effect estimates were combined using random-effects meta-analysis. A total of 9482 children were included. Air pollution exposure during pregnancy, particularly NO2, was associated with reduced psychomotor development (global psychomotor development score decreased by 0.68 points [95% confidence interval = -1.25 to -0.11] per increase of 10 μg/m in NO2). Similar trends were observed in most regions. No associations were found between any air pollutant and cognitive development. Air pollution exposure during pregnancy, particularly NO2 (for which motorized traffic is a major source), was associated with delayed psychomotor development during childhood. Due to the widespread nature of air pollution exposure, the public health impact of the small changes observed at an individual level could be considerable.

A peer-reviewed open access journal published by the National Institute of Environmental Health Sciences

A peer-reviewed open access journal published by the National Institute of Environmental Health Sciences

Context Low maternal free thyroxine (FT4) has been associated with poor child neurodevelopment in some single-centre studies. Evidence remains scarce for potential adverse effects of high FT4 and whether associations differ in countries with a different iodine status. Objective To assess the association of maternal thyroid function in early pregnancy with child neurodevelopment in countries with a different iodine status. Design, Setting and Participants Meta-analysis of individual-participant data compromising 9,036 mother-child pairs from three prospective population-based birth cohorts: INMA (Spain), Generation R (The Netherlands) and ALSPAC (United Kingdom). Exclusion criteria were multiple pregnancies, fertility treatments, thyroid interfering medication usage, and known thyroid disease. Main outcomes Child non-verbal IQ at 5-8 years of age, verbal IQ at 1.5-8 years of age, and autistic traits within the clinical range at 5-8 years of age. Results FT4 97.5^th percentile was associated with a 1.9 (1.0 to 3.4) fold higher risk of autistic traits. No independent associations were found with thyrotropin. Conclusions Low maternal FT4 was consistently associated with lower IQ across cohorts. Further studies should replicate the findings of autistic traits and investigate the potential modifying role of maternal iodine status. FT4 seems a reliable marker of fetal thyroid state in early pregnancy, regardless of the type of immunoassay.