Background: Little is known about developmental neurotoxicity of particulate matter composition. We aimed to investigate associations between exposure to elemental composition of outdoor PM2.5 at birth and cognitive and psychomotor functions in childhood. Methods: We analyzed data from 4 European population-based birth cohorts in the Netherlands, Germany, Italy and Spain, with recruitment in 2000-2006. Elemental composition of PM2.5 measurements were performed in each region in 2008-2011 and land use regression models were used to predict concentrations at participants' residential addresses at birth. We selected 8 elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium and zinc) and used principal component analysis to combine elements from the same sources. Cognitive (general, verbal, and non-verbal) and psychomotor (fine and gross) functions were assessed between 1 and 9years of age. Adjusted cohort-specific effect estimates were combined using random-effects meta-analysis. Results: 7246 children were included in this analysis. Single element analysis resulted in negative association between estimated airborne iron and fine motor function (-1.25 points [95% CI -2.45 to -0.06] per 100ng/m 3 increase of iron). Association between the motorized traffic component, derived from principal component analysis, and fine motor function was not significant (-0.29 points [95% CI -0.64 to 0.06] per unit increase). None of the elements were associated with gross motor function or cognitive function, although the latter estimates were predominantly negative. Conclusion: Our results suggest that iron, a highly prevalent element in motorized traffic pollution, may be a neurotoxic compound. This raises concern given the ubiquity of motorized traffic air pollution.

Additional Metadata
Keywords Air pollution, Child development, Child health, Neuropsychological tests, Particulate matter
Persistent URL dx.doi.org/10.1016/j.envint.2017.09.015, hdl.handle.net/1765/102249
Journal Environment International
Grant This work was funded by the European Commission 7th Framework Programme; grant id h2020/633595 - Understanding the dynamic determinants of glucose homeostasis and social capability to promote Healthy and active aging (DYNAHEALTH), This work was funded by the European Commission 7th Framework Programme; grant id h2020/733206 - Early-life stressors and LifeCycle health (LIFECYCLE), This work was funded by the European Commission 7th Framework Programme; grant id fp7/211250 - European Study of Cohorts for Air Pollution Effects (ESCAPE), This work was funded by the European Commission 7th Framework Programme; grant id fp7/243406 - Transport related Air Pollution and Health impacts – Integrated Methodologies for Assessing Particulate Matter (TRANSPHORM)
Citation
Lubczyńska, M.J. (Małgorzata J.), Sunyer, J, Tiemeier, H.W, Porta, D, Kasper-Sonnenberg, M, Jaddoe, V.W.V, … Guxens Junyent, M. (2017). Exposure to elemental composition of outdoor PM2.5 at birth and cognitive and psychomotor function in childhood in four European birth cohorts. Environment International. doi:10.1016/j.envint.2017.09.015