Health impact assessment of the chemical exposome in European children

BACKGROUND: We aimed to assess the impact of the chemical exposome on the health of European children since previous health impact assessments (HIA) were limited to a few chemicals. METHODS: 74 out of 484 substance-outcome associations had an overall level of evidence at least likely and were therefore considered for HIA. For 51 of the 74 associations, dose-response relationships were identified from systematically searched meta-analyses or epidemiological studies. For 41 of these, exposure levels were compatible for HIA. Exposure levels were based on biomarker concentrations assessed in 1301 pregnant women and children of the HELIX cohorts in 6 European countries. The baseline burden of disease were from national estimates of the World Health Organisation for 8 outcomes. The attributable burden of disease was estimated by combining exposures and dose-response relationships and expressed in terms of population attributable fraction, disability-adjusted life years (DALYs) or variations in mean level for quantitative health outcomes. Associated uncertainty was taken into account using Monte-Carlo simulations. RESULTS: Each substance harmful for cognition or birth weight entailed an average estimated decrease in Intellectual Quotient by 1.7 points (95% confidence interval (CI) 0, 4.3) and in birth weight by 57 g (95%CI 0, 138). The chemical exposome entailed 1.65 (95%CI 0.63; 2.90) DALYs for 1,000 children per year. The main contributors to the impact were perfluoroalkyl substances, other persistent organic pollutants and tobacco. The impact was mainly due to neurodevelopment (0.4 DALY), congenital heart defects (0.6 DALY), respiratory health (0.4 DALY) and sudden infant death syndrome (0.3 DALY). CONCLUSIONS: Our study is one of the largest HIA in terms of number of chemicals considered. The results exclude urban exposures such as air pollution and are probably largely underestimated because of a lack of data on dose-response relationships and baseline burden of disease. KEY MESSAGES: • Chemical exposures (mainly perfluoroalkyl substances, persistent organic pollutants, metals and tobacco) contribute to the burden of disease in European children. • Chemical exposures have an impact on fetal and infant death, neurodevelopment, cardiometabolism, respiratory and reproductive health of children.