Chemical exposure in childhood: A study on organophosphate flame retardants and plasticizers in a Flemish birth cohort

Humans are exposed daily to contaminants such as organophosphorus flame retardants (PFRs), legacy plasticizers (LPs), and alternative plasticizers (APs). To date, most biomonitoring studies in children have only focused on analysis of LP metabolites and a subset of PFRs and APs. This study investigated exposure to multiple PFRs, LPs and APs in the ENVIRONAGE birth cohort quantifying 13 PFR metabolites in 655 urine samples, while we measured 8 LP and 13 AP metabolites in urine of 328 children. For PFRs, more than 50 % of children were exposed to TNBP, TPHP, TDCIPP, TCIPP and EHDPHP. More than 93 % of children were exposed to the measured LPs (DEP, DiBP, DnBP, BBzP and DEHP), while for APs more than 50 % of children showed exposure to DEHA, DEHTP, DINCH and DIDP. Concentrations of PFR metabolites were higher in summer, while the presence of a pet in the house was associated with higher LP metabolite concentrations. Risk characterization ratios (RCRs) for single compounds and hazard indices (HIs) for compound classes suggested no risk for adverse health effects due to PFR exposure. For LPs, two children showed a HI above 1, while for APs, ten children had a HI above 1. The results indicate widespread exposure to PFRs and plasticizers, with most children being exposed to levels that are considered safe. However, the current study confirms a shift in exposure from LPs to APs, implying the need for further research on exposure to multiple APs in future studies.