Biomonitoring of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human milk: Exposure and risk assessment for lactating mothers and breastfed children from Spain

The main objective of the present research was to evaluate the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the human milk of Spanish lactating women who participated in the BETTERMILK project so that exposure and risk could be assessed for these mothers and their breastfed children. The total ∑PCDD/Fs + dl-PCBs TEQ2005 concentrations in the upper-bound (UB) ranged from 1.29 to 13.48 pgTEQ2005 g−1 lipid. The estimated geometric mean level for the sum of PCDD/F and dl-PCBs was 4.10 and 4.42 pgTEQ2005 g−1 lipid, lower-bound (LB) and UB respectively and were below the reference level reported by EFSA, which is associated with adverse effects in boys of 9 years and related to lactating mothers' exposure values of the tolerable weekly intake (TWI) of around 2 pgTEQ2005 kg−1 bw per week. Nevertheless, it was exceeded when the 95th percentile (8.31 pgTEQ2005 g−1 lipid, as UB) was considered. Results from a multiple regression analysis showed that age has a significant impact on milk ∑PCDD/Fs + dl-PCBs levels, with higher concentrations observed in the milk from older mothers. [Display omitted] •First Spanish biomonitoring study of dioxins in milk from non-hot spot mothers.•Geometric mean levels ranged from 1.29 to 13.48 pgTEQ2005 g−1 lipid (UB).•Age of the mother was a factor highly related to PCDD/Fs and dl-PCBs levels.•PCDD/Fs + dl-PCBs mean levels were below the value associated with TWI in mothers.•Mean levels were below that associated with adverse effects in children.