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 t:RMILK project so that exposure and risk could be assessed for these mothers and their breastfed children. The total Sigma PCDD/Fs + dl-PCBs TEQ(2005) concentrations in the upper-bound (UB) ranged from 129 to 13.48 pg-TEQ(2005) g(-1) lipid.The estimated geometric mean level for the sum of PCDD/F and dl-PCBs was 4.10 and 4.42 pg-TEQ(2005) 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 pg-TEQ(2005) kg(-1) bw per week. Nevertheless, it was exceeded when the 95th percentile (8.31 pg-TEQ(2005) g(-1) lipid, as UB) was considered. Results from a multiple regression analysis showed that age has a significant impact on milk Sigma PCDD/Fs + dl PCBs levels, with higher concentrations observed in the milk from older mothers. (C) 2020 Elsevier B.V. All rights reserved.