Update of the risk assessment on dioxins and dioxin‐like PCBs in feed and food

Abstract The European Commission asked EFSA to update its 2018 risk assessment on polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/Fs) and dioxin‐like polychlorinated biphenyls (DL‐PCBs) in feed and food, based on the 2022 WHO Toxic Equivalency Factors (WHO2022‐TEFs). A decrease in sperm concentrations as a consequence of early‐life exposure was still considered the critical effect in rodents and humans. This can only be prevented by ensuring sufficiently low exposure to PCDD/Fs and DL‐PCBs of future mothers. Using the WHO2022‐TEFs, the critical human study in the 2018 Opinion still showed a significant inverse association between PCDD/Fs and sperm concentration, but not when including DL‐PCBs. Therefore, this study was not used to derive a Tolerable Weekly intake (TWI). Instead, a developmental study with TCDD in rats was used to derive a TWI of 0.6 pg. WHO2022‐toxic equivalents (TEQ)/kg bw per week, based on decreased sperm production. Human studies were used as supporting evidence, including an evaluation of necessary uncertainty factors. Dietary exposure assessment based on occurrence data in food from the last decade, showed that using the new TEFs resulted in 27%–35% lower total‐TEQ exposure. Mean exposure (lower to upper bound) to PCDD/Fs and DL‐PCBs for European adult populations varied between 1.87 and 6.10 pg. WHO2022‐TEQ/kg bw per week, and at the P95 between 4.15 and 12.0 pg. WHO2022‐TEQ/kg bw per week. The CONTAM Panel concluded that exposure for European women of childbearing age raises a health concern for their sons at the mean (80%–90% certainty) and P95 (95%–99% certainty) exposure. Including uncertainties regarding the TEFs for DL‐PCBs decreased this certainty. Human milk data confirmed the exceedance of the TWI but to a lesser extent than dietary exposure. The change in TEFs does not affect the transfer rates of individual congeners but it could impact the transfer rates when using Total‐TEQ levels.