C06 | Dietary exposure to polyfluoroalkyl substances through egg consumption: risk estimation using the Relative Potency Factor approach in the European population

G. Rampazzo¹, G. Depau¹, G. Pagliuca¹, E. Zironi¹, F. Arioli², T. Gazzotti¹. | ¹Dipartimento di Scienze Mediche Veterinarie, Alma Mater Studiorum Università di Bologna; ²Dipartimento di Medicina Veterinaria e Scienze Animali, Università di Milano.

Purpose. The purpose of the study is to estimate exposure to per- and polyfluoroalkyl substances (PFAS) through the consumption of eggs and egg products in the European population, using the Relative Potency Factor (RPF) approach, referring to liver toxicity. This approach, inspired by previous similar applications (dioxins, PCBs), is derived from standardised toxicological assessments according to JRC/ECHA/SCHEER criteria. Exposure, expressed in PFOA equivalents (PEQ), allows for a risk assessment, both for individual substances and cumulatively, in line with the most recent regulatory developments supporting the adoption of new, scientifically recognised methodological approaches (NAM) aimed at strengthening knowledge through the integrated analysis of data obtained using methods alternative to animal testing. Methods. PFAS contamination data were extracted from the 2020 EFSA scientific opinion on the presence of PFAS (18 congeners) in food (Annex A), focusing on the food category “eggs and egg products”. In order to make a realistic estimate, only the 95th percentile lower bound (P95 LB) values were considered. The contamination data were combined with consumption data specific to consumer categories from the EFSA Comprehensive Food Consumption database, considering four age groups: children, adolescents, adults and the elderly. To harmonise toxicity between different PFAS, RPFs based on liver toxicity (liver hypertrophy in rats) as a critical effect were applied. Both a single-compound risk assessment and a cumulative assessment (sum of PFAS) were performed. Exposure, calculated for each consumer category and expressed in PFOA equivalents (ng/kg body weight per week), was then compared with the Tolerable Weekly Intake (TWI) established by EFSA in 2020. Results. Weekly exposure to PFAS expressed in PEQ shows higher levels in younger age groups. The estimated P95 values are 1.30 ng/kg bw in children, 0.69 ng/kg bw in adolescents, 0.53 ng/kg bw in adults and 0.50 ng/kg bw in the elderly. The main contribution to the exposure estimate comes from PFOS and PFOA. Cumulative exposure in PEQ represents 30%, 16%, 12% and 11% of the TDS (4.4 ng/kg bw/week), respectively, according to the lower-bound (LB) approach. Conclusions. Although exposure levels are below the TDS, the consumption of eggs and egg products represents a significant source of PFAS, considering the intake from other sources in the diet, particularly in children. The use of the RPF approach allows the different toxicological potential of individual congeners to be balanced, providing an integrated estimate of the exposure risk associated with specific critical effects. The results obtained highlight the importance of official controls throughout the livestock supply chain and the importance of adopting up-to-date tools for assessing chemical risk in food.