Perfluoroalkyl compound levels in breast milk of mothers in Riyadh, Kingdom of Saudi Arabia

Per- and Polyfluoroalkyl substances (PFAS) are persistent environmental contaminants widely used in consumer and industrial applications including stain- and water-repellent textiles, nonstick cookware, firefighting foams, and food packaging. Their persistence and bioaccumulation potential raise concerns about early-life exposure through breastfeeding. Despite increasing international attention, no biomonitoring data on PFAS in breast milk have been reported from Saudi Arabia. The study aim to quantify perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in breast milk from lactating women in Riyadh and estimate infant exposure via breastfeeding using standardized exposure assessment methods. Breast milk samples were collected from 25 mothers within 30 days postpartum. Samples were analyzed by LC-MS/MS following solid-phase extraction. Estimated daily intake (EDI) for PFOA and PFOS was calculated using the equation EDI = (CBM × VBM) / BW, assuming an average infant body weight of 2.5 kg and daily milk intake of 292.5 mL during early infancy. Quantifiable concentrations (> LLOQ = 25 ng/L) were detected in 4 of 25 participants. PFOA concentrations ranged from < LLOQ to 73.3 ng/L, and PFOS concentrations ranged from < LLOQ to 85.2 ng/L. Median concentrations for both compounds remained < LLOQ. Infant EDI values were below the U.S. EPA oral reference dose (20 ng/kg-bw/day) but exceeded EFSA benchmark values in 12% of samples for PFOA (EFSA = 0.857 ng/kg-bw/day) and 16% of samples for PFOS (EFSA = 1.857 ng/kg-bw/day). This study provides the first biomonitoring evidence of PFAS in breast milk in Saudi Arabia, demonstrating low but measurable exposure among lactating women. The findings underscore a need for expanded biomonitoring and assessment of potential exposure sources in the region.