Per- and Polyfluoroalkyl Substances in Pediatric Cerebrospinal Fluid: Evidence of Central Nervous System Exposure

Abstract Per- and polyfluoroalkyl substances (PFAS) have been implicated in neurodevelopmental toxicity, yet direct evidence of their presence within the central nervous system (CNS) of children remains limited. We quantified 12 PFAS in cerebrospinal fluid (CSF) samples from 47 pediatric patients undergoing clinically indicated lumbar puncture in Nanjing, China. PFAS were detected in 100% of samples, with PFOA (detection frequency: 98%), PFHxS (96%), PFOS (89%), and 6:2 Cl-PFESA (68%) most prevalent; their CSF distribution patterns were generally consistent with those observed in pediatric serum samples from nearby regions. Median concentrations were numerically higher in children under 2 and under 6 years of age, but these differences were not statistically significant (p = 0.450 and p = 0.322; rank-biserial r = 0.110 and 0.145) and should be interpreted as nonsignificant in this small, clinically heterogeneous sample. The presence of PFAS in children’s CSF adds to the growing concerns about early-life neurotoxicant exposure. Importantly, this study involved a small cohort (n = 47) of critically ill children. Given the limited sample size, the underpowered age subgroups, and the potential influence of disease-related changes in barrier permeability, the measured concentrations should not be generalized to healthy children, and all age-related comparisons are exploratory.