Distribution of perfluorinated compounds in blood compartments during prenatal exposure

Perfluorinated compounds (PFCs) are a class of persistent environmental toxicants widely used in industrial and consumer products due to their unique chemical and physical properties. Knowledge on the health effects in humans is sparse and have most often been studied only for PFOS and PFOA, but use of other PFCs are emerging, not at least after restriction of PFOS in the Stockholm Convention. Knowledge of prenatal exposure, and distribution between blood compartments for a wider range of PFCs in humans is therefore needed.
We present prenatal exposure data for 19 perfluorinated organic compounds from 100 mother and child pairs. The compounds were quantified in maternal serum as well as in umbilical cord blood and serum from the child at birth. The samples were collected between 1999-2001 at the Faroe Islands. The quantified compounds includes the two major subgroups perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonates (PFSAs) ranging from C4-C12, as well as perfluorooctanesulfonamides (FOSAs) and perfluorooctanesulfonamidoacetic acids (FOSAAs).
Maternal and foetal levels were significantly correlated for nearly all PFCs with median concentrations in cord serum ranging between 30-95% of the maternal concentration, while cord whole blood levels were lower. The only exception was FOSA that binds to erythrocytes and therefore occur at significantly higher concentration in whole blood. The apparent partition of the PFCs across the placental barrier varied according to chain length, branching and active group. Increasing chain length was associated with decreased passage. Branched PFOS were comparatively higher on the foetal side than linear PFOS, and the carboxylates seemed to pass more easily than sulfonates for compounds at the same length.