Table 3.

PFAS Levels measured in the airport drinking water and in the first serum samples from all 26 airport employees.

PFAS	Airport drinking water (ng/mL)	Serum level in the first samples {ng/mL [median (range)]}	Serum/water ratioa
PFCAsb
PFHxA	0.33	0.38 (0.16–1.1)	1.15
PFHpA	0.097	0.46 (0.07–2.2)	4.74
PFOA	0.30	9.1 (2.9–31)	30.3
PFSAs
PFBS	0.20	0.33 ($<\text{LOD}$–1.3)	1.65
PFPeS	0.18	6.9 (1.4–17)	38.3
PFHxS	0.71	76 (17–402)	107
PFHpS	0.016	1.3 (0.28–6.2)	81.3
L-PFOS	0.062	9.5 (5.4–28)	153
B-PFOS	0.064	6.4 (2.2–28)	100

Note: B-PFOS, branched PFOS; L-PFOS, linear PFOS; LOD, limit of detection; PFAS, perfluoroalkyl substances; PFBS, perfluorobutane sulfonic acid; PFCA, perfluorinated carboxylic acid; PFHpA, perfluoroheptanoic acid; PFHpS, perfluoroheptane sulfonic acid; PFHxA, perfluorohexanoic acid; PFHxS, perfluorohexane sulfonic acid; PFOA, perfluorooctanoic acid; PFPeS, perfluoropentane sulfonic acid; PFSA, perfluorinated sulfonic acid.

^aSerum/water ratio was calculated as median serum level divided by drinking-water level.

^bPFBA and PFPeA were elevated in the drinking water but below the LOD in all the serum samples, so no ratio is presented.