Personal PFAS Blood Testing: What the Numbers Mean
PFAS blood testing—once available only in research studies—is increasingly accessible to individuals through primary care physicians, environmental health clinics, and direct-to-consumer laboratory services. As awareness of PFAS health effects grows, individuals who have lived near military bases, industrial facilities, or PFAS-contaminated water systems are seeking blood tests to characterize their personal exposure. Understanding what serum PFAS concentrations mean for individual health risk—and what, if anything, can be done to reduce them—requires navigating evolving science and communicating carefully with healthcare providers.
NHANES National Exposure Data: What’s “Normal”?
The CDC’s National Health and Nutrition Examination Survey (NHANES) provides the benchmark for background PFAS blood concentrations in the US population. The most recent NHANES PFAS data (2017–2018) shows median serum concentrations: PFOS: 4.1 ng/mL; PFOA: 1.3 ng/mL; PFHxS: 0.7 ng/mL; PFNA: 0.5 ng/mL. These “normal” background levels reflect decades of PFAS exposure through food, drinking water, and consumer products—they are not “safe” levels but rather what’s common in the US population. Importantly, NHANES data shows a 70% decline in PFOS and PFOA concentrations in the US population between 1999 and 2018—reflecting the impact of manufacturing phase-outs—but PFAS are still present in virtually all Americans tested.
Health-Based Guidance Values for Blood PFAS
Several regulatory bodies have established health-based values for PFAS in blood serum that can be used to interpret individual test results. ATSDR’s Minimal Risk Levels (MRLs), converted to blood concentration equivalents: PFOS: 7.0 ng/mL; PFOA: 7.0 ng/mL; PFNA: 7.0 ng/mL; PFHxS: 7.0 ng/mL. HBM4EU (European Human Biomonitoring program) established blood PFAS guidance values for policy action: 6.9 ng/mL sum of PFOS+PFOA+PFHxS+PFNA. Germany’s Human Biomonitoring Commission: 5 ng/mL sum of 4 PFAS for precautionary action trigger. Studies of contaminated populations (Ronneby, Sweden; Pease AFB, NH) show residents with blood PFAS 5–50 times higher than NHANES background following high-concentration drinking water exposure.
Medical Management for High PFAS Exposure
There is currently no approved medical treatment to accelerate PFAS elimination from the body. Cholestyramine (a bile acid sequestrant) showed limited efficacy in small studies—the hypothesis being that interrupting enterohepatic circulation could accelerate PFAS excretion—but controlled trials have not demonstrated significant clinical benefit. Clinical management for individuals with high PFAS exposure focuses on: enhanced surveillance for PFAS-associated cancers (kidney, testicular, thyroid) with earlier screening initiation; thyroid function monitoring; lipid monitoring (PFAS are associated with elevated cholesterol); enhanced preconception counseling for women of reproductive age; and removal of ongoing exposure through drinking water treatment or source switching. The most important intervention is eliminating continued exposure—replacing contaminated drinking water with certified-filtered alternatives immediately reduces ongoing PFAS accumulation.
Individual PFAS blood testing provides valuable information about personal exposure history, but the most actionable response is always the same: eliminate ongoing exposure through certified water filtration, choose PFAS-free food packaging, and ensure healthcare providers are aware of exposure history for appropriate cancer surveillance.