Chemical exposure
Replacement PFAS Are Showing Up in Pregnancy Samples
A July 2026 New York City pregnancy cohort study found PFBS in most measured samples, highlighting how chemical replacements can create new exposure questions.
A July 16, 2026 Environmental Research study measured prenatal serum concentrations of 13 PFAS in 500 participants from a New York City pregnancy cohort.
The study included PFBS, a short-chain replacement PFAS that has been measured less often in U.S. epidemiologic studies.
PFBS was quantified in 95.6% of samples.
The median PFBS concentration was 0.40 nanograms per milliliter.
The authors described this as unexpectedly higher than serum PFBS concentrations reported in other U.S. cohorts.
PFBS was not strongly correlated with other PFAS measured in the study.
Participant characteristics and location of residence did not clearly explain the PFBS pattern.
The study did not establish health outcomes from PFBS exposure.
It does show that replacing older chemicals does not automatically settle the exposure question.
For consumers, this is a reminder that chemical phaseouts should be followed by testing of replacement compounds.
