Starting this fall, Pennsylvania and federal health officials hope to recruit 1,000 adults and 300 children in Bucks and Montgomery Counties for a national study on the impacts of PFAS chemicals on thyroids, cholesterol levels, kidneys, immune systems, livers, and even behavioral problems.

It’s another chance for residents of Horsham, Warminster, and Warrington Townships whose drinking water was contaminated by nearby military bases to get their blood tested.

As in a 2018 pilot test that preceded the national project, the testing won’t look for links to cancer, and at least to start, will not be focused on people who once worked at the Naval Air Warfare Center Warminster and Naval Air Station Willow Grove, where the “forever chemicals” leached off the bases from firefighting foam.

Rather, the study will seek volunteers from among the residents of the same communities, which are adjacent to the bases.

PFAS — per- and polyfluoroalkyl substances — are a class of man-made chemical compounds used in producing products such as nonstick cookware coatings, fire retardant furniture, and foam used in firefighting. PFOA, once used to make Teflon, and PFOS, once used in Scotchgard, are among the most widely known, yet there are hundreds more still being used in manufacturing.

Though the full health effects of PFAS are still being studied, known impact includes increased cancer risk, hormonal interference, infertility, increased cholesterol, and issues surrounding growth, learning, and behavior of infants and children, according to the Pennsylvania Department of Health.

Officials held a two-hour Zoom meeting Thursday night with residents about the upcoming PFAS National Multi-Site Health Studies being conducted by the U.S. Centers for Disease Control and Prevention (CDC) and Agency for Toxic Substances and Disease Registry (ATSDR) on effects of PFAS exposure. The study includes participants from six states, including Pennsylvania and New Jersey.

The national study presents the opportunity for more Horsham, Warrington, and Warminster residents to get their blood tested, after many had already taken part in an earlier pilot study. That 2018 study showed residents tested had elevated levels of PFAS in their blood compared with average Americans.

New results from that pilot study released in a Department of Health report ahead of Thursday’s meeting indicated follow-up tests in 2019 didn’t reveal significant links between levels of PFAS in dust or water in 14 homes, and levels of PFAS in the blood of the homes’ occupants.

The exception was for PFNA, one type of the compound: There was a link between PFNA in one home’s tap water with a resident’s blood level.

Representatives of the Pennsylvania Department of Health, ATSDR, Buxmont Coalition, Temple, and Brown Universities, and the nonprofit research group RTI International outlined the parameters of the blood and urine tests set to begin for the national study later this year.

“You’re a really highly engaged community,” Sharon Watkins, chief epidemiologist for the DOH, said Thursday on Zoom, explaining why the area was chosen to participate. She cited the history and level of exposure as a primary reason.

Residents posted a range of questions, such as who will be allowed to participate, whether PFAS is linked to higher risks with COVID-19 (not immediately, they were told), and which communities would be included in the study.

The testing would include:

  • Households in areas closest to the military bases subjected to greater concentrations of PFAS over longer periods of time.

  • Adults 18 and older and children 4-17.

  • About 235 residents who already participated in a pilot study that looked at the compounds in blood and urine, as well as dust and drinking water in homes.

It would exclude:

  • People who haven’t been exposed to PFAS for 15 years or longer.

  • People exposed to the chemicals through work.

  • Prisoners or those under house arrest.

» READ MORE: Archive of Inquirer PFAS coverage

Officials hope this fall to recruit volunteers for blood and urine testing. A full public analysis won’t be complete until spring 2024, though participants will get their own results much earlier.

A headquarters will be set up in the area for the yearlong program, staffed with an office manager, field interviewers, clinical interviewers, phlebotomists, a nursing assistant, and laboratory technician.

Adult volunteers will be paid $50 per blood or urine test, and children will be paid $75. Children under 5 will complete behavioral tests up to 90 minutes long that will include memory games, item sorting, puzzles, and reactions to photos.

A website,, which is not yet active, will provide further information.

Answering a question from an anonymous military veteran and area resident, Ted Lillys, an environmental engineer with RTI, said there was no plan to look specifically at base workers, but testing could be expanded in the future.

Area resident William Gildea-Walker asked if there would be any additional funding to study links between cancer and PFAS.

Resa Jones, chair of Temple’s epidemiology and biostatistics department, said the group might look at the possibility in the future.

The ATSDR and Pennsylvania DOH looked at cancer cases in the area from 1985 through 2013 but did not find clusters that might be expected with an environmental cause.

Correne Kristiansen, chief of staff for State Sen. Maria Collett, who represents parts of Montgomery and Bucks Counties, asked if the group will look at potential links between PFAS levels and severity of COVID-19.

Officials said that is not included in the initial study parameters, but might be added.

Staff writer Justine McDaniel contributed to this article.