PA PFAS Multi-site Health Study

Initial Summary PFAS Results

The table below shows the community averages for PFOA, PFOS, PFHxS, and PFNA for the 1253 adults and 89 children with PFAS results who participated in the PA PFAS MSS Health Study. Note* table includes 2 adults who are missing questionnaire data. You can see the comparison of your community’s values with the national averages (shown in the National Health National Health and Nutrition Examination Survey (NHANES)).

The 50th percentile is the result which 50% of results are below and 50% are above.
The 95th percentile is the result which 95% of results are below and 5% of results are above.

At this time, there are no specific levels of PFAS that can be used to predict or diagnose disease. The comparison with the NHANES 50th and 95th percentile provides a way to compare PFAS blood levels for people participating in the PA PFAS MSS Health Study with people living in the U.S.

These results show that levels of PFOA, PFOS, and PFHxS, in adult Health Study participants exceed what would be expected in about 95 percent of the U.S. adult population.

PA PFAS Levels for Adults and Children Compared to the National Health and Nutrition Examination Survey (NHANES) in ng/mL
Age Group	PFAS	N	PA 50th Percentile	NHANES 50th Percentile^1,2	PA 95th Percentile	NHANES 95th Percentile^1,2
Adult	PFOA	1253	2.27	1.47	6.57	3.87
	PFOS	1253	5.90	4.70	24.10	15.1
	PFHxS	1253	4.30	1.20	25.60	3.80
	PFNA	1253	0.50	0.40	1.40	1.40

Child 12-17	PFOA	48	1.27	1.17	3.37	2.34
	PFOS	48	2.09	2.60	7.00	7.30
	PFHxS	48	1.70	0.80	6.60	3.40
	PFNA	48	0.20	0.40	0.90	1.20

Child 4-11	PFOA	41	1.67	1.94	3.27	3.84
	PFOS	41	2.30	2.65	8.40	8.41
	PFHxS	41	1.80	0.85	4.90	4.14
	PFNA	41	0.30	0.75	1.30	3.19

¹ CDC. 2021. 2017-2018 NHANES 50^th to 95^th percentiles among children 12-19 years old and adults 20+ years old from the Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables, March 2021.

²CDC. 2018. 2013-2014 NHANES 50th to 95th percentiles among children 6-11 old from the Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables, March 2018.

The table below presents clinical guidance by the National Academies of Sciences, Engineering, and Medicine (NASEM) for follow-up with patients after PFAS testing by exposure level. We also provide the number and percent of the adult and child participants in the PA PFAS MSS Health Study with PFAS results who fall into each NASEM exposure category. Note* table includes 2 adults who are missing questionnaire data.

Clinical guidance for follow-up with patients after PFAS testing¹
Total PFAS Level and Clinical Follow-up Recommendation	PA Adults (N=1253)	PA Children (N=89)
>20 (ng/mL) PFAS*	High Exposure	High Exposure
Encourage PFAS exposure reduction if a source of exposure is identified, especially for pregnant persons. In addition to the usual standard of care, clinicians should: Prioritize screening for dyslipidemia with a lipid panel (for patients over age 2) following guidelines for high-risk children and adults At all well visits: Conduct thyroid function testing (for patients over age 18) with serum thyroid stimulating hormone (TSH) Assess for signs and symptoms of kidney cancer (for patients over age 45), including with urinalysis For patients over age 15, assess for signs and symptoms of testicular cancer and ulcerative colitis	N=379 (30.2%)	N=4 (4.5%)
2-<20 (ng/mL) PFAS	Moderate Exposure	Moderate Exposure
Encourage PFAS exposure reduction if a source has been identified, especially for pregnant persons. Within the usual standard of care clinicians should: Prioritize screening for dyslipidemia with a lipid panel (once between 9 and 11 years of age, and once every 4 to 6 years over age 20) Screen for hypertension disorders of pregnancy at all prenatal visits Screen for breast cancer based on clinical practice guidelines based on age and other risk factors	N=863 (68.9%)	N=84 (94.4%)
<2 (ng/ML) PFAS*	Low Exposure	Low Exposure
Provide usual standard of care	N=11 (0.9%)	N=1 (1.1%)
* Simple additive sum of PFOA and PFOS (linear and branched isomers), PFHxS, PFNA, PFDA, PFUnDA, and MeFOSSA in serum or plasma ¹Adapted from: National Academies of Sciences, Engineering, and Medicine. 2022. Guidance on PFAS Exposure, Testing, and Clinical Follow-Up. Washington, DC: The National Academies Press. https://doi.org/10.17226/26156.

Frequently Asked Questions

RTI International, the Pennsylvania Department of Health (PA DOH), Temple University, and Brown University received federal funding to study PFAS and possible health effects from drinking PFAS-contaminated water in Pennsylvania.

What is the goal of the study?

The goal of the PA PFAS Multi-site Health Study is to learn more about the relationship between PFAS exposure and health outcomes among differing populations exposed to PFAS-contaminated drinking water. It will also compare different levels of PFAS exposure from different sites and health outcomes.

What are PFAS?

PFAS are human-made chemicals used since the 1950s in a variety of products, including some cosmetics; water, grease, and oil-resistant products; and some firefighting foams.

What is known about PFAS exposure and health effects?

There is much to learn, but some studies show high levels of certain PFAS may lead to the following:

Increased cholesterol levels
Changes in liver enzymes
Decreased vaccine response in children
Increased risk of high blood pressure or preeclampsia in pregnant women
Small decreases in infant birth weights
Increased risk of kidney or testicular cancer

Who is eligible to participate?

Adults who are age 18 and older and children ages 5 through 17 (with parent or guardian permission) who resided in households exposed to PFAS-contaminated drinking water, either via the public water system or private wells, may be eligible. Children exposed in utero or during breastfeeding may also be eligible.

Who is not eligible?

Residents who were potentially exposed to PFAS on their job (e.g., ever worked as a firefighter or used firefighting foam and/or ever worked at facilities using PFAS chemicals) are not eligible to participate.

Residents who only had exposure to PFAS-contaminated drinking water before 2005 are not eligible to participate. Someone would be ineligible to participant in the study if they did not have relatively recent exposure to PFAS-contaminated drinking water. This requirement is to ensure that PFAS levels remain high enough to be measured in the blood.

Will I receive compensation to participate?

There are no costs for the tests. Adults can receive up to $50 in gift cards for completing the entire study, and children can receive up to $75 in gift cards for completing the entire study.

What is the enrollment goal and target population?

The enrollment goal is 1,000 adults and 300 children. Recruitment will target groups of participants from these townships: Abington, Hatboro, Horsham, Ivyland, Northampton, Upper Dublin, Upper Moreland, Upper Southampton, Warminster, Warrington, and Warwick and participants who took part in the 2018-2019 Pennsylvania PFAS biomonitoring project. More information about the biomonitoring project can be found under Other Studies.

What is the study timeline?

In the fall of 2021, eligible residents will be invited to schedule a clinical visit and complete tests for the study.

What types of tests will be performed and what will they measure?

Trained professionals from the community will:

Collect your blood and urine samples (samples will NOT reveal drug/alcohol use)
Take your body and clinical measurements
Ask questions about your residential, drinking water usage, occupational, and medical histories
Study behaviors in child participants

With your consent, staff will also collect information from your medical records and your child's school records.

The study will examine associations between PFAS compounds and lipids, renal function and kidney disease, thyroid hormones and disease, liver function and disease, glycemic parameters and diabetes, and immune response and function in both children and adults. In addition, the study will investigate PFAS differences in sex hormones and sexual maturation, vaccine response, and neurobehavioral outcomes in children. In adults, additional outcomes of interest include cardiovascular disease, osteoarthritis and osteoporosis, endometriosis, and autoimmune disease.

How will results be used?

Participants' results will be used to inform public health specialists on how PFAS impacts human health. In addition, each individual participant will receive their own testing results, enabling them to learn more about their own health.

How did PFAS get into the drinking water?

Aqueous Film Forming Foams (AFFF). Large-scale drinking water contamination has occurred in many states among communities near military bases where PFAS were used in firefighting exercises. These bases were routinely performing firefighting trainings using PFAS-containing Aqueous Film-Forming Foams (AFFF) for several decades. The use of AFFF in training exercises led to direct emissions of PFAS into surface and ground waters. Montgomery and Bucks counties in Southwestern Pennsylvania were the locations of two such large military bases.

Bucks County. The former Naval Air Warfare Center (NAWC) in Warminster Township, Bucks County, Pennsylvania, was used to research, develop, and test naval aircraft systems, and was located near four of the 18 Warminster Municipal Authority (WMA) public water supply wells. PFAS compounds were detected in the WMA system in the summer of 2013. Further study was performed by the U.S. Environmental Protection Agency (EPA), and as of September 2015, PFAS were detected in 93 out of the 100 private wells within a 1- to 3-mile radius of the military site.

Montgomery County. The Horsham Air Guard Station (HAGS) in Horsham Township, Montgomery County, Pennsylvania, located a few miles away from NAWC is on a 1,200-acre site that was shared with the Naval Air Station Joint Reserve Base. Military operations began during the 1920s and the base is currently operated under the Pennsylvania Air National Guard. The AFFF used on the HAGS base resulted in PFAS-contamination of two nearby public water systems — the Horsham Water and Sewer Authority and the Warrington Township Water and Sewer Department.

Is it OK to drink the water?

Yes, PFAS drinking water contamination in the area impacted by the former and current Department of Defense bases has been addressed. Contaminated public water wells in the Horsham, Warrington, and Warminster public systems were taken out of service by July 2014, and bottled water and later public water hookups were provided to certain residents with contaminated private wells. A subset of additional private wells with lower levels of PFAS within 25 percent of the perfluorooctanesulfonic acid (PFOS) or perfluorooctanoic acid (PFOA) Preliminary Health Assessment Levels (PHALs) are being monitored through quarterly resampling.

Does the PA PFAS Multi-site Health Study include questions about cancer?

Yes, the PA PFAS Multi-site Health Study will be asking questions about personal and family history of cancer.

Will your study protocol also include questions around diet, lifestyle, and other exposures to potentially harmful chemicals like tobacco, drugs, and alcohol?

The PA PFAS Multi-site Health Study is using the same questionnaire that is being used in the Pease, NH, study. The adult questionnaire includes sections on Residential History and Drinking Water Exposures, Occupational History, Medical History, Reproductive History (women only) including use of birth control pills, Family Medical History, and Social History including questions about smoking and alcohol use. The currently approved questionnaire does not include questions around diet or use of prescription, over-the-counter, or illicit drugs.

What is of more concern with respect to exposure: contact through the skin when bathing/showering, brushing teeth, laundry and dish washing, or ingestion with cooking and drinking?

Based on current knowledge, ingestion is clearly the dominant concern. Inhalation of house dust represents an additional path of exposure, but there are uncertainties about its contribution to human exposure. Risks associated with dermal exposures, either through direct contact with PFAS-containing materials (e.g., carpets or bathing/swimming in waters contaminated with PFAS at typical levels) remain largely unknown. However, the information available suggests that environmental conditions for dermal exposure may not make this a major contributor to overall exposure.

Can massive amounts of lawn chemicals used on golf courses 50 years ago contribute to PFAS issues in groundwater/wells?

Although most mixtures of pesticides, herbicides, and insecticides used at golf courses to maintain their turf do not consist of PFAS chemicals, there is evidence that some pesticide and herbicide formulations may contain some PFAS. Thus, application of large amounts of PFAS-containing lawn care chemicals could be another potential pathway for PFAS to contaminate groundwater.

Will this study compare any past evidence obtained over time (i.e., the unused sera from the mandatory, periodic blood tests performed on active duty U.S. military service members maintained by the Department of Defense Serum Repository)?

ATSDR selected a cross-sectional study design for the PA PFAS Multi-site Health Study to be comparable with other studies and to establish a baseline for potential follow-up in longitudinal studies. The cross-sectional study design involves looking at data from a population at one specific point in time; therefore, this study will not compare any past evidence obtained over time. However, the results of this research will be available to the public under CDC’s Open Access plan. Thus, future researchers with access to the Department of Defense Serum Repository could build on the results of the PA PFAS Multi-site Health Study to conduct a longitudinal study using this resource.

What research on the health effects of PFAS would you recommend if we wanted to learn more?

Unfortunately, there is not a good layperson's guide to the health effect of PFAS. Below are links to some factsheets and reports that provide useful information.

ATSDR/CDC, “What are the health effects of PFAS?” (March 2020):
https://www.atsdr.cdc.gov/pfas/health-effects/index.html
American Cancer Society, “Perfluorooctanoic Acid (PFOA), Teflon, and Related Chemicals” (March 2020):
https://www.cancer.org/cancer/cancer-causes/teflon-and-perfluorooctanoic-acid-pfoa.html
NRDC, “PFAS in Drinking Water: Scientific and Policy Assessment for Addressing Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water (April 2019):
https://www.nrdc.org/sites/default/files/media-uploads/nrdc_pfas_report.pdf
Georgetown University, “PFAS and Children’s Health” (May 2019):
https://georgetown.app.box.com/s/iu24h09wl085b9nk01ezfyadtkgjahcg

Total Number of Health Study Participants by Race/Ethnicity and Sex
Race	Female	Male	Total
White Not Hispanic	728	530	1258 (93.9%)
White Hispanic	8	7	15 (1.1%)
Asian	7	6	13 (1.0%)
Black or African American	11	3	14 (1.0%)
American Indian/Native Hawaiian/More than One Race	14	5	19 (1.4%)
Unknown/Not Reported	11	10	21 (1.6%)
Total	779 (58.1%)	561 (41.9%)	1340