PFAS Exposure Assessment: Lubbock County, Texas

Background

The Air Force used aqueous film forming foam (AFFF) containing PFAS at the former Reese Air Force Base (AFB). In time, these PFAS seeped into the groundwater.

The Air Force discontinued use of AFFF following base closure in 1997. The Base has since been converted into a business and research park, the Reese Technology Center.

Why the Lubbock County site was selected

When selecting exposure assessment (EA) sites, ATSDR considered the extent of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) contamination in drinking water supplies. It also considered:

• The duration that exposure may have occurred.
• The number of potentially affected residents.

As early as the 1970s, the Base likely used AFFF containing PFAS for its firefighter training. Over time, these PFAS entered the ground. PFAS then moved into the groundwater to offsite locations and affected nearby private wells.

PFAS were first detected in private wells downgradient of the Base in September 2017. To reduce levels of PFAS in drinking water, the Air Force installed whole-house treatment systems in affected homes and supplied bottled water.

ATSDR has determined that all households with private wells tested by the Air Force have a drinking water supply that meets or is below the EPA's 2016 health advisory (HA). It also meets or is below state public health guidelines for PFAS in drinking water. Households that receive bottled water and/or have water filtration systems installed by the Air Force should continue to use these alternative sources of water.

Sampling area

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Timeline

How testing was conducted

ATSDR invited all Lubbock County residents living near the Reese Technology Center to participate in the PFAS exposure assessment. To be eligible to participate, household residents must have:

• Used a private well for drinking water in the affected area for at least one year before September 30, 2019.
• Been older than three years at the time of sample collection.
• Not been anemic or had a bleeding disorder that would prevent giving a blood sample.

Residents served by the City of Lubbock Water Department were not included in the exposure assessment.

Results

In November 2020, CDC/ATSDR released a summary of the biological and environmental test results. The full report was released May 11, 2022. A summary of the report's findings is below.

In February and March 2020, ATSDR collected samples and other information from participants. ATSDR analyzed data from:

• 214 people, including
  • 190 adults.
  • 24 children.
• 96 households.
• Questionnaires completed by all participants.
• Blood and urine samples provided by most participants.
• Samples of tap water and dust from some homes.

ATSDR sent individual results to each participant in November 2020.

Other testing

Only two PFAS (PFBA and PFHxS) were detected in urine and at low concentrations.

All tap water samples collected from private wells during the EA in 2020 met the EPA's HA and the Texas Commission on Environmental Quality's (TCEQ's) protective concentration levels (PCLs) for specific PFAS in drinking water.

PFAS contamination in house dust was similar to that reported in other studies.

Key takeaways

Levels of PFHxS and PFOA in the blood of Lubbock County EA participants were 4.2- and 1.2-times national levels, respectively. Other PFAS were not higher than the national levels or were detected too infrequently to compare to national averages. In addition:

• Elevated blood levels may be linked with past drinking water contamination.
• Some demographic and lifestyle characteristics were linked with higher PFAS blood levels.

All tap water samples collected from Lubbock County private wells during the EA in 2020 met the EPA's HA and TCEQ's PCLs for specific PFAS in drinking water.

What these results mean

Advisory

Based on PFAS drinking water results from private wells tested by the Air Force in Lubbock County, households that receive bottled water and/or have water filtration systems installed by the Air Force should continue to use them.

This EA provides evidence that residents' past exposures to PFAS in private drinking water wells have impacted their levels of some PFAS. These PFAS are eliminated from the body over a long period of time. This allowed ATSDR to measure PFAS even though exposures through drinking water were mitigated, or lowered, years ago.

The exposure contribution from PFAS in private well water at the Lubbock County EA site has been mitigated in most private wells. There are still actions community members and other stakeholders can take to further reduce exposures to PFAS and protect public health.

Future direction

What was learned about PFAS levels in blood

Of the seven PFAS tested at the Lubbock County EA site, five PFAS were detected in more than 77% of the blood samples collected:

• PFHxS
• PFOS
• PFOA
• PFNA
• PFDA

Since 1999, the National Health and Nutrition Examination Survey (NHANES) has measured PFAS levels in blood in the U.S. population. PFAS levels are shown to be age dependent and tend to increase with age in part due to longer periods of exposure.

ATSDR adjusted blood levels of EA participants at the Lubbock County EA site for age to enable meaningful comparison to the NHANES dataset. After adjusting for age, the same two PFAS were still higher than national levels, but slightly less so. Age-adjusted averages are more representative of the Lubbock County EA site community.

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Information to protect our communities

Two PFAS (PFHxS and PFOA) were detected in Lubbock private wells as early as 2017. It is likely that contamination began earlier, but no data are available before 2017.

Between 2017 and 2019, actions taken by the Air Force reduced PFAS levels in the drinking water of most private wells in the affected area below EPA HA for PFOS and PFOA and TCEQ's PCLs for multiple PFAS.

Due to the long half-lives of PFHxS and PFOA in the human body, past drinking water exposures may have contributed to the EA participants' blood levels. Typically, residents who had elevated blood levels of PFHxS also had elevated levels of PFOA. This suggests a common source of exposure, such as contaminated groundwater that supplies drinking water to private wells in the area. Other sources of exposure were not measured but could have contributed to PFAS concentrations measured in blood of the EA participants.

There was 1 year and 4 months between the end of exposure via contaminated drinking water and the collection of the EA blood samples. There are long half-lives of PFHxS and PFOA in the human body. Therefore, past drinking water exposures may have contributed to blood levels in participants.

Statistical findings

ATSDR used statistical models to study relationships between various demographic and lifestyle characteristics of the tested residents. The models showed that, in general:

PFHxS, PFOS, and PFOA levels in blood were higher in older participants.

Males had higher blood levels of PFOS and PFOA than females.

The difference in PFOA levels was larger in younger people.

Residents who had carpeting in any room had higher PFHxS and PFOA levels.

Residents reporting contact with soil a few times per month or more had higher PFHxS blood levels.

Women who gave birth had lower PFHxS levels than women who had not.

Women who breastfed had 27% lower blood levels of PFOS than women who did not breastfeed.

Exposure in children

Children who were breastfed had higher blood levels of PFOS.

Infants born to mothers exposed to PFAS can be exposed in utero and while breastfeeding. Current science still shows that the benefits of breastfeeding outweigh the risks for infants exposed to PFAS in breast milk.

Because of the small sample size, results for children should be interpreted with caution. The final aggregate report on all exposure assessment sites will include a more detailed analysis.

What else can be done

Community members

The bottled and/or drinking water from filtration systems installed by the Air Force currently meet all federal and state guidelines for PFAS.

Households should continue to use alternative/treated water if they receive bottled water and/or have water filtration systems installed by the Air Force. Residents should coordinate monitoring and maintenance of the water filtration systems with the Air Force.

All treatment systems to remove PFAS from private well water in Lubbock County should be maintained appropriately to ensure that PFAS concentrations remain below EPA's HA and the TCEQ's PCLs for specific PFAS in drinking water.

Private well owners living in the area affected by PFAS should consider having their wells tested for PFAS if testing has not been conducted before. For more information contact: Air Force Installation and Mission Support Center (AFIMSC) at AFIMSC.PA.workflow@us.af.mil or call Paul Carrol, AFCEC Program Manager, at (806) 885-010.

Verify a water filter's ability to reduce PFOA and PFOS. NSF International, the global health organization, developed a test method to verify a water filter's ability to reduce PFOA and PFOS to below the HA levels set by the EPA.

To find NSF International-approved devices, go to the bottom of the Search for NSF Certified Drinking Water Treatment Units page. Then check the boxes for PFOA Reduction and PFOS Reduction.

All private well owners should follow public health best practices for testing, operation, and maintenance of their wells.

Discuss any health concerns or symptoms with your health care provider. Share results of PFAS blood testing with your health care provider and make them aware of ATSDR resources for clinicians.

Follow the advice of your health care provider and the recommendations for checkups, vaccinations, prenatal care, and health screening tests.

ATSDR does not recommend retesting for PFAS in EA participants. At this time, ATSDR does not have plans to conduct additional blood testing for PFAS. The biological half-lives of many of the PFAS measured in people's blood are long. PFHxS, in particular, has one of the longest half-lives. Some estimates range in the decades. This means that PFAS blood levels are not expected to change significantly in the near-term, even if exposure stops. Additionally, it is unclear what an individual's PFAS test results mean in terms of possible health effects.

For the general population, blood tests for PFAS are most useful when they are part of a scientific investigation like the EA. Test results tell you how much of each PFAS is in your blood, but it is unclear what the results mean in terms of possible health effects. In addition, blood testing for PFAS is not a routine test offered by most doctors or health departments. Talk to your health care provider and make them aware of ATSDR resources for clinicians.

Nursing mothers should continue breastfeeding. Based on current science, the benefits of breastfeeding outweigh the risks for infants exposed to PFAS in breast milk.

Eliminate or decrease potential exposure to PFAS in consumer products such as stain-resistant products and food packaging materials when possible.

Pay attention to advisories about food consumption, such as local fish advisories.

Follow the advice of your child's health care provider and the recommendations for well child checkups, vaccinations, and health screening tests. Refer to information to help identify those vaccinations and tests.

For more information on environmental exposures and children's health, contact the Pediatric Environmental Health Specialty Units, a nationwide network of experts in reproductive and children's environmental health.

The Air Force

With permission from homeowners, test private wells in the affected area that have not been previously tested.

Continue to work on developing a cooperative agreement with the City of Lubbock to build water lines to affected homes within the city limits.

Continue to provide whole-house water treatment system installation, monitoring, and maintenance. When the Air Force installs a system, continue to monitor it on a routine basis to ensure proper operation.

Resources

• PFAS Exposure Assessment, Lubbock County, TX: Report (4/11/2022)
• PFAS Exposure Assessment, Lubbock County, TX: Report Appendix (4/11/2022)
• PFAS Exposure Assessment, Lubbock County, TX: Report Consumer Summary (4/11/2022)
• PFAS Exposure Assessment, Lubbock County, TX: Fact Sheet
• PFAS Exposure Assessment, Lubbock County, TX: Community-Level Summary Results Fact Sheet