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Monthly Variations in Perfluorinated Compound Concentrations in Groundwater
Megan Steele1, Converse Griffith2, Christin Duran3
1UES, Force Health Branch, United States Air Force School of Aerospace Medicine, 711 Human Performance Wing, Dayton, OH 45431, USA. megan.steele.1.ctr@us.af.mil.
Toxics
|September 19, 2018
Summary
Temporal variations in perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) at a military site in Alaska and Pease Air Force Base showed no significant predictive value for contaminant concentrations, despite new EPA advisory levels.
Area of Science:
- Environmental Science
- Environmental Chemistry
- Toxicology
Background:
- Poly- and perfluorinated compounds (PFAS) are persistent environmental contaminants due to large-scale manufacturing.
- US EPA lowered drinking water advisory levels for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) to 70 ng/L.
- Small temporal variations in PFOS and PFOA concentrations can determine compliance with new advisory limits.
Purpose of the Study:
- To evaluate monthly temporal variations in PFOS and PFOA concentrations at a contaminated military site in Alaska and former Pease Air Force Base.
- To assess the predictive value of collection date on contaminant concentrations.
- To collect and evaluate data on other PFAS, including perfluorobutanesulfonic acid (PFBS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA).
Main Methods:
- Collected and analyzed newly sampled data from an Alaskan military site and historical data from Pease Air Force Base.
- Evaluated monthly variations in PFOS and PFOA concentrations.
- Assessed statistical significance and R² values to determine temporal trends and predictive value.
Main Results:
- No statistically significant temporal trend was observed for PFOS and PFOA in the Alaska data.
- Statistically significant temporal trends were observed at Pease Air Force Base, but low R² values indicated limited predictive value of collection date.
- Average concentrations of PFBS, PFHxS, PFHpA, and PFNA were evaluated for both sites.
Conclusions:
- Monthly variations in PFOS and PFOA concentrations at the studied sites do not reliably predict contaminant levels.
- Collection date has minimal value in predicting PFOS and PFOA concentrations at these locations.
- Further investigation into other PFAS compounds was conducted.
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