Toxicity of fluorinated and fluorine-free foams: potential implications on firefighter renal health.

Details

• Personal Author:
  Beitel S ; Burgess J ; Calkins M ; Coyle J ; Rojanasakul L ; Ruyle B ; Slitt A ; Stueckle, Todd A. ; Sunderland E
• Description:
  Military Specification aqueous film forming foams (AFFF)-typically comprised of complex mixtures of per- and polyfluorinated alkyl substances (PFAS), solvents, stabilizers, and wetting agents-are used to extinguish liquid fuel fires. Health concerns from use of AFFF have emerged because of studies documenting elevated PFAS serum levels in some firefighter populations, including firefighters with known exposure to AFFF, compared to the public. PFAS exposure is associated with increased risk for chronic conditions, including decreased kidney function and cancer. With a scheduled phase out of AFFF containing PFAS in the US by 2024, synthetic fluorine-free foams (SFFF) are an attractive replacement; however, little is known about their potential occupational health risks. This project's objective was to conduct rapid high-throughput screening of cultured human kidney cells to identify potential adverse outcome pathways associated with renal injury. Commercial AFFF and SFFF were analyzed for total fluorine using combustion ion chromatography. Human renal proximal tubule epithelial cells with over-expressed organic anion transporter 1 (RPTEC-OAT1) were exposed to serial dilutions of 5 AFFF (A-E), 5 SFFF (F-J), and 7 frequently detected PFAS in cell culture media for 6 - 24 hours. High-throughput screening for cytotoxicity, mitochondrial polarization, and intracellular reactive oxygen species (ROS) levels of exposed cells was performed by multiplex fluorescence and image analysis using a high content imaging platform. All tested AFFF resulted in acute cytotoxicity (IC50) at concentrations ranging from 109-262 ppm (v:v) while SFFF F exhibited the greatest toxicity at IC50 = 3.3 ppm (v:v). Toxicity in SFFF G - J ranged from 33 to 278 ppm. Perfluorooctane sulfonate (PFOS) and perfluorooctanoate acid displayed IC50 at 74 and 200 ppm (m:v), respectively, while all C4 to C6 PFAS were not acutely cytotoxic. A majority of AFFF, perfluorohexanesulfonic acid (PHFxS), and PFOS caused decreases in mitochondrial depolarization at sub-toxic doses. SFFF F enhanced intracellular ROS dose-dependently 6 and 24 hours post-exposure while the other treatments did not differ from unexposed controls. In summary, AFFF showed similar kidney cell cytotoxicity to C8 PFAS-exposed cells suggesting PFAS within AFFF contributes to kidney cell cytotoxicity. Effects of SFFF varied substantially, signifying additional need for future hazard characterization. [Description provided by NIOSH]
• Subjects:
  Cytotoxins Firefighters Fuel Oils Occupational Health Safety Toxicology
• Keywords:
  Toxicology; Fuels; Fire extinguishing agents; Fire suppression; Fire fighters; Health effects; Renal toxicity; Kidney toxins; Cellular effects; Cytotoxicity; Per- and polyfluoroalkyl substances; PFAS
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Arizona ; Massachusetts ; Ohio ; OSHA Region 1 ; OSHA Region 3 ; OSHA Region 5 ; OSHA Region 9 ; Rhode Island ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; DFSE - Division of Field Studies and Engineering
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  66
• Volume:
  186
• NIOSHTIC Number:
  nn:20064919
• Citation:
  Toxicologist 2022 Mar; 186(S1):66
• CAS Registry Number:
  Fluorine (CAS RN 7782-41-4)
• Federal Fiscal Year:
  2022
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 61st Annual Meeting & ToxExpo, March 27-31, 2022, San Diego, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:bff0ba70ea043fa222370de0c7cff64633332205ac10fb23349f87061063c8ee5d348dcdba97bb5445994dde36a703bd022c5f80481e47f2f1271d7cb4f6b629
• Download URL:
  https://stacks.cdc.gov/view/cdc/249274/cdc_249274_DS1.pdf
• File Type:
  [PDF - 252.67 KB ]