Study finds PFCs (perfluorinated compounds) in nearby creeks one decade after use of fire-fighting foam at Pearson International Airport

Friday, April 15, 2011 9:38:00 AM

Research News

The following article has been published since the posted news article below on this research in Environmental Science and Technology journal.

ARTICLE: E. Awad, X. Zhang, S. Bhavsar, S. Petro, P.W. Crozier, E.J. Reiner, R. Fletcher, S.A. Tittlemier, and E. Braekevelt.  Long-Term Environmental Fate of Perfluorinated Compounds after Accidental Release at Toronto AirportEnvironmental Science and Technology 45 (19): 8081-8089. 

Available online for U of T faculty, staff and students at

By Satyendra Bhavsar

Researchers from the University of Toronto, Ontario Ministry of Environment, and Health Canada have detected concentrations of PFCs (perfluorinated compounds) in creeks one decade after the discharge of fire-fighting foam at Toronto Pearson International Airport.  Research team member Dr. Satyendra Bhavsar will present the findings of this research at the Centre for Environment's Research Day on Wed April 20, 2011.

In June 2000, a fire alarm at an airline hanger at the airport malfunctioned, releasing 22000 litres of fire-fighting foam into the storm sewers which then discharged into nearby Moore's Creek.  In August 2005, 48000 litres of fire-fighting foam was applied to extinguish the fire caused by Air France flight 358 overrunning the runway. The majority of the foam applied was washed into Moore's Creek by the diluting water and heavy precipitation.  

A research team, which included Dr. Satyendra Bhavsar, of the Ontario Ministry of Environment (OMOE) and Centre for Environment, and Dr. Eric Reiner, of OMOE and Department of Chemistry, examined spatial and long-term (9-year) temporal trends of PFCs in water, sediment, fish and fish liver collected in 2003, 2006 and 2009 from 10 locations stretching approximately 20 km in Etobicoke and Spring Creeks, into which Moore Creek flows.  Fire-fighting foam is of concern because it is a major source of PFCs in the form of perfluorooctane sulfonate (PFOS).   PFCs are a family of fluorine-containing chemicals with unique properties to make materials stain and stick resistant as well as surfactant (to enhance foaming). They have been used since the 1950s in a wide array of consumer products such as popcorn bags, non-stick frying pans, outdoor clothing, stain-resistant carpet, and certain firefighting foams.  Because these compounds are extremely resistant to breakdown, they are turning up in unexpected places around the world including the arctic region. Over the last decade, scientists have found that PFCs may cause long-lasting environmental contamination, including accumulation in humans.

Even a decade after the spill, sediment PFOS concentrations are still elevated in Spring Creek Pond which received the foam discharge from Moore's Creek, however, the major impact is relatively localized likely due to the storm water detention nature of the creek. Fish and fish liver PFOS concentrations at a Spring Creek location declined by about 70 and 85%, respectively, between 2003 and 2009.  Compared to PFOS measurements for fish liver collected from airport property 21 days after the spill, PFOS levels in Spring Creek Pond were 92-99% lower in 2009. Spring Creek flows into larger Etobicoke Creek where fish and water PFOS concentrations dropped further. PFOS in water at locations further downstream Etobicoke Creek have declined by more than 99.99% since the spill.  Overall, the impact of the spill on Etobicoke Creek quality is now minimal likely because the creek acts as a conduit.

Partial funding for the study was provided by Health Canada through the Chemical Management Plan Monitoring and Surveillance Fund. 

Satyendra Bhavsar is a Research Scientist at the Ontario Ministry of Environment and Adjunct Professor at the Centre for Environment.  For more information, please contact him at