Long-Term Environmental Fate of Perfluorinated Compounds after Accidental Release at Toronto Airport

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• 作者：Emily Awad ; Xianming Zhang ; Satyendra P. Bhavsar ; Steve Petro ; Patrick W. Crozier ; Eric J. Reiner ; Rachael Fletcher ; Sheryl A. Tittlemier ; Eric Braekevelt
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：October 1, 2011
• 年：2011
• 卷：45
• 期：19
• 页码：8081-8089
• 全文大小：929K
• 年卷期：v.45,no.19(October 1, 2011)
• ISSN：1520-5851

文摘

Perfluorooctane sulfonate (PFOS; a perfluorinated compound or PFC), its salts, and perfluorooctane sulfonyl fluoride have recently been listed in Annex B of the Stockholm Convention due to their widespread presence, persistence, and toxicity. Because of the persistent nature of PFCs, it is generally presumed that the impact of direct discharges of these chemicals on a receiving environment would be long-lasting. However, long-term environmental fate studies based on field measurements are rare. We 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 spanning 20 km in Etobicoke and Spring Creeks, where an accidental release of fire fighting foam containing PFOS from nearby Toronto International Airport occurred in 2000. Even a decade after the spill, sediment PFOS concentrations are still elevated in Spring Creek Pond which received the foam discharge; however, the major impact is relatively localized likely due to the stormwater management nature of the pond and the diluting effect of Etobicoke Creek. Fish and fish liver PFOS concentrations at a Spring Creek location downstream of Spring Creek Pond declined by about 70 and 85%, respectively, between 2003 and 2009. PFOS in water at locations further downstream in Etobicoke Creek have declined by >99.99% since the spill; however, the 2009 water and fish levels were 2鈥?0 times higher than upstream locations likely due to the long-term impact of the spill as well as urbanization. The decrease in the upstream PFOS concentrations likely reflects the reduction of PFOS sources due to phased out production by 3M and regulations on the use of PFOS in fire fighting foams. Field-based sediment/water distribution coefficients (K_D) and bioaccumulation factors (BAF) were calculated from environmental measurements. Log K_D values were 0.54鈥?.65 for perfluoroalkyl sulfonates (PFASs) and 1.00鈥?.85 for perfluorocarboxylates (PFCAs). Log BAF_fish ranged from 1.85 to 3.24 for PFASs and 0.88鈥?.47 for PFCAs, whereas log BAF_{fish liver} ranged from 2.1鈭?.3 for PFASs and 1.0鈥?.0 for PFCAs.