Concentrations, distribution, and persistence of perfluoroalkylates in sludge-applied soils near Decatur, Alabama, USA.
Sludges generated at a wastewater treatment plant (WWTP) in Decatur, Alabama have been applied to agricultural fields for more than a decade. Waste-stream sources to this WWTP during this period included industries that work with fluorotelomer compounds, and sludges from this facility have been found to be elevated in perfluoroalkylates (PFAs). With this knowledge, the U.S. Environmental Protection Agency collected soil samples from sludge-applied fields as well as nearby "background" fields for PFA analysis. Samples from the sludge-applied fields had PFAs at much higher concentrations than in the background fields; generally the highest concentrations were perfluorodecanoic acid (≤ 990 ng/g), perfluorododecanoic acid (≤ 530 ng/g), perfluorooctanoic acid (≤ 320 ng/g), and perfluorooctane sulfonate (≤ 410 ng/g). Contrasts in PFA concentration between surface and deeper soil samples tended to be more pronounced in long-chain congeners than shorter chains, perhaps reflecting relatively lower environmental mobilities for longer chains. Several PFAs were correlated with secondary fluorotelomer alcohols (sec-FTOHs) suggesting that PFAs are being formed by degradation of sec-FTOHs. Calculated PFA disappearance half-lives for C6 through C11 alkylates ranged from about 1 to 3 years and increase with increasing chain-length, again perhaps reflecting lower mobility of the longer-chained compounds.
Ecosystems Research Division, National Exposure Research Laboratory, Office of Research and Development, Environmental Protection Agency, Athens, Georgia 30605, USA. Washington.john@epa.gov
John W
JW
Washington
Hoon
H
Yoo
J Jackson
JJ
Ellington
Thomas M
TM
Jenkins
E Laurence
EL
Libelo
D000383:Agriculture; D000407:Alabama; D000478:Alkylation; D002210:Caprylates / Q000032:analysis / Q000737:chemistry; D003652:Decanoic Acids / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring; D005466:Fluorocarbons / Q000032:analysis* / Q000737:chemistry; D006207:Half-Life; D007850:Lauric Acids / Q000032:analysis / Q000737:chemistry; D008956:Models, Chemical; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D014865:Waste Disposal, Fluid
D002210:Caprylates; D003652:Decanoic Acids; D005466:Fluorocarbons; D007850:Lauric Acids; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; C036567:perfluorodecanoic acid; C023036:perfluorooctanoic acid; C522391:perfluorododecanoic acid