Perfluorinated phosphonic acids in Canadian surface waters and wastewater treatment plant effluent: Discovery of a new class of perfluorinated acids

Abstract

The environmental prevalence of a new class of perfluorinated acids, the perfluorinated phosphonic acids (PFPAs), was determined in Canadian surface waters and wastewater treatment plant (WWTP) effluent. For quality control and comparison, the C8- to C11-perfluorinated carboxylic acids and perfluorooctane sulfonic acid were included in the analysis. Water samples were extracted using weak anion-exchange solid-phase extraction cartridges. Perfluorinated phosphonic acids were observed in 80% of surface water samples and in six of the seven WWTP effluent samples. The C8-PFPA was observed at concentrations ranging from 88 +/- 33 to 3400 +/- 900 pg/L in surface waters and from 760 +/- 270 to 2500 +/- 320 pg/L in WWTP effluent. To our knowledge, this is the first observation of PFPAs in the environment. Given their structural similarities with perfluorinated carboxylic and sulfonic acids, PFPAs are expected to be persistent. The observation of PFPAs in the majority of samples analyzed here suggests they are prevalent environmental contaminants and should be considered in future environmental monitoring campaigns to better understand the total burden of fluorinated materials in the environment.

Uptake and elimination of perfluorinated phosphonic acids in the rat

“…Because human activities are often the major source of material to WWTPs, the presence of contaminants in a WWTP can be used as a proxy for human use and exposure. The observation here of di-PFPAs in WWTP sludge, and the previous observation of mono-PFPAs in a WWTP effluent sample [12], demonstrate the likelihood of human exposure to these chemicals.…”

“…The mono-PFPAs have been observed in surface waters and WWTP effluent [12]. The first observation of di-PFPAs in environmental media is reported here, with the observation of the C6/C6 and C6/C8 di-PFPAs in the NIST WWTP sludge SRM 2781.…”

“…As described previously [12], the mono-PFPAs fragment exclusively to PO , which presumably results from the loss of one fluorinated tail and the addition of a fluorine to the phosphonate moiety. The mechanism responsible for this product ion is not known; however, it is likely similar to that responsible for the common fragment ion FSO À 3 (99 m/z) monitored for the PFSAs.…”

“…Both the mono-and di-substituted PFPAs (mono-PFPAs and di-PFPAs) were listed as high production volume chemicals in 1998 and 2002 with 10-500 k pounds (4.5-230 k kg) of each produced annually [11]. The monoPFPAs have been detected in the environment, with measurable concentrations observed in 80% of Canadian surface water samples analyzed (concentrations of the C8 mono-PFPA ranged from 88 AE 33 to 3,400 AE 900 pg/L) and six out of seven wastewater treatment plant (WWTP) effluent samples (concentrations of the C8 mono-PFPA ranged from 760 AE 270 to 2,500 AE 320 pg/L) [12]. Wastewater treatment plant contamination can be used as a proxy for human chemical use and exposure.…”

“…We were also interested in the analysis of paired whole blood and plasma samples to evaluate whether human plasma and sera samples are an appropriate proxy for the contamination present in whole blood. Although both the mono-PFPAs and di-PFPAs are used commercially, only mono-PFPA contamination was investigated in surface water and WWTP effluent samples [12]. To confirm the presence of the di-PFPAs in similar media, we analyzed a WWTP sludge standard reference material (SRM) from the National Institute for Standards and Technology (NIST) for six di-PFPA congeners (Table 1).…”