Pharmaceuticals account for a significant proportion of the extractable organic fluorine in municipal wastewater treatment plant sludge

Abstract

Fluorine mass balance studies have shown that monomeric per- and polyfluoroalkyl substances (PFAS) with perfluoroalkyl chain lengths of ~5-14 carbon atoms (i.e., “conventional” PFAS) account for a fraction (~2%) of the extractable organic fluorine (EOF) in municipal wastewater treatment plant (WWTP) sludge. The identity of the remaining EOF has thus far been unclear, but may be partly attributable to fluorine-containing pharmaceuticals and pesticides used throughout society. To test this hypothesis, we applied high resolution mass spectrometry-based suspect screening to samples of municipal WWTP sludge which had been previously subjected to a fluorine mass balance. Sixteen pharmaceutical substances (including transformation products [TPs]), one pesticide, and thirteen conventional PFAS were confirmed at confidence levels 1-4, with concentrations ranging from 0.07-155 ng/g dw. Notably, eight pharmaceutical substances did not meet the OECD definition of PFAS. When converted to fluorine equivalents, the newly detected organofluorine substances increased the percentage of known EOF from ~2% to ~27%, of which ~22% was attributed to pharmaceutical- and pesticide substances, with the greatest contributions from a ticagrelor TP (4.0%), ezetimibe (3.9%), and bicalutamide (3.5%). These data highlight the importance of considering both unconventional- and non-PFAS organofluorine substances in addition to conventional PFAS when closing the organofluorine mass balance in WWTP sludge.

Taking a look at the surface: μ-XRF mapping and fluorine K-edge μ-XANES spectroscopy of organofluorinated compounds in environmental samples and consumer products

“…Very recent work showed the signicance of uorinated drugs and pesticides in the uorine mass balance of sewage sludge samples. 42 Moreover, the spectra of spots P4 and P5 exhibit additional XANES features as observed in the spectra of 4-FBA, tolyluanid or Na-TFMS (see Fig. S19-S23 †).…”

Fluorine Mass Balance, including Total Fluorine, Extractable Organic Fluorine, Oxidizable Precursors, and Target Per- and Polyfluoroalkyl Substances, in Pooled Human Serum from the Tromsø Population in 1986, 2007, and 2015

“…62 While we are not aware of studies investigating the contribution of pharmaceuticals and pesticides toward the EOF mass balance in human blood, a recent study determined that ∼22% of the EOF in wastewater treatment plant sludge (which mirrors societal use of chemicals) was attributable to these substances, many of which do not contain fluoroalkyl functionalities. 64 Mean age was not a significant predictor of UEOF, but women had higher UEOF values than men (Table S8, Figure 4). As for target PFAS, the evaluation of differences in concentrations between men and women at each time-point was limited by statistical power, and significant differences were observed only in 2007 (Table S9).…”

Identifying Unknown Fluorine-Containing Compounds in Environmental Samples Using 19F NMR and Spectral Database Matching

“…As aromatic CF 3 groups are increasingly common in both agricultural and pharmaceutical chemicals, − 19 F NMR has become a powerful tool for the identification of these compounds in many samples. Recent literature indicates that a significant fraction of total extractable organic fluorine arises from the aromatic CF 3 substituent in pharmaceutical and agricultural compounds . The exact chemical shift of the Ar-CF 3 fluorines is heavily dependent on the position and type of other substituents within the aromatic system.…”

“…Recent literature indicates that a significant fraction of total extractable organic fluorine arises from the aromatic CF 3 substituent in pharmaceutical and agricultural compounds. 32 The exact chemical shift of the Ar-CF 3 fluorines is heavily dependent on the position and type of other substituents within the aromatic system. Trifluoromethoxy substituents on aromatic systems are deshielded due to the proximity of the trifluoromethyl group to the oxygen nucleus.…”