Discovery of a Novel Polyfluoroalkyl Benzenesulfonic Acid around Oilfields in Northern China

The existence of more than 3000 per- and polyfluoroalkyl substances (PFASs) on the global market has prompted the identification and hazard characterization of hitherto unknown PFASs. In the present study, a novel PFAS, sodium <i>p</i>-perfluorous nonenoxybenzenesulfonate (OBS), was identified using Orbitrap MS/MS in water samples around a suspected application area, Daqing Oilfield, China. The peak OBS concentration was 3.2 × 10<sup>3</sup> ng/L in a sample taken near the oil well with the longest production history in Daqing. The concentrations of OBS and contribution to the sum of PFASs in surface waters displayed considerable variation among the three sampling areas (mean levels at 6.9, 50, and 5.6 × 10<sup>2</sup> ng/L with mean percentages at 9.8%, 45%, and 69% in the background, new and old oilfield areas respectively) confirming that the density of oil wells and the oil production history are important factors influencing OBS contamination in the studied areas. A preliminary assessment of acute toxicity and environmental fate indicates that OBS exhibits similar toxicity and environmental persistence to perfluorooctanesulfonic acid (PFOS). The widespread occurrence of OBS, in conjunction with its potential hazard properties, underscores the need to further study on the bioaccumulation and potential for human exposure.