Target, Nontarget, and Suspect Screening and Temporal Trends of Per- and Polyfluoroalkyl Substances in Marine Mammals from the South China Sea

Abstract

Per- and polyfluoroalkyl substances (PFASs) have been manufactured and widely used for over 60 years. Currently, there are thousands of marketed PFASs, but only dozens of them are routinely monitored. This work involved target, nontarget, and suspect screening of PFASs in the liver of Indo-Pacific humpback dolphin (Sousa chinensis) and finless porpoise (Neophocaena phocaenoides), two resident marine mammals in the South China Sea, stranded between 2012 and 2018. Among the 21 target PFASs, perfluorooctane sulfonate and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA) predominated in the samples, accounting for 46 and 30% of the total PFASs, respectively. Significantly higher total target PFAS concentrations (p < 0.05) were found in dolphin liver samples [3.23 × 103 ± 2.63 × 103 ng/g dry weight (dw)] than in porpoise liver samples (2.63 × 103 ± 1.10 × 103 ng/g dw). Significant increasing temporal trends (p < 0.05) were found in the concentrations of two emerging PFASs, perfluoroethylcyclohexane sulfonate and 2,3,3,3-tetrafluoro-2-propanoate in porpoises, indicating increasing pollution by these emerging PFASs. Forty-four PFASs from 9 classes were additionally identified by nontarget and suspect screening, among which 15 compounds were reported for the first time in marine mammals. A primary risk assessment showed that the emerging PFAS 6:2 Cl-PFESA could have possible adverse effects in terms of reproductive injury potential on most of the investigated cetaceans.

Adverse Effects of Perfluorooctane Sulfonate on the Liver and Relevant Mechanisms

“…In 2006, PFOS was considered a priority substance under the EU Water Framework Directive (WFD), which restricts the production and use of PFOS throughout the European Union [ 28 ]. As a globally present environmental pollutant, PFOS was recognized as a persistent organic pollutant (POP) in 2009 and was listed in the Stockholm Convention to call for global production restrictions [ 29 ]. The Stockholm Convention has been ratified by 179 countries and measures have been introduced to restrict the production and use of PFOS [ 30 , 31 ], and PFOS has been phased out or banned in Canada [ 32 ], the United States [ 33 ], and the European Union [ 34 ].…”

A pilot study on extractable organofluorine and per- and polyfluoroalkyl substances (PFAS) in water from drinking water treatment plants around Taihu Lake, China: what is missed by target PFAS analysis?

“…Recent studies have identied EOF and different classes of emerging PFAS in various environmental media. [23][24][25][26][27][28][29] These techniques, however, were mostly applied to wastewater or biota samples. Studies focusing on drinking water are limited.…”

Bioaccumulation of per- and polyfluoroalkyl substance in fish from an urban river: Occurrence, patterns and investigation of potential ecological drivers

“…PFECHS presents a lower bioaccumulation factor (BAF) than PFOS in Carassius carassius (Wang et al, 2016) while the contrary is observed for 6:2 Cl-PFESA in zebrafish (Tu et al, 2019). The latter was reported in Greenland marine mammals (Gebbink et al, 2016), fish and marine organisms from China (Shi et al, 2015;Liu et al, 2017;Wang et al, 2021). HFPO-DA and ADONA have never been measured in aquatic biota and exhibit low bioaccumulation potential (Munoz et al, 2019).…”