Version 2 2016-06-28, 13:23Version 2 2016-06-28, 13:23
Version 1 2016-02-29, 11:55Version 1 2016-02-29, 11:55
journal contribution
posted on 2016-02-18, 00:00authored byJames C.W. Lam, Jinling Lyu, Karen
Y. Kwok, Paul K.S. Lam
Perfluorinated sulfonic acids (PFSAs) and perfluorinated carboxylic
acids (PFCAs), as well as the replacement for the phase-out C8 PFSAs
were determined in the liver samples of Indo-Pacific humpback dolphins
(Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) from the South China Sea between
2002 and 2014. Levels of total perfluoroalkyl substances (PFASs) in
samples ranged from 136–15,300 and 30.5–2,720 ng/g dw
for dolphin and porpoise, respectively. Significant increasing trends
of several individual PFCAs and perfluorobutane sulfonate (PFBS) were
found in cetacean samples from 2002 to 2014, whereas no significant
temporal trends of ∑PFASs appeared over the sampling period.
This pattern may be attributed to the increasing usage of PFCAs and
C4-based PFSAs following the restriction/voluntary withdrawal of the
production and use of perfluorooctane sulfonate (PFOS) related products.
In addition, significantly increasing temporal shifting trends of
PFOS to PFBS were observed in the dolphin liver samples. This pattern
may be attributed to the substitution of PFOS by its alternative,
PFBS. The highest levels of PFOS were observed in the liver samples
of dolphin as compared with other marine mammal studies published
since 2006, indicating high contamination of PFAS in the South China
region. An assessment of relatively high concentrations of C8-based
PFASs in the liver samples of cetaceans predicted that concentrations
of PFOS would be expected to affect some proportion of the cetacean
populations studied, based on the toxicity thresholds derived.