Bioaccumulation of perfluoroalkyl acids including the isomers of perfluorooctane sulfonate in carp (Cyprinus carpio) in a sediment/water microcosm

Abstract

Carp (Cyprinus carpio) were exposed to perfluoroalkyl acids (PFAAs) including perfluorooctane sulfonate (PFOS) isomers in an artificially contaminated sediment/water microcosm. The uptake constant of PFAAs increased with increasing carbon chain length, whereas the elimination coefficient displayed the opposite trend, suggesting that carbon chain length plays an important role in the bioaccumulation of PFAAs. When the contribution of suspended particulate matter was taken into account, the bioaccumulation factors (BAFs) became lower (3.61-600 L/kg) compared with BAFs derived from only considering the absorption from free PFAAs in water (3.85-97000 L/kg). The results indicate that suspended particulate matter in water constitutes an important source of exposure for aquatic organisms to long-chain PFAAs. Linear (n-)PFOS was preferentially accumulated compared with branched isomers in carp. Among the branched isomers, 1m-PFOS displayed the greatest bioaccumulation, whereas m -PFOS had the lowest. Linear PFOS displayed greater partitioning ability from blood to other tissues over branched PFOS (br-PFOS) isomers, leading to a relatively lower n-PFOS proportion in blood. In summary, suspended particulate matter made a contribution to the accumulation of long-chain PFAAs in aquatic organisms, and n-PFOS was preferentially accumulated compared with br-PFOS isomers. Environ Toxicol Chem 2016;35:3005-3013. © 2016 SETAC.

Dietary Uptake and Depuration Kinetics of Perfluorooctane Sulfonate, Perfluorooctanoic Acid, and Hexafluoropropylene Oxide Dimer Acid (GenX) in a Benthic Fish

“…Other laboratory studies have reported similar findings (Sharpe et al ; Chen et al ); field studies with polar bears (Greaves and Letcher ) and fish and invertebrates (Asher et al ) have observed differences in percentage composition of linear‐ and branched‐PFOS within specific tissues. The reasons for these discrepancies are not well described, but they are thought to be due to isomer‐specific differences in pharmacokinetics, biotransformation, elimination capacity between species, and potential differences in the sources of dietary PFOS in each group (Sharpe et al ; Fang et al ). Organ‐specific differences in PFOS isomer elimination rates have also been observed in rainbow trout, with the gills and kidneys having been identified to preferentially eliminate branched‐PFOS (Sharpe et al ).…”

“…One of the major production methods used to create PFOS is electrochemical fluorination, which results in the formation of a mixture of PFOS isomers that usually has a fairly consistent ratio of linear (70%) and branched (30%) isomers (Sharpe et al 2010;Fang et al 2016). However, measured PFOS isomer ratios in terrestrial and aquatic wildlife sometimes deviate from this, exhibiting either enriched (>70%) or reduced (<70%) linear-PFOS ratios (Sharpe et al 2010;Greaves and Letcher 2013).…”

“…Furthermore, differences in tissue distribution, total body burden, and elimination rates also occur depending on the predominant route of absorption into the bloodstream (i.e., via the gills [aqueous] or via the gut wall [dietary]; Martin et al 2003aMartin et al , 2003bGoeritz et al 2013;Falk et al 2015). For example, PFOS biological half-lives (whole fish) in dietary studies are in the range of 11 to 17 d (Martin et al 2003b;Goeritz et al 2013;Falk et al 2015), whereas in aqueous exposure studies the values are 29 to 35 d (Sakurai et al 2013;Fang et al 2016). Fish that are exposed via the dietary route tend to have the highest PFAS concentrations in the liver, followed by blood and kidney (Goeritz et al 2013;Falk et al 2015), whereas fish that are exposed via the aqueous route tend to have the highest concentrations in blood, and then kidney and liver (Martin et al 2003a).…”

“…The partitioning and sorption characteristics of PFOS and PFOA have also been shown to be affected by organic content and salinity, indicating that benthic food webs in estuarine environments may be at increased risk of exposure (relative to freshwater environments; Hong et al 2015). However, most laboratoryderived data on PFAS accumulation kinetics in fish are based on freshwater model species such as zebrafish, carp, and rainbow trout (Martin et al 2003b;Keiter et al 2012;Fang et al 2016). To address this knowledge gap, we focused on examining PFAS bioaccumulation in a benthic, sediment-associated estuarine fish species.…”

Prenatal exposure and transplacental transfer of perfluoroalkyl substance isomers in participants from the upper and lower reaches of the Yangtze River

“…Besides, in plasma of pregnant women from south central Vietnam (81%) (Rylander et al, 2009), maternal whole blood (81.6%) and cord whole blood (79.7%) of pregnant women from Hubei Province, China (Zhao et al, 2017), women's serum (84.6%) from Fujian Province, China (Wang et al, 2018a), and cord serum (75.2%) of infants from Guangzhou, China , n-PFOS% also exceeded 70%. It has been revealed that n-PFOS accumulated preferentially (Fang et al, 2016) but eliminated slower (Chen et al, 2015) than br-PFOS in carp, which might lead to the enrichment of n-PFOS. In human bodies, br-PFOS showed higher transplacental transfer efficiencies (Beesoon and Martin, 2015) and excretion efficiencies (Zhang et al, 2013b) than n-PFOS, which may account for the high n-PFOS% in the maternal serum of the present study.…”