2 research outputs found
Accumulation of Perfluoroalkylated Substances in Oceanic Plankton
The bioaccumulation of perfluoroalkylated
substances (PFASs) in
plankton has previously been evaluated only in freshwater and regional
seas, but not for the large oligotrophic global oceans. Plankton samples
from the tropical and subtropical Pacific, Atlantic and Indian Oceans
were collected during the <i>Malaspina 2010</i> circumnavigation
expedition, and analyzed for 14 ionizable PFASs, including perfluorooctanoate
(PFOA), perfluorooctanesulfonate (PFOS) and their respective linear
and branched isomers. PFOA and PFOS concentrations in plankton ranged
from 0.1 to 43 ng g<sub>dw</sub><sup>ā1</sup> and from 0.5
to 6.7 ng g<sub>dw</sub><sup>ā1</sup>, respectively. The relative
abundance of branched PFOA in the northern hemisphere was correlated
with distance to North America, consistent with the historical production
and coherent with previously reported patterns in seawater. The plankton
samples showing the highest PFOS concentrations also presented the
largest relative abundances of branched PFOS, suggesting a selective
cycling/fractionation of branched PFOS in the surface ocean mediated
by plankton. Bioaccumulation factors (BAFs) for plankton were calculated
for six PFASs, including short chain PFASs. PFASs Log BAFs (wet weight)
ranged from 2.6 Ā± 0.8 for perfluorohexanesulfonic acid (PFHxS),
to 4.4 Ā± 0.6 for perfluoroheptanoic acid (PFHpA). The vertical
transport of PFASs due to the settling of organic matter bound PFAS
(biological pump) was estimated from an organic matter settling fluxes
climatology and the PFAS concentrations in plankton. The global average
sinking fluxes were 0.8 Ā± 1.3 ng m<sup>ā2</sup>d<sup>ā1</sup> for PFOA, and 1.1 Ā± 2.1 ng m<sup>ā2</sup>d<sup>ā1</sup> for PFOS. The residence times of PFAS in the surface ocean, assuming
the biological pump as the unique sink, showed a wide range of variability,
from few years to millennia, depending on the sampling site and individual
compound. Further process-based studies are needed to constrain the
oceanic sink of PFAS
Deriving an optimal transcriptomic metric to establish protective and relevant transcriptomic points of departure for risk assessment application (ICEM 2022)
Presentation to the 13th International Conference on Environmental Mutagens (ICEM) August 2022Search for CCTE records in EPAās Science Inventory by typing in the title at this link.https://cfpub.epa.gov/si/si_public_search_results.cfm?advSearch=true&showCriteria=2&keyword=CCTE&TIMSType=&TIMSSubTypeID=&epaNumber=&ombCat=Any&dateBeginPublishedPresented=07/01/2017&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&DEID=&personName=&personID=&role=Any&journalName=&journalID=&publisherName=&publisherID=&sortBy=pubDate&count=25</p