TY - JOUR
T1 - Vertical transport and sinks of perfluoroalkyl substances in the global open ocean
AU - González-Gaya, Belén
AU - Casal, Paulo
AU - Jurado, Elena
AU - Dachs, Jordi
AU - Jiménez, Begoña
N1 - Funding Information:
This work was funded by the Spanish Ministry of Economy and Competitiveness (Circumnavigation Expedition Malaspina 2010: Global Change and Biodiversity Exploration of the Global Ocean. CSD2008-00077). The BBVA Foundation is acknowledged for its economic support of the PhD fellowship granted to B. G.-G. The CSIC and MAGRAMA are also acknowledged for additional financial support. P. C. acknowledges a FPI fellowship from the Economy and Competitiveness Ministry. The officers, crew and UTM personnel of the R/V Hesperides are acknowledged for their great support during the field work. We thank Professor David Siegel, from the Earth Research Institute, University of California, for the organic carbon global climatology. Ana Gomes, Prof. Josep M. Gasol (ICM-CSIC), and the rest of the people on board measuring bacterial abundances are also acknowledged. Dr Bieito Fernandez Castro and Dr Beatriz Mourino (Vigo University) are specially acknowledged for their comments on eddy diffusive fluxes calculations.
Funding Information:
This work was funded by the Spanish Ministry of Economy and Competitiveness (Circumnavigation Expedition Malaspina 2010: Global Change and Biodiversity Exploration of the Global Ocean. CSD2008-00077). The BBVA Foundation is acknowledged for its economic support of the PhD fellowship granted to B. G.-G. The CSIC and MAGRAMA are also acknowledged for additional nancial support. P. C. acknowledges a FPI fellowship from the Economy and Competitiveness Ministry. The officers, crew and UTM personnel of the R/V Hespérides are acknowledged for their great support during the eld work. We thank Professor David Siegel, from the Earth Research Institute, University of California, for the organic carbon global climatology. Ana Gomes, Prof. Josep M. Gasol (ICM-CSIC), and the rest of the people on board measuring bacterial abundances are also acknowledged. Dr Bieito Fernández Castro and Dr Beatriz Mouriño (Vigo University) are specially acknowledged for their comments on eddy diffusive uxes calculations.
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019/11
Y1 - 2019/11
N2 - The ubiquitous occurrence of perfluoroalkyl substances (PFAS) in the open ocean has been previously documented, but their vertical transport and oceanic sinks have not been comprehensively characterized and quantified at the oceanic scale. During the Malaspina 2010 circumnavigation expedition, 21 PFAS were measured at the surface and at the deep chlorophyll maximum (DCM) in the Atlantic, Indian and Pacific oceans. In this work, we report an extended data set of PFAS dissolved phase concentrations at the DCM. ∑PFAS at the DCM varied from 130 to 11000 pg L-1, with a global average value of 500 pg L-1. Perfluorooctanesulfonate (PFOS) abundance contributed 39% of ∑PFAS, followed by perfluorodecanoate (PFDA, 17%), and perfluorohexanoate (PFHxA, 12%). The relative contribution of the remaining compounds was below 10%, with perfluorooctanoate (PFOA) contributing only 5% to PFAS measured at the DCM. Estimates of vertical diffusivity, derived from microstructure turbulence observations in the upper (<300 m) water column, allowed the derivation of PFAS eddy diffusive fluxes from concurrent field measurements of eddy diffusivity and PFAS concentrations. The PFAS concentrations at the DCM predicted from an eddy diffusivity model were lower than field-measured concentrations, suggesting a relevant role of other vertical transport mechanisms. Settling fluxes of organic matter bound PFAS (biological pump), oceanic circulation and potential, yet un-reported, biological transformations are discussed.
AB - The ubiquitous occurrence of perfluoroalkyl substances (PFAS) in the open ocean has been previously documented, but their vertical transport and oceanic sinks have not been comprehensively characterized and quantified at the oceanic scale. During the Malaspina 2010 circumnavigation expedition, 21 PFAS were measured at the surface and at the deep chlorophyll maximum (DCM) in the Atlantic, Indian and Pacific oceans. In this work, we report an extended data set of PFAS dissolved phase concentrations at the DCM. ∑PFAS at the DCM varied from 130 to 11000 pg L-1, with a global average value of 500 pg L-1. Perfluorooctanesulfonate (PFOS) abundance contributed 39% of ∑PFAS, followed by perfluorodecanoate (PFDA, 17%), and perfluorohexanoate (PFHxA, 12%). The relative contribution of the remaining compounds was below 10%, with perfluorooctanoate (PFOA) contributing only 5% to PFAS measured at the DCM. Estimates of vertical diffusivity, derived from microstructure turbulence observations in the upper (<300 m) water column, allowed the derivation of PFAS eddy diffusive fluxes from concurrent field measurements of eddy diffusivity and PFAS concentrations. The PFAS concentrations at the DCM predicted from an eddy diffusivity model were lower than field-measured concentrations, suggesting a relevant role of other vertical transport mechanisms. Settling fluxes of organic matter bound PFAS (biological pump), oceanic circulation and potential, yet un-reported, biological transformations are discussed.
UR - http://www.scopus.com/inward/record.url?scp=85074964054&partnerID=8YFLogxK
U2 - 10.1039/c9em00266a
DO - 10.1039/c9em00266a
M3 - Article
C2 - 31393489
AN - SCOPUS:85074964054
SN - 2050-7887
VL - 21
SP - 1957
EP - 1969
JO - Environmental Science: Processes and Impacts
JF - Environmental Science: Processes and Impacts
IS - 11
ER -
