Jordi Dachs

Publications (101) View all

• Article: Vertical eddy diffusion as a key mechanism for removing perfluorooctanoic acid (PFOA) from the global surface oceans.

  Rainer Lohmann, Elena Jurado, Henk A Dijkstra, Jordi Dachs
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  ABSTRACT: Here we estimate the importance of vertical eddy diffusion in removing perfluorooctanoic acid (PFOA) from the surface Ocean and assess its importance as a global sink. Measured water column profiles of PFOA were reproduced by assuming that vertical eddy diffusion in a 3-layer ocean model is the sole cause for the transport of PFOA to depth. The global oceanic sink due to eddy diffusion for PFOA is high, with accumulated removal fluxes over the last 40 years of 660 t, with the Atlantic Ocean accounting for 70% of the global oceanic sink. The global oceans have removed 13% of all PFOA produced to a depth greater than 100 m via vertical eddy diffusion; an additional 4% has been removed via deep water formation. The top 100 m of the surface oceans store another 21% of all PFOA produced (∼1100 t).
  Environmental pollution (Barking, Essex: 1987) 05/2013; 179C:88-94. · 3.43 Impact Factor
• Article: Polychlorinated biphenyls, hexachlorocyclohexanes and hexachlorobenzene in seawater and phytoplankton from the Southern Ocean (Weddell, South Scotia, and Bellingshausen Seas).

  Cristóbal Galbán-Malagón, Sabino Del Vento, Naiara Berrojalbiz, M José Ojeda, Jordi Dachs
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  ABSTRACT: The Southern Ocean is one of the most pristine environments in the world but is nonetheless affected by inputs of persistent organic pollutants (POPs). In the present work we report the concentrations of hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and 26 polychlorinated biphenyl (PCBs) congeners in seawater and phytoplankton from samples obtained during three Antarctic cruises in 2005, 2008 and 2009. The levels of PCBs, HCHs and HCB are low in comparison to the few previous reports for this region and studies from other oceans. The long term decline of POP concentrations in the Southern Ocean seawater since early 1980 is consistent with half-lives of 3.4 and 5.7 years for HCHs and PCBs, respectively. There is a large variability of PCBs, HCHs and HCB concentrations in water and phytoplankton within the Bransfield Strait, South Scotia, Weddell and Bellingshausen Seas that masks the differences between the studied Seas. However, the variability of PCBs concentrations in phytoplankton is significantly correlated with phytoplankton biomass with lower concentrations in the most productive waters. This trend is more apparent for the more hydrophobic congeners consistent with the role of settling fluxes of organic matter decreasing the concentrations of hydrophobic POPs in productive waters. The present work reports the most extensive dataset on concentrations in seawater and phytoplankton for the Southern Ocean, and points out to the important biogeochemical drivers, such as settling and degradation, influencing the occurrence of POPs in the ocean.
  Environmental Science & Technology 04/2013; · 4.80 Impact Factor
• Article: Climatic and biogeochemical controls on the remobilization and reservoirs of persistent organic pollutants in Antarctica.

  Ana Cabrerizo, Jordi Dachs, Damia Barcelo, Kevin C Jones
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  ABSTRACT: After decades of primary emissions, reservoirs of persistent organic pollutants (POPs) have accumulated in soils and snow/ice in Polar Regions. These reservoirs can be remobilized due to decreasing primary emissions or due to climate change driven warmer conditions. Results from a sampling campaign carried out at Livingston Island (Antarctica) focusing on field measurements of air-soil exchange of POPs, show that there is a close coupling of the polychlorinated biphenyls (PCBs) in the atmosphere and snow/ice and soils, with a status close to air-surface equilibrium to a net volatilization from Antarctic reservoirs. This remobilization of PCBs is driven by changes in temperature and soil organic matter (SOM) content, and providing strong evidence that the current and future remobilization and sinks of POPs are a strong function of the close coupling of climate change and carbon cycling in the Antarctic region and not only due to warming. While an increase of 1 ºC in ambient temperature due to climate change would increase current Antarctic atmospheric inventories of PCBs by 21-45 %, a concurrent increase of 0.5 % SOM would counteract the influence of warming by reducing the POP fugacity in soil. A 1 ºC increase in Antarctic temperatures will induce an increase of the soil-vegetation organic carbon and associated POP pools by 25 %, becoming a net sink of POPs, and trapping up to 70 times more POPs than the amount remobilized to the atmosphere. Therefore, changes in soil biogeochemistry driven by perturbations of climate may increase to a larger degree the soil fugacity capacity than the decrease in air and soil fugacity capacity due to higher temperatures. Future research should focus in quantifying these remobilization fluxes and sinks for the Antarctic region.
  Environmental Science & Technology 04/2013; · 4.80 Impact Factor
• Source

  Available from: Rainer Lohmann

  Dataset: Gioia et al Atlantic PCBs EST'08SI

  Rosalinda Gioia, Luca Nizzetto, Rainer Lohmann, Jordi Dachs, Christian Temme, Kevin C Jones
• Source

  Available from: Rainer Lohmann

  Dataset: Nizzetto et al Ocean-dioxins EST'10SI

  Luca Nizzetto, Rainer Lohmann, Rosalinda Gioia, Jordi Dachs, Kevin C Jones