title: Oceanic biogeochemical controls on global dynamics of persistent organic pollutants.
abstract: Understanding and quantifying the global dynamics and sinks of persistent organic pollutants (POPs) is important to assess their environmental impact and fate. Air-surface exchange processes, where temperature plays a central role in controlling volatilization and deposition, are of key importance in controlling global POP dynamics. The present study is an assessment of the role of oceanic biogeochemical processes, notably phytoplankton uptake and vertical fluxes of particles, on the global dynamics of POPs. Field measurements of atmospheric polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and furans (PCDFs) are combined with remote sensing estimations of oceanic temperature, wind speed, and chlorophyll, to model the interactions between air-water exchange, phytoplankton uptake, and export of organic matter and POPs out of the mixed surface ocean layer. Deposition is enhanced in the mid-high latitudes and is driven by sinking marine particulate matter, rather than by a cold condensation effect. However, the relative contribution of the biological pump is a function of the physical-chemical properties of POPs. It is concluded that oceanic biogeochemical processes play a critical role in controlling the global dynamics and the ultimate sink of POPs.
authors.affiliation: Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona, Barcelona, Catalunya, Spain. jdmqam@cid.csic.es
authors.forename: Jordi
authors.initials: J
authors.lastname: Dachs
authors.forename: Rainer
authors.initials: R
authors.lastname: Lohmann
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Ockenden
authors.forename: Laurence
authors.initials: L
authors.lastname: Méjanelle
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Eisenreich
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Jones
mesh_terms: D001572:Benzofurans / Q000032:analysis* / Q000378:metabolism; D000072338:Dibenzofurans, Polychlorinated; D009792:Oceans and Seas; D009930:Organic Chemicals / Q000032:analysis; D010839:Phytoplankton; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D013696:Temperature; D014835:Volatilization; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D014919:Wind
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D009930:Organic Chemicals; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls