|Seasonal soil/snow-air exchange of semivolatile organic pollutants at a coastal arctic site (Tromsø, 69°N) |
Auteur(s): Paulo Casal, Castro-Jimenez J., Pizarro Mariana, Katsoyiannis Athanasios, Dachs Jordi
(Article) Publié: Science Of The Total Environment, vol. 636 p.1109 - 1116 (2018)
Ref HAL: hal-01785141,_v1
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Soils are amajor reservoir of semivolatile organic pollutants such as polychlorinated biphenyls (PCBs) and polycyclicaromatic hydrocarbons (PAHs), and exert a control on their atmospheric occurrence. We present here anassessment of the atmospheric occurrence and seasonality of soil/snow-air partitioning and exchange of PCBs,PAHs, hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs) in the arctic city Tromsø, northernNorway. The fugacities of the organic pollutants in soils and snow were determined using a soil fugacity samplerby equilibrating the air concentrations with those in the surface soil/snow. The concentrations in soils did notshowa significant seasonality. Conversely, the ambient air concentrations and the soil (or snow) fugacity showeda clear seasonality for PCBs, HCH, HCB and some PAHs, related to temperature. Fugacities in soil/snow were correlatedwith those in the ambient gas phase, suggesting a close seasonal air-soil/snow coupling. Generally, therewas a net deposition or close to equilibrium conditions during the winter, which contrasts with the net volatilizationobserved during the warmer periods. The chemicalswith lower octanol-air partition coefficients showed alarger tendency for being volatilized and thus remobilized from this coastal arctic environment. Conversely, themore hydrophobic compounds were close to air-soil/snow equilibrium or showed a net deposition.