Seasonal soil/snow-air exchange of semivolatile organic pollutants at a coastal arctic site (Tromsø, 69°N)

• Published in: Science of The Total Environment
• Main Authors: Casal, Paulo, Castro-Jiménez, Javier, Pizarro, Mariana, Katsoyiannis, Athanasios, Dachs, Jordi
• Other Authors: Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas Madrid (CSIC), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Norsk Institutt for Luftforskning (NILU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: PAH; PCB; Arctic; Organic pollutants; Air-soil exchange; envir; geo; Norway; Tromsø; Northern Norway
• Online Access: https://doi.org/10.1016/j.scitotenv.2018.04.330; https://hal.archives-ouvertes.fr/hal-01785141/file/Casal%20et%20al_2018_STOTEN_HAL.pdf; https://hal.archives-ouvertes.fr/hal-01785141

International audience Soils are a major reservoir of semivolatile organic pollutants such as polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), and exert a control on their atmospheric occurrence. We present here an assessment 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, northern Norway. The fugacities of the organic pollutants in soils and snow were determined using a soil fugacity sampler by equilibrating the air concentrations with those in the surface soil/snow. The concentrations in soils did not show a significant seasonality. Conversely, the ambient air concentrations and the soil (or snow) fugacity showed a clear seasonality for PCBs, HCH, HCB and some PAHs, related to temperature. Fugacities in soil/snow were correlated with those in the ambient gas phase, suggesting a close seasonal air-soil/snow coupling. Generally, there was a net deposition or close to equilibrium conditions during the winter, which contrasts with the net volatilization observed during the warmer periods. The chemicals with lower octanol-air partition coefficients showed a larger tendency for being volatilized and thus remobilized from this coastal arctic environment. Conversely, the more hydrophobic compounds were close to air-soil/snow equilibrium or showed a net deposition.