Impact of Saharan dust events on radionuclide levels in Monaco air and in the water column of the northwest Mediterranean Sea

Authors
Pham, Mai Khanh; Chamizo, Elena; Mas Balbuena, José Luis; Miquel, Juan Carlos; Martín de Nascimento, Jacobo; Osvath, Iolanda; Povinec, Pavel P.
Publication Year
2017
Language
English
Format
article
Status
Published version
Description
Characterization of atmospheric aerosols collected in Monaco (2004–2008) and in sediment traps at 200 m and 1000 m water depths at the DYFAMED (Dynamics of Atmospheric Fluxes in the Mediterranean Sea) station (2004) was carried out to improve our understanding of the impact of Saharan dust on ground-level air and on the water column. Activity concentrations of natural (210Pb, 210Po, uranium and radium isotopes) and anthropogenic (137Cs, 239Pu, 240Pu, and 239+240Pu) radionuclides and their isotopic ratios confirmed a Saharan impact on the investigated samples. In association with a large particulate matter deposition event in Monaco on 20 February 2004, the 137Cs (∼40 Bq kg−1) and 239+240Pu (∼1 Bq kg−1) activities were almost a factor of two higher than other Saharan deposition dust events. This single-day particle flux represented 72% of the annual atmospheric deposition in Monaco. The annual deposition of Saharan dust on the sea was 232–407 mBq m−2 for 137Cs and 6.8–9.8 mBq m−2 for 239+240Pu and contributed significantly (28–37% for 137Cs and 34–45% for 239+240Pu) to the total annual atmospheric input to the northwest Mediterranean Sea. The 137Cs/239+240Pu activity ratios in dust samples collected during different Saharan dust events confirmed their global fallout origin or mixing with local re-suspended soil particles. In the sediment trap samples the 137Cs activity varied by a factor of two, while the 239+240Pu activity was constant, confirming the different behaviors of Cs (dissolved) and Pu (particle reactive) in the water column. The 137Cs and 239+240Pu activities of sinking particles during the period of the highest mass flux collected in 20 February 2004 at the 200 m and 1000 m water depths represented about 10% and 15%, respectively, of annual deposition from Saharan dust events.
Fil: Pham, Mai Khanh. IAEA-Environment Laboratories; Mónaco
Fil: Chamizo, Elena. Universidad de Sevilla; España
Fil: Mas Balbuena, José Luis. Universidad de Sevilla; España
Fil: Miquel, Juan Carlos. IAEA-Environment Laboratories; Mónaco
Fil: Martín de Nascimento, Jacobo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina
Fil: Osvath, Iolanda. IAEA-Environment Laboratories; Mónaco
Fil: Povinec, Pavel P.. Comenius University; Eslovaquia
Subject
AIR MONITORING
DYFAMED
NORTHWEST MEDITERRANEAN
RADIONUCLIDES
SAHARAN DUST
SEDIMENT TRAP
Meteorología y Ciencias Atmosféricas
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/64048