Aerosol deposition and origin in French mountains estimated with soil inventories of 210Pb and artificial radionuclides

Abstract

Radionuclide inventories were measured in soils from different French mountainous areas: Chaıˆne des Puys (Massif Central), Eastern Corsica, Jura, Montagne Noire, Savoie, Vosges and Rhine Valley. 210 Pb soil inventories were used to estimate long-term (475 yr) deposition of submicron aerosols. Whereas 210 Pb total deposition is explained partly by wet deposition, as demonstrated by increase of 210 Pb inventory with annual rainfall; a part of 210 Pb in the soils of higher altitude is caused by orographic depositions. Using measurements of radionuclides coming from nuclear aerial weapon tests ( 137 Cs and Pu isotopes), we were able to estimate the origin of aerosols deposited in high-altitude sites and to confirm the importance of occult deposition and feeder-seeder mechanism. Using a simple mass balance model, we estimate that occult deposition and feeder-seeder mechanisms account to more than 50% of total deposition of 210 Pb and associated submicron aerosols in French altitude sites.

Stable (206Pb, 207Pb, 208Pb) and radioactive (210Pb) lead isotopes in 1year of growth of Sphagnum moss from four ombrotrophic bogs in southern Germany: Geochemical significance and environmental implications

“…There is a strong and well established correlation between 210 Pb deposition to terrestrial ecosystems and amount of precipitation (Hill, 1960;Winkler and Rosner, 2000;Garcia-Orellana et al, 2006;Likuku, 2006). Given the linear regression of 210 Pb deposition versus precipitation for a large number of studies in Europe (Garcia-Orellana et al, 2006;Le Roux et al, 2008), total 210 Pb deposition to the four bogs studied should be much greater than at Neuherberg.…”

“…The supply of atmospheric 210 Pb to the soils and plants of terrestrial ecosystems, therefore, is very strongly correlated with the amount of precipitation (Hill, 1960;Winkler and Rosner, 2000;Garcia-Orellana et al, 2006;Likuku, 2006). However, occult deposition might be important at high altitude sites (Graustein and Turekian, 1989;Le Roux et al, 2008). Dry deposition onto plant surfaces can also be important (Bondietti et al, 1984), with woodland canopies enhancing the interception of 210 Pb, relative to grassland soils .…”

Deposition of artificial radionuclides from atmospheric Nuclear Weapon Tests estimated by soil inventories in French areas low-impacted by Chernobyl

“…5b, ESI 3]. This can be due to snow accumulation or atmospheric processes such as orographic deposition (Le Roux et al, 2008), which are not well taken into account in the AURELHY method to spatialize annual precipitations. These different hypotheses should be further investigated, for example in Pyrenees mountain range.…”

“…The aims of this research study were 1) to validate rain-deposition estimation of global fallout and check if there were also artificial radionuclides from Chernobyl accident; 2) to investigate into details global fallout in mountain areas where deposition of atmospheric pollutants (POP, heavy metals) is known to be higher due to occult and orographic deposition (Graustein and Turekian, 1989;Roe, 2005;Daly and Wania, 2005;Le Roux et al, 2008).…”

Variabilité spatiale des activités en césium-137 dans les sols d’un bassin versant du massif du Jura : étendue et principales sources de variation

“…Les zones les plus contaminées sont les zones humides qui présentent en moyenne des activités nettement supérieures aux trois autres types d'occupation du sol. En résumé, l'on constate que dans une région de moyenne montagne dont on sait qu'elle a été impactée à la fois par les retombées des essais nucléaires et par celles de l'accident de Tchernobyl (Badot et al, 1984 ;Le Roux et al, 2008) …”