Influence of major African dust intrusions on the 137Cs and 40K activities in the lower atmosphere at the Island of Tenerife

Abstract The influence of two intensive low-altitude atmospheric-dust intrusions on the activity levels of 137Cs and 40K as well as atmospheric particle matter (PM10) concentrations in the lower atmosphere of the Canary Islands are analysed here. These two events took place at the beginning of January 2002 and March 2004, respectively. 3D atmospheric back-trajectories indicated that the main source of dust material involved in the considered atmospheric intrusions came from NW Africa. A consequence of these dust intrusions was the major increase of PM10 concentrations in the lower atmosphere. Both episodes were characterised by having weekly averages of PM10 concentration surpassing 150 μg m−3, higher than the daily PM10 limit value established by the EC/1999/30 directive for PM10 from 2005. Similarly, during these two events, both 137Cs and 40K activities increased by a factor of 6 and 13 as well as 13 and 14, respectively, over the basal values calculated for each radionuclide and time period (0.59±0.02 and 0.88±0.07 μBq m−3 as well as 12±6 and 24±8 μBq m−3).

[1]  F. Livens,et al.  Distribution of radiocesium in the soil-plant systems of upland areas of Europe. , 1991, Health physics.

[2]  G. Kallos,et al.  Saharan dust contributions to PM10 and TSP levels in Southern and Eastern Spain , 2001 .

[3]  R. Arimoto,et al.  Color-related differences in the chemical composition of aerosol-laden filters , 2001 .

[4]  Mar Viana,et al.  Influence of African dust on the levels of atmospheric particulates in the Canary Islands air quality network , 2002 .

[5]  O. Llinâs,et al.  Saharan dust storms over the Canary islands during winter 1998 as depicted from the advanced very high-resolution radiometer , 2002 .

[6]  John D. Spengler,et al.  Particles in our air : concentrations and health effects , 1996 .

[7]  G. Gobbi,et al.  Altitude-resolved properties of a Saharan dust event over the Mediterranean , 2000 .

[8]  J. Hernández-Brito,et al.  Variability of dust inputs to the CANIGO zone , 2002 .

[9]  N. Middleton,et al.  Saharan dust storms: nature and consequences , 2001 .

[10]  Pinhas Alpert,et al.  Vertical distribution of Saharan dust based on 2.5-year model predictions , 2004 .

[11]  W. C. Graustein,et al.  Temporal variability of summer‐time ozone and aerosols in the free troposphere over the eastern North Atlantic , 1995 .

[12]  G. A. Nielsen,et al.  Cesium-137 in Montana soils. , 1989, Health physics.

[13]  S. Rodríguez,et al.  Monitoring of ozone in a marine environment in Tenerife (Canary Islands) , 2001 .

[14]  J. García,et al.  Caracterización de las masas de aire en la región subtropical , 2001 .