Fallout radionuclides as indicators of soil degradation in Latin American and Caribbean countries

LOHAIZA, F.; JURI AYUB, J.; VELASCO, R. H.; DERCON, G.

Soils Newsletter

INTERNATIONAL ATOMIC ENERGY AGENCY

Lugar: Vienna; Año: 2011 vol. 33 p. 16 - 20

1011-2650

As part of the RLA/5/051 project activities, the Grupo de Estudios Ambientales (GEA, IMASL, Universidad Nacional de San Luis/Conicet), in Argentina, identified the best strategy for using FRNs (in particular 7Be) in this part of the region. The study site was located in central Argentina (S 33°9´; W 66°18´); 15 km north of San Luis City (Province of San Luis). In this region the average annual temperature is 17ºC, while in summer (December?March), the mean temperature is 23ºC. Annual rainfall ranges from 600 mm to 800 mm. The 7Be activity concentrations in rainwater ranged from 0.7 ± 0.3 Bq l-1 to 3.2 ± 0.7 Bq l-1, with a mean value of 1.7 Bq l-1 (sd = 0.53 Bq l-1). The magnitude of precipitation ranged from 1 to 59 mm. Taking into account the 7Be content in rainwater and the regional precipitation regime, the 7Be atmospheric depositional flux was estimated at 1140 ± 120 Bq m-2a-1. As a consequence of this rainwater activity concentration was independent of rainfall, with a linear relationship found between the activity density deposition and the rainfall.