Spatial variability and Cesium-137 inventories in native forest

Abstract

With the nuclear fi ssion discovery and development of nuclear weapons in 1940s, artifi cial radioisotopes were introduced in the environment. This contamination is due to worldwide fallout by superfi cial nuclear tests realized from early 1950s to late 1970s by USA, former URSS, UK, France and China. One of theses radioisotopes that have been very studied is cesium-137. Cesium-137 has a half-life of 30.2 years and its biological behavior is similar to the potassium. The behavior in soil matrix, depth distribution, spatial variability and inventories values of cesium-137 has been determinate for several regions of the world. In Brazil, some research groups have worked on this subject, but there are few works published about theses properties of cesium-137. The aim of this paper was study the depth distribution, spatial variability, and inventory of cesium-137 in native forest. Two native forests (Mata 1 and Mata UEL) were sampling in region of Londrina, PR. The results shows that there is a spatial variability of 40% for Mata 1 and 42% for Mata UEL. The depth distribution of cesium-137 for two forests presented a exponential form, characteristic to undisturbed soil. Cesium-137 inventory determinate for Mata 1 was 358 Bq m −2 and for Mata UEL was 320 Bq m −2 .

Cs-137 distribution in forest floor and surface soil layers from two mountainous regions in Bulgaria

“…A probable explanation for the higher values and the relatively stronger contamination of D2 in these plots could be the influence of soil micro-and mesoflora and micro-and mesofauna, erosion processes (Andrello and Appoloni, 2004) or differences in the initial cesium contamination before Chernobyl due to other sources. If we observe the plots from Central Balkan the tendencies in cesium profiles in plots PB1 and PB2 are quite similar and the content of cesium decreases clearly in depth.…”

Establishing a sediment budget for a small agricultural catchment in southern Brazil, to support the development of effective sediment management strategies

“…This study used 137 Cs measurements to document soil erosion rates on well weathered tropical soils with sandy texture, at a latitude close to 20°S. Andrello and Appoloni (2004) also reported encouraging results when using 137 Cs to estimate rates of soil loss from more clayey subtropical soils in southern Brazil. Other studies reported by Bacchi et al (2003Bacchi et al ( , 2011 and Correchel et al (2006) have further confirmed the validity of the approach.…”

Measurements of the fallout flux of beryllium-7 and its variability in the soil

“…The average inventory of beryllium-7 was 211 Bq.m -2 with a spatial variability around of 23%. Andrello et al (2004b) presented spatial variability of cesium-137 in Londrina region as about 19%. Although, cesium-137 and beryllium-7 has different origin, the spatial variability represents the topographic, microtopographic and pluviometric variability of the region.…”