Depth Profile of 137Cs Fallout in Soil in Cameron Highlands

Zaini Hamzah,Che Yasmin Amirudin,Ahmad Saat

doi:10.11113/mjfas.v8n1.118

Zaini Hamzah, Che Yasmin Amirudin + Show 1 more

Open Access

https://doi.org/10.11113/mjfas.v8n1.118

Copy DOI

Abstract

137Cs is one of the important man-made radionuclide introduced into the environment through nuclear weapons testing and nuclear accidents. In Cameron Highlands meaningful activity concentration of 137Cs radionuclide has been measured. The present study embarked on the determination of 137Cs activity concentration in soils of the sloping area. This would enable the distribution profile in the soil be investigated. Soil profile samples were collected by using scrapper plate in the sloping area which covers top, centre and bottom of the hills and a core in the forest for comparison purpose. The scrapper is 40 cm long and able to obtain slice of 2 cm interval of soil with diameter of 15.2 cm. Soil samples were oven dried, ground, sieved, homogenize and seal properly into a plastic container. The 137Cs activity concentration was measured by using low background coaxial hyper pure germanium detector gamma spectrometer based on 137Cs 661.66 KeV gamma ray. Results showed there were trend of low activity on the top of the hill and subsequently increases downhill. In all location, two trends of profiles were observed starting from the depth of 0 cm to 18 cm and 18 cm to 30 cm which indicating the presence of two sources of 137Cs. The 137Cs activity concentrations range detected at top location was from 0.05 Bq/kg to 1.53 Bq/kg, centre was 0.22 Bq/kg to 2.11 Bq/kg, bottom was from 0.00 Bq/kg to 2.03 Bg/kg and forest was 0.00 Bq/kg to 0.96 Bq/kg. The basic parameters of the soil such as pH (top; 3.72, centre; 4.26, bottom; 4.02), density (top; 1.45 g/m3, centre; 1.41 g/m3 , bottom; 1.59 g/m3 ) and organic matter content (top; 17.08 %, centre; 16.75 %, bottom; 20.32 %) also being tested. These results show that the relative activity concentration of 137Cs at the top is lowest, while at the bottom is highest, representing the presence of downward transport. However, identical pattern of profiles were observed at the three points of the slopes.

Highlights

137Cs is one of the important man-made radionuclide introduced into the environment through nuclear weapons testing and nuclear accidents
Bomb-derived 137Cs has been used to document soil degradation in different environment of has been seen by geomorphorlogists and soil scientist in determination of patterns and rate of soil redistribution [7]. 137Cs contamination is positively correlated with altitude, so northern and southern hemispheres
Based on the field measurement, there is a similarity of the depth distribution of bomb-derived 137Cs with Chernobyl-derived 137Cs for the main soil type [2]

Summary

INTRODUCTION

Exchange sites on the surface soil particles and remains in this state almost in all terrestrial environments [6]. Due to its relatively long physical half-live (30.2 years) and profile in a hill of agricultural area and forest in Cameron bioavailability, 137Cs is one of the great concern fission Highlands, Pahang products [3] It is has a long residence in the environment and is a hazard if found in sufficient concentrations [4]. The specific study area was in agricultural area where it is the second major land used after forestry with 16.4 percent of the total land area [9] It is one of the areas with high altitude in Malaysia ; the chance to receive fallout of 137Cs radionuclide is relatively high.

Sampling and Sample Preparation

Depth Distribution Profile of 137Cs

CONCLUSION