International Journal of Environmental Monitoring and Protection
Abstract
Natural radioactivity is wide spread in the earth's environment and it exists in various geological formations in soils, rocks,
plants, water and air. The growing worldwide interest in natural radiation exposure has led to extensive surveys in many
countries. The study was carried out to evaluate alpha radioactivity concentration in ten various brands of rice was collected
from Iraqi market. Alpha sensitive CR-39 plastic track detectors commonly known as "Solid State Nuclear Track Detectors"
were used to measure the radium and radon exhalation rate. The alpha particles emitted from the radon causes the radiation
damaged tracks. The Chemical etching in NaOH at 70°C for about 8 h was done to reveal these latent tracks, which were then
scanned and counted by an optical microscope of suitable magnification. The radon concentration and radium concentration in
various brands of rice vary from 1.252 ×103 Bq/m3 to 23.110×103 Bq/m3 with an average 6.940×103 Bq/m3 and from 0.149
Bq/kg to 2.757 Bq/kg with an average 0.775 Bq/kg, respectively. The radon exhalation rates varied from 1.129 mBq/kg.h to
20.838 mBq/kg.h with an average 5.861 mBq/kg.h and surface exhalation rates from 20.268 mBq/m2.h to 374.051 mBq/m2.h
with an average 105.212 mBq/m2.h. Radium concentrations in the samples of this study were at higher concentrations of
radium in grain products in the United States, China, Japan, Poland and Romania it were within the ranges of concentrations
of radium in grain products in Germany and the United Kingdom. Excellent correlation has been observed between radium
concentration and the radon exhalation rate in different rice samples.
ليث أحمد نجم | Laith Ahmed Najam | 11479