Measurement of Natural Radionuclides Concentration in Libyan Food Spices Samples
Awareness of radioactivity concentrations in human diet are of high concern for the estimation of radiological hazards to human health. However, not many studies of radioactivity in food have been conducted in Libya. In this study the activity concentration of naturally occurring radionuclide levels in a set of 30 samples of food spices was determined. Samples were collected from one of the biggest local markets in Tripoli, Libya; Souliman Khater. All samples were prepared and analyzed at the department of Nuclear Engineering, University of Tripoli to establish activity concentrations associated with the 238U and 232Th natural decay chains and the 40K.
The activity concentrations of 238U, 232Th and 40K based on their weighted average values across samples were (1.92±0.72), (2.70±0.61) and (529.50±0.04) Bq kg-1, respectively, Achieved results showed that the activity concentration was within the acceptable level for 238U, 232Th while, the 40K level was high in samples of Cardamom and Hot red pepper imported from India, Nalta jute from Tunis, Turmeric, Mixed Turmeric from Libya, and they were significantly higher than as reported by the UNSCEAR (2000).
The highest activity concentration of 238U, 232Th was recorded for Cinnamon from India, which were 16.32±1.64 and 16.30±1.65 Bq kg-1 respectively. The range of 40K was found to be between 66.41±5.11 Bq kg-1 for White pepper and 1284.33±88.32 Bq kg-1for Cardamom. The annual effective dose equivalent in μSv y-1 ranged between 9.52 and 72.57 μSv y-1while the world average annual effective dose equivalent (AEDE) from outdoor or indoor terrestrial gamma radiation was 290 μSv y-1.
The results of this study were slightly higher than those achieved in many other studies conducted in Egypt, Iraq, and other countries. High concentration of potassium was recorded in many samples. Therefore, it is important to concern about the daily potassium intake by looking at the combination of food and potassium concentration in it, such as by increasing consumption of food spices.