Measurement Of Activity Concentrations Of 226Ra, 232Th, 40K And 137Cs In Some Common Spices Consumed By Inhabitants In Accra Metropolis, Ghana

A spice is a vegetable substance of indigenous or exotic origin which is or has a hot, pigment taste, used to enhance taste of foods or to add to them the stimulant ingredients contained in them. Knowledge of radioactivity levels in human diet is of particular concern for the estimation of possible radiological hazards to human health. In this study, the radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs in some selected natural and processed spices of different brands in the Madina District of Accra Metropolis were determined and the ingested doses via food consumption were also assessed using gamma spectrometry. The average activity concentration of 226Ra, 232Th, 40K and 137Cs in the natural spices were 0.81 ± 0.2 BqKg-1, 0.98 ± 0.4 BqKg-1, 2.19 ± 0.9 BqKg-1 and 0.06 ± 0.01 BqKg-1 respectively. For the processed spices, the average activity concentration of 226Ra, 232Th, 40K and 137Cs were 0.18 ± 0.1 BqKg-1, 0.3 ± 0.1 BqKg-1, 1.3 ± 0.8 BqKg-1 and 0.02 ± 0.01 BqKg-1 respectively. The levels of 137Cs observed in the samples are within the range of ‘background’ concentrations. The estimated total annual effective dose received from 226Ra, 232Th and 137Cs, due to consumption of natural (fresh) and processed spices by the inhabitants of Madina in the Accra metropolis was 8.47 μSvy-1 and this is far below the average radiation dose of 0.29 mSvy-1 received per caput worldwide due to ingestion of natural radionuclides provided in UNSCEAR (2000) report. The results indicate insignificant radiological health hazard to the public due to the consumption of spices via foods.