English

W R Alharbi

doi:10.5897/ijps2016.4527

Abstract

Standards and guidelines are needed in the manufacture of household cooking dishes from clay, ceramic, and stone in Saudi Arabia. The radioactivity levels due to the presence of 40K, 232Th, and 226Ra in these materials were determined using gamma spectrometry equipped with high purity germanium (HPGe) detector. The activity concentrations of 226Ra ranged from 5.75 Bq kg−1 (Yemen stone sample) to 192.35 Bq kg−1 (China ceramic sample), those of 232Th ranged from 6.17 Bq kg−1 (Yemen stone sample) to 192.41 Bq kg−1 (China ceramic sample), and those of 40K ranged from 43.92 Bq kg−1 (clay sample manufactured in Bahrah, Saudi Arabia) to 656.96 Bq kg−1 (ceramic sample from Romania). Radiological indices were measured for all samples to ascertain the potential radiation health hazards. The average concentrations for 226Ra and 232Th and the absorbed dose rate (DR) in clay and ceramic dishes exceeded the permissible global limits, with the exception of clay samples from Makkah, Saudi Arabia. The 226Ra and 232Th concentrations in all cooking dishes manufactured from stone were within safety limits. However, most of the average values obtained for the activity concentration of 40K exceeded the recommended limit. The radium equivalent (Raeq), annual gonadal dose equivalent (AEDE), external hazard index (Hex), and gamma activity index (Iγ) were found to be below the internationally accepted safe limit, except in a ceramic sample imported from China. The sample also had an annual effective dose (AEDE) that slightly above unity. The concentrations of a total of 33 chemical elements were estimated by using an ARL QUANT’X energy-dispersive X-ray fluorescence spectrometer. In most samples, the elements’ concentrations exceeded the reference level values. In conclusion, care must be taken when using cooking dishes manufactured from clay, ceramic, and stone. Key words: Energy-dispersive X-ray fluorescence (EDXRF) analyzer, gamma spectrometry, radiation hazard, household cooking dishes, natural radioactivity.

Highlights

Exposure to the natural radionuclides 232Th, 226Ra, and 40K is undesirable
The aims of the present study were to analyze household cooking dishes manufactured from clay, ceramic, and stone (1) to determine the natural radionuclide levels using high-resolution gamma-ray (HPGe) spectrometry to evaluate the radiological risks and human exposure, and (2) to specify the concentrations of elements using Energy-dispersive X-ray fluorescence (EDXRF) spectrometry
The activity concentrations ranged between 14.52–62.71 Bq kg−1 in clay samples, 34.51– 170.88 Bq kg−1 in ceramic samples, and 4.12–22.83 Bq kg−1 in stone samples for 226Ra; 18.80–103.13 Bq kg−1 in clay samples, 46.79–164.17 Bq kg−1 in ceramic samples, and 4.85–28.31 Bq kg−1 in stone samples for 232Th; and 43.92–562.69 Bq kg−1 in clay samples, 132.53–656.96 Bq kg−1 in ceramic samples, and 73.57–523.10 Bq kg−1 in stone samples for 40K

Summary

Introduction

Exposure to the natural radionuclides 232Th, 226Ra, and 40K is undesirable. They cause an internal exposure risk resulting from radon and its decay products and an external exposure risk due to their gamma emission PACS: 89.60.-k. Chronic exposure to low doses of natural radioactivity can cause adverse health effects (Najam et al, 2015). Most household cooking dishes manufactured from clay, ceramic, and stone contain various concentrations of the natural radionuclides 226Ra, 232Th and 40K. The precise concentrations depend on the chemical composition of the material, which is related to the geological conditions and geophysical characteristics of their origin (Salas et al, 2006). The materials may contain radionuclides from both natural sources and waste products in addition to some minerals from certain slags. The present study centers on radiological baseline information of the Jeddah region in particular and Saudi Arabia in general

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Conclusion