Natural radionuclides distribution and environmental impacts of ferruginous sand-siltstone (raw material) and their manufactured Ahmer oxide used as wall paints

摘要

Commercially known Ahmer oxide paints are prepared from raw material mainly composed of red iron oxides (hematite) and iron oxyhydroxides. The raw material used in manufacturing of Ahmer oxide comes from some localities in southwest Sinai such as Abu Thor, Allouga, and El lehian. The adsorption of uranium and other radioelements on iron oxides could make the raw material (red iron oxides) and their products environmentally hazardous. The studied samples were subjected to radiometric analysis using NaI (Tl) gamma-ray spectrometer. The average activity concentration of U, Th, Ra, and K are 108.7, 458.8, 88.8, and 627.5Bqkg(-1), respectively in raw material and 136.4, 14.6, 58.3, and 95.9Bqkg(-1) in Ahmer oxide. High values of activity concentrations of U-238, Ra-226, and K-40 were recorded in Allouga and El lehian raw material. High radioactivities of Allouga and El lehian raw material are mainly attributed to the presence of torbernite, zircon, and monazite, in addition to adsorbed elemental uranium in Ahmer oxide. absorbed dose rate (D), annual effective dose equivalent, radium equivalent activity (Ra-eq), external hazard index (H-ex), and internal hazard index (H-in), as well as representative gamma index (I) were determined from the activity concentrations of Ra-226, Th-232, and K-40. Some of the studied samples do not satisfy the universal standards.