Radiological and environmental hazards of granitic rocks in Wadi Faliq El Sahl and El Waar area, North Eastern Desert, Egypt.

Abstract

Chronologically, the main exposures in the study area include; tonalite, granodiorite, adamellite, Hammamat Sediments, monzogranite, syenogranite, rapakivi syenogranite, alkali feldspar granite and dykes. This work aims to determine the suitability of the granitic rocks for using as ornamental stones through detecting their radiological and ecological impacts. The studied samples were measured radiometrically by using Na-I detector for determination of ²²⁶Ra, ²³²Th and ⁴⁰K concentrations. External hazard indices (H_ex) in some samples are more than unity, also, the (Raeq) are higher than the exemption limits (370 Bq.kg^-1) exceeds the upper limit of exposure. The hierarchical cluster analysis (HCA) was applied to investigate the correlation between the radionuclides and the corresponding radiological hazard variables. Based on the statistical analysis, ²³²Th and ²²⁶Ra mainly contribute to the radioactive risk of the studied rocks. Regarding ecological indices, 42.1% of younger granite samples have Pollution load index values greater than 1, indicating deterioration, while the majority of older granite samples are lower than 1 suggesting perfection samples. Where, some sample from the older granitoids and younger granites have many radiological and ecological parameters greater than the recommended international limits, so, these samples should not be used in construction for safety reasons.