Environmental Investigation of Natural Radioactivity and Health Risk Assessment in Basaltic Volcanic Building...

Area of Science:

• Geochemistry
• Environmental Science
• Radiological Science

Background:

• Basaltic volcanic rocks are widely used as construction materials.
• Their natural radioactivity poses potential environmental and health risks.
• Understanding the radiological properties of basalt is crucial for safe application.

Purpose of the Study:

• To conduct an integrated geological and environmental radiological analysis of basaltic rocks from the Northern Eastern Desert of Egypt.
• To assess the suitability of these basaltic rocks as construction materials based on their radioactivity.
• To identify the primary radionuclides contributing to radiological risk.

Main Methods:

• Sample collection of 35 representative basaltic rocks.
• Analysis using HPGe high-resolution gamma-ray spectrometry.
• Petrographic analysis to identify mineral composition.
• Calculation of radiological indices and statistical analyses (correlation, clustering, PCA).

Main Results:

• Petrographic analysis revealed plagioclase, olivine, and pyroxene as main minerals, with secondary alteration products.
• Average activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K were 53 ± 20, 54 ± 14, and 1178 ± 269 Bq kg^-1, respectively, exceeding global reference limits.
• Radiological indices indicated acceptable overall hazard, but some samples neared or exceeded indoor hazard standards.
• ²³⁸U and ⁴⁰K were identified as the major contributors to radiological risk.

Conclusions:

• The studied basaltic rocks exhibit elevated natural radioactivity, particularly from ²³⁸U and ⁴⁰K.
• While overall radiological hazard indices are acceptable, caution is advised for using these basalts in indoor construction due to potential risks.
• This study provides a baseline for environmental monitoring and highlights the need for careful consideration of basaltic materials in built environments.