Investigation of Building Materials' Radioactivity in a Historical Building-A Case Study

Area of Science:

• Environmental Science
• Radiological Health
• Building Materials Science

Background:

• Historical buildings undergoing reconstruction may contain natural radionuclides in their materials.
• Assessing radiation exposure from building materials is crucial for public health and safety.

Purpose of the Study:

• To evaluate potential radiological hazards from natural radionuclides in building materials of a historical structure.
• To assess indoor and outdoor radiation risks for future housing occupants.

Main Methods:

• Measured activity concentrations of natural radionuclides (226Ra, 232Th, 40K) in stone and brick samples.
• Calculated radiological indices (gamma index) and estimated annual effective doses.
• Compared measured values and calculated doses against international safety limits and recommendations.

Main Results:

• Average total activity concentration (594.0 Bq/kg) exceeded the global average.
• Gamma indices (0.26-0.60) were below the restricted limit (Iγ = 1).
• Average annual effective dose (0.53 mSv/y) was within the limit (1 mSv/y) but contributed to a higher-than-recommended gamma dose excess.

Conclusions:

• The building materials, particularly bricks, exhibited higher natural radiation levels than typical.
• Despite elevated levels, the estimated radiation doses do not pose a significant health risk.
• The reconstructed building is deemed suitable for residential use following reconstruction.