# Evaluation of Natural Radioactivity and Radiological Hazards Associated With Earthen Building Materials Commonly Used in Bureti, Kericho County, Kenya

## TL;DR

This study assesses natural radioactivity in earthen building materials in Bureti, Kenya, finding elevated radionuclide levels that pose health risks.

## Contribution

The paper provides new radiological hazard data for earthen building materials in Bureti, Kenya, highlighting risks exceeding international safety standards.

## Key findings

- Measured radionuclide concentrations in earthen materials were three times higher than global averages.
- Indoor absorbed dose rates and annual effective dose rates exceeded international reference values.
- Internal hazard indices and cancer risk values were significantly above global standards.

## Abstract

This study investigates the radioactivity due to naturally occurring radionuclides in earthen building materials commonly used in Bureti, Kenya. Building materials derived from the earth’s crust often contain naturally occurring radionuclides, which may pose radiological health risks. In regions such as Bureti, Kenya, where earthen materials are widely used for construction, assessing their radioactivity is essential for public safety. Thallium‐activated sodium iodide detector was used to measure the activity concentrations of 40K, 226Ra, and 232Th in the said materials and average values of 106 ± 61, 104 ± 8, and 82 ± 6 Bqkg−¹, respectively, which are about three times higher than global averages were recorded. Radiological hazard parameters including radium equivalent activity, absorbed dose rate, annual effective dose rate (AEDRIN), hazard indices, excess lifetime cancer risk (ELCR), annual gonadal effective dose (AGED), and activity utilization index (AUI) were calculated to evaluate potential exposure risks. Indoor absorbed dose rates (mean 270.76 ± 18.84 nGyh−¹) and AEDRIN (mean 1.00 ± 0.07 mSv y−¹) exceeded international reference values, with 73.3% of samples surpassing the European Commission limit of 1 mSv y−¹. While external hazard indices (mean 0.83) were largely within safe limits, internal hazard (mean 1.10) and gamma indices (mean 1.11) exceeded permissible thresholds. ELCR (mean 3.49 × 10−3), AGED (mean 997.27 μSv y−1), and AUI (mean 2.04) values were significantly above global standards, indicating elevated long‐term health risks. The findings demonstrate that Bureti earthen building materials contain enhanced radionuclide concentrations, rendering them radiologically unsafe under international guidelines. Continuous monitoring and regulatory oversight are crucial to mitigate radiation exposure and safeguard residents’ health.