RADON in a high karst area of Montenegro - A case study

Area of Science:

• Environmental Science
• Geology
• Public Health

Background:

• National radon surveys in Montenegro identified a rural, high-karst region with exceptionally high indoor radon concentrations.
• Annual average radon concentrations (C_Rn,ind) in this region ranged significantly, indicating a potential public health concern.

Purpose of the Study:

• To investigate the causes of elevated indoor radon concentrations in a high-karst area of Montenegro.
• To assess the influence of geogenic factors and building characteristics on indoor radon levels.

Main Methods:

• Measurements included soil properties (humidity, conductivity, pH), radionuclide activity (²²⁶Ra, ²³⁸U, ²³⁵U, ²³²Th, ⁴⁰K), soil gas radon concentration (c), soil permeability (k), and gamma dose rate.
• Geogenic Radon Potential (GRP) and Radon Index (RI) were calculated. Building characteristics like floor slab quality (FSQ) were also evaluated.
• Multivariate regression analysis was employed to determine the relationship between indoor radon and various environmental and building parameters.

Main Results:

• The karstic region exhibited high soil permeability (average 1.53·10^-11 m²), leading to elevated GRPs and RI values.
• Nine locations showed Extremely High RI, and nine showed Very High RI.
• A regression model incorporating FSQ, c, k, GRP, and ²³⁸U activity explained 29.1% of the variance in indoor radon concentrations.

Conclusions:

• Geogenic factors, particularly soil permeability and radon potential in karst areas, significantly contribute to high indoor radon levels.
• Building characteristics, especially floor slab quality, play a role in modulating indoor radon concentrations.
• While geogenic factors are primary drivers, building construction details are important for mitigating indoor radon exposure.