J Environ Radioact. 2026 Mar 27;295:107969. doi: 10.1016/j.jenvrad.2026.107969. Online ahead of print.
ABSTRACT
This study assessed indoor 222Rn concentrations, health risk, and key determinants in residential dwellings across Al Khums and Al Sahel, Libya. Al Khums showed an Arithmetic Mean (AM) of 54 Bq/m3 (Exceedance Rate 4.3%), while Al Sahel registered an AM of 102 Bq/m3. Crucially, the high AM in Al Sahel was statistically divergent from its low Geometric Mean (GM) (38 Bq/m3), which was even lower than the GM in Al Khums (45 Bq/m3). This divergence, coupled with a 17.9% exceedance rate in Al Sahel, confirmed that the high risk is heavily skewed and driven by a small number of critically high-concentration dwellings, not a geographical factor. Multiple Linear Regression analysis which explained 46.7% of the variance (Adjusted R2) confirmed that concentrations are primarily governed by non-linear structural and behavioral factors. Significant negative correlations were found for the Reciprocal of Modified Ventilation Rate (1/(V+2)), and the Reciprocal of Modified Storey Level (1/(S+2)), confirming ventilation duration and distance from the soil as dominant mitigation factors. The Quality of Window Opening Method also provided significant negative correlation, highlighting the power of occupant behavior. Conversely, Natural Gas Use for Cooking showed a significant positive correlation; identified as both a direct source of 222Rn and a catalyst for the “stack effect,” where combustion-induced depressurization enhances the infiltration of radon-rich soil gas. Based on a realistic occupancy factor of 7000 h/year, the resulting Excess Relative Risks (ERR) for lung cancer in Al Khums and Al Sahel were estimated at 0.859 and 1.633, respectively, underscoring the necessity of integrating these non-linear predictive factors into regional building codes and public health mandates.
PMID:41904837 | DOI:10.1016/j.jenvrad.2026.107969
