Indoor and Outdoor Radon Concentration Levels in Lebanon

Abstract

Lebanon's lung cancer rates, among the highest in the Arab region, contribute to the burden of noncommunicable diseases. A number of studies have shown that lung cancer risk increases when smokers vs. nonsmokers exposed to elevated radon levels are compared. This research employs indoor and outdoor space and time concentration surveys across Lebanon, where the smoking rate among the population is among the highest in the world. The distributional properties of measured radon concentration were shown to be lognormal with median indoor and outdoor concentrations of 17 and 10 Bq m, respectively. Standard deviation for indoor concentrations was 1.2 times smaller than its outdoor counterpart, suggesting that weather-related patterns affect outdoor radon concentration variability. No significant spatial association was detected across seasons for indoor and outdoor radon concentrations. Geographical location, proximity to faults, and housing construction material had no significant impact on outdoor and indoor radon concentration variations. When lognormal distributions were used to determine exceedance probability of the recommended reference radon concentration, they were smaller than 0.1%. While exhibiting high seasonal variability, the study shows that radon does not appear to be a public health concern in Lebanon.

Outdoor Radon as a Tool to Estimate Radon Priority Areas—A Literature Overview

“…Among passive detectors, solid state nuclear track detectors, polyallyl diglycol carbonate (PADC)—CR-39 were used in 40.7% of analysed surveys [ 45 , 46 , 77 , 82 , 83 , 89 , 92 , 93 , 94 , 95 , 96 ], polycarbonate foil of Makrofol in 7.4% [ 78 , 85 ], one survey (3.7%) with electrostatic integrating monitor based on LR115 [ 79 ]. One survey (3.7%) was performed by electret ion chamber (EPERM ® ) [ 81 ]. Active devices were used in 44.4% of the surveys, out of which: Two (7.4%) ionization chambers (AlphaGUARD) [ 74 , 97 ], four (14.8%) EEC Rn devices [ 75 , 98 , 99 , 100 ], five (18.5%) scintillators [ 66 , 87 , 91 , 101 , 102 ] and one (3.7%) Passivated Implanted Planar Silicon (PIPS) detector for alpha spectrometry [ 73 ].…”

“…It is low cost and convenient for long-term measurements. However, results need corrections for background radiation and the surface should be free of dust, which could be a problem for outdoor measurements [ 81 ].…”

“…Higher values in winter were also measured in Turkey (by a factor of 2) [ 77 ], in a nationwide survey in Japan [ 78 ] and China (by an average factor of 1.8) [ 79 ]. However, other references indicate that the lowest values were in winter, presumably due to a snow cover, large humidity or strong winds [ 46 , 80 , 81 , 82 ]. Finally, in the measurement campaign performed in Slovenia, no significant difference between outdoor radon concentrations in any of the 4 seasons was found [ 45 ].…”

“…The aim of research performed by [ 82 ] was to measure radioactivity levels in Fen Complex, Norway, a former Fe and Nb mining cite. In Lebanon, the investigation of indoor and outdoor Rn was performed due to a very large number of lung cancer cases and smoking rates [ 81 ]. In Ireland, first estimation of outdoor radon was from the national indoor radon survey, assuming that the difference between indoor and outdoor radon should follow a lognormal distribution [ 115 ].…”

“…Statistical analysis has shown a moderate correlation between thoron concentration and gamma dose rate (0.56), as well as between radon and gamma dose rate (0.64) [ 82 ]. In Punjab, India, indoor and outdoor equilibrium equivalent radon concentrations EECRn were measured daily for 3 months in winter [ 75 ] In Lebanon, radon detectors of indoor and outdoor radon concentrations were simultaneously deployed [ 81 ]. Although the paper did not explicitly give correlation between indoor and outdoor radon concentrations, authors of this review have calculated correlation from the available data.…”