The activities of 210Po and 210Pb in cigarette smoked in Tunisia.

In this study, the activity concentration of polonium 210 in cigarette for Tunisian consumers was investigated by alpha spectrometry. After chemical digestion of tobacco, 210Po was extracted, auto-deposited on disc and measured. The activity of 210Pb was assessed after radioactive equilibrium was achieved. The activity levels of 210Po ranged between 7.8 ± 0.3 and 17 ± 0.5 mBq per cigarette with an average of 12.9 ± 0.4 mBq per cigarette. Effective doses per year due to cigarette smoking were calculated assuming that 22% of the 210Pb and 210Po in tobacco were retained in the lungs of the smokers. It is concluded that for a smoker in Tunisia, the average effective dose is about 90.6 ± 3.3 µSv per year for a cigarette consumption of one pack of cigarettes per day. This value is somewhat lower than 106.4 ± 5.3 µSv per year estimated as the mean global effective dose from smoking.

Exposure to radiation from the natural radioactivity in Tunisian building materials.

Building materials can expose public and workers to radiation because of their content of radium, thorium and potassium isotopes. This is why it is very important from the radiological point of view to survey the natural radioactivity content of commonly used building materials in any country. This work consists of the measurement of (226)Ra, (232)Th and (40)K activity concentrations in a variety of commonly used building materials in Tunisia and on the estimation of their radiological hazard. The maximum value of radium equivalent for the studied materials was equal to 169 Bq kg(-1) and corresponds to the clay brick, which is lower than the recommended value of 370 Bq kg(-1). In this work, several radiological indexes were calculated and were found to be under their highest permitted limit.

Uranium isotopes in Tunisian bottled mineral waters.

(234)U and (238)U activity concentrations and their relative effective doses have been determined in 10 bottled mineral waters in Tunisia. Alpha spectrometry was used as technique to measure uranium isotopes. The obtained isotopic ratio (234)U/(238)U varies between 1.1 and 3 which means that the two isotopes are not in radioactive equilibrium. Measured activity concentration varies between 3.2 and 40 mBq/l for (234)U and between 1.5 and 26.3 mBq/l for (238)U. Effective doses (assuming 2 litres per day of water consumption) coming from this two isotopes are found to vary between 0.16 and 2.02 microSv/a which is lower than the maximum recommended dose level by the WHO.