Total Indicative Dose Determination in Water from the North Riviera Well Field of SODECI in Abidjan, Cote d’Ivoire

The Uranium-238 (238U), Thorium-232 (232Th) families and Potassium-40 (40K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of 238U, 232Th and 40K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides238U, 232Th, and 40K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.

Measurement of Radon Concentration and Estimation of Cancer Risk in Twenty-Four Model Houses in the Town of Koudougou

The objective of our study is to evaluate the concentration of radon (86Rn) inside houses in the town of Koudougou in order to estimate its impact on the health of the population. Indeed, when uranium-rich minerals are found near the surface of the ground, radon concentrations can reach tens of becquerels per cubic meter in enclosed spaces. Given the nature of the geological base of Burkina Faso, this situation is quite probable and certain places that are sometimes poorly ventilated (house, school, office, etc.) can have radon levels high enough to constitute a health problem for occupants. Thus, twenty-four (24) sample houses were identified. In each house, the Corentium digital detector was between 0.8 m and 2 m for at least one week in a place where the occupants estimate that they spend more time of time and measure the concentration of radon in the long term and short term. The recorded data allowed us to determine the Absorbed Dose and the Annual Effective Dose of radon gas for each house in order to estimate the Risk of Cancer and the probable Number of Cases of Lung Cancer per million inhabitants. Thus, the results indicate that the long-term radon concentration varies between 6 Bq/m3 and 285 Bq/m3 respectively in houses 11 and 4 compared to 1 Bq/m3 to 208 Bq/m3 in the short term in the same houses. Also, in the long term, in control houses 1, 3 and 4, the radon level is above the recommended threshold interval. For the short term, these are houses 1, 3, 4 and 17 respectively with 110 Bq/m3, 142 Bq/m3, 208 Bq/m3 and 105 Bq/m3. As for the long-term and short-term effective doses, only houses 1, 3, 4, 17 and 24 have values between 3 - 10 Sv/year. The estimation of the relative risk of lung cancer gives values relatively close to unity and between 1.006 and 1.142 with an average of 1.035 and that of the Number of Lung Cancer Cases per million inhabitants gives values between 8 and 166 with an average of 42. Thus, we can conclude that with the exception of houses 1, 3, 4 and 17, the radon concentrations are relatively low in the twenty-four control houses in the city of Koudougou. The lifestyle of the populations can well explain this situation when we know that people are in the habit of always leaving doors and windows open, especially when they are not sleeping. We can therefore say that the risk of population exposure to radon gas is relatively low in the town of Koudougou.

Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant

Coal is the main energy source for electricity generation in the world. In Morocco, 37% of electricity generation comes from combustion coal in thermal power plants. This combustion process generates large amounts of fly and bottom ashes. In recent years, these ashes became a great topic of interest because of their different uses and especially in construction materials. In this work, we assess radiation risks due to natural radioactivity in samples of fly and bottom ashes collected from JLEC (Jorf Lasfar Energy Company) thermal power plant, and different analyses are performed through two nuclear techniques such as gamma spectrometry and alpha dosimetry based on the use of LR115 films detectors. Our analysis shows that 226Ra activities and 232Th in both ash samples are well above the permissible activity. The values of the external risk index (Hex) and internal one (Hin) for these ashes are below unity, with the exception of 1.28 in fly ash for Hin. The obtained values for the equivalent radium Raeq and annual effective doses Ėin fly and bottom ashes are 324 Bq/kg and 210 Bq/kg, and 0.18 mSv/y and 0.11 mSv/y, respectively. The surface radon exhalation rates for the samples of fly and bottom ashes are 276 mBq⋅m-2⋅h-1 and 381 mBq⋅m-2⋅h-1, respectively. Based on these results, we have shown that fly ash and bottom one from thermal power plant JLEC didn’t have, in any case, a health risk to the public so it can be effectively used in various construction activities.

Cancer Risk Due to the Natural Radioactivity in Cigarette Tobacco

Thirty-one samples of cigarettes have been collected from local markets of different types of origins. The samples were selected according to a survey distributed to smokers by paper and digital survey to see the most heavily traded among smokers and in addition to a number of questions to see how the awareness and the culture of smokers in diseases caused by smoking and considered this study the first survey in Iraq. The aim of this research is to assess the number of cancer cases due to cigarette smoking. Through the use of High-Purity Germanium system (HPGe) (efficiency 40%) we determinated the radionuclides in cigarette tobacco. The average values were (14.86 ± 3.76, 10.84 ± 3.13, 1050.64 ± 47.57) Bq/kg for Ra-226, Th-232 and K-40, respectively, and the excess lifetime of cancer risk values ranged from 0.54 to 130 at average of 76 per million person per year. Raeq values varied from 18.50 to 87.21.4 Bq/kg with an average value of 39.51 Bq/kg for tobacco samples. The annual effective dose (HE) varies from 16.38 μSv/y to 44.69 μSv/y with an average value of 24.97 μsv/y. The Annual Gonadal Dose Equivalent (AGDE) varies from 0.3 to 0.64 (mSv/y) with an average value of 0.42 for all tobacco samples under investigation.

Preliminary Studies on ²²²Rn Concentration in Groundwater of Yaounde, Cameroon

This work presents a preliminary study on groundwater samples carried out from selected groundwaters of some localities of Yaounde, Cameroon. Radon concentration was ranged from 0.11 Bq∙l-1 to 1 Bq∙l-1, with an average of 0.48 Bq∙l-1. The comparison between the physico-chemical parameters and the radon concentrations in groundwater showed a good correlation between these radon concentrations and the values of Electroconductivity (EC). The annual effective dose due to ingestion of radon in water ranged from 0.30 μSv∙y-1 to 7.90 μSv∙y-1 with an average of 1.93 μSv∙y-1. The obtained results of this study were shown that the concentrations of radon in groundwaters and annual effective doses due to ingestion of this groundwater were below the references recommended by WHO.

Natural radioactivity measurements of frozen red meat samples consumed in Iraq

Purpose In the present study,the activity concentrations of long-lived gamma-ray emitters(^(238)U,^(232)Th and ^(40)K)in ten dif-ferent types of frozen red meat samples selected from markets in Iraq were measured.Methods The technique of gamma spectrometer equipped with scintillation detector NaI(Tl)was used.Results The annual effective dose was estimated in adults and kids.The results showed that the concentrations of ^(238)U,^(232)Th and ^(40)K were found in the range of permissible limits of 30,32 and 400 Bq kg−1,respectively.On the other hand,the maximum values of ^(238)U and ^(232)Th in beef samples are higher than in lamb meat samples.The annual effective dose of adults and kids was observed to be below the limit(1.0 mSv)recommended by ICRP.Conclusion The frozen red meat samples are safe for human consumption and have gamma-ray emitter concentrations lower than the maximum permissible levels.