| Autor: |
Ndjana Nkoulou, J. E.1,2 (AUTHOR) nndjana@yahoo.fr, Saïdou1,3 (AUTHOR), Hamadou Yerima, A.1 (AUTHOR), Oumar Bobbo, M.4 (AUTHOR), Nugraha, E. D.4 (AUTHOR), Ipan, A. S.5 (AUTHOR), Najam, L. A.6 (AUTHOR), Suárez‐Navarro, J. A.7 (AUTHOR), Yoho, B.8 (AUTHOR), Kwato Njock, M. G.2 (AUTHOR) |
| Předmět: |
|
| Zdroj: |
Journal of Geophysical Research. Atmospheres. 7/16/2024, Vol. 129 Issue 13, p1-15. 15p. |
| Abstrakt: |
The objectives of the current study are to carry out soil gas radon (Rn) measurements, to evaluate the total inhalation effective dose, to determine risk levels over the lithological formations of the study area. The behavior investigation of Rn activity concentration distributions in dwellings and soils, and soil Rn mapping were also conducted. Soil gas Rn measurements were made at 102 sampling points by Markus 10 instrument. This data was combined with previously reported results from 140 indoor Rn RADTRAK dosimeters to determine the total inhalation effective dose and to conduct a statistical analysis. Overall, the Rn activity concentrations in soil and dwellings range from 4 to 66 kBq m−3 and from 15 to 140 Bq m−3, with averages of 31 ± 15 kBq m−3 and 41 ± 24 Bq m−3 respectively. The corresponding total inhalation effective dose ranges from 0.35 to 3.53 mSv y−1, with a mean value of 1.37 ± 0.58 mSv y−1. For soil gas Rn, the chlorite schist lithology showed the highest average concentration level. Which could be justified by the possible presence, within chlorite minerals, highly emitting zones of alpha particles, leading to the formation of radioactive halos. Normal and high‐risk level of Rn were found for about 82% and 11% of the total area surveyed respectively. These findings highlight the need for preventive measure against Rn exposure in homes within the investigated areas. This study contributes valuable insights into Rn distribution patterns and risk assessment, offering a basis for targeted interventions in the region. Plain Language Summary: Radon (222Rn (Rn or radon)) is the ubiquitous natural radioactive gas in the earth's crust. It is responsible for about 50% of the total dose received by the public from exposure to natural ionizing radiation. This gas have been recognized as the second leading cause of lung cancer in the world. The current work objectives are to measure the soil gas Rn activity concentrations, to assess the total inhalation dose received by the public and to determine risk levels of various lithological formations. In general, we found that the chlorite schist lithology had the highest average concentration level, due to the presence of minerals such as biotite and chlorite. Public exposure to Rn is greater indoors than outdoors with average inhalation dose relatively higher than the worldwide average. This is due to the numerous factors such as type of construction, building materials, low indoor air renewal rates, etc. The whole study area surveyed were classified as normal‐risk zones. These results reveal that preventive and protective measures against the public exposure to Rn are required from the construction of dwellings. Based on the activity concentrations distribution model and risk assessment, areas that could be targeted for potential intervention could be identified. Key Points: First in situ direct measurement of soil gas Rn activity concentration using Markus‐10 instrument in the various lithological formationsValuable insights into indoor and soil gas Rn distribution patterns and risk assessment, offering a basis for targeted interventionsProduction of a map of Rn distribution in the soil in this part of the country for the first time [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
|
Plný text