Seasonal Determination of Radon Concentrations inside Dwellings in Aboisso, Côte d’Ivoire

Abstract

Background: Radon is a naturally occurring radioactive gas and an important indoor environmental contaminant because prolonged exposure may increase the risk of lung cancer. Indoor radon concentrations can vary considerably between dwellings and may also be influenced by seasonal conditions, building characteristics, and household ventilation practices. However, information on seasonal variations in indoor radon concentrations in Aboisso, Côte d’Ivoire, remains limited. Aims: This study aims to determine concentrations of the carcinogenic gas radon inside dwellings in order to contribute to the data needed to create the national radon map of Côte d’Ivoire. Place and Duration of Study: The study was conducted in the city of Aboisso over a period of four months. Methodology: Fifty samples of the non-strippable LR 115 Solid State Nuclear Track Detector (SSNTD) were exposed inside dwellings to measure radon. Twenty-five samples were exposed for two months during the dry season in 25 distinct dwellings throughout the city using a sampling grid. The other 25 samples were exposed for two months during the wet season in the same 25 dwellings. Afterwards, all 50 samples were collected and analysed chemically and optically. Results: Indoor radon concentrations obtained in the dry and wet seasons ranged from (41 ± 18) Bq/m3 to (1231 ± 555) Bq/m3, with an average of (175 ± 79) Bq/m3, and from (5 ± 2) Bq/m3 to (202 ± 91) Bq/m3, with an average of (113 ± 51) Bq/m3, respectively. Conclusion: Seasonal trends in these concentrations were not observed during the dry and wet seasons. During the four-month period, 2% and 36% of the measurements showed values exceeding the levels of 300 Bq/m3 and 150 Bq/m3 used for comparison with the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA), respectively.