Radon exposure assessment and its decay products aerosols in some houses of the province of El Jadida, Morocco

Abstract

In this study, indoor and outdoor activities of radon and its progeny were measured using the passive dosimetry CR-39 detectors inside and outside of 60 houses of El Jadida province, Morocco. Thereafter, three radiological parameters namely the potential alpha energy concentrations (PAEC), the annual effective dose (E), and the lung cancer cases per year per million person (CPPP) were calculated. The obtained results showed that the nature of construction materials, the presence of wells inside houses and the proximity of the industrial zone of Jorf Lasfar have a significant impact on indoor radon concentrations and its decay products. In fact, the registered activities go from 52 Bq m⁻³ in modern houses whose age is less than 20 years to 266 Bq m⁻³ in old houses of more than 50 years located near the industrial zone of Jorf Lasfar. The average values of the potential alpha energy concentrations, the annual effective doses, and the lung cancer risks per year per million person measured in the different houses vary respectively from 9.1 mWL, 1.50 mSv y⁻¹, 27 in modern houses to 48 mWL, 7.82 mSv y⁻¹, 141 in old houses of more than 50 years located near the industrial zone of Jorf Lasfar, values which remain close to the admissible safety limits (53.33 mWL, 10 mSv y⁻¹, 230). Due to this, it would be interesting and desirable to prohibit houses near industrial areas and borehole wells inside houses with a choice of construction materials adapted to the criteria of the limitation of doses.