Natural radioactivity in building materials, indoor radon measurements, and assessment of the associated risk indicators in some localities of the Centre Region, Cameroon

• Published in: Environmental science and pollution research international 2022-08, Vol.29 (36), p.54842-54854
• Main Authors: Ndjana Nkoulou II, Joseph Emmanuel, Manga, André, Saïdou, German, Olga, Sainz-Fernandez, Carlos, Kwato Njock, Moïse Godfroy
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Building codes; Building materials; Concrete; Construction materials; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Exploitation; Floors; Gamma rays; Indicators; Indoor air pollution; Indoor environments; Inhalation; Iodides; Mineral resources; Mortars (material); Natural radioactivity; Population; Radiation; Radioactivity; Radium 226; Radium isotopes; Radium radioisotopes; Radon; Radon levels; Research Article; Residential areas; Respiration; Risk levels; Sensors; Sodium iodide; Structural members; Walls; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-19781-z

The objective of the current study is to investigate the natural radioactivity of some building materials, the resulting long-term external and internal effective dose equivalents (EEDE and IEDE) analysis followed by indoor radon measurements, and the assessment of some radiological risk indicators associated with radon exposure. A total of 37 samples of building materials were analyzed with a sodium iodide detector (NaI (Tl)), and the computer code RESRAD-BUILD was used for the analysis of the EEDE and IEDE of the structural elements of the houses (walls and floor). For indoor radon measurements, 140 houses were selected, and in each of them was placed 01 RADTRAK dosimeter. Inhalation dose, total dose, and some radiological risk indicators were calculated. The specific activities of 226 Ra, 232 Th, and 40 K for the overall sampled building materials were found to vary between 10 ± 2–52 ± 7, 10 ± 1–95 ± 10, and 31 ± 1–673 ± 20 Bq kg −1 , respectively. The dwelling types with bare brick walls, cement mortar plastered walls, and concrete floors show EEDE and IEDE values well below the recommended limits. The corresponding dwelling type contributions to the measured average indoor radon concentration (42 ± 12 Bq m −3 ) are 22%, 13%, and 16%, respectively. Inhalation dose resulting from the measured indoor radon concentrations varies from 0.35 to 3.24 mSv y −1 with a mean value of 0.96 ± 0.55 mSv y −1 , which represents about 65% of the total dose simulated (1.49 ± 0.88 mSv y −1 ) by the RESRAD-BUILD code. The overall analysis of indoor radon-related radiological risk indicators shows low levels of risk relative to permissible limits.