Assessment of Annual Tracheobronchial Effective Dose from Indoor Radon Inhalation in Selected Residential Buildings in Southwestern Nigeria

Abstract

Background and Purpose: Radon-222 is a major human health challenge among all sources of ionizing radiation. For most people, the greatest exposure to radon comes from homes and affects mainly the respiratory tract, especially the tracheobronchial region. This work assesses the annual tracheobronchial effective dose from indoor radon inhalation in residential buildings with different covering materials for walls, ceilings and floor using different dosimetric lung models. Method: A total of 180 residential buildings with commonest combination of covering materials in some cities in South-western Nigeria were investigated using an active electronic radon gas detector, RAD 7. The commonest combination of covering materials were (A): paint, paint, carpet; (B): paint fiber board, plastic tiles; (C): paint, fiber board, ceramic tiles for walls, ceilings and floors respectively. Result: The mean indoor radon concentration measured ranged between 23.08 Bq m-3 and 72.14 Bq m-3 for all the residential buildings investigated. Buildings with covering materials C, presented the highest radon concentration. Generally, the mean indoor radon concentration for all combinations of covering materials in all the cities investigated were found to be lower than the recommended action level of 200 Bqm-3 and the reference level of 100 Bqm-3 set by International Commission on for Radiation Protection and World Health Organization respectively. The annual tracheobronchial effective dose estimated for the different lung dose models ranged from 0.91 mSv – 3.27 mSv for combination (A), 1.00 mSv - 3.60 mSv for combination (B) and 1.09 mSv – 3.94 mSv for combination (C). It revealed that the more recent model gives greater value of the annual tracheobronchial effective dose. It was observed that only the annual tracheobronchial effective doses obtained by the James model presented values that are within the recommended ICRP intervention level of (3-10) mSvy-1. Other models gave values of annual tracheobronchial effective doses below the ICRP recommended intervention levels. Conclusion: These imply that all the residential buildings and the different combination of covering materials surveyed in this work will not pose any radiological hazard to the inhabitants. Key words: Indoor Radon Inhalation, Radon-222, annual tracheobronchial effective dose, residential buildings

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“…The findings of this study show that the level of radon exposure experienced by Jigawa State people is safe. In residential buildings with varied wall, ceiling, and floor covering materials, Olukunle, et al [50] assessed the tracheobronchial effective dosage from radon inhalation. Using various dosimetric lung models, 180 residential buildings in some cities in south-western Nigeria with the most frequent combinations of covering materials were investigated using a RAD 7 active electronic radon gas detector.…”

Indoor radon concentration levels in some selected offices at Ibrahim Badamasi Babangida University, Lapai, Nigeria and its attendant annual effective dose

“…Few literatures on radon levels in buildings are available in developing countries. However, in Nigeria only radon concentration levels in buildings from south-western part of the country were reported (Oni et al, 2012;Okeji et al, 2013;Ademola et al, 2015;Afolabi et al, 2015;Asere and Ajayi 2017;Obed et al, 2018;Sokari, 2018;Usikalu et al, 2018;Akabuogu et al, 2019;Chenko et al, 2019;Avwiri et al, 2020;Oladapo et al, 2020;Olaoye et al, 2020;Ndubisi et al, 2021;Asere et al, 2022;Olowookere et al, 2022). Hence, this work investigates the radon concentration levels in IBB University buildings and its effect on the occupants.…”

"Radiological Implications of Radon Levels on Human Health: Systematic Review in Nigeria"

“…The progeny cause damage to the cells lining the airways as they are being deposited there because they release radiation which is ionizing in the type of alpha particles [10,12]. If breathed in radon decomposed daughters (such as solid form of polonium-218 and pol-214), whether free or attached to the outside in aerosols, dust or particles in smoke, turn into extremely wedged in the respiratory organ such as lung, where they can emit radiation and infiltrate the cells of the mucous membranes, pulmonary tissue and bronchi [16]. Comparable reports encompass that once taken in radon decays daughters (Pol-218 & Pol-214), must radiate the lung tissue.…”

“…This raises anxiety in the pragmatic increase in lung disorders such as cancer cases surrounded by wide-ranging public could be due to exposure to radon, particularly for persons who spend their time indoor [17]. Additionally, research has shown that radon has the ability to trigger genetic disorders at any concentration [16]. Some Radon progenies (218P0 and 214Po) interact with biological tissue and harm cells, DNA, and chromosomes, leading to a variety of health issues.…”