Indoor radon, external dose rate and assessment of lung cancer risk in dwellings: the case of Ebolowa town, Southern Cameroon

Mbembe, Serge Mbida; Mbembe, Bertrand Akamba; Manga, André; Abiama, P. Ele; Saïdou, -; Meye, Philippe Ondo; Ateba, P. Owono; Ben-Bolie, G. H.

doi:10.1080/03067319.2021.1946684

Cited by 7 publications

(3 citation statements)

References 32 publications

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“…The highest radon concentration of 2,620 Bq/m 3 was found in a dwelling of the city of Ebolowa, the capital of the South Region [30]. This high radon concentration could be explained by the geology of the area and the type of dwelling, which is not naturally ventilated sufficiently.…”

Section: Jrprmentioning

confidence: 93%

From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon

Saïdou¹,

Tokonami

Hosoda

et al. 2022

J Radiat Prot Res

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Background: The current study reports measurements of activity concentrations of radon (222Rn) and thoron (220Rn) in dwellings, followed by inhalation dose assessment of the public, and then by the development of regulation and the national radon action plan (NRAP) in Cameroon.Materials and Methods: Radon, thoron, and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings. From 2019 to 2020, radon track detectors (commercially RADTRAK) were deployed in 1,400 dwellings. It was found that activity concentrations of radon range in 1,850 houses from 10 to 2,620 Bq/m3 with a geometric mean of 76 Bq/m3.Results and Discussion: Activity concentrations of thoron range from 20 to 700 Bq/m3 with a geometric mean of 107 Bq/m3. Thoron equilibrium factor ranges from 0.01 to 0.6, with an arithmetic mean of 0.09 that is higher than the default value of 0.02 given by UNSCEAR. On average, 49%, 9%, and 2% of all surveyed houses have radon concentrations above 100, 200, and 300 Bq/m3, respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40%. Thus, thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies. Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020. Reference levels of 300 Bq/m3 and 1,000 Bq/m3 were recommended for dwellings and workplaces.Conclusion: Priority actions for the coming years include the following: radon risk mapping, promotion of a protection policy against radon in buildings, integration of the radon prevention and mitigation into the training of construction specialists, mitigation of dwellings and workplaces with high radon levels, increased public awareness of the health risks associated with radon, and development of programs on the scientific and technical aspects.

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Section: Jrprmentioning

confidence: 93%

From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon

Saïdou¹,

Tokonami

Hosoda

et al. 2022

J Radiat Prot Res

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“…Hypothesis testing was also carried out to statistically compare the mean values obtained for each participating CT facility [9][10][11]. The null hypothesis was that two compared data sets were drawn from the same population with the same mean (H0: µx -µy = 0), while the alternative hypothesis was that two compared data sets were drawn from different populations with different means (H1: µx ≠ µy).…”

Section: Journal Of Multidisciplinary Applied Natural Sciencementioning

confidence: 99%

Establishment of Typical Dose Reference Level (DRL) Values for Adult Patients Undergoing Computed Tomography in Three Hospitals in Brazzaville, Congo Republic

Dallou,

Meye,

Bazoma

et al. 2024

J. Multidiscip. Appl. Nat. Sci.

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The present study aimed at to establish typical dose reference level (DRL) values for adult patients undergoing computed tomography (CT) examinations in three hospitals in Brazzaville, Congo Republic. The examinations considered were head, chest, abdomen-pelvis, chest-abdomen-pelvis and lumbar spine CT scans. For each examination, the median of the distribution for the volume CT dose index (CTDIvol) and dose-length product (DLP) were determined. The median values were considered as the typical DRL values. Hypothesis testing was also carried out to statistically compare the mean values obtained for each participating CT facility. In the case of head scan, the typical values proposed in the present study in terms of CTDIvol and DLP were 15–48% and 28–60% lower than the DRL values reported in the literature, respectively. In the case of lumbar spine, the typical value determined in this study in terms of DLP was 48–70% greater than the DRL values provided in the literature. The typical values proposed for chest, abdomen-pelvis and chest-abdomen-pelvis were within the DRL values reported in the literature. It is possible that the adoption of the typical values proposed in the present study will help in reducing the dose received by adult patients undergoing CT examination in Congo Republic.

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“…Correlations have often been found between Rn levels observed indoors and the underlying soils on which these homes are built (Åkerblom & Mellander, 1997;Neznal et al, 2006). Numerous substantial studies on public exposure to Rn in dwellings have been conducted in Cameroon since 2014 by Saïdou et al (2014), Bineng et al (2020), Takoukam et al (2019), Ndjana Nkoulou II et al (2019), Soumayah et al (2022), Gondji et al (2022), Mbida et al (2021), and Koyang et al (2022). The data resulting from these works were used to develop and establish the Cameroon National Radon Plan (NRP), which has fixed the indoor Rn reference value at 300 Bq m 3 .…”

Section: Introductionmentioning

confidence: 99%

Lithological Impact on Radon Levels: A Study of Indoor and Soil Gas Radon in the Centre Region of Cameroon

Ndjana Nkoulou,

Saïdou,

Hamadou Yerima

et al. 2024

JGR Atmospheres

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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.

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Indoor radon, external dose rate and assessment of lung cancer risk in dwellings: the case of Ebolowa town, Southern Cameroon

Cited by 7 publications

References 32 publications

From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon

From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon

Establishment of Typical Dose Reference Level (DRL) Values for Adult Patients Undergoing Computed Tomography in Three Hospitals in Brazzaville, Congo Republic

Lithological Impact on Radon Levels: A Study of Indoor and Soil Gas Radon in the Centre Region of Cameroon

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