O O Awe, I C Okeyode, A O Abayomi-Alli, A O Mustapha, Chutima Kranrod, Yasutaka Omori, Masahiro Hosoda, Shinji Tokonami
{"title":"尼日利亚西南部三个连续地质构造的住宅和工作场所的室内氡和钍。","authors":"O O Awe, I C Okeyode, A O Abayomi-Alli, A O Mustapha, Chutima Kranrod, Yasutaka Omori, Masahiro Hosoda, Shinji Tokonami","doi":"10.1007/s00411-025-01135-1","DOIUrl":null,"url":null,"abstract":"<p><p>The first regional survey of concurrent indoor radon and thoron measurements in Southwestern Nigeria was organized using the passive radon-thoron discriminative detectors RADUET. The measurements were carried out in various dwellings and workplaces across three geological formations within the Southwestern Nigeria basin, which consists of recent sediments in Akoka (Lagos State), cretaceous sediments known as Abeokuta formation in Ilishan (Ogun State), and basements in Alabata (Abeokuta, Ogun State). Both radon and thoron concentrations at 193 sites showed log-normal distributions, with significantly (p < 0.05) higher values of thoron than radon concentrations and a weak correlation (R = 0.224) between the two. The ranges and arithmetic means of the concentrations were 6-132 Bq m<sup>-3</sup>and 24 ± 21 Bq m<sup>-3 </sup>for radon and 2-709 Bq m<sup>-3</sup> and 94 ± 124 Bq m<sup>-3</sup> for thoron, respectively. ANOVA results showed significant variations in radon and thoron concentrations according to the underlying geology, with radon concentrations in Ilishan (cretaceous sedimentary) significantly (p < 0.05) higher than those of Akoka (recent sedimentary) and Alabata (basement complex). No significant differences (p = 0.09) were found between thoron concentrations in Alabata and Ilishan, and both locations had significantly higher (p < 0.05) concentrations of thoron than those recorded in Akoka. A test of the influence of building types showed that radon and thoron concentrations in offices were significantly (p < 0.05) lower than those in homes. None of the thoron concentrations were zero, and almost all were higher than the corresponding radon concentrations. Some of the radon concentrations exceeded the recommended reference level of 100 Bq m<sup>-3</sup>, but all were below the action level of 300 Bq m<sup>-3</sup>. This study has shown that with high concentrations of thoron, its contributions should not be neglected in indoor radon measurements, particularly in the areas with old sedimentary and basement complex geology. It is noted that dose evaluation is required to quantify the relative contributions of radon and thoron to human exposures in the three locations. Meanwhile, occupants of buildings in the study areas should be encouraged to optimize indoor ventilation.</p>","PeriodicalId":21002,"journal":{"name":"Radiation and Environmental Biophysics","volume":" ","pages":""},"PeriodicalIF":1.5000,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Indoor radon and thoron in dwellings and workplaces across three contiguous geological formations in Southwest Nigeria.\",\"authors\":\"O O Awe, I C Okeyode, A O Abayomi-Alli, A O Mustapha, Chutima Kranrod, Yasutaka Omori, Masahiro Hosoda, Shinji Tokonami\",\"doi\":\"10.1007/s00411-025-01135-1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The first regional survey of concurrent indoor radon and thoron measurements in Southwestern Nigeria was organized using the passive radon-thoron discriminative detectors RADUET. The measurements were carried out in various dwellings and workplaces across three geological formations within the Southwestern Nigeria basin, which consists of recent sediments in Akoka (Lagos State), cretaceous sediments known as Abeokuta formation in Ilishan (Ogun State), and basements in Alabata (Abeokuta, Ogun State). Both radon and thoron concentrations at 193 sites showed log-normal distributions, with significantly (p < 0.05) higher values of thoron than radon concentrations and a weak correlation (R = 0.224) between the two. The ranges and arithmetic means of the concentrations were 6-132 Bq m<sup>-3</sup>and 24 ± 21 Bq m<sup>-3 </sup>for radon and 2-709 Bq m<sup>-3</sup> and 94 ± 124 Bq m<sup>-3</sup> for thoron, respectively. ANOVA results showed significant variations in radon and thoron concentrations according to the underlying geology, with radon concentrations in Ilishan (cretaceous sedimentary) significantly (p < 0.05) higher than those of Akoka (recent sedimentary) and Alabata (basement complex). No significant differences (p = 0.09) were found between thoron concentrations in Alabata and Ilishan, and both locations had significantly higher (p < 0.05) concentrations of thoron than those recorded in Akoka. A test of the influence of building types showed that radon and thoron concentrations in offices were significantly (p < 0.05) lower than those in homes. None of the thoron concentrations were zero, and almost all were higher than the corresponding radon concentrations. Some of the radon concentrations exceeded the recommended reference level of 100 Bq m<sup>-3</sup>, but all were below the action level of 300 Bq m<sup>-3</sup>. This study has shown that with high concentrations of thoron, its contributions should not be neglected in indoor radon measurements, particularly in the areas with old sedimentary and basement complex geology. It is noted that dose evaluation is required to quantify the relative contributions of radon and thoron to human exposures in the three locations. 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Indoor radon and thoron in dwellings and workplaces across three contiguous geological formations in Southwest Nigeria.
The first regional survey of concurrent indoor radon and thoron measurements in Southwestern Nigeria was organized using the passive radon-thoron discriminative detectors RADUET. The measurements were carried out in various dwellings and workplaces across three geological formations within the Southwestern Nigeria basin, which consists of recent sediments in Akoka (Lagos State), cretaceous sediments known as Abeokuta formation in Ilishan (Ogun State), and basements in Alabata (Abeokuta, Ogun State). Both radon and thoron concentrations at 193 sites showed log-normal distributions, with significantly (p < 0.05) higher values of thoron than radon concentrations and a weak correlation (R = 0.224) between the two. The ranges and arithmetic means of the concentrations were 6-132 Bq m-3and 24 ± 21 Bq m-3 for radon and 2-709 Bq m-3 and 94 ± 124 Bq m-3 for thoron, respectively. ANOVA results showed significant variations in radon and thoron concentrations according to the underlying geology, with radon concentrations in Ilishan (cretaceous sedimentary) significantly (p < 0.05) higher than those of Akoka (recent sedimentary) and Alabata (basement complex). No significant differences (p = 0.09) were found between thoron concentrations in Alabata and Ilishan, and both locations had significantly higher (p < 0.05) concentrations of thoron than those recorded in Akoka. A test of the influence of building types showed that radon and thoron concentrations in offices were significantly (p < 0.05) lower than those in homes. None of the thoron concentrations were zero, and almost all were higher than the corresponding radon concentrations. Some of the radon concentrations exceeded the recommended reference level of 100 Bq m-3, but all were below the action level of 300 Bq m-3. This study has shown that with high concentrations of thoron, its contributions should not be neglected in indoor radon measurements, particularly in the areas with old sedimentary and basement complex geology. It is noted that dose evaluation is required to quantify the relative contributions of radon and thoron to human exposures in the three locations. Meanwhile, occupants of buildings in the study areas should be encouraged to optimize indoor ventilation.
期刊介绍:
This journal is devoted to fundamental and applied issues in radiation research and biophysics. The topics may include:
Biophysics of ionizing radiation: radiation physics and chemistry, radiation dosimetry, radiobiology, radioecology, biophysical foundations of medical applications of radiation, and radiation protection.
Biological effects of radiation: experimental or theoretical work on molecular or cellular effects; relevance of biological effects for risk assessment; biological effects of medical applications of radiation; relevance of radiation for biosphere and in space; modelling of ecosystems; modelling of transport processes of substances in biotic systems.
Risk assessment: epidemiological studies of cancer and non-cancer effects; quantification of risk including exposures to radiation and confounding factors
Contributions to these topics may include theoretical-mathematical and experimental material, as well as description of new techniques relevant for the study of these issues. They can range from complex radiobiological phenomena to issues in health physics and environmental protection.