Assessment of Natural Radiation Exposure Due to 222Rn and External Radiation Sources: Case of the Far North, Cameroon

Abstract This paper assesses public exposure to natural radioactivity from radon and external radiation sources in the Far North region, Cameroon, and studies the correlation between radon data obtained using several techniques. The RADTRAK, RadonEye, and Markus 10 detectors were used to measure radon concentrations in dwellings and soil, respectively. To understand radon variations in the study area, a correlation coefficient between radon in soil and in dwellings was determined. The ambient equivalent dose rate was measured using a RadEye PRD-ER, and the effective doses from internal and external radiation were determined. In soil, 20% of the measuring points had a concentration above 50 kBq m−3, the action value for radon exposure from soil according to Swedish Radiation Protection Institute regulations. After 90 d of measurement using RADTRAK, half of the concentrations in the dwellings were greater than or equal to 160 Bq m−3, which is above the WHO reference level of 100 Bq m−3. The ambient equivalent dose rate and the external and internal radiation effective dose were 0.08 μSv h−1, 0.6 mSv y−1, and 2.86 mSv y−1, respectively. These results reveal a strong correlation between the radioactivity level of a locality and its geological and mineralogical structure. Although these different results in general do not present a very high risk of radiological exposure for the public, it is nevertheless necessary that the rules of radiation protection are respected in order to reduce it.

[1]  R. Schumann,et al.  A Preliminary Evaluation of Environmental Factors Influencing Day-to-Day and Seasonal Soil-Gas Radon Concentrations , 2020 .

[2]  Saïdou,et al.  Indoor Radon Measurements Using Radon Track Detectors and Electret Ionization Chambers in the Bauxite-Bearing Areas of Southern Adamawa, Cameroon , 2020, International journal of environmental research and public health.

[3]  D. Maletic,et al.  Radon variability due to floor level in two typical residential buildings in Serbia , 2020 .

[4]  M. Sridhar,et al.  Determination of Residential Soil Gas Radon Risk Indices Over the Lithological Units of a Southwestern Nigeria University , 2020, Scientific Reports.

[5]  P. Kurttio,et al.  Indoor Radon Measurements in Finnish Daycare Centers and Schools—Enforcement of the Radiation Act , 2020, International journal of environmental research and public health.

[6]  S. Tokonami,et al.  The Importance of Direct Progeny Measurements for Correct Estimation of Effective Dose Due to Radon and Thoron , 2020, Frontiers in Public Health.

[7]  Z. Žunić,et al.  DIURNAL AND SPATIAL VARIATIONS OF RADON CONCENTRATION AND ITS INFLUENCE ON IONIZATION OF AIR , 2020 .

[8]  D. Bongue,et al.  SIMULTANEOUS INDOOR RADON, THORON AND THORON PROGENY MEASUREMENTS IN BETARE-OYA GOLD MINING AREAS, EASTERN CAMEROON. , 2019, Radiation protection dosimetry.

[9]  Saïdou-,et al.  Natural radioactivity measurements in drinking water and ingestion dose assessment: case of the uranium bearing region of Poli, Cameroon , 2019, International Journal of Low Radiation.

[10]  S. Tokonami,et al.  Simultaneous measurements of indoor radon and thoron and inhalation dose assessment in Douala City, Cameroon , 2019, Isotopes in environmental and health studies.

[11]  S. Tokonami,et al.  Natural radioactivity measurements and external dose estimation by car-borne survey in Douala city, Cameroon , 2018, Radioprotection.

[12]  G. Malinovsky,et al.  RADON MEASUREMENTS IN KINDERGARTENS IN URAL REGION (RUSSIA) , 2017, Radiation protection dosimetry.

[13]  S. Akiba,et al.  Radiation dose due to radon and thoron progeny inhalation in high-level natural radiation areas of Kerala, India , 2017, Journal of radiological protection : official journal of the Society for Radiological Protection.

[14]  Ashutosh Kumar,et al.  Dose assessment from exposure to radon, thoron and their progeny concentrations in the dwellings of sub-mountainous region of Jammu & Kashmir, India , 2017, Journal of Radioanalytical and Nuclear Chemistry.

[15]  O. Motapon,et al.  Determination of 226Ra, 232Th, 40K, 235U and 238U activity concentration and public dose assessment in soil samples from bauxite core deposits in Western Cameroon , 2016, SpringerPlus.

[16]  S. Tokonami,et al.  Comparative study of natural radiation exposure to the public in three uranium and oil regions of Cameroon , 2015 .

[17]  S. Akiba,et al.  Estimation of External Dose by Car-Borne Survey in Kerala, India , 2015, PloS one.

[18]  India.,et al.  Measurement of radon activity in soil gas using RAD 7 in the Environs of Chitradurga District , Karnataka , , 2015 .

[19]  R. Somashekar,et al.  Temporal variation in Indoor air and soil-gas radon concentrations , 2015 .

[20]  Saïdou-,et al.  Indoor radon measurements in the uranium regions of Poli and Lolodorf, Cameroon. , 2014, Journal of environmental radioactivity.

[21]  V. Duggal,et al.  Measurement of soil-gas radon in some areas of northern Rajasthan, India , 2014, Journal of Earth System Science.

[22]  R. Mehra,et al.  Estimation of annual effective dose due to Radon level in indoor air and soil gas in Hamirpur district of Himachal Pradesh , 2014 .

[23]  N. Damla,et al.  Radon survey and soil gamma doses in primary schools of Batman, Turkey , 2014 .

[24]  N. Damla,et al.  Radon survey and soil gamma doses in primary schools of Batman, Turkey , 2014, Isotopes in environmental and health studies.

[25]  C. Szabó,et al.  Mapping the geogenic radon potential: methodology and spatial analysis for central Hungary. , 2014, Journal of environmental radioactivity.

[26]  N. Hamada,et al.  Radiological protection against radon exposure , 2014 .

[27]  J. D. Appleton,et al.  Geological controls on radon potential in England , 2013 .

[28]  R. C. Ramola,et al.  Measurements of radon flux and soil-gas radon concentration along the Main Central Thrust, Garhwal Himalaya, using SRM and RAD7 detectors , 2013, Acta Geophysica.

[29]  W. Alharbi,et al.  Measurement of radon concentrations in soil and the extent of their impact on the environment from Al-Qassim, Saudi Arabia , 2013 .

[30]  P. Bossew,et al.  The European map of the geogenic radon potential , 2013, Journal of radiological protection : official journal of the Society for Radiological Protection.

[31]  R. C. Ramola,et al.  Deposition-based passive monitors for assigning radon, thoron inhalation doses for epidemiological studies. , 2012, Radiation protection dosimetry.

[32]  Φίλιππος Χ. Τσιμπόγλου,et al.  Report to the General Assembly , 2012 .

[33]  Ekobena Fouda Henri,et al.  Determination of Uranium in Rocks and Soils of South Cameroon by γ-ray Spectrometry , 2011 .

[34]  B. Tracy,et al.  RADON EMANATION IN SASKATCHEWAN SOILS , 2011, Health physics.

[35]  Saïdou,et al.  Natural radioactivity measurements and dose calculations to the public: Case of the uranium-bearing region of Poli in Cameroon , 2011 .

[36]  M. Cushing,et al.  Mapping of the geogenic radon potential in France to improve radon risk management: methodology and first application to region Bourgogne. , 2010, Journal of environmental radioactivity.

[37]  N. Ali,et al.  Estimation of mean annual effective dose through radon concentration in the water and indoor air of Islamabad and Murree. , 2010, Radiation protection dosimetry.

[38]  E. Blanchardon,et al.  Lung Cancer Risk from Radon and Progeny and Statement on Radon , 2010, Annals of the ICRP.

[39]  David S.-K. Ting,et al.  WHO Handbook on Indoor Radon: A Public Health Perspective , 2010 .

[40]  E. Tóth,et al.  Indoor radon mapping and its relation to geology in Hungary , 2009 .

[41]  C. Baixeras,et al.  Indoor radon levels and their dynamics in relation with the geological characteristics of La Garrotxa, Spain , 2008 .

[42]  R. C. Ramola,et al.  Radon exhalation rate from soil samples of South Kumaun Lesser Himalayas, India , 2008 .

[43]  R. C. Ramola,et al.  Variation in radon concentration and terrestrial gamma radiation dose rates in relation to the lithology in southern part of Kumaon Himalaya, India , 2006 .

[44]  D. Caillaud,et al.  [Indoor radon exposure and lung cancer risk. Results of an epidemiological study carried out in France]. , 2005, Revue des maladies respiratoires.

[45]  J. Kemski,et al.  Radon transfer from ground to houses and prediction of indoor radon in Germany based on geological information , 2005 .

[46]  R Doll,et al.  Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies , 2004, BMJ : British Medical Journal.

[47]  A. Sundal,et al.  The influence of geological factors on indoor radon concentrations in Norway. , 2004, The Science of the total environment.

[48]  Nations United sources and effects of ionizing radiation , 2000 .

[49]  S. A. Durrani,et al.  Radon measurements by etched track detectors : applications in radiation protection, earth sciences and the environment , 1997 .

[50]  N. Varley,et al.  Radon and its Correlation with Some Geological Features of the South-West of England , 1992 .

[51]  John A. S. Adams,et al.  Thorium, uranium and potassium in some sandstones , 1958 .