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Ponciano-Rodríguez G, Gaso MI, Armienta MA, Trueta C, Morales I, Alfaro R, Segovia N. Indoor radon exposure and excess of lung cancer mortality: the case of Mexico-an ecological study. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:221-234. [PMID: 32839955 DOI: 10.1007/s10653-020-00662-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Radon is a radioactive gas that can migrate from soils and rocks and accumulate in indoor areas such as dwellings and buildings. Many studies have shown a strong association between the exposure to radon, and its decay products, and lung cancer (LC), particularly in miners. In Mexico, according to published surveys, there is evidence of radon exposure in large groups of the population, nevertheless, only few attention has been paid to its association as a risk factor for LC. The aim of this ecological study is to evaluate the excess risk of lung cancer mortality in Mexico due to indoor radon exposure. Mean radon levels per state of the Country were obtained from different publications and lung cancer mortality was obtained from the National Institute of Statistics, Geography and Informatics for the period 2001-2013. A model proposed by the International Commission on Radiological Protection to estimate the annual excess risk of LC mortality (per 105 inhabitants) per dose unit of radon was used. The average indoor radon concentrations found rank from 51 to 1863 Bq m-3, the higher average dose exposure found was 3.13 mSv year-1 in the north of the country (Chihuahua) and the mortality excess of LC cases found in the country was 10 ± 1.5 (range 1-235 deaths) per 105 inhabitants. The highest values were found mainly in the Northern part of the country, where numerous uranium deposits are found, followed by Mexico City, the most crowded and most air polluted area in the country. A positive correlation (r = 0.98 p < 0.0001) was found between the excess of LC cases and the dose of radon exposure. Although the excess risk of LC mortality associated with indoor radon found in this study was relatively low, further studies are needed in order to accurately establish its magnitude in the country.
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Affiliation(s)
- G Ponciano-Rodríguez
- Departamento de Salud Publica, Facultad de Medicina, UNAM, Ciudad Universitaria, 04510, Mexico, D.F., Mexico.
| | - M I Gaso
- ININ, Instituto Nacional de Investigaciones Nucleares, 52750, Ocoyoacac, Edo. México, Mexico
| | - M A Armienta
- IGFUNAM, Ciudad Universitaria, 04510, Mexico, D.F., Mexico
| | - C Trueta
- Instituto Nacional de Psiquiatría Ramón de la Fuente, Mexico, D.F., Mexico
| | - I Morales
- IGFUNAM, Ciudad Universitaria, 04510, Mexico, D.F., Mexico
| | - R Alfaro
- Instituto de Investigaciones en Ciencias de la Tierra, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Mexico
| | - N Segovia
- SNI, Sistema Nacional de Investigadores, Mexico, Mexico
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Mireles F, Dávila JI, García ML, Pinedo JL, López H. Evaluation of efficiency calibration parameters of the LR-115 radon detector. HEALTH PHYSICS 2010; 98 Suppl 2:S63-S68. [PMID: 20386194 DOI: 10.1097/hp.0b013e3181d27376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Measurement of 222Rn is an important research concern because of the high-energy alpha emission of its 218Po and 214Po progeny. The LR-115 passive detector is the basis of a solid-state nuclear track detector (SSNTD) whose use for radon measurements has been well established. The usage of the SSNTD technique requires calibration by comparison. The aim of this work is to evaluate the efficiency calibration parameters for the radon measurement system that three steps: (1) irradiation conditions, (2) etching conditions, and (3) track counting. The following parameters were evaluated: breakdown and counting voltages for the spark counter, detector thickness, etching time, temperature and NaOH concentration as etching conditions for the LR-115 detector. Calibrating factors of 0.035 and 0.028 tracks cm-2 Bq-1 m3 d-1 for the open- and closed-chamber radon monitors, respectively, were determined considering the best efficiency calibration parameter values.
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Affiliation(s)
- F Mireles
- Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas, Ciprés 10, Frac La Peñuela, Zacatecas, Zac., CP 98068, Mexico
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Segovia N, Gaso MI, Armienta MA. Environmental radon studies in Mexico. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2007; 29:143-53. [PMID: 17288007 DOI: 10.1007/s10653-006-9069-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Radon has been determined in soil, groundwater, and air in Mexico, both indoors and outdoors, as part of geophysical studies and to estimate effective doses as a result of radon exposure. Detection of radon has mainly been performed with solid-state nuclear track detectors (SSNTD) and, occasionally, with active detection devices based on silicon detectors or ionization chambers. The liquid scintillation technique, also, has been used for determination of radon in groundwater. The adjusted geometric mean indoor radon concentration (74 Bq m-3) in urban developments, for example Mexico City, is higher than the worldwide median concentration of radon in dwellings. In some regions, particularly hilly regions of Mexico where air pollution is high, radon concentrations are higher than action levels and the effective dose for the general population has increased. Higher soil radon levels have been found in the uranium mining areas in the northern part of the country. Groundwater radon levels are, in general, low. Soil-air radon contributing to indoor atmospheres and air pollution is the main source of increased exposure of the population.
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Affiliation(s)
- N Segovia
- Instituto de Geofisica, UNAM, Ciudad Universitaria, Circuito Exterior, C.U., Mexico, DF, 04510, Mexico
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Montero Cabrera M, Colmenero Sujo L, Villalba L, de la Cruz Gandara S, Sáenz Peinado J, Rentería Villalobos M, Sanín Aguirre L, Herrera Peraza E, Lopez J, Gardea-Torresdey J. Rn-222 air concentrations in Chihuahua State (Mexico) dwellings and in the U.S./Mexico border. Microchem J 2005. [DOI: 10.1016/j.microc.2005.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gaso M, . NS, . SP, . AL, . GP, . PP. Indoor Radon and Annual Effective Doses at a High Altitude Region in Central Mexico. ACTA ACUST UNITED AC 2005. [DOI: 10.3923/jas.2005.1356.1362] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Colmenero Sujo L, Montero Cabrera ME, Villalba L, Rentería Villalobos M, Torres Moye E, García León M, García-Tenorio R, Mireles García F, Herrera Peraza EF, Sánchez Aroche D. Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2004; 77:205-219. [PMID: 15312704 DOI: 10.1016/j.jenvrad.2004.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/11/2004] [Indexed: 05/24/2023]
Abstract
High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.
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Affiliation(s)
- L Colmenero Sujo
- Centro de Investigación en Materiales Avanzados, S.C., Complejo Industrial Chihuahua, Miguel de Cervantes 120, Chihuahua, 31109 Chih., Mexico
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Mireles F, Dávila JI, Quirino LL, Lugo JF, Pinedo JL, Ríos C. Natural soil gamma radioactivity levels and resultant population dose in the cities of Zacatecas and Guadalupe, Zacatecas, Mexico. HEALTH PHYSICS 2003; 84:368-372. [PMID: 12645772 DOI: 10.1097/00004032-200303000-00010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The study of natural gamma radioactivity was made to determine the concentrations of natural radionuclides in soil. Twenty soil samples collected in the cities of Zacatecas and Guadalupe and their suburban areas in the Mexican state of Zacatecas were analyzed by gamma-ray spectrometry to determine the activity concentrations of 226Ra, 232Th, and 40K. Gamma-spectrometry measurements were made using a hyperpure germanium detector surrounded with shielding material to reduce the background counting rate. The GammaVision-32 MCA emulation software was used for gamma-ray spectrum analysis and the TRUMP card of 2k as a MCA emulator. Conversion factors were used to calculate the dose to the population from outdoor exposure to terrestrial gamma rays. The measured activity concentration of 226Ra varies from 11 to 38 Bq kg(-1), the activity concentration of 232Th varies from 8 to 38 Bq kg(-1). The activity concentration of 40K is in the range 309-1,049 Bq kg(-1). The overall population mean outdoor terrestrial gamma dose rate is 44.94 nGy h(-1).
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Affiliation(s)
- F Mireles
- Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas, Ap. Postal 579C, Zacatecas, Zac, CP 98068, Mexico.
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Nikezić D, Baixeras C. Radon, radon progeny and equilibrium factor determination using an LR115 detector. RADIAT MEAS 1996. [DOI: 10.1016/1350-4487(95)00305-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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