List of Radon Level by Country (Please send comments and corrections to: Jan_Zielinski@hc-sc.gc.ca)
Country Name WHO Code ISO Population 106 a AM GM GSD Max Classification of AMb Source OriginalReference for AM, possibly GM, GSD, Max
Algeria 1010 DZA 32.85 30     140   UNSCEAR 2000 report Cherouati, D.E. and S. Djeffal. Measurements of radon and radon daughters in dwellings in Algiers. Radia. Prot. Dosim. 25: 137-139 (1988).
Egypt 1125 EGY 74.03 9     24   UNSCEAR 2000 report Kenawy, M.A. and A.A. Morsy. Measurements of environmental radon-222 concentration in indoor and outdoors in Egypt. Nucl. Tracks Radiat. Meas. 19:343-345 (1991).
Ghana 1180 GHA 22.11       340   UNSCEAR 2000 report Oppon, O. C.; Aniagyei, H. M., and  Kyere, A. W. K. Monitoring of natural background radiation in some Ghanaian homes.   In: M. Sohrabi, J. U. Ahmed S. A. Durrani, eds.  Proceedings of an international conference on high levels of natural radiation. 3-7 November, 1990.  Ramsar, Iran. Vienna., Austria: IAEA; 1993: 385-389. 
Armenia 4007 ARM 3.02 104   1.3 216   UNSCEAR 2000 report  
China 3068 CHN 1315.84 43.8 34.4   596 CWA UNSCEAR 2006 survey Shang, B., D. Xu, H. Cui, L. Zhang, B. Chen, J. Wu, Y. Wang, Y. Gao, Z. Li and Q. Sun. Radon Levels Survey in Residences in China. National Institute for Radiological Protection, China (2006).
China, HK   CNH 7.04 41     140   UNSCEAR 2000 report Tso, M.W. and J.K.C. Leung. Survey of indoor 222Rn concentrations in Hong Kong. Health Phys. 60: 237-241 (1991).
China, Taiwan 3070 CNT 22.89 10 8.5 0.6 63.5 RA UNSCEAR 2004 survey Chen C.J.,Liu C.C., Lin, Y.M. Surveillance of indoor and outdoor radon concentrations in Taiwan. Nucl. Sci. J. 31(2),117-128 (1994) (in Chinese).
Cyprus 3080 CYP 0.84 7 7 2.6 78   UNSCEAR 2000 report Christofides, S. and Christodoulides, G. Airborne 222Rn concentration in Cypriot houses. Health Physics. 1993 Apr; 64(4):392-396; and  Anastasiou, T.; Tsertos, H.; Christofides, S., and Christodoulides, G. Indoor radon (222Rn) concentration measurements in Cyprus using high-sensitivity portable detectors. Journal of Environmental Radioactivity. 2003; 68(2):159-69.
India 3100 IND 1103.37 57 42 2.2 210   UNSCEAR 2000 report Subba Ramu, M. C.; Shaikh, A. N.; Muraleedharan, T. S.; Ramachandran, T. V., and Nambi, K. S. V. Environmental radon monitoring in India: a plea for national effort. S. Kumar S. and A. R. Reddy  , eds. Proceedings of the National Conference on Particle Tracks in Solids, Jodhpur, India, 9-11 October 1991.:  Jodhpur, India: Defense Laboratory ; 1991: 11. 
Indonesia 3110 IDN 222.78 35.1 35.1 1.2 165 CWA UNSCEAR 2001 survey Bunawas, S. and Warsona, A.  Distribution of Radon Concentration in Dwelling and Lung Cancer Risk.  Proceedings  of  The National Scientific Meeting on Safety, Health and Environment. 23-24 October 2001  ; Jakarta, Indonesia.  2001.
Iran 3130 IRN 69.52 82     3070 CWA UNSCEAR 2002 survey  
Israel 3150 ISR 7.15 47       CWA WWW Haquin G. etal. Radon Survey of Israel. Proceeding of the Conference of Nuclear Societies in Israel, Dead Sea, February 2006.
Japan 3160 JPN 128.08 16 13 1.8 208   UNSCEAR 2000 report Fujimoto, K., S. Kobayashi, M. Uchiyama et al. Nationwide indoor radon survey in Japan. Hoken Butsuri 32: 41-51 (1997);    Sanada, T., K.Fujimoto, K.Miyano et al. Measurements of nationwide indoor radon concentration in Japan. Environ. Radioact. 45(2): 129-137 (1999)
Kazakhstan 4182 KAZ 14.83       5000 CWA UNSCEAR 2001 survey  
Kuwait 3190 KWT 2.69 14 10.6 0.7 119.2 CWA UNSCEAR 2005 survey  
Malaysia 3236 MYS 27.25 14     20   UNSCEAR 2000 report  
Pakistan 3290 PAK 157.94 30     83   UNSCEAR 2000 report Tufail, M., M. Amin, W. Akhtar et al. Radon concentration in some houses of Islamabad and Rawalpindi, Pakistan. Nucl. Tracks Radiat. Meas. 19: 429-430 (1991).
Palestine   PSE 0.40 34     105   UNSCEAR 2006 survey Yassin, S. S. and Steck, D. J. A preliminary survey of radon and radon progeny concentrations throughout the Gaza Strip in Palestine.  W. Burkart; M. Sohrabi, and A. Bayer, eds.  Proceedings of the 5th International Conference on High Levels of Natural Radiation and Radon Areas: Radiation Dose and Health Effects. Munich. 4-7 September 2000.Amsterdam, Netherlands: Elsevier ; 2002  ICS 1225.
Philippines 3300 PHL 83.05 23 22 1.1 62 CWA UNSCEAR 2001 survey Info provided in UNSCEAR Survey 2006 is problematic
Russia 4272 RUS 143.20 55         WHO 2007 survey  
Saudi Arabia 3340 SAU 24.57 16     36   UNSCEAR 2006 survey Abu-Jarad, F. and Al-Jarallah, M. I. Radon in Saudi Houses. Radiation Protection Dosimetry. 1986; 14(3):243-249.
South Korea 3325 KOR 48.85 53.4 43.3 1.8 1350 CWA UNSCEAR 2001 survey Kim, C. K.; Lee, S. C.; Lee, D. M.; Chang, B. U.; Rho, B. H., and Kang, H. D. Nationwide survey of radon levels in Korea. Health Physics. 2003 Mar; 84(3):354-360.
Syria 3370 SYR 19.04 44     520   UNSCEAR 2000 report Othman, I., M. Hushari, G. Raja et al. Radon in Syrian houses. J. Radiol. Prot. 16(1): 45-50 (1996).
Thailand 3380 THA 64.23 23 16 1.2 480   UNSCEAR 2000 report  
Albania 4005 ALB 3.13 120 105 2.0 270   UNSCEAR 2000 report  
Austria 4010 AUT 8.19 99     1100   MEDLINE_2007 Friedmann, H. Final results of the Austrian Radon Project. Health Physics . 2005 Oct; 89(4):339-48.
Belarus 4018 BLR 9.76 31.8     221 CWA UNSCEAR 2006 survey  
Belgium 4020 BEL 10.42 48 38 2.0 12000 CWA UNSCEAR 2001 survey Poffijn, A.; Marijns, R.; Vanmarcke, H., and Uyttenhove, J. Results of a preliminary survey on radon in Belgium. Science of the Total Environment. 1985 Oct; 45:335-342.;  and Zh, H. C.; Charlet, J. M., and Poffijn, A. Radon risk mapping in southern Belgium: an application of geostatistical and GIS techniques. Science of the Total Environment. 2001 May 14; 272(1-3):203-210.
Bulgaria 4030 BGR 7.73 29 22 2.1 250 CWA UNSCEAR 2003 survey  
Croatia 4038 HRV 4.55 68 50 2.3 751 CWA EURO_MAP_2005 Radolic, V.; Vukovic, B.; Stanic, D.; Katic, M.; Faj, Z.; Šuveljak, B.; Lukaevic, I.; Faj, D.; Lukic, M., and Planinic, J. National survey of indoor radon levels in Croatia. Journal of Radioanalytical and Nuclear Chemistry. 2006; 269(1):87-90.
Czech Republic 4045 CZE 10.22 140       CWA EURO_MAP_2005 Hulka, J. and Thomas, J. National Radon Programme : 20 years of experience in . In. Proceedings of the 11th Congress of the International Radiation Protection Association (IRPA-11) Madrid,  Spain 23-28 May, 2004.; Madrid,, Spain.  2004..
Denmark 4050 DNK 5.43 59 39 2.2 1200 CWA UNSCEAR 2001 survey Andersen, C. E.; Ulbak, K.; Damkjaer, A., and Gravesen, P. Radon I danske boliger.  (in Danish with English summary). Copenhagen, Denmark : National Institute of Radiation Hygiene; 2001; ISBN: 87-90951-71-9..;  and Statens Institut for Stralehygiejne. Naturlig straling I danske boliger (in Danish). 1987
Estonia 4055 EST 1.33 60      1040 CWA EURO_MAP_2005 Pahapill, L.; Rulkov, A., and Rajamäe, R. Radon in Estonian dwellings - Results from a National Radon Survey. SSI rapport:2003:16, ISSN 0282-4434.  2003 Oct.; and Petersell, V. Ĺkerblom G.; Ek, B.; Enel, M.; Mőttus, V., and Täht, K. Radon risk map of Estonia. Explanatory text to the radon risk map set of Estonia at scale of 1:500 000.  SSI Report 2005:16/SGU Dnr. 08-466/2002. Tallinn-Stockholm ; 2005; ISBN:  9985-815-55-6.
Finland 4070 FIN 5.25 120 84 2.1 20000 CWA UNSCEAR 2004 survey Arvela, H. Population distribution of doses from natural radiation in Finland  W. Burkart; M. Sohrabi, and A. Bayer, eds. Proceedings of the 5th International Conference on High Levels of Natural Radiation and Radon Areas: Radiation Dose and Health Effects. Munich. 4-7 September 2000.Amsterdam, Netherlands: Elsevier ; 2002   ICS 1225..; and  Arvela, H; Mäkeläinen, I, and Castren, 0.  Otantatutkimus asuntojen radonista Suomessa  [Radiation in a sample of Finnish houses].  Helsinki: Finnish Centre for Radiation and Nuclear Safety; 1992. (STUK-A108).
France 4080 FRA 60.50 63     4968 CWA MEDLINE_2007 Billon, S.; Morin, A.; Caer, S.; Baysson, H.; Gambard, J. P.; Backe, J. C.; Rannou, A.; Tirmarche, M., and Laurier, D. French population exposure to radon, terrestrial gamma and cosmic rays. Radiation Protection Dosimetry. 2005 Apr 28; 113(3):314-320.; and Baysson, H.; Billon, S.; Laurier, D.; Rogel, A., and Tirmarche, M. Seasonal correction factors for estimating radon exposure in dwellings in France. Radiation Protection Dosimetry. 2003 May 2; 104(3):245-252.
Germany 4085 DEU 82.69 49 37 2.0 10000 CWA WHO 2007 survey S. Menzler; A. Schaffrath Rosario; H.E. Wichmann, and L. Kreienbrock . Abschätzung des attributablen
Lungenkrebsrisikos in Deutschland durch Radon in Wohnungen. Landsberg am Lech: Ecomed
Verlag; 2006.
Greece 4140 GRC 11.12 55 44 2.4 1700 CWA UNSCEAR 2006 survey Nikolopoulos, D.; Louizi, A.; Koukouliou, V.; Serefoglou, A.; Georgiou, E.; Ntalles, K., and Proukakis, C. Radon survey in Greece--risk assesment. Journal of Environmental Radioactivity. 2002; 63(2):173-186.
Hungary 4150 HUN 10.10 82 62 2.1 58000 CWA MEDLINE_2007 Hamori, K.; Toth, E.; Pal, L.; Koteles, G.; Losonci, A., and Minda, M. Evaluation of indoor radon measurements in Hungary. Journal of Environmental Radioactivity. 2006; 88(2):189-98.
Iceland 4160 ISL 0.29 10     26 CWA UNSCEAR 2006 survey Ennow, K. R. and Magnusson, S. M. Natural radiation in Iceland and the Faroe Islands. National Institute of Radiation Hygiene, Copenhagen. SIS Report November 1982.
Ireland 4170 IRL 4.15 89 57 2.4 1924 CWA UNSCEAR 2001 survey Marsh D. 1991. Radiation mapping and soil radioactivity in the Republic of Ireland. MSc Thesis University of Dublin. Ireland.; Fennell, S. G.; Mackin, G. M.;  Madden, J. S.; McGarry, A. T.; Duffy, J. T.; O'Colmain, M.; Colgan, P. A., and Pollard, D. Radon in Dwellings. The Irish National Radon Survey. Dublin, Ireland: Radiological Protection Institute of Ireland; 2002. (Report RPII-02/1).
Italy 4180 ITA 58.09 70 52 2.1 1040 CWA UNSCEAR 2006 Survey Bochicchio, F.; Campos-Venuti, G.; Piermattei, S.; Nuccetelli, C.; Risica, S.; Tommasino, L.; Torri, G.; Magnoni, M.; Agnesod, G.; Sgorbati, G.; Bonomi, M.; Minach, L.; Trotti, F.; Malisan, M. R.; Maggiolo, S.; Gaidolfi, L.; Giannardi, C.; Rongoni, A.; Lombardi, M.; Cherubini, G.; D'Ostilio, S.; Cristofaro, C.; Pugliese, M.; Martucci, V.; Crispino, A.; Cuzzocrea, P.; Sansone Santamaria, A., and Cappai, M.  Annual average and seasonal variations of residential radon concentration for all the Italian Regions: Proceedings of the 22nd International Conference on Nuclear Tracks in Solids.  Radiation Measurements. 2005 Nov; 40(2-6):686-694.
Latvia 4186 LVA 2.31 70         WHO 2007 survey  
Liechtenstein   LIE 0.03 80     1098   UNSCEAR 2001 survey  
Lithuania 4188 LTU 3.43 55 36.5   636 CWA UNSCEAR 2004 survey Morkunas, G. and Akerblom, G. The outcome of the Lithuanian radon survey. Science of the Total Environment. 2001 May 14; 272(1-3):243-244.;   Griciene, B.;  and Ladygiene, R.; Morkunas, G., and Pilkyte, L. Current status of internal dosimetry in Lithuania. Radiation Protection Dosimetry. 2003; 105(1-4):491-494.
Luxembourg 4190 LUX 0.46 110 70 2.0 2500 CWA UNSCEAR 2004 survey  
Montenegro 4350 SCG 0.63 184 110 2.7 1128 CWA UNSCEAR 2001 survey Center for Ecotoxicological Research of Montenegro. Program of systematic investigation of radionuclide contents in Montenegro environment, Chapter IX: Radon measurements, years 1999;2000;2001.
Netherlands 4210 NLD 16.30 23 18 1.6 380   UNSCEAR 2000 report Stoop, P.; Glastra, P.; Hiemstra, Y.; Hiemstra, Y., and Lembrechts, J. Results of the second Dutch national survey on radon in dwellings. RIVM Report No. 610058006.   1998.
Norway 4220 NOR 4.62 89     50000 CWA EURO_MAP_2005 Jensen, C. L. ; Strand, T.; Ramberg, G. B.; Ruden, L., and Anestad, K. The Norwegian radon mapping and remediation program. In. Proceedings of the 11th Congress of the International Radiation Protection Association (IRPA-11) Madrid,  Spain 23-28 May, 2004.; Madrid,, Spain.  2004.
Poland 4230 POL 38.53 49 31 2.3 3260 CWA UNSCEAR 2006 survey Jajielak J.,  Biernacka M., Henschke J., Sosińska A.. Radiation Atlas of Poland 1997. Aries, ISBN 83-85787-22-4, (1998).
Portugal 4240 PRT 10.49 62 45 2.2 2700   UNSCEAR 2000 report Faisca, M. C.; Teixeira, M. M. G. R., and Bettencourt, A. O. Indoor radon concentrations in Portugal - a national survey. Radiation Protection Dosimetry. 1992; 45: 465-467.
Romania 4270 ROU 21.71 50     24000 CWA WHO 2007 survey Iacob, O.; Grecea, C., and Botezatu, E. Population exposure to inhaled radon and thoron progeny.J.P. McLaughlin; E.S. Simopoulos, and F. Steinhäusler, eds. Seventh International Symposium on the Natural Radiation Environment (NRE-VII) Rhodes, Greece, 20-24 May 2002.Amsterdam, Netherlands: Elsevier ; 2005.
Russia 4272 RUS 143.20 55         WHO 2007 survey  
Slovakia 4274 SVK 5.40 87     3750   UNSCEAR 2000 report  
Slovenia 4276 SVN 1.97 87 60 2.2 1330   UNSCEAR 2000 report Krizman, M.; Ilic, R.; Skvarc J. , and Jeran, Z. A national survey of indoor radon concentrations in dwellings in Slovenia. D. Glavic-Cindro, ed. Proceedings of International Radiation Protection Association (IRPA) Regional Symposium on Radiation Protection in Neighbouring Countries in Central Europe.; Portoroz,Slovenia. Ljubljana, Slovenia:  Josef .Stefan Institute; 1995: 66-70.
Spain 4280 ESP 45.06 90.4 45.7 2.9 15400 CWA UNSCEAR 2006 survey Quindos, L. S.; Fernandez, P. L.; Sainz, C.; Gomez, J.; Matarranz, J. L., and Suarez Mahou, E. The Spanish experience on HBRA: High Levels of Natural Radiation and Radon Areas: Radiation Dose and Health Effects. International Congress Series. 1276, 2005 Feb: 50-53.; and Data from the  CSN (Consejo de Seguridad Nuclear or Spanish Nuclear Security Agency) on-line radiological monitoring network, years 2002-03-04. 
Sweden 4290 SWE 9.04 108 56   84000 CWA UNSCEAR 2002 survey Swedjemark, G. A.; Mellander, H., and Mjones, L. Radon levels in the 1988 Swedish housing stock . In: P. Kalliokoski; M. Jantunen, and O. Seppaenen, eds.  Proceedings of the Sixth International Conference on Indoor Air Quality and Climate,  Indoor Air '93: Particles, microbes, radon. Helsinki, 4-8 July 1993.Otaniemi, Finland: Helsinki University of Technology; 1993: 491-496.; and Swedjemark, G. A.; Mellander, H., and Mjönes, L. Radon . In: U. Norlén  and K. Anderson, (eds.).  The indoor climate in Swedish residential buildings (in Swedish with English abstract). Stockholm , Sweden: Swedish Building Research Institute; 1993 (Report TN:30).
Switzerland 4300 CHE 7.25 73 59 1.8 15000 CWA UNSCEAR 2006 survey Menzler, S. and Kreienbrock, L. Attributive Risiken durch Radon in der Schweiz: Abschlussbericht. Im Auftrag des Bundesamtes für Gesundheit, Bern, Schweiz (Bericht) Hannover: Institut für Biometrie, Epidemiologie und Informationsverarbeitung, Stiftung Tierärztliche Hochschule, 2005, S. 1-180.  2005.; and CPR.  Otantatutkimus asuntojen radonista Suomessa  [Radiation in a sample of Finnish houses].Analyse des contributions ŕ l’irradiation de la population Suisse en 2004. Berne, Suisse: Commission fédérale de la protection contre les radiations et de surveillance de la radioactivité (CPR) ; 2005.
United Kingdom 4308 GBR 59.67 20 14 3.2 17000 CWA UNSCEAR 2000 report Wrixon, A. D. ; Green, B. M. R.; Lomas, P. R.; Miles, J. C. H.; Cliff, K. D.; Francis, E. A.; Driscoll, C. M. H.; James, A. C., and O'Riordan, M. C. Natural radiation exposure in UK dwellings.  Chilton , United Kingdom: National Radiological Protection Board; 1988. (Report NRPB-R190).; and Gunby, J. A.; Darby, S. C.; Miles, J. C.; Green, B. M., and Cox, D. R. Factors affecting indoor radon concentrations in the United Kingdom. Health Physics. 1993 Jan; 64(1):2-12.
Canada 2090 CAN 32.27 28.35 11.2 3.9 1720 CWA JMZ Letourneau, E. G.; Krewski, D.; Zielinski, J. M., and McGregor, R. G. Cost effectiveness of radon mitigation in Canada. Radiation Protection Dosimetry. 1992; 45:593-598.;  and Letourneau, E. G.; McGregor, R. G., and Walker, W. B. Design and interpretation of large surveys for indoor exposure to radon daughters . Radiation Protection Dosimetry. 1984; 7(1):303-308.
Cuba 2150 CUB 11.27 7.7 5.2 3.3 15.3 CWA UNSCEAR 2004 survey Tomas Zerquera, J.; Prendes Alonso, M.; Fernandez Gomez, I. M.; Rodriguez Castro, G. V.; Martinez Ricardo, N.; Lopez Bejerano, G.; Ara do Lopez, J. O.; Acosta Rodriguez, N.; Carrazana Gonzalez, J.; Brigido Flores, O.; Hernandez Perez, A., and  Diaz Rizo, O. Studies on internal exposure doses received by the cuban population due to the intake of radionuclides from the environmental sources. Radiation Protection Dosimetry. 2006 Dec 1; 121(2):168-174.;  and  Tomas Zerquera, J.; Perez Sanchez, D.; Prendes Alonso, M. Brigido Flores O., and Hernández Pérez, A. Study on External Exposure Doses Received by the Cuban Population from Environmental Radiation Sources. Radiation Protection Dosimetry. 2001 May 1; 95(1):49-52.
Mexico 2310 MEX 107.03 140 90   1193   UNSCEAR 2006 survey Martinez, T.; Cabrera, L.; Oliveres, J. L., and Gonzalez, P. Radon and thoron levels in Mexico city dwellings.  Proceedings of the V Regional Congress on Radiation Protection and Safety.  Recife, Brazil. Brasil; 2001.; and Canoba, A.; López, F. O.; Arnaud, M. I.; Oliveira, A. A.; Neman, R. S.; Hadler, J. C.; Iunes, P. J.; Paulo, S. R.; Osorio, A. M.; Aparecido, R.; Rodríguez, C.; Moreno, V.; Vasquez, R.; Espinosa, G.; Golzarri; J. I. ; Martínez, T.; Navarrete, M.; Cabrera, I.; Segovia, N.; Peńa, P.; Taméz, E.; Pereyra, P.; López-; Herrera, M. E., and Sajo-Bohus, L. Indoor radon measurements in six Latin American countries. Geofisica Internacional. 2002; 41(4):453-457.
United States 2450 USA 298.21 46 25 3.1   CWA UNSCEAR 2000 report Marcinowski, F.; Lucas, R. M., and Yeager, W. M. National and regional distributions of airborne radon concentrations in U.S. homes. Health Physics. 1994 Jun; 66(6):699-706.; and United States Environmental Protection Agency. National residential radon survey. EPA 402/R-92-011.  1992
Australia 5020 AUS 21.05 11 8 2.1 420   UNSCEAR 2000 report Langroo, M. K.; Wise, K. N.; Duggleby, J. C., and Kotler, L. H. A Nation-Wide Survey of Radon and Gamma Radiation Levels in Australian Homes. ARL/TR090. ISSN 0157-1400, April 1990. ; and Langroo, M. K.; Wise, K. N.; Duggleby, J. C., and Kotler, L. H. A nationwide survey of 222Rn and gamma radiation levels in Australian homes. Health Physics . 1991 Dec; 61(6):753-761..
New Zealand 5150 NZL 4.03 21.5 19.5   80 CWA UNSCEAR 2001 survey  
Argentina 2020 ARG 38.75 40     286 CWA WHO 2007 survey Canoba, A., López, F. O., Arnaud, M. I., Oliveira, A. A. , Neman, R. S., Hadler, J. C., Iunes, P. J., Paulo, S. R., Osorio, A. M., Aparecido, R., Rodríguez, C., Moreno, V., Vasquez, R., Espinosa, G., Golzarri, J. I. , Martínez, T., Navarrete, M., Cabrera, I., Segovia, N., Peńa, P., Taméz, E., Pereyra, P., López-, Herrera, M. E., and Sajo-Bohus, L. 2002. Indoor radon measurements in six Latin American countries. Geofisica Internacional 41:453-457.
Brazil 2070 BRA 186.40 81.95     310   UNSCEAR 2006 survey Canoba A. etal. Indoor radon measurements in six Latin American countries. Geofisica Internacional 41(4):453-457, 2002.
Chile 2120 CHL 16.30 25     86   UNSCEAR 2000 report Stuardo, E. Natural radiation measurements in Chile. Radiation Protection Dosimetry. 1996; 67(2):129-133..
Ecuador 2180 ECU 13.23 94     226 CWA WHO 2007 survey Canoba A. etal. Indoor radon measurements in six Latin American countries. Geofisica Internacional 41(4):453-457, 2002.
Paraguay 2360 PRY 6.16 28     51   UNSCEAR 2000 report  
Peru 2370 PER 27.97 32.29     50.2   UNSCEAR 2006 survey Canoba A. etal. Indoor radon measurements in six Latin American countries. Geofisica Internacional 41(4):453-457, 2002.
Venezuela 2470 VEN 26.75 52.5     346   UNSCEAR 2006 survey Canoba A. etal. Indoor radon measurements in six Latin American countries. Geofisica Internacional 41(4):453-457, 2002.
a Data are estimates for July 2005, taken from the United Nations World Populations Prospects Report (2004 revision).
 b CWA - Country Wide Average;  RA - Regional Average.