The paper presents the results of assessment of natural effective radiation doses on the basis of the projected outpatient dosimetry in 70 households living in Mau and Mo village of Nam Xe, Phong Tho distrist, Lai Chau province.
91 95 61 124 164* 130 151* 68 83 90 150* 58 76 90 51 75 88 87 151* 96 35 99 84 79 26 26 78 22 62 20 24 40 67 88 65 90 57 78 67 32 Gamma dose rate (µSv.h-1) 0.57 0.63 0.59 0.65 0.37 0.54 0.55 0.60 0.60 0.67 0.58 0.68 0.35 0.40 0.37 0.44 0.39 0.42 0.49 0.52 0.53 0.58 0.50 0.50 0.67 0.76 0.64 0.76 0.50 0.55 0.55 0.56 0.51 0.53 0.42 0.45 0.41 0.49 0.27 0.38 Effective dose (mSv.year-1) 8.56 8.02 9.71 10.18 8.47 10.39 5.87 5.86 6.54 9.10 6.78 7.42 7.90 8.64 6.49 5.68 6.66 6.35 6.43 5.55 NGUYEN VAN DUNG et al TT Head of household name Indoors, outdoors 55 Vang Van Chinh (Mau) 56 Vang A Chinh (Mau) 57 Vui Mai Chac (Mo) 58 Vui Mai Binh (Mo) 59 Lo Van Chat (Mau) 60 Mai Van Cheo (Mo) 61 Tao Van Xanh (Mo) 62 Tao Van Nam (Mo) 63 Tao Van Ngan (Mo) 64 Tao Van Tinh (Mo) 65 Lo Van Coong (Mo) 66 Lo Van Cheo (Mo) 67 Lo Van on (Mo) 68 Lo Van Cao (Mo) 69 Hoang Van Chien (Mo) 70 Lo Van Ly (Mo) outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors outdoors Indoors Radon Concentration (Bq.m-3) 35 75 32 54 69 73 86 92 28 29 74 75 66 63 60 101* 41 62 105 48 55 60 79 69 98 48 101* 92 62 87 82 80 Gamma dose rate (µSv.h-1) 0.40 0.47 0.38 0.76 0.56 0.74 0.34 0.37 0.30 0.50 0.53 0.58 0.43 0.47 0.50 0.61 0.39 0.44 0.46 0.47 0.35 0.39 0.40 0.42 0.44 0.47 0.36 0.39 0.41 0.43 0.41 0.37 Effective dose (mSv.year-1) 6.20 7.65 8.65 6.31 5.02 7.57 6.25 8.25 5.71 6.30 5.37 6.12 6.20 6.62 6.50 6.09 Mau: Mau hamlets; Mo: Mo hamlets (* radon concentration in the home exceeds 100 Bq.m-3[9]) Table I shows that in 70 households, the natural radiation dose from the two main sources of radiation is gamma and radon: recommendations on the dose rate of gamma in the environment, sites with a gamma dose rate of is greater than or equal to 0.6 Sv.h-1 exceeded the radiation dose for permits for long-term housing [2] - There are 32 out of 70 households have a gamma dose rate in the house is greater than or equal to 0.6 Sv.h-1 Based on 33 ESTIMATION OF EFFECTIVE RADIATION DOSE FOR HOUSEHOLDS LIVING IN … - There are 30 out of 70 households have a radon concentration in the home is greater than 100 Bq.m-3, exceeding the allowable limit for indoor radon concentration is less than or equal to100 Bq.m-3 [9] In the coming time, Nam Xe mine will be exploited and processed to increase the level of natural radiation in the area Therefore, measures must be taken to minimize the effect of radiation on the environment in the area - There are 19 out of 70 households have total irradiation doses of two components: external irradiation by gamma irradiation and radon induced radiation is greater than or equal to 10 mSv.year-1 According to the International Commission on Radiation Safety (ICRP) [3], this is the starting point to consider interventions to reduce the radiation dose ACKNOWLEDGMENT The authors sincerely thank the leaders of the Geological and Radioactive Resources Division, Department of Natural Resources and Environment of Lai Chau and leaders of Nam Xe Commune have provided documents and created conditions for the authors in the process of field survey, data collection in the study area The reason is that families have used building materials such as bricks, sand of the locality to build houses and some families have built houses right on the rare earth ore body in the color village REFERENCES [1] Ministry of Trade and Industry, "The detailed plan for exploration, mining, processing and use of radioactive ores period to 2020, with a 2030" Hanoi, 2011 In the hamlets Mau and Mo, the mine has rare earth ores containing high levels of radioactive substances, causing high levels of natural radiation exposure for households living and working in the area [2] Ministry of Science and Technology, Circular IV CONCLUSIONS [3] International Commission on Radialogical "Provisions on control and ensure the safety of irradiated and irradiated career public", No.19/2012/TT-BKHCN, Hanoi, 2012 Protection - The 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, 2007 Survey results of radioactive environment inside and outside the house for the households are living, working in Mau and Mo hamlets, Nam Xe rare earth mining, Phong Tho, Lai Chau based on method of calculation the natural radiation background on the population under UNSCEAR has identified 32 out of 70 households with a radiation dose rate of is greater than or equal to 0.6 Sv.h-1, which is a recommended dose reduction measure in permanent residential settings; there are 15 out of 70 households receive an annual dose of is greater than or equal to 10 mSv.year-1, which is a high dose, which is the start of the dose reduction measures [4] Le Khanh Phon, "Investigating the epidemiology of people living in the rare earth mine of Phong Tho district, Tam Duong province" Final report on provincial level code 09.10.ĐTLC-KY Library of University of Mining and Geology, 2014 [5] Nguyen Van Dung et al., Research and development of radiation emission models for the environment due to ore exploration activities containing rare earth rock, Nam Tho, Phong Tho, Lai Chau effects of radioactivity on the environment, research topics at the grassroots level Library of Hanoi University of Mining and Geology, Hanoi, 2013 34 NGUYEN VAN DUNG et al [6] Nguyen Phuong, Final report scientific subjects [9] National Standard 7889:2008 Natural gas and technology ministry level, “Impact assessment of radioactivity on the environment in some mines and proposing prevention solutions” Code number: B2013-02-15, 2015 radon concentration in the house - general level and method of measurement [10] UNSCEAR, 2000 (Scientific A nnex B) ANNEX A: Dose assesment methodologies ANNEX B: Exposures from radiation sources [7] National standard TCVN 9415:2012 Environmental geological survey - equivalent dose determination method, Hanoi, 2012 [8] National standardTCVN9416:2012 Investigation and assessment of environmental geological methods of radioactive gas 35 ... the epidemiology of people living in the rare earth mine of Phong Tho district, Tam Duong province" Final report on provincial level code 09.10.ĐTLC-KY Library of University of Mining and Geology,... rare earth ores containing high levels of radioactive substances, causing high levels of natural radiation exposure for households living and working in the area [2] Ministry of Science and Technology,... Based on 33 ESTIMATION OF EFFECTIVE RADIATION DOSE FOR HOUSEHOLDS LIVING IN … - There are 30 out of 70 households have a radon concentration in the home is greater than 100 Bq.m-3, exceeding the