title: Intercomparison of environmental gamma doses measured with A NaI (Tl) survey meter and thermoluminescent dosimeters (TLDs) in the Poonch division of Azad Kashmir, Pakistan.
abstract: This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a NaI (Tl) based survey meter along with thermoluminescent dosimeters (TLDs) and estimation of excess lifetime cancer risk (ELCR), for the inhabitants of Poonch division of the Azad Kashmir, Pakistan. CaF2: Dy (TLD-200) card dosimeters were installed at height of 1 m from ground at fifteen different locations covering the entire Poonch division comprising of three districts. During three distinct two month time periods within the six month study period, all the installed dosimeters were exposed to outdoor environmental gamma radiations, retrieved and read out at Radiation Dosimetry Laboratory, Health Physics Division, PINSTECH laboratory, Islamabad. The ambient outdoor gamma dose rate measurements were also taken with NaI (Tl) based portable radiometric instrument at 1 m above the ground. To estimate the annual gamma doses, NaI (Tl) based survey data were used for one complete year following the deployment of the dosimeters. The mean annual gamma dose rates measured by TLDs and survey meter were found as 1.47±0.10 and 0.862±0.003 mGy/y respectively. Taking into account a 29% outdoor occupancy factor, the annual average effective dose rate for individuals was estimated as 0.298±0.04 and 0.175±0.03 mSv/y by TLDs and survey meter, respectively. For outdoor exposure, the ELCR was calculated from the TLD and survey meter measurements. The environmental outdoor average annual effective dose obtained in present study are less than the estimated world average terrestrial and cosmic gamma ray dose rate of 0.9 mSv/y reported in UNSCEAR 2000. The possible origins of gamma doses in the area and incompatibilities of results obtained from the two different measurement techniques are also discussed.
authors.affiliation: University of Michigan, Department of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104, USA; Department of Physics University of Azad Jammu and Kashmir Muzaffarbad, 13100, Azad Kashmir, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Rafique
authors.affiliation: University of Michigan, Department of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104, USA.
authors.forename: Kimberlee J
authors.initials: KJ
authors.lastname: Kearfott
authors.affiliation: Radiation Dosimetry Laboratory, Health Physics Division, PINSTECH, 45650, Nilore Islamabad, Pakistan.
authors.forename: Khalil
authors.initials: K
authors.lastname: Ahmad
authors.affiliation: Radiation Dosimetry Laboratory, Health Physics Division, PINSTECH, 45650, Nilore Islamabad, Pakistan.
authors.forename: Jabeen
authors.initials: J
authors.lastname: Akhter
authors.affiliation: Department of Physics University of Azad Jammu and Kashmir Muzaffarbad, 13100, Azad Kashmir, Pakistan.
authors.forename: Abdul Razzaq
authors.initials: AR
authors.lastname: Khan
authors.affiliation: Department of Physics University of Azad Jammu and Kashmir Muzaffarbad, 13100, Azad Kashmir, Pakistan.
authors.forename: Raja Azhar
authors.initials: RA
authors.lastname: Saeed
authors.affiliation: Department of Medical Physics, Nuclear Medicine, Oncology and Radiotherapy Institute, 44000, Islamabad, Pakistan.
authors.forename: Saeed Ur
authors.initials: SU
authors.lastname: Rahman
authors.affiliation: Directorate of Systems and Services, PINSTECH, 45650, Nilore Islamabad, Pakistan.
authors.lastname: Matiullah
authors.affiliation: Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), 45650, Nilore Islamabad, Pakistan.
authors.forename: Muhammad Usman
authors.initials: MU
authors.lastname: Rajput
mesh_terms: D005720:Gamma Rays / Q000009:adverse effects; D006801:Humans; D009369:Neoplasms / Q000209:etiology; D010154:Pakistan; D011834:Radiation Monitoring / Q000295:instrumentation*