scholarly journals Assessment of Background Radiation, Annual Effective Dose and Excess Lifetime Cancer Risk in Gonabad City

Author(s):  
Hamed Masoumi ◽  
Mohammad Keshtkar

Purpose: Humans are always exposed to ionizing radiation from their environment, which can have destructive effects. This study aimed to measure background gamma radiation and estimate annual effective dose and excess cancer risk in Gonabad city. Materials and Methods: The dose rate due to indoor and outdoor background radiation was measured by RDS-30 radiation survey meter at five zones on the map, including North, South, East, West, and center. Then, the annual effective dose and excess lifetime cancer risk were calculated by associated equations. Results: Mean dose rates for outdoor and indoor spaces were 0.111 µSv/h and 0.139 µSv/h, respectively. The mean background dose rate of indoor space was significantly higher than that of outdoor space. Annual effective dose and excess lifetime cancer risk were obtained as 0.817 and 2.85×10-3, respectively. Conclusion: Background radiation dose, annual effective dose, and cancer risk for Gonabad city were higher than global ones. Further investigations are needed to encompass internal background radiation doses in annual effective dose.

Author(s):  
M. U. Audu ◽  
G. O. Avwiri ◽  
C. P. Ononugbo

Study of the terrestrial Background Ionizing Radiation levels of selected Oil Spill Communities of Delta State, Nigeria have been carried out using Digilert 200 and Radalert 100 nuclear radiation monitor and a geographical positioning system (Garmin GPSMAP 76S). The exposure rates of the five communities ranges from 0.016 to 0.030  at Jones Creek, 0.014 to 0.034  at Opuwade Community, 0.015 to 0.037   at Okpare community, 0.007 to 0.029  at OtuJeremi community and 0.011to 0.040  at Otor-Edo community. The obtained mean exposures rates were higher than ICRP standard limit of 0.013. The absorbed dose rates calculated ranged from 139.2 to 261 (Jones Creek), 121.8 to 259.8 nGyh-1 (Opuwade Community), 130.5 to 321.9 nGyh-1 (Okpare community), 60.9 to 252.3 nGyh-1 (OtuJeremi community) and 95.9 to 348 nGyh-1 (Otor-Edo community). The estimated annual effective dose equivalent varies from  0.21 to 0.40 , 0.19 to  0.45 , 0.20 to  0.49 , 0.09 to 0.39  and  0.15 to 0.53  for Jones Creek, Opuwade Community, Okpare community, Otu Jeremi community and Otor-Edo community respectively while the excess lifetime cancer risk calculated for Jones Creek varies from (0.75  to 1.40)  x 10-3, Opuwade community (0.65 to 1.59 )×, Okpare community (0.70 to 1.73 ) x , OtuJeremi community (0.33 to 1.35)× and Otor-Edo community (0.51 to 1.87)×. All the mean values of absorbed dose, annual effective dose and excess lifetime cancer risk exceeded their recommended safe values. The results obtained in this work may not constitute any immediate health risk to the residents of the selected oil spill communities but long term exposure in the area may lead to detrimental health risks.


2021 ◽  
Vol 14 (3) ◽  
pp. 267-274

Abstract: The activity concentrations of natural radionuclides of the elements (40K, 238U and 232Th), collected from Kutha district of Babylon governorate are studied and evaluated. Twenty soil samples with (0-15) cm in depth are collected. Gamma spectrometer NaI (TI) source is used for calibration. The radioactivities of natural isotopes K-40, U-238 and Th-232, were assessed. These studies show that radio activities of isotopes are acceptable according to the standard levels. Also, the activity of radium equivalent, the rate of annual effective dose, average air volume and external risk index are evaluated. The results are found within the internationally tolerable values. The results show that the mean of the radioactivity of 238U is (19.1565)Bq / kg, while it is (54.501) Bq/kg for 232Th and (179.578) Bq/kg for 40K. The study results showed that the average of radiological effects, like the Radium equivalent (Raeq), the rate of absorbed dose (Dr), the index of external hazard (Hex), the index of internal hazard (Hin), the index of representative gamma hazard (Iγ), the Annual Effective Dose Equivalent (AEDE) and the Excess Lifetime Cancer Risk (ELCR) are as follow: 110.920 Bq/kg, 50.1838 nGy/h, 0.29953, 59.1530, 27.996, 0.34 mSv/y and 1.268x10-3, respectively. Keywords: Natural radioactivity, Absorption, External hazard, Effective annual dose, Excess lifetime cancer risk.


2020 ◽  
Vol 108 (7) ◽  
pp. 573-579 ◽  
Author(s):  
Aslı Kurnaz ◽  
Şeref Turhan ◽  
Aybaba Hançerlioğulları ◽  
Elif Gören ◽  
Muhammet Karataşlı ◽  
...  

AbstractIn this study, content of natural radionuclides (226Ra, 232Th and 40K) and radon emanating power and radon mass exhalation rate of surface soil samples collected around industrial province Karabük in which the first iron steel plant was built in 1937 were determined by high-resolution γ-ray spectrometry with a high purity germanium detector. The average activity concentration of 226Ra, 232Th and 40K in soil samples were measured as 30 ± 2, 28 ± 2 and 251 ± 20 Bq kg−1, respectively. The average value of radon emanating power and mass exhalation rate of soil samples were found as 31 % and 19 μBq kg−l s−l, respectively. Assessment of possible radiation hazards to the people due to external exposure was done by estimating the outdoor absorbed gamma dose rate in the air at 1 m above the soil, the corresponding annual effective dose, and the excess lifetime cancer risk. The average outdoor gamma dose rate, annual effective dose, and lifetime cancer risk were estimated as 41 nGy h−1, 51 μSv y−1 and 2.0 × 10−4, respectively. A comparison of the activity and radiological results obtained for the studied samples with the corresponding worldwide average values indicates that the results are below the world average values.


2018 ◽  
Vol 184 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Marjan Hashemi ◽  
Leila Akhoondi ◽  
Mohammad Hossien Saghi ◽  
Akbar Eslami

Abstract Natural radiation is a feature of the environment in which we live. One of the contributions of human exposure to ionizing radiation due to natural sources arises from gamma radiation. Therefore, present study was aimed to evaluate and map indoor gamma dose rate in Tehran. The corresponding annual effective dose (AED) and excess lifetime cancer risk (ELCR) were also calculated. All measurements were performed by a Geiger Muller detector in 43 dwellings in Tehran. The average indoor gamma dose rate in Tehran was appointed as 343.2 nGy/h. AED and ELCR were calculated as 2.4 mSv and 10.3 × 10−3, respectively. The evaluated indoor gamma dose rate and calculated AEDs and lifetime cancer risk were found higher than the world average value.


BIBECHANA ◽  
2018 ◽  
Vol 16 ◽  
pp. 187-195
Author(s):  
Parkash Pantha ◽  
Tanka Prasad Bhusal ◽  
Budha Ram Shah ◽  
Rajendra Prasad Koirala

The study of natural background radiation dose at thirty two locations of Kathmandu valley has been done successfully using the instrument Radalert 100. The average dose rates and annual effective dose were measured. From the measurements, the least value of average dose rate was found to be (22.3±3.9)×10-3 mR/hr for Sundhara and the greatest value of average dose rate was  found to be (37.7±7)×10-3 mR/hr for Budhanilkantha 3.  As per the annual effective dose, the least value was 0.391 mSv/yr for Sundhara and the greatest value was 0.661 mSv/yr for Budhanilkantha 3. The average annual effective dose of Kathmandu valley was 0.475 mSv/yr ranging from 0.391 mSv/yr to 0.661 mSv/yr. The values thus obtained were compared to the worldwide average value of annual effective dose, 0.48 mSv/yr. Also, the obtained values were compared to the legal dose limit (annual effective dose), 1 mSv/yr set by International Commission on Radiological Protection (ICRP) for non-radiation workers and members of public. Among these thirty two locations, eight locations were chosen such that they had larger range of the observed dose rates. Those eight locations were re-observed. Further, Chi-square test was carried out to test whether the observed dose rates were following normal distribution or not. From the calculation, it was observed that the observed dose rates were following the normal distribution.BIBECHANA 16 (2019) 187-195


2016 ◽  
Vol 26 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Nevzat Damla ◽  
Ayhan Kara ◽  
Eyüp Tel ◽  
Cafer M. Yesilkanat

Radon and its short-lived daughter products, leading to lung cancer, are the most significant contribution to the exposure of man to ionizing radiation from natural sources. Therefore, the present study aimed to assess indoor radon measurements in 39 rooms of 15 health centres in Osmaniye city, Turkey using CR-39 solid-state nuclear track detectors based on radon dosimeters. Indoor radon concentrations were found to change from 8 to 108 Bq·m−3. The associated radiological parameters such as the annual effective dose and excess lifetime cancer risk were computed for staff/patient in the rooms surveyed. The mean annual effective dose and excess lifetime cancer risk values were estimated to be 0.29 mSv and 1.02 × 10−3, respectively. The annual computed effective doses are lower than the suggested action level (3–10 mSv·y−1). Also, with ordinary Kriging method, by using R programing language and quantum geographic information system, indoor radon concentration, annual effective dose, and excess lifetime cancer risk interpolated values were recorded and mapped. The findings obtained in the current study concerning radon levels and their variations will provide baseline values for future research surveys.


2021 ◽  
Vol 5 (1) ◽  
pp. 34-51
Author(s):  
E C D K Addison ◽  
R A Opoku ◽  
C E B N Addison ◽  
W I Aniagyei

Purpose: A study was conducted to estimate the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR) caused by the presence of an artificial cobalt-60 radioactive source producing ionizing radiation levels within the radiotherapy facility at Komfo Anokye Teaching Hospital (KATH) in Ghana. This study validated the safety of cobalt-60 radioactive sources, as well as the notion of calculating the Annual Effective Dose Equivalent (AEDE) and Excess Lifetime Cancer Risk (ELCR), which contributed to reducing occupational and public exposures inside the facility. Methodology: The investigation was carried out with the use of a portable OD-01 Ionization Chamber Survey Meter. The absorbed dose rate (ADR) in air was changed between 5 m and 40 m, with measurements taken inside and around the cobalt 60 bunker, as well as at sixteen other sites within the radiation facility. Findings: From 5 m to 40 m surrounding the Cobalt-60 source, the estimated Absorbed Dose Rate in air inside the cobalt-60 bunker ranged from 0.299 0.001 to 0.977 0.005 Sv/h, with an average of 0.498 0.005 Sv/h. The estimated Annual effective dose equivalent varied from 1.100 mSv/yr to 3.595 mSv/yr around the cobalt-60 source inside the Co-60 bunker. Radiation exposure levels ranged from 0.268 0.008 Sv/h to 0.678 0.005 Sv/h, with an average of 0.440 0.004 Sv/h observed around the fifteen sites chosen. Excess Lifetime Cancer has values ranging from 3.85 10-3 to 12.58 10-3 and 3.45 10-3 to 8.73 10-3. Risks were evaluated for the cobalt and the sixteen places inside the plant. The absorbed dose values at 5 m, 10 m, and 15 m inside the Co-60 bunker and the location Co-60 bunker as part of the facility exceeded the ICRP-recommended limit of 0.57. The AEDE and ELCR levels were within the ICRP's acceptable limits. The AEDE and ELCR statistics acquired indicate that the Cobalt-60 unit and its surroundings are radiation safe, although the likelihood of employees contracting cancer from the absorbed dose and background ionizing radiation is significant over a lifetime. Recommendation: However, it is recommended that absorbed dose level monitoring and evaluation of the Radiation Therapy Technologist (RTT) and other workers surrounding the unit be monitored on a regular basis. It is also recommended that Occupational Staff, such as RTTs, spend as little time as possible in the bunker  


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