International Journal of Low Radiation (7 papers in press)
Natural radioactivity of environmental samples and their impact on the population at Assalamya-Alhomira area in Yemen
by Imran Saleh, Abdallah El-mageed, Abd El-Hadi El-Kamel, Abd El-Bast Abady, Shaban Herb
Abstract: The present work investigated the radioactivity level of the rocks, soil and water samples at Assalamia-Alhomira area, Abyan district in Yemen. Thirty two rocks and soil samples and 3 groundwater samples from Assalamia-Alhomira area were analyzed by gamma-ray spectrometry using NaI(Tl) detector with specially designed shield. The concentration of three natural radionuclides namely 226Ra, 232Th, and 40K has been determined. The radioactivity levels obtained expressed in Bq kg-1. The results showed that these radionuclides were present in concentrations of (48.68
Keywords: radioactivity; radiological effects; Assalamia-Alhomira; gamma spectroscopy.
Radon, thoron and their progeny dosimetry in multi-storeyed malls in Delhi NCR (India) using plastic track detectors
by Nitin Gupta, Krishan Kant, Maneesha Garg
Abstract: Environmental radioactivity due to radon, thoron and their progeny in the ambient air in the multi-storeyed malls situated in Delhi National Capital Region (NCR) including district Faridabad, Haryana (India) was evaluated using LR-115 (type-II) solid state nuclear track detectors. The potential alpha energy concentration, annual exposure and annual effective dose to the workers and visitors were also calculated and have been reported. Seasonal variation has also been studied. The average value of activity in different seasons due to radon and thoron varied from 18.45
Keywords: radon; thoron; progeny; radioactivity; detector; multi-storied mall.
Evaluation of environmental radioactivity impacts and its associated radiological hazards with monitoring of radon-222 in rock and sand samples from Sinai, Egypt
by Soad Fares
Abstract: Determination of the natural radionuclide (226Ra, 238U, 232Th and 40K) contents of soil and rock samples collected from various geological formations in some mountains and valleys in Sinai, Egypt, has been carried out using gamma spectrometry. The total average concentrations of radionuclides 226Ra, 238U, 232Th, and 40K were 51.37, 50.02, 19.34, and 286.66 Bq kg-1, respectively. Correlations made among these radionuclides prove there is no existence of secular equilibrium in the investigated soils. The total average absorbed dose rate in the study areas is found to be 47.08 nGy h-1, whereas the indoor and outdoor annual effective dose equivalent has an average value of 0.23 and 0.06 mSv y-1 respectively. The external and internal hazard indices and the radium equivalent activity associated with the investigated soils do not exceed the permissible limits. Moreover, the radio-elemental concentrations of uranium, thorium and potassium, evaluated for the various geological features in the study areas, were calculated to indicate whether relative depletion or enrichment of radioisotopes had occurred. The results are discussed and compared with internationally recommended values. Some mathematical equation models are used to estimate the activity concentrations of 222Rn in the air and compare them with the activities of 226Ra in vegetables, as well as the dose rates that result from vegetable consumption and from inhalation of radon gas. The range of 226Ra activity found was from 11.15
Keywords: radioactivity concentration; absorbed dose; activity concentrations of 222Rn; gamma spectrometry; external and internal hazard indices; radium equivalent activity.
Natural radioactivity in farm soils and major food crops grown in Ayetoro, Ogun State, Southwestern Nigeria
by Shamsideen Alausa, Omotomilola Omotosho
Abstract: Radioactivity data in food and farm soil in sedimentary rocky areas such as Ayetoro are scarce. Maize, cassava and the undersoil samples were collected from Ayetoro. The 40K, 226Ra and 232Th activity concentrations in the samples were measured with a gamma ray spectrometer. The soil-to-food crop transfer factors, ingestion effective dose rates due to the crops and the outdoor effective dose rates due to soils were evaluated. The mean 40K, 226Ra and 232Th activity concentrations in maize were 160.3
Keywords: natural radioactivity; farm soils; food crops; health impact; sedimentary rocks; gamma-ray; activity concentration; transfer factor; effective dose; Abeokuta formation; Ayetoro; Nigeria.
Evaluation of naturally occurring radioactive materials in an in the south east of Libya
by Usama Elghawi, Feisal A. Abutweirat, Taha S. Barka
Abstract: The huge volume of naturally occurring radioactive materials (NORM) wastes produced annually by the oil and gas industry in Libya deserves the attention of the national environmental protection authority, radioactive waste management and regulatory bodies. An investigation was carried out to find out the concentration of NORM in the sludge in evaporation ponds in a south eastern oilfield of Libya. Twenty soil samples were collected from five evaporation ponds sludge. Activity concentrations of 226Ra, 232Th and 40K in soil generated during oil production operations were determined using a gamma spectroscopy system based on high purity germanium (HPGe) detector. Concentrations ranged from 83 to 1000 Bq kg-1 for 226Ra, 59 to 315 Bq kg-1 for 232Th and 109 to 304 Bq kg-1 for 40K. To evaluate the radiological effects, radium equivalent activity and external hazard are calculated. The magnitude of these results demonstrates the need for a special treatment (remediation) of these ponds on site to reduce the exposure to a value below 100
Keywords: NORM; radioactivity; NORM regulations and guidance; oilfield; evaporation ponds; health hazards; Libya.
Assessment of DNA damage in lymphocytes of inhabitants of Mamuju (a high background radiation area) using alkaline single cell gel electrophoresis
by Tur Rahardjo, Wiwin Mailana, Teja Kisnanto, Darlina Darlina, Siti Nurhayati, Devita Tetriana, Dwi Ramadhani, Mukh Syaifudin
Abstract: Mamuju in Indonesia has a highest average dose rate compared to other regions in Indonesia and is considered as a high background radiation area (HBRA). Mamuju inhabitants received a chronic low radiation dose exposure in their life. The biological effects of low dose radiation exposure in humans have not been fully understood until now. Here in this research a preliminary study to evaluate DNA damage using the alkaline comet assay in healthy individuals from Takandeang village, Mamuju, and subjects from a nearby normal level natural radiation area was conducted. Blood samples from 55 healthy donors living in Takandeang village and 22 donors from the area near to Mamuju were obtained and processed into the assay. Briefly, lymphocyte isolation, slides preparation, lysis process, alkali unwinding and electrophoresis were done according to standard procedures. DNA damage was estimated in terms of comet tail length (TL) and comet tail moment (TM). From 50 comets in each subject the TL and TM were measured using CASP software. Results showed that there were insignificant differences between TL and TM between normal and high background radiation groups (p = 0.578, 0.174). Regression analysis revealed that the DNA damage increased with age in subjects from the normal-level natural radiation area, even though the correlation was not significant (p>0.01). In contrast, a significant negative correlation (p = 0.02, 0.02) was observed in Takandeang inhabitants. Results found in this research should be validated in a larger study using more samples from Mamuju.
Keywords: comet assay; DNA damage; high background radiation area; lymphocytes; Mamuju; Indonesia.
Estimation of annual effective dose due to external and internal exposure in the residents of coastal villages of Kanya Kumari district, Tamil Nadu, India
by D. Deva Jayanthi, C.G. Maniyan, S. Perumal
Abstract: In this study, the annual effective radiation dose received by the residents of coastal villages of Kanya Kumari district of Tamil Nadu is estimated. External exposure and the internal exposure are added to get the annual effective dose. External dose is calculated using TLD and the internal dose is calculated via inhalation and ingestion. Inhalation dose is calculated using SSNTD, which is a passive measuring technique, and the ingestion dose is calculated through the intake of water and the food (meals). Ten coastal villages were selected that all come under the Natural High Background Radiation Area. Among the villages the annual effective dose varies from 3.7 mSv to 9.8 mSv.
Keywords: radiation exposure; ingestion; inhalation; external dose; effective dose.