Preliminary assessment of natural radioactivity and associated radiation hazards in a phosphate mining site in southern area of Togo

Introduction Because of the increasing use of phosphate in industries worldwide,especially in Togo,it is interesting to investigate the potential radioactivity exposure of phosphate ores,especially in the one being exploring in Togo nowadays.Material and methods The contents of natural radionuclides(40K,226Ra,232Th,235U and 238U)were assessed in phosphate soil samples from Kpogamé,Dagbati and Kpéméin the maritime region of Togo by using gamma spectrometry-based Broad Energy Germanium detector(BEGe6530).Since no study was made prior to the exploitation,the samples from the control area of Anfoin-Kpota far away from the three others were considered as reference.Results and discussion The results are discussed and compared with the data from other countries.The activity concentration of 40K,226Ra,232Th,235U and 238U are between(59.45 and 129.99),(20.19 and 779.93),(16.81 and 121.42),(2.26 and 52.03)and(16.66 and 841.14)Bq kg^(−1),respectively.The values obtained shows that the exploitation sites(Dagbati and Kpogamé)and treatment site(Kpémé)have a very high level of radioactivity than the control area(Anfoin-Kpota).The Kpogaméand Dagbati exploitation and Kpéméwaste discharging phosphate deposit sites were found to have higher activity concentration than many others exploited phosphate sedimentary deposits around the world.The average annual effective dose of the above studied sites is 0.36,0.24 and 0.48 mSv year−1,respectively.The value related to the discharge waste site is about 2%of the 1.0 mSv year−1 recommended by the International Commission on Radiological Protection as the maximum annual dose to the public.Conclusions The obtained result of both radioactivity and radiological level in the studied areas will be considered as a pre-operational baseline to estimate the possible radiological impacts due to mining and processing phosphate industrial activities.

Assessment of Radiation Hazard from External and Internal Exposures at Adham and Surroundings in KSA

Twenty-eight environmental samples (eight well water, sixteen granitic rocks and four soils) were collected from different parts of Adham governorate (Adham, Haqal and Al-Jaizah), to assess the radiological hazard and cancer risk from different perspectives. Adham is situated in a valley between two granitic mountain chains, where much of water supply for drinking, house use and irrigation comes from wells collecting water rains. The activity concentrations of naturally occurring 40K, 226Ra and 232Th and radionuclides were measured by gamma-ray spectrometry for all samples using RGK-1, RGU-1 and RGTh-1, IAEA reference standards issued by the International Atomic Energy Agency, for detector efficiency calibration. The measured values were utilized to evaluate the internal and external exposures both outdoors and indoors. Different standard room models were adopted for this respect to evaluate the indoor gamma-rays exposure from construction materials as well as internal exposure to radon gas emanating from them. Radon concentration indoors, exceeded the upper reference level in dwellings set at 300 Bq/m3 by the world health organization, in many scenarios. The mean value of the total excess lifetime cancer risk (due to external exposure from gamma-rays) was 2.29 × 10-3, above the world average value of 1.45 × 10-3. Furthermore, the measured radon concentrations in all water samples exceeded the EPA (Environmental Protection Agency) 11.1 Bq·L-1 standard for drinking water, ranging from 12 to 38 Bq·L-1 with a mean value of 27 Bq·L-1. The total annual effective dose (due to inhalation and ingestion) from radon in water, ranged from 58 to 192 μSv/y (for adults) exceeding the international permissible limit of 100 μSv/y, in seven out of eight samples. According to obtained results, the internal exposure from radon in directly used water from wells, might be the major reason of any suspected radiological health hazard especially in Haqal. The second reason might be the internal exposure from indoor radon gas inhalation in poorly ventilated dwellings.

RADIATION HAZARD AND PROTECTION OF LOW ENERGY ACCELERATORS

In this paper, the origin and type of radiation hazards as well as the main aspects of radiation protection for low-energy accelerators are discussed in general, and the problems of radiation protection and the experimental results of the operational monitoring of the five accelerators in the institute of Nuclear Science and Technology,Sichuan University, namely, one 1.2 M cyclofron, two Cockroft-waltons and two Van de Graafts, as well as a powerful electron accelerator for industrial irradiation are described. The discussion and evaluation are made according to the requirments of the National standards GB 5172-85.

A Real-time EMF Measuring System for Mobile Communication Towers in Sri Lanka

Telecommunications Regulatory Commission of Sri Lanka is the governing body which is responsible for the frequency allocation and monitoring the unauthorized Electromagnetic frequency(EMF)signal transmitting violations.However,in Sri Lanka,currently there is not any proper mechanism to monitor the radiation hazard level and its impact to the people living in the vicinity of mobile communication towers.There are approximately 7000 mobile transmitting towers in Sri Lanka to date and the used frequency range lies between 900 MHz to 3 GHz for mobile communication.Over the last few decades,many of the health hazard conditions were reported due to the radiation of those harmful EMFs.To cater this problem,a portable real time EMF signal strength measuring system with a radiation hazard level indicator was developed to monitor the EMF level and its impact.The proposed system operates with three intermediate frequency bands(i.e.900 MHz,1800 MHz and 2400 MHz)and it’s capable of measuring the power density and the radiation hazard level at that particular point which is being measured.Moreover,the corresponding radiation hazard level is indicated with reference to the standard power density levels published by the International Commission on Non-Ionizing Radiation Protection(ICNIRP^(*)).The system works with the overall accuracy of 88%in terms of identifying the power densities and its corresponding radiation hazard levels.

Investigation on 226Ra, 238Th, 4040K and 137Cs Concentrations in Common Polishing Materials Consumed by Inhabitants in Saudi Arabia

Knowledge of radioactivity present in polishing materials enables one to assess any possible radiological risks to human health. In this work, the radioactivity due to the presence of 226Ra, 232Th, 40K, and 37Cs has been measured in polishing materials con-sumed in Saudi Arabia using gamma spectrometry with HPGe. The activity concentra-tions of 226Ra, 232Th, 40K and 137Cs ranged from 13.61 ± 0.005 to 0.60 ± 0.002, 18.43 ± 0.003 to 0.78 ± 0.001, 342.59 ± 0.009 to 2.47 ± 0.001 and 1.47 ± 0.001 to 0.55 ± 0.001 Bq/l, respectively. For 226Ra and 40K, the highest values are measured in stainless steel polisher. The highest values also measured in metal polisher (copper-chrome) and disinfectant cleaner and polisher sample for 232Th and 137Cs. Radium equivalent activ-ity due to the natural radioactivity of the investigated samples ranged from 51.37 to 1.24 Bq/l. This value is less than the recommended values in the established standards. The evaluated data were compared with the literature data. Our results indicate that no significant radiological hazards arise from using investigated samples hence quite safe to be used as polishing materials.