|Year : 2014 | Volume
| Issue : 3 | Page : 115-116
Studies on natural radionuclides and...
Ex. BARC and Editor, Radiation Protection and Environment, India
|Date of Web Publication||10-Apr-2015|
Ex. BARC and Editor, Radiation Protection and Environment
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pushparaja. Studies on natural radionuclides and... Radiat Prot Environ 2014;37:115-6
Studies on natural radionuclides in the environmental and other matrices continue to interest the researchers world over. This combined issue of Radiation Protection and Environment consists of 11 papers out of which 7 papers are related to the studies on natural radionuclides. one paper each on personal dosimetry; measurement depth profile of toxic elements in sediments; plutonium estimation in waste drums, and the use of activated charcoal to remove radioactive iodine from effluent streams.
In another paper from Ghana, attempts were made to evaluate the concentration of airborne dust, 232 Th and 238 U, at various distances and directions around Diamond Cement Factory in the Volta Region of Ghana. The samples of dust were collected on filter papers and later analyzed for the concentration (mg/kg) of 232 Th and 238 U using neutron activation analysis. From the radiological safety point of view, the study concluded that the people living in the vicinity of the cement factory are not at risk to significant radiological hazards.
A similar study is reported where natural radioactivity ( 226 Ra, 232 Th and 40 K) concentrations in 30 granite samples collected from Alvand granitic rocks in Hamadan, Iran were evaluated using high-resolution gamma spectrometry systems. Radium equivalent activity, the effective dose, the internal and external hazard indices values were derived, and were much lower than the acceptable values.
Comparison of natural pattern of uranium distribution in groundwater in the vicinity of tailings management facilities at Jaduguda and Turamdih in Singhbhum region, Jharkhand was investigated by the local health physics staff. Uranium concentrations vary depending on the nature of uranium mineralization at the sites. The concentrations of uranium in the well waters in the villages, within a distance of 0.5 km from tailings pond at either site are very low. The results reflect the natural distribution of uranium around the facility and contribution of tailings pond was not found in groundwater sources adjoining these facilities.
Tiruchirappalli District in Tamil Nadu state, India has enriched resources of building materials such as stone, granite, sand, brick, cement, etc. Radon exhalation rate from the building materials of Tiruchirappalli district was studied by Sankaran Pillai et al. The sealed can technique with solid state nuclear track detector (SSNTD) was employed for the measurement of radon exhalation. The activity concentration in these building materials follows a descending order: Granite > sand > cement > brick > sandstone. The study concluded that the radon exhalation from the building materials is lower than the limit prescribed by the ICRP.
Studies on the determination of radon, thoron and their progeny concentrations to assess inhalation dose in dwellings of Gogi region, Yadgir District, Karnataka, India was carried out by the researcher from Gulbarga University, Karnataka and BARC. The dwellings were so chosen that they were within 5 km range from the uranium mining area. Measurements were carried out using passive detector systems: Pinhole dosimeters for radon and thoron and deposition based progeny sensors for radon and thoron progeny. The values were found to be within the permissible UNSCEAR limits.
Measurement of radon activity, exhalation rate and radiation doses in soil samples from Banda district, UP, India was made using SSNTDs. Effective dose due to indoor inhalation exposure to radon has been estimated, and the average value is found to be 16.8 μSv/year.
Radon measurements in different water samples from the western desert of Egypt, and corresponding dose estimates using nuclear track detectors were reported in one of the papers. The obtained results reveal that there is no significant public health risk from radon ingested with drinking water in the region studied.
Dosimetry studies conducted in lab conditions of photon, high energy beta and the mixed photons and beta fields, indicated that the thermoluminescent dosimeters (TLD) and direct reading dosimeters (DRD) doses match well in photon field while the doses calculated using TLD and DRD show discrepancy when used in mixed fields. The DRD doses are always higher, in the range of 15-30%, than the dose estimated by TLD due to the beta response of the DRD. The results reported in this paper would be helpful in understanding the discrepancy arising out of variable response of DRD to beta radiations in workplaces, and will be useful in resolving the discrepancy in such cases.
One of the papers reports the results of measurements carried out in the sediment cores of Mumbai Harbour Bay to study depth profile of some of the biologically significant toxic elements such as Cr, Cu, Co, Ni and Pb. Another paper by Vaishali et al. reports development of monitoring system for estimation of radioactive waste drums for plutonium using BF 3 neutron detector- HDPE moderator system. The system could detect 85 mg of plutonium in the drum at min. counting time of 1000s.
Activated carbon is widely used in various industries as an adsorbent material for removal of pollutants from effluents. There are different methods for producing the activated charcoal. The most common methods are physical and chemical activation that includes heat treatment, amination and impregnation. The effect of three impregnates including NaOH, KI and ZnCl 2 on the quality of activated charcoal for 131 I removal, was investigated. The results showed that the sodium hydroxide impregnated activated charcoal is more effective for 131 I removal.