首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
A monitoring of radioactivity content was performed in drinking waters collected in Kahramanmaras. Gross alpha and gross beta activities concentration were measured. The values of measured gross alpha and gross beta are compared with recommended WHO (World Health Organisation) and ITS (Institution of Turkish Standards) guideline activity concentration. Obtained results are in good agreement with the values recommended by WHO and ITS guideline activity concentrations for drinking water (except for two values).  相似文献   

3.
In this work, we collected 101 geothermal water samples to investigate comprehensively the radioactivity of geothermal water in Beijing. The concentrations of gross beta, 226Ra and 222Rn were measured and the obtained values were in the range of 0.032–7.060, 0.023–0.363 and 0.470–29.700 Bq/L, respectively. The samples with higher concentration of 222Rn were found to be located near large faults. The effective dose of 222Rn in the air for three cases were calculated to be greater than radiation dose limit of 1 mSv/a.  相似文献   

4.
U, Th and Ra isotopic activities have been measured in water and sediment samples collected over three years from the Guadalquivir river channel (South of Spain). The study of the radioactivity levels and activity ratios evolution in space and time has provided information on the behavior of the radionuclides mentioned above in the estuarine and non-estuarine zones of the river.  相似文献   

5.
Radon and its progenies in indoor environment have been identified as the main sources of radiation dose to the people from natural radioactive sources. Presence of radon in drinking water causes radiation related health hazards both through inhalation and ingestion. In this study 36 drinking water samples from taps, boreholes and deep tube wells within the Main Campus of the University of Peshawar and adjoining area were analyzed with RAD7 electronic device for radon content determination. These water samples have a mean, maximum and minimum radon value of 8.8 ± 0.8, 18.2 ± 1.0, and 1.6 ± 0.3 Bq L−1, respectively. Eleven drinking water samples analyzed have radon levels in excess of the EPA recommended maximum contaminant level (MCL) of 11.1 Bq L−1. These include 89% from tube wells, 8% from tap water, and 50% from shallow boreholes. Radon levels of about 31% of the total samples used by the inhabitants of the study area are higher than the EPA advised level of 11.1 Bq L−1. The annual effective dose from radon in water due to its ingestion and inhalation per individual has also been estimated. The mean radon concentration and mean annual effective dose due to radon in water of this study have been compared with the mean radon concentration and mean annual effective dose of earlier investigators due to radon in water from different localities of India and Pakistan. The mean annual effective doses of all the samples are lower than the reference level of 0.1 mSv a−1 for drinking water of WHO and EU Council. It has been concluded that drinking water of the study area is generally safe as far as radon related health hazards are concerned with the exception of a few isolated cases. It has been found that radon levels within the region have a positive correlation with depth of the water sources.  相似文献   

6.
Radioactivity measurements were carried out in 26 groundwater samples from Tunisia. Activity concentrations of uranium were studied by radiochemical separation procedures followed by alpha spectrometry and that for radium isotopes by gamma-ray spectrometry.The results show that, the concentrations in water samples range from 1.2 to 69 mBq/L.1, 1.3 to 153.4 mBq/L, 2.0 to 1630.0 mBq/L and 2.0 to 1032.0 mBq/L for 238U, 234U, 226Ra and 228Ra, respectively. The U and Ra activity concentrations are low and similar to those published for other regions in the world. The natural radioactivity levels in the investigated samples are generally increased from mineral waters through therapeutic to the spring waters.The results show that a correlation between total dissolved solids (TDS) values and the 226Ra concentrations was found to be high indicating that 266Ra has a high affinity towards the majority of mineral elements dissolved in these waters. High correlation coefficients were also observed between 226Ra content and chloride ions for Cl?–Na+ water types. This can be explained by the fact that radium forms a complex with chloride and in this form is more soluble.The isotopic ratio of 234U/238U and 226Ra/234U varies in the range from 0.8 to 2.6 and 0.6 to 360.8, respectively, in all investigated waters, which means that there is no radioactive equilibrium between the two members of the 238U series. The fractionation of isotopes of a given element may occur because of preferential leaching of one, or by the direct action of recoil during radioactive decay.The annual effective doses due to ingestion of the mineral waters have been estimated to be well below the 0.1 mSv/y reference dose level.  相似文献   

7.
The comparator instrumental neutron activation analysis (INAA) method was used for certification of arsenic in Korea Research Institute of Standards and Science (KRISS) reference materials 108-04-001 (Oyster Tissue). The certified value was determined by analyzing one sample of approximately 0.15 g from ten bottles selected by random sampling. Potentially significant sources of uncertainty were taken into consideration using the guideline given by ISO. A complete evaluation of all sources of uncertainty yielded an expanded uncertainty for the mean value of this reference material of 4.7% at approximately 95% level of confidence.  相似文献   

8.
Radioactivity levels in soil samples, collected from mid Rechna interfluvial region, Pakistan have been estimated by using gamma ray spectrometric technique. 226Ra, 232Th, the primordial radionuclide 40K and the artificial radionuclide 137Cs have been measured in the soil of the study area. The mean radioactivity levels of 226Ra, 232Th, 40K and 137Cs were found to be 49.0 ± 1.6, 62.4 ± 3.2, 670.6 ± 33.9 and 3.5 ± 0.4 Bq kg−1 respectively. The mean radium equivalent activity (Raeq), outdoor radiation hazard index (H out), indoor radiation hazard index (H in) and terrestrial absorbed dose rate for the area under study were determined as 189.9 ± 8.8 Bq kg−1, 0.51, 0.65 and 70.1 nGy h−1 respectively. The annual effective dose to the public was estimated to be 0.43 mSv. The measured values are comparable with other global radioactivity measurements and are found to be safe for public and environment.  相似文献   

9.
The determination of 90Sr and the gross particleactivity originating from radium isotopes was performed on water samples atvarious stages of treatment taken from water treatment plants before distributionto the consumers.  相似文献   

10.
Sand is extensively used in construction of buildings. The presence of natural radioactivity in it results in internal and external exposure to the general public. Therefore, it is desirable to determine the concentration of naturally occurring radio-nuclides, namely 232Th, 226Ra and 40K in sand. In this regard, in continuation of our earlier studies, 42 sand samples were collected from fourteen different locations along the banks of river Indus from Gilgit to Lowarian in the northern part of Pakistan covering an area of ~500 km. In order to measure the specific activities in these samples, a P-type coaxial high purity germanium based gamma-ray spectrometer was used. Average values of the measured activities of 226Ra, 232Th and 40K were found to be 45.6 ± 3, 74.73 ± 3 and 339.8 ± 3.6 Bq kg?1, respectively which results in an average absorbed dose rate 83.54 nGy h?1. From the measured activities, average radium equivalent activity was found to be 178.59 Bq kg?1. External and internal hazard indices were also calculated and found to be 0.48 and 0.61, respectively. Average effective dose expected to be received due to the gamma rays was 0.26 mSv y?1. Measured natural radioactivity, hazard indices and effective doses received by the population were found to be within the recommended limits.  相似文献   

11.
Journal of Radioanalytical and Nuclear Chemistry - An evaluation of the environmental radioactivity levels in soil samples from Sakarya province (Turkey) was undertaken in order to create a...  相似文献   

12.
Spring waters used as spas may contain significant amounts of natural radionuclides, so, in some circunstances, a radiation protection issue can arise for the population and/or the spas workers. EU has identified some groups of employees to be exposed to natural radiation in the 1996 Euratom Directive. Among these are workers of thermal spas who may be exposed to high radiation doses due to high radon concentrations in indoor air. In order to evaluate the potencial risk of the spring waters used as spas, gross-α and gross-β activity, 226Ra and 222Rn concentration levels were measured in 82 spas all over the country. Gross-alpha and gross-beta concentrations ranged from LLD to 17 Bq·l−1 and from LLD to 60 Bq·l−1, respectively. 226Ra concentrations ranged from <4 to 3,660 mBq·l−1. 222Rn concentrations ranged from <4 to 1868 Bq·l−1. Correlations between 226Ra concentrations and gross-α activity were obtained.  相似文献   

13.
The conditions to measure the gross alpha and gross beta radioactivity in water samples from Zacatecas and Guadalupe cities in the State of Zacatecas, Mexico were established. The gross alpha and beta radioactivity of water samples were measured using a liquid scintillation detector. The results show that the gross beta radioactivity in all cases is lower than the maximum contaminant level and the gross alpha radioactivity is higher in the samples collected from Guadalupe City and in the samples collected from the Southwest of Zacatecas City.  相似文献   

14.
This study is part of an effort to assess the level of background radiation for Erzincan Province of eastern Turkey. Radionuclide activity concentrations in soil samples were measured through gamma-ray spectrometry and the average activities were determined as 8.93, 11.39, 281.94, and 9.52 Bq/kg for the radionuclides 238U, 232Th, 40K, and 137Cs, respectively. The average annual effective dose from these natural radioactivity sources (238U series, 232Th series and 40K,) was calculated to be 27.9 μSv. Radioactivity levels in drinking and potable water samples were studied using a multi-channel low level proportional counter. The average gross alpha activity concentration was found to be 0.0477 Bq/L (min. 0.007 Bq/L; max. 0.421 Bq/L) and the average gross beta activity was measured as 0.104 Bq/L (min. 0.008 Bq/L; max. 1.806 Bq/L). These values lead to an average annual effective dose of 9.75 μSv from the alpha emitters and 56.34 μSv from the beta emitting radionuclides in water. The radioactivity levels in the water samples investigated were found to comply with the reference levels recommended by WHO and the regulations set forth by the Turkish Health Ministry.  相似文献   

15.
Tritium activity in potable drinking water samples from Adana city were measured using liquid scintillation counting after distillation procedure. The results exposed that the activity concentrations of the tritium measured in one-third of these samples were lower than minimum detectable activity which has a value of 2 Bq/L for counting time of 1,500 min. However, the maximum and mean value of the tritium activity was found to be 9.1 Bq/L (77.3 TU) and 7.0 Bq/l (59.4 TU), respectively. These values were substantially below the 100 Bq/L which is normative limit in Turkey for waters intended for human consumption. The highest values of annual effective dose received by infants, children and adults due to measured tritium activity were estimated as 0.041, 0.057 and 0.120 μSv/y, respectively.  相似文献   

16.
In order to evaluate the evolution of contamination we collected river water and sediment samples in the every spring season since 1998. The elemental analysis of water and sediment samples was performed by PIXE using the 3×2 MeV NEC Tandem accelerator at the Taipei Institute of Physics. The characterization of - and -radioactive levels for water and sediment samples was performed by a BH1216, low background radioactivity instrument at the Shanghai Institute of Nuclear Research. The PIXE results showed that the elemental contents of Cl, K, Ca, Cr, Mn, Fe, Zn and Pb in river water gradually decreased with the rising tide. At high tide, their concentrations were minimum and then increased toward the ebb tide. The analysis also demonstrated that the radioactivity of water samples had been gradually decreasing year by year. It was found that the decreasing rate of -radioactivity was a little quicker than that of -radioactivity. Further aspects of environmental data evaluation and assessment are also discussed.  相似文献   

17.
18.
Journal of Radioanalytical and Nuclear Chemistry - In this study, natural (226Ra, 232Th, 40K) and artificial (137Cs) radionuclide activity concentration levels of 63 greenhouse soils collected from...  相似文献   

19.
River water samples before and after mixing with industrial effluents were collected at an interval of 4 weeks for one year and analyzed for simultaneous determination of Fe3+, Cr3+, Mn2+, Cu2+, Ni2+and Co2+ after preconcentration using pentamethylene dithiocarbamate (PMDTC) as derivatizing reagent and subsequent solvent extraction by high performance liquid chromatography (HPLC). The average levels (n = 12) of metal ions were found in the range of 14.2–542 μg/L. The results were then compared with a standard flame atomic absorption spectrophotometric method revealed no significant differences.  相似文献   

20.
Perchlorate ion (ClO4) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined—the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 μg l−1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号