ABSTRACT
A survey on long-lived artificial radionuclides (137)Cs and (90)Sr in vegetables produced in Finland was carried out in 2009-2010. The mean (137)Cs concentrations of all the outdoor vegetables were well below 0.5 Bq kg(-1), ranging from <0.01 to 8.15 Bq kg(-1) (fresh weight). The highest (137)Cs contents were found in potato and root vegetables. The uneven distribution of the (137)Cs deposition after the Chernobyl accident in 1986 was still seen in the (137)Cs contents of outdoor vegetables. The (137)Cs contents of greenhouse vegetables varied from <0.01 to 9.3 Bq kg(-1), and the highest concentrations were found in organic lettuce grown in peat pots. The concentrations of (90)Sr in the vegetables varied from 0.0087 to 0.17 Bq kg(-1) fresh weight. The mean effective dose resulting from (137)Cs and (90)Sr in vegetables in 2009-2010 was <0.3 µSv a(-1) and poses no health risk to the consumers.
Subject(s)
Cesium Radioisotopes/analysis , Strontium Radioisotopes/analysis , Vegetables/chemistry , FinlandABSTRACT
Natural radioactivity due to the presence of 226Ra, 232Th and 40K in selected building materials (cement, sand, bricks, gypsum and ceramic) used in Egypt was measured using a gamma-ray spectrometer with an HPGe detector. The average activity concentrations observed in different building materials ranged from 10.0 +/- 1.3 to 109 +/- 6, <2 to 55.8 +/- 2.2 and 5.5 +/- 1.7 to 684 +/- 34 Bq kg(-1) for 226Ra, 232Th and 40K, respectively. Based on these, together with previously reported results, the effective doses received by the residents of different types of house within all Egyptian governorates were assessed using the WinMat computer program. The results were below 1 mSv a(-1) in all cases. The collective effective dose indoors was assessed as 15,000 man Sv and the excess effective dose due to building materials was 0.07 mSv a(-1).
Subject(s)
Construction Materials , Environmental Exposure , Radiation Dosage , Radiation Monitoring/methods , Egypt , Humans , Potassium Radioisotopes/analysis , Radiometry , Radon/analysis , Spectrometry, Gamma , Thorium/analysisABSTRACT
The activity concentrations of (226)Ra and (228)Ra in drinking water were determined in water samples from 176 drilled wells. (226)Ra activity concentrations were in the range of <0.01-1.0 Bq l(-1) and (228)Ra activity concentrations in the range of <0.03-0.3 Bq l(-1). The mean activity concentration of (226)Ra and (228)Ra were 0.041 and 0.034 Bq l(-1), respectively. High radium activity concentrations in drinking water were rare. Only 2-4% of the drilled wells exceeded a (226)Ra concentration of 0.5 Bq l(-1) and 1-2% of the wells exceeded a (228)Ra concentration of 0.2 Bq l(-1). These are the activity concentrations that cause a 0.1 mSv annual effective dose for users of drinking water. The maximum annual effective doses from (226)Ra and (228)Ra for users of drilled wells were 0.21 mSv, and 0.16 mSv respectively. The elevated activity concentrations of (226)Ra and (228)Ra did not occur simultaneously in the same groundwaters and the correlation between (226)Ra and (228)Ra was small.
Subject(s)
Background Radiation , Environmental Exposure/analysis , Radiation Monitoring/methods , Radiation Protection/methods , Radon/analysis , Water Pollutants, Radioactive/analysis , Water Supply/analysis , Body Burden , Finland , Humans , Radiation Dosage , Relative Biological EffectivenessABSTRACT
For the first time, a comparison of radon activity concentration in air has been performed within the scope of Euromet. In the project 657, 'Comparison of calibration facilities for the radon activity concentration,' 12 participants from 9 countries compared different radon reference atmospheres at 1, 3 and 10 k Bq m-3 via a transfer standard. The comparison was listed as BIPM supplementary comparison EUROMET.RI(II)-S1. The results of most participants are correlated due to common traceability to one single radon gas standard producer. This makes a careful correlation analysis necessary to achieve an appropriate comparison reference value. The results of the comparison as well as the complex analysis of the correlated set of data is presented and discussed.
Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollutants, Radioactive/standards , International Cooperation , Radiation Monitoring/methods , Radiation Monitoring/standards , Radon/analysis , Radon/standards , Calibration/standards , Europe , Guidelines as Topic , Radiation Dosage , Reference Standards , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
A preliminary intercomparison on gamma-ray spectrometry determination of natural radionuclides in building materials was carried out in 1999-2002. Samples measured were fly ash, sand and tuff. Laboratories used different experimental equipment and procedures. Corrections for blank, spectral interference, self-absorption and coincidence summing effects were applied in most cases. The agreement between results was within 15-20%, most often within the reported uncertainties. Several general conclusions can be drawn regarding procedures correctness, uncertainty budget, secular equilibrium condition, and radionuclide representativeness in each natural series. Further studies are needed to draw more specific conclusions.
