In this work the performance of a screening analytical method for Energy Dispersive X-Ray Fluorescence (EDXRF) analysis in terms of accuracy and precision was evaluated through analysis of rock standard reference mate...In this work the performance of a screening analytical method for Energy Dispersive X-Ray Fluorescence (EDXRF) analysis in terms of accuracy and precision was evaluated through analysis of rock standard reference materials. The method allowed the division of elements into four groups taking into account the excitation energies and measurement conditions of the sample. Two standard reference materials were used and 15 sample replicates were prepared and analyzed, then statistics were applied to assess the precision and accuracy of analytical results. The obtained results show that major compounds or elements (SiO<sub>2</sub>, P<sub>2</sub>O<sub>5</sub>, K<sub>2</sub>O, CaO, Fe<sub>2</sub>O<sub>3</sub>, Ti) can be determined in fine powder sample with a deviation lower than 15%, and a relative standard deviation in the range (1 - 10)%. The deviation was found to be lower than 5% for major compounds such as K<sub>2</sub>O, and CaO, which suggest that the EDXRF is accurate in evaluating major elemental concentrations in rock samples. It was also found that the method seems to be more accurate and precise for major elements than for trace element investigation. This screening analytical method can be used for routine analysis with acceptable results, even though the method should be optimized to increase its precision and accuracy.展开更多
This work draws attention to the effects of the second cause of lung cancer which is also the largest source of exposure to ionizing radiation, radon, during the lockdown recommended by the World Health Organization (...This work draws attention to the effects of the second cause of lung cancer which is also the largest source of exposure to ionizing radiation, radon, during the lockdown recommended by the World Health Organization (WHO) due to the Covid-19 pandemic. The basic assumption is that the exposure times have been assimilated to the 03-month lockdown time and the 02-week maximum incubation period of the disease. Doses during these periods and Relative Risk of Lung Cancer (RRLC), Lung Cancer Cases per year per million people (LCC) and Excess Lifetime Risk of Cancer (ELRC), were evaluated based on the concentrations obtained in high natural background radiation area in Cameroon. The existing exposure situation due to radon is then reevaluated and ranged from 0.76% to 17.55%. These results show that the reconsidered exposure time would be equivalent to the exposure time of a worker over one year, with their respective doses values becoming equivalent. The risks of developing lung cancer were also evaluated and it has been found that due to this pandemic it unfortunately increased.展开更多
文摘In this work the performance of a screening analytical method for Energy Dispersive X-Ray Fluorescence (EDXRF) analysis in terms of accuracy and precision was evaluated through analysis of rock standard reference materials. The method allowed the division of elements into four groups taking into account the excitation energies and measurement conditions of the sample. Two standard reference materials were used and 15 sample replicates were prepared and analyzed, then statistics were applied to assess the precision and accuracy of analytical results. The obtained results show that major compounds or elements (SiO<sub>2</sub>, P<sub>2</sub>O<sub>5</sub>, K<sub>2</sub>O, CaO, Fe<sub>2</sub>O<sub>3</sub>, Ti) can be determined in fine powder sample with a deviation lower than 15%, and a relative standard deviation in the range (1 - 10)%. The deviation was found to be lower than 5% for major compounds such as K<sub>2</sub>O, and CaO, which suggest that the EDXRF is accurate in evaluating major elemental concentrations in rock samples. It was also found that the method seems to be more accurate and precise for major elements than for trace element investigation. This screening analytical method can be used for routine analysis with acceptable results, even though the method should be optimized to increase its precision and accuracy.
文摘This work draws attention to the effects of the second cause of lung cancer which is also the largest source of exposure to ionizing radiation, radon, during the lockdown recommended by the World Health Organization (WHO) due to the Covid-19 pandemic. The basic assumption is that the exposure times have been assimilated to the 03-month lockdown time and the 02-week maximum incubation period of the disease. Doses during these periods and Relative Risk of Lung Cancer (RRLC), Lung Cancer Cases per year per million people (LCC) and Excess Lifetime Risk of Cancer (ELRC), were evaluated based on the concentrations obtained in high natural background radiation area in Cameroon. The existing exposure situation due to radon is then reevaluated and ranged from 0.76% to 17.55%. These results show that the reconsidered exposure time would be equivalent to the exposure time of a worker over one year, with their respective doses values becoming equivalent. The risks of developing lung cancer were also evaluated and it has been found that due to this pandemic it unfortunately increased.
