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981.
Al-Jundi J Li WB Abusini M Tschiersch J Hoeschen C Oeh U 《Journal of environmental radioactivity》2011,102(6):574-580
High indoor radon concentrations in Jordan result in internal exposures of the residents due to the inhalation of radon and its short-lived progeny. It is therefore important to quantify the annual effective dose and further the radiation risk to the radon exposure. This study describes the methodology and the biokinetic and dosimetric models used for calculation of the inhalation doses exposed to radon progeny. The regional depositions of aerosol particles in the human respiratory tract were firstly calculated. For the attached progeny, the activity median aerodynamic diameters of 50 nm, 230 nm and 2500 nm were chosen to represent the nucleation, accumulation and coarse modes of the aerosol particles, respectively. For the unattached progeny, the activity median thermodynamic diameter of 1 nm was chosen to represent the free progeny nuclide in the room air. The biokinetic models developed by the International Commission on Radiological Protection (ICRP) were used to calculate the nuclear transformations of radon progeny in the human body, and then the dosimetric model was applied to estimate the organ equivalent doses and the effective doses with the specific effective energies derived from the mathematical anthropomorphic phantoms. The dose conversion coefficient estimated in this study was 15 mSv WLM−1 which was in the range of the values of 6-20 mSv WLM−1 reported by other investigators. Implementing the average indoor radon concentration in Jordan, the annual effective doses were calculated to be 4.1 mSv y−1 and 0.08 mSv y−1 due to the inhalation of radon progeny and radon gas, respectively. The total annual effective dose estimated for Jordanian population was 4.2 mSv y−1. This high annual effective dose calculated by the dosimetric approach using ICRP biokinetic and dosimetric models resulted in an increase of a factor of two in comparison to the value by epidemiological study. This phenomenon was presented by the ICRP in its new published statement on radon. 相似文献
982.
Kurnaz A Kucukomeroglu B Damla N Cevik U 《Journal of environmental radioactivity》2011,102(4):393-399
The activity concentrations and absorbed gamma dose rates due to primordial radionuclides and 137Cs have been ascertained in 222 soil samples in 18 counties of the Trabzon province of Turkey using a HPGe detector. The mean activity concentrations of 238U, 232Th, 40K and 137Cs in soil samples were 41, 35, 437 and 21 Bq kg−1, respectively. Based on the measured concentrations of these radionuclides, the mean absorbed gamma dose in air was calculated as 59 nGy h−1 and hence, the mean annual effective dose due to terrestrial gamma radiation was calculated as 72 μSv y−1. In addition, outdoor in situ gamma dose rate (D) measurements were performed in the same 222 locations using a portable NaI detector and the annual effective dose was calculated to be 66 μSv y−1 from these results. The results presented in this study are compared with other parts of Turkey. Radiological maps of the Trabzon province were composed using the results obtained from the study. 相似文献
983.
Aerial measurement of radioxenon concentration off the west coast of Vancouver Island following the Fukushima reactor accident 总被引:1,自引:0,他引:1
Sinclair LE Seywerd HC Fortin R Carson JM Saull PR Coyle MJ Van Brabant RA Buckle JL Desjardins SM Hall RM 《Journal of environmental radioactivity》2011,102(11):1018-1023
In response to the Fukushima nuclear reactor accident, on March 20th, 2011, Natural Resources Canada conducted aerial radiation surveys over water just off the west coast of Vancouver Island. Dose-rate levels were found to be consistent with background radiation, however a clear signal due to 133Xe was observed. Methods to extract 133Xe count rates from the measured spectra, and to determine the corresponding 133Xe activity concentration, were developed. The measurements indicate that 133Xe concentrations on average lie in the range of 30-70 Bq/m3. 相似文献
984.
农地城市流转中不同利益集团的福利状况韭已成为学者和政策制定者关注的焦点.农民集体作为影响最为深刻的利益集团之一,其福利在农地城市流转中能否实现以及如何实现均衡成为本文研究的核心内容.本文首先介绍了农民集体福利的概念及其测度方法,然后论述福利均衡的概念,提出农民集体福利均衡分析的三个假设,在此基础上,对农地城市流转中的农民集体福利进行分析,提出实现农民集体福利均衡的条件,结果表明农地城市流转中农民集体福利均衡的必要条件为农民集体获得的经济补偿大于或等于其福利损失.然后通过比较分析发现当前土地征收中农民集体获得的福利补偿不能弥补其福利损失,农地城市流转前后农民集体福利呈现不均衡状态.最后提出农地城市流转中要尊重农民集体的土地产权,进一步提高农地征收的补偿标准,使农民集体获得的货币补偿能够弥补其由于土地财产损失造成的福利损失,以实现农民集体福利的均衡;政府应当通过改善农村交通、通讯、电力、饮水、居住等条件,完善农村社会保障体系等措施提高农民集体的福利水平,以弥补农民集体土地发展权受限造成的二次福利损失. 相似文献
985.
Xue Yang Chang Wang Lihua Yang Qi Zheng Qiongyu Liu Nicholas J.P.Wawryk Xing-Fang Li 《环境科学学报(英文版)》2022,34(7):129-140
Halobenzoquinones(HBQs) are emerging disinfection byproducts(DBPs) with a widespread presence in drinking water that exhibit much higher cytotoxicity than regulated DBPs. However, the developmental neurotoxicity of HBQs has not been studied in vivo. In this work, we studied the neurotoxicity of HBQs on zebrafish embryos, after exposure to varying concentrations(0-8 μmol/L) of three HBQs, 2,5-dichloro-1,4-benzoquinone(2,5-DCBQ), 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), and 2,5-dibromo-1,4-benzoqu... 相似文献
986.
987.
988.
Ariamalar Selvakumar Mary Ellen Tuccillo Swarna Muthukrishnan Asim B. Ray 《补救:环境净化治理成本、技术与工艺杂志》2009,19(2):135-142
Several compositions of Fenton's Reagent and hydrogen peroxide alone were used to disinfect combined sewage samples from a wastewater treatment facility. The presettled samples contained suspended solids (SS) and dissolved organic carbon (DOC) at concentrations of 28 and 290 mg/L, respectively. Disinfection with Fenton's Reagent was carried out at a pH between 5.90 and 6.0 and at a temperature of 25°C. All disinfected samples contained residual oxidants. Under all reaction conditions studied, complete inactivation of E. coli was achieved within one minute of the addition of Fenton's Reagent. Disinfection with hydrogen peroxide alone under similar conditions is incomplete even under much longer contact times. © 2009 Wiley Periodicals, Inc. 相似文献
989.
990.
根据泰州市保护局公布的2006 ~ 2010泰州市环境空气的监测数据,利用灰色系统GM(1,1)残差修正模型,分析预测未来5年的环境空气质量.预测结果显示,泰州市未来5年环境空气质量将持续好转,这表明,泰州市近年来采取的产业结构调整和清洁能源战略实施卓有成效. 相似文献