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The Use of Natural Stone Material Radioactivity Level Investigation and Risk Assessment of Beijing

Author: ZhangQin
Tutor: LuoYun
School: Chinese Geology University (Beijing)
Course: Safety Technology and Engineering
Keywords: natural stone radioactivity survey risk assessment radom
CLC: TU521.2
Type: PhD thesis
Year: 2014
Downloads: 3
Quote: 0
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Abstract

In recent years， more and more people are electing natural stones to decoratehomes、offices and entertainment arenas for the decorative effects of natural stoneswith noble, gorgeous, simple and natural odds.However, natural stones will beharmful to the human body due to their radioactive influences. Currently, a reasonablestandard of stone building materials and safety regulations havn’t been made. What’smore, safety assessment database was out. Therefor, we carried out a study which aimto the Beijing public awareness and the level of radiation protection after the sitesurveys. And radio nuclides of natural stones and radon exhalation rate wasanalysised, and risk assessment was operated. In addiction,appropriate protectivemeasures and guidances was proposed.Firstly, the study did a preliminary research to the stone markets in Beijing.Theresults of public awareness and access to protection level to the radioactivity ofnatural stone was obtained by contrasting, collecting relevant literature and surveyingthe Beijing residents,workers in stone markets. Secondly, we expect to determine thelevel of radioactivity in Beijing natural stone through the field surveys and samplingto select natural stones samples. Moreover, the RAD7and other instruments wereused to detect radon exhalation rate for comparison with selected radonconcentration.Finally, combined with fuzzy mathematics method and the LEC method,we make use of the risk analysis methods in terms of hazard levels, people,management, and environment to examine the factors and do a risk assessment.The results of the survey showed that the lower level of stone radioactiveawareness and consciousness level of protection for natural stone with the staff andresidents of Beijing. According to the test level of radioactivity of the stone, therewere three kinds of stone class B in the19kinds of random samples of stone andnon-Class A stone was15.8%, which was lower than the national average. What’smore, there were four kinds of stone over the1mSv/a in the per capita annualeffective dose estimates, requiring restrictive use. According to the measurement results of radon concentration and exhalation rate, natural stone radon exhalation rateand indoor radon concentrations were related to many factors and different types ofstone was different in radon exhalation rate.In Beijing random test sample, theaverage radon exhalation rate of2.04×10-3Bq/m2·s.Thanks to this field work and testing, The types and colors of stone have a greateffect on contents and the concentration of radon exhalation rate were concluded. Thesouthern region of radiation is larger than others, and dark stones were moredangerous. Nowadays, we pay more attention to safety, especially in the modern city—Beijing. Neither the universality about Stone radiation hazards and training effortsnor the appropriate government departments for its strict management and supervisionare sufficient. Due to the migrant workers and difficult management, they lead peopleto stone radiation hazards contempt. This is a significant risk of physical injury.

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