Measurement And Analysis Of Radioactivity Of Common Building Materials In Liaoning Province

Compared with the chemical substances such as formaldehyde,benzene,people often neglect the radiation damage of building materials,and the damage is often unpredictable,and the incubation period is long,the harm to body is usually appeared in a few years later,therefore,detecting and analysis the level of radioactivity in building materials detection,to guide the people correctly select the material when construction and decoration,has very important significance.In this study,the radioactivity of building materials in Liaoning was measured and analysis by gamma spectrum analysis.Through data analysis and combining with related literature,the reasons for the level of radiation levels are excessive were summarized.By reference to national building materials radionuclide limit,calculating the radium equivalent activity,internal exposure index,external exposure index,annual effective dose equivalent,the radiation safty was evaluated.The conclusion of this study as follows:The average of specific activity of 115 granites for 226Ra?232Th?40K were 80.78,27.18,368.85 Bq/kg respectively.Although the test samples in our study belongs to A kind of stone,but considered radium equivalent activity,and annual effective dose equivalent,some granites still cannot be used for indoor decorate if the area is lesser.Especially the radioactive level of red granitesis easy to exceed standard,residents should be careful when choose.The granite's radioactivity produced in Guangdong,Guangxi,Shandong,Fujian area are higher than that produced in other areas.Radioactivity of granite produced in Guangdong is highest.The radioactive levelof deep color granites is significantly higher than light-colored granites,especially the beige and white granitescan be used safty.Lithological characters and forming times are important factors influencing the radioactivity of stone.Most red granite are acid rock,radioactivity of acid rock is relatively high,so the radioactivity of red granite is high.Newer Yanshan period granite appeared in the south of China,thus,average radioactivity level of granite produced in southern province is higher than that produced in northern province.Red granite appeared in Guangdong region contains iron oxide,zinc,fluorite,these mineral caused the radioactivity of granite appeared in Guangdong region is high.The average of specific activity of 27 ceramic tiles for 226Ra?232Th?40K were 164.28,77.35,478.29 Bq/kg.Due to the materials of ceramic tile generally drawn nearby,radioactivity of ceramic tile is related to local natural radioactivity.Although glaze in the ceramic tile is only a thin layer,its contribution to the radioactivity of ceramic tile is very big.Therefore,in the production process of ceramic tile,we should strengthen the detection of glaze,to control the radioactivityof glaze in a certain range.The average of specific activity of 489 cements for 226Ra?232Th?40K were 46.6,33.2,231.7 Bq/kg.In general,the order of radioactivity level of different kinds of cement rankings is portland fly-ash cement>complex portland cement>complex portland cement>portland blast furnace slag cement>ordinary portland cement,clinker has much effect on the radiation levels of cement.Before production,we should investigate the level of radioactivity of mine.Radioactivity of cement produced by the same manufacturer is relatively stable,relevant departments can appropriately decrease the times of spot check and inspection,and to alleviate the burden of enterprises.When choose the building materials,residents should comprehensively considerate each evaluation index.We should not choice according to a single national standard for building materials,we should also considerate internal and external exposure index,radium equivalent activity,annual effective dose equivalent.