Radioactive in granites

In order to determine the use of granite rocks in line with environmental goals and sustainable development, the effective radiation dose of these granites was calculated. The research method was based on determining the values ​​of 226Ra, 232Th and 40K isotopes by mass spectrometer on 62 samples of granitoid rocks collected from 13 regions of Iran. In order to verify the isotopic information, petrographic studies including texture, color, type of main and secondary minerals and determining the exact name of granite using polarizing microscope were also performed on rock samples.

The findings of this study show that microscopic observations and isotopic data are in good agreement with each other. In other words, the lighter the color of the studied granite samples and the richer the secondary minerals (such as zircon, apatite and titanite), the higher the concentration of radioactive elements in them. The highest mean values ​​of 226Ra, 232Th and 40K cores are 128, 11.8 and 136.46 Bq kg-1 for Kurdistan, Birjand and Zanjan granites, respectively. The average concentration of the above three isotopes for Iran is 60, respectively. 39 78. 47, and Bq kg-1 884. 72. In addition, each of these values ​​is higher than the world standard set for granites.

                                                        

Using Excel software and standard formulas, the most important hazard indicators were calculated for 62 granite samples and the average information under the headings of radium equivalent activity (Bq kg-1) (240. 72), the amount of external and internal radiation dose in the open air (0 0-32506 (65012), internal radiation dose (0.81334), effective annual dose rate 0.13759 mSv / yr), cancer risk risk dose (Sv / yr 0.48155) and gamma radiation index (0 88856) was calculated. The results show that the average risk indices in the studied granites for public places are less than the allowable limit set by the UNSCEAR standard, but due to the high risk of radiation, the use of these granites in the interior of the building, especially for Closed spaces such as hospitals, educational spaces, prisons, sanatoriums, decoration and decorative equipment are not allowed.

Considering that the environment is one of the main indicators of sustainable development, observance of the standards of this research regarding the radiation dose of each of the risk indicators, reduces diseases caused by natural radioactivity and significantly contributes to achieving sustainable development. Development (economy, society and environment).