A study of the natural radioactivity and radon exhalation rate in some cements used in India and its radiological significance

Abstract

The presence of natural radioactivity and radon exhalation from building materials contribute to the radiation dose received by human. So, it is essential to evaluate the activity levels of the primordial radionuclides (238 U, 226 Ra, 232 Th and 40 K) present in the building materials for the assessment of natural radiation dose. Cement is one of the major component of the building materials and is used on a large scale. In the present study, the commercially available cement samples of fifteen different brands were used to study the radon exhalation rate and activity concentration of 238 U, 226 Ra, 232 Th and 40 K nuclides. The radon exhalation rate was measured using the can technique, while the concentration of radionuclides content was determined by using gamma ray spectroscopy. The radon exhalation rate from different brands of cements was found in the range from 1.56 to 13.1 mBqkg À1 h À1 with a mean value of 5.27 mBqkg À1 h À1. The specific activity of uranium was found in the range 45.3e218.9 Bqkg À1 with a mean value of 111.2 Bqkg À1 ; 226 Ra from 20.3 to 60.1 Bqkg À1 with a mean value of 35.8 Bqkg À1 ; 232 Th from 18.8 to 60.1 Bqkg À1 with a mean value of 33.2 Bqkg À1 and 40 K varied from 160.9 to 248.1 Bqkg À1 with a mean value of 199.1 Bqkg À1. The radiological parameters e radium equivalent activity, absorbed dose rate, annual effective dose, external hazard index, internal hazard index, gamma activity index and alpha index were also evaluated to assess the potential radiological hazard associated with these cement samples. Correlation coefficients for the different radionuclides have been evaluated and studied.

A Study of Natural Radioactivity in Some Building Materials in Nigeria

“…The results of this work are in good agreement with the results of a previous study of building materials conducted in Nigeria (3) . Even the specific activities for cement are in line with results published elsewhere (11)(12)(13)(14)(15)(16)(17)(18)(19) . In contrast, the analyzed samples of sand in this study show a distinctly higher specific radioactivity than in other studies (19)(20)(21)(22)(23) , except for 40 K that reported two values which are higher by factors of 1.18 (China) and 1.50 (South Korea), respectively.…”

Radiological Investigation of High Background Radiation Areas

“…The maximum value for activity concentration index is 2 (I ≤ 2) to meet 0.3 mSvyr −1 dose criterion and I ≤ 6 to meet 1 mSvyr −1   26,27 .…”

Assessment of natural radioactivity in various commercial tiles used for building purposes in Nigeria

“…The origin of these materials is the Earth's crust, but they find their way into building materials, air, water, food and the human body itself. The world wide average indoor effective dose due to gamma rays from building materials is estimated to be about 0.4 mSv per year [ [3] , [4] ]. Globally, building materials that contain radioactive nuclides have been used for many decades.…”