Natural Radioactivity of Building Materials Used in the Thoubal and Bishnupur Districts of Manipur, India

Natural radioactivity concentrations have profound implications for our environment and the health of all living beings. Human have always been exposed to natural radiation throughout their life, which is out of control. Natural radioactivity levels in different types of houses vary due to different building materials. Assessment of this radioactivity of various types of houses is important because high levels of radioactivity may increase stochastic effects on humans including animals.

A study of natural radionuclides of different types of houses was conducted at 522 houses in the Thoubal and Bishnupur districts of Manipur, India. The average annual effective doses of gamma radiation levels in indoor and outdoor were estimated from the measurements using Micro R-survey meter and found as 1.3 ± 0.1 (range: 1.0 – 1.4) mSv/y and 0.8 ± 0.1 (range: 0.6 – 1.0) mSv/y for reinforced cement concrete (RCC) houses, followed by 1.1 ± 0.1 (range: 0.8 – 1.3) mSv/y and 0.7 ± 0.1 (range: 0.6 – 0.9) mSv/y for Assam-type (AT) brick houses, 1.0 ± 0.1 (range: 1.0 – 1.2) mSv/y and 0.8 ± 0.1 (range: 0.7 – 1.0) mSv/y for Adobe laid earthen houses, 0.8 ± 0.1 (range: 0.4 – 1.1) mSv/y and 0.7 ± 0.1(range: 0.2 – 1.0) mSv/y for AT mud houses and 0.7 ± 0.1 (range: 0.7 – 0.8) mSv/y and 0.7 ± 0.1 (range: 0.6 – 0.8) mSv/y for AT katcha houses. The activity concentrations of 226Ra, 232Th and 40K are 37 (range: 22 – 65) Bq/kg, 113 (range: 22 – 211) Bq/kg and 1196 (range: 689 – 2280) Bq/kg respectively. Moreover, the annual effective dose conceived from building material was found as 0.8 mSv/y from brick, followed by 0.7 mSv/y from sand, 0.6 mSv/y from Portland cement and 0.4 mSv/y from concrete.

Recognizing the implications of measured radioactivity concentrations of different types of houses reported by researchers is crucial for devising strategies to mitigate potential hazards associated with it. It is important for governments and regulatory bodies to establish guidelines and effective measures may be taken on particular types of houses with high levels of natural radioactivity to protect human beings and other organisms from radiation risks.