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Background radiation levels, or those generated by natural sources such as rocks, sand, or mountains, are nearly three times higher in areas of Kerala than previously thought, according to pan-India research conducted by experts at the Bhabha Atomic Research Centre (BARC).
Key highlights:
- According to the current study, the average natural background level of gamma radiation in India is 94 nGy/hr (or around 0.8 millisieverts/year).
- The most recent study of this kind, which was done in 1986, found that this radiation was 89 nGy/hr. Even though one number refers to outgoing radiation and the other to biological exposure, 1 Gray is the same as 1 Sievert.
- The current study discovered that levels in the Kollam area (where Chavara is located) were 9,562 nGy/hr, or around three times higher. This amounts to around 70 milligrams per year or slightly more than what a worker at a nuclear plant is exposed to.
- Nevertheless, the maximum radiation dose was observed in 1986 at Chavara, Kerala, at 3,002 nGy/year.
- In contrast to the 1986 survey, which only mapped 214 places, the present study detected radiation levels at approximately 100,000 locations across the country.
- Despite being incredibly energetic, they are not harmful unless present in high concentrations.
Reasons for a higher radiation level:
- The elevated radiation levels in Kollam are attributed to the thorium-rich monazite sands, which have been part of India’s long-term strategy to create nuclear fuel sustainably for many years.
- Thorium deposits total around 360,000 metric tons (coastal regions of South India). Monazite in beach sands (25 per cent of world reserves).
- Thorium is not a fissile material; hence, it cannot fission to create energy. It must go through a three-stage process in a reactor powered by other fissile elements to be converted into U-233.
- Because there is a lot of granite and basaltic volcanic rock in southern India, uranium deposits there give off more radiation.
Radiation exposure levels:
- The International Atomic Energy Agency (IAEA) defines maximum radiation exposure levels, which India’s atomic energy sector has also embraced.
- Public exposure should not exceed 1 millisievert per year, and individuals who work in plants or are exposed through their work should not be subjected to more than 30 millisieverts per year.
- The sievert (Sv) is the measure of radiation dosage that affects the human body.
Radiation:
- It is produced by the dissolving nucleus of an unstable element and can come from everywhere, including our bodies and the constituents of matter.
- Gamma rays are a kind of radiation that may travel through materials without being hindered.
Background radiation:
- Natural radiation is always present in the environment. It comprises cosmic radiation from the sun and stars, terrestrial radiation from the Earth, and internal radiation found in all living things. The amount of naturally occurring radioactive elements in soil, water, and air changes from location to location and through time.
Source: The Hindu