A pan-India study on radiation has been carried out by scientists at the Bhabha Atomic Research Centre (BARC) and it was published in the peer-reviewed Journal of Environmental Radioactivity.
Key findings
- In parts of Kerala, background radiation levels, or that emitted from natural sources such as rocks, sand, or mountains, are nearly three times more than what’s been assumed. This doesn’t however translate to an elevated health risk.
- Radiation results from the disintegrating nucleus of an unstable element and these can be from anywhere, including from inside our bodies to the constituents of matter.
- Gamma rays are a kind of radiation that can pass unobstructed through matter. Though extremely energetic, they are harmless unless present in large concentrated doses. It’s similar to heat from a fire feeling pleasant until a sustained, concentrated burst can scald or worse, ignite.
- Especially around nuclear plants, gamma radiation levels are monitored as also the average quantity of radiation that plant workers are exposed to.
- The International Atomic Energy Agency (IAEA) specifies maximum radiation exposure levels and this has also been adopted by India’s atomic energy establishment.
- Public exposure shouldn’t exceed 1 milli-Sievert every year, those who work in plants or are by virtue of their occupation shouldn’t be exposed to over 30 milli-Sievert every year.
- The present study found that the average natural background levels of gamma radiation in India were 94 nGy/hr (nano Gray per hour) (or roughly 0.8 millisievert/year). The last such study, conducted in 1986, computed such radiation to be 89 nGy/hr. 1 Gray is equivalent to 1 Sievert, though one unit refers to radiation emitted and the other to biological exposure.
- The 1986 study measured the highest radiation exposure at Chavara, Kerala at 3,002 nGy/year. The present study found that the levels in the Kollam district (where Chavara is situated) were 9,562 nGy/hr, or about three times more. This computes to about 70 milliGray a year, or a little more than what a worker in a nuclear plant is exposed to.
- The higher radiation levels in Kollam are attributed to monazite sands that are high in thorium, and this for many years, is part of India’s long-term plan to sustainably produce nuclear fuel.
- Southern India, because of the presence of granite and basaltic, volcanic rock has higher levels of radiation from uranium deposits.
(Source: The Hindu)
