Background radiation higher in Kerala, but no risk: study

Subject :Science and Technology

Section: Nuclear technology

Concept :

In parts of Kerala, background radiation levels are nearly three times more than what’s been assumed, a pan-India study by scientists at the Bhabha Atomic Research Centre (BARC) has found.

Background radiation

Background radiation is a measure of the level of ionizing radiation present in the environment which is not due to deliberate introduction of radiation sources.
Background radiation originates from a variety of sources, both natural and artificial.
Background radiations are the radioactive radiations such as alpha, beta, and gamma.

How radiation occurs?

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.

Limitations on radiation exposure:

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 should not exceed 1 milli-Sievert every year.
Those who work in plants shouldn’t be exposed to over 30 milli-Sievert every year.

Current levels in Kerala:

The present study found that average natural background levels of gamma radiation in India was roughly 0.8 milli sievert/year.
This doesn’t mean that those at Kollam are being exposed to higher, dangerous levels of radiation.

Causes of background radiation in India:

The higher radiation levels in Kollam (Kerala) are attributed to monazite sands that are high in thorium.
In southern India, because of the presence of granite and basaltic, volcanic rock has higher levels of radiation from uranium deposits.

Sievert (symbol: Sv)

It is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection.