Beware: Your ground water could be radioactive

There are plenty of studies and scientific papers that prove that Bangalore’s ground water is highly contaminated. There are other studies that talk about depleting ground water levels and others that warn of a serious epidemic if the chemicals and pollutants are not brought under permissible limits.

However, what is shocking is that recent studies have indicated that the ground water in Bangalore has a substantial quantity of Radon, a radioactive chemical that is capable of causing caner and that is termed carcinogenic.

This is the result of a combined study by the Department of Environmental Studies, Bangalore University, and Bhabha Atomic Research Centre, Mumbai. However, this is not the first study that has detected Radon in Bangalore. Years ago, researchers had discovered Radon in houses and this was way back in 2005 and its presence had been tracked to quarries in and around Bangalore.

This time around, the survey was in relation to water and the presence of Radon. The study has shocked people as it has discovered large quantities of Radon and this is more than sufficient to give Bangaloreans cancer and other respiratory related diseases.

Now the question is what is Radon and why is it so dangerous?.

Radon is a radioactive chemical element with symbol Rn. Its atomic number is 86. Like Oxygen, it is odorless, tasteless and colorless but unlike Oxygen it is extremely harmful to all living beings. It is a naturally occurring indirect decay product of  Uranium or Thorium.

It is a health hazard due to its radioactive nature. What few people know is that intense radioactivity has hindered chemical studies of Radon and, therefore, only a few compounds are known.

It is often the single largest contributor to an individual's background radiation dose and epidemiological studies have shown direct link between Radon and lung cancer. It is now classified as the second largest cause of lung cancer after cigarettes. In the United States alone, it caused 21,000 deaths.

Imagine the dangers that Bangaloreans face when another study revealed that Radon has been found to be present 100 times above the permissible limit in water samples analysed across several places the City.

Moreover,  high radon concentration in groundwater an cause  stomach cancer. Radon is perhaps why the incidence of stomach cancer is more than other cancers, according to the Cancer Registry of Bangalore. Moreover, when an individual is exposed to radon and its progenies, the part of the body that receives

the highest dose of ionizing radiation is the bronchial epithelium, although the extra thoracic airways and the skin may also receive appreciable doses.

The Registry says during the last three years, the number of stomach cancer cases in Bangalore has increased by  9.29 per cent among men and by 4.3 per cent among women.

This study was taken up by the Central Ground Water Board following a directive from the Union Ministry of Water Resources.
The results have been published in this month’s edition of the “Journal of the Geological Society of India”. 

The study involved analyses of 30 ground water samples taken from borewells across the City. The permissible limit for Radon in water is 11.83 Bq/L (Becquerel per litres). The study showed that Radon concentration varied between 56 Bq/L and 947 Bq/l in the samples.
Water from a borewell at Talghatapura revealed the highest radon concentration of 1189 Bq/l, while samples from a borewell at Majestic in Central Bangalore area showed 946.69 Bq/l. The lowest presence of Radon, 55.96 Bq/L was detected in a water taken from a borewell in Srinivasapura. More worringly, not a single well showed Radon to be below the permissible limits.

The study was done across Bangalore, from Uttarahalli to Banashankari and included several other parts. Chickpet and Hebbal also reported the highest radon concentration. The data gathered in this study was analysed with the help of RAD7 which is with Bangalore University.

The CGWB says groundwater dissolves radon from the soil or aquifer and releases certain quantity to air when it comes in contact

with it. Drinking of radon contaminated groundwater for a longer period may cause stomach cancer.

Another grave issue is that neither the BWSSB, CGWB nor any authority  have RAD7 equipment to measure radon content in the water.

Bangalore University had imported the equipment from USA.

There is an urgent need to import the equipment as the World Health Organisation (WHO) mandates regular and continuous checking, analysis and sampling of Radon contaminated water. Apart from Bangalore, Radon has been recorded at Keolari-Nainpur area and the Seoni-Mandla district in Madhya Pradesh, and parts of Bhatinda, Gurdaspur, Garhwal, Himachal Pradesh, the Shivalik Himalayas and the underground waters of the Doon Valley in India.

Is there no way to make ground water safe from Radon. Yes, there is.

There are two principal ways to remove radon from water supplies dependent on groundwater sources. The first is Aeration, which forces radon from the water to the air, can be highly effective and the second is bubble plate aeration and diffused bubble aeration as point-of-entry units are capable of achieving removal efficiencies in excess of 99% at loading rates of 185 Bq/l and more.

Incidentally, L. A. Sathish of the Post Graduate Department of Physics, Government Science College, Bangalore; K. Nagaraja of the Department of Physics, Bangalore University; and T. V. Ramachandran of the Ex-Environmental Assessment Division, Bhabha Atomic Research Center, Mumbai conducted research on “The spatial and volumeric variations of radon in Bangalore Metropolitan area in 2011”. They studied ten houses in Bangalore for Radon contamination and found that the concentrations of indoor 222Rn, 220Rn and their progeny levels are higher in poor

ventilated houses than in well ventilated houses. Besides, Radon

levels in houses were found to be inversely related to room sizes.