The nitrate effect

Earlier posts had dwelt on the presence of chemicals in the ground water of Bangalore and the need to take remedial steps.

This post will deal with the presence of nitrates and the best and easiest way to tackle its presence in ground water.

Nitrate, which affects the blood cells, varies from 16 to 554 mg against a permissible level of 50 mg per litre in many areas of Bangalore. One of the main reasons for the presence of nitrates in ground water is the inefficient garbage disposal system. This has led to people dumping garbage in open areas. This is aggravated by the fact that  the landfills where Bangalore’s domestic waste is dumped is not scientific.

The nitrates in garbage seeps into the groundwater when it rains. A report published by the Geological Society of India has shed light  on the ground water and its nitrate, fluoride and chromium content, all of which is dangerous.

It says the permissible limit is 45mg of nitrates per litre of water. But the reading for underground water in Sanjay Gandhi Nagar is 335mg/ litre and in Old Yelahanka, 335mg/ litre. Even more shocking is the 554mg/ litre in Nayandahalli on Mysore Road.

Excess nitrate is also found in:

Nayandahalli------------------------554 mg/l

Sanjay Gandhi Nagar---------------375 mg/l

Old Yelahanka-----------------------335 mg/l

Anjananagar-------------------------298 mg/l

Santhammanahalli------------------294 mg/l

Permissible limit: 45mg/l

The nitrates in the water react with the haemoglobin in the blood to produce methemoglobin, which impairs the capacity of the red blood cells to carry oxygen to different parts of the body.

It also causes methemoglobinemia, or blue baby syndrome, a condition in which newborn babies die due to lack of oxygen supply.

Another recent study conducted by Department of Environmental Science, Bangalore University and the Bhabha Atomic Research Centre, Mumbai, says groundwater in Bangalore has a high concentration of nitrate.

This study was conducted by Jiban Singh M., Somashekar R.K., Prakash K.L., and Shivanna K., and  81 samples were collected for the study between January 29 and February 3, 2013.

This study too found the nitrate values in the groundwater from the central core of the city ranged from 10 to 400 mg/L.

Another study on ground water is by  M A Farooqi, scientist at Central Groundwater Board. He was conferred a doctorate by Bangalore University for his work on “Municipal waste disposal practices and their impact on groundwater quality in Bangalore Metropolitan Region”.

The study said 50 per cent of the ground water has high Nitrate levels. It says North, North-East and Southern parts of Bangalore have levels of nitrate that is ten times more than permissible limits.. 

The high nitrate content can also cause cancer, when it reacts with protein compounds in the body to form nitrosamine, a cancer-causing agent. It can also cause cyanosis among infants and also gastric cancer when present in high quantity. Nitrite is absorbed in the blood and hemoglobin gets converted to methemoglobin. Methemoglobin does not carry oxygen efficiently, resulting in a reduced oxygen supply to vital tissues such as the brain. Methemoglobin in infant blood cannot change back to hemoglobin, which normally occurs in adults. Severe methemoglobinemia can result in brain damage and even death.

Pregnant women, adults with reduced stomach acidity, and people deficient in the enzyme that changes methemoglobin back to normal hemoglobin are all susceptible to nitrite-induced methemoglobinemia or blue baby syndrome. The most obvious symptom of methemoglobinemia is a bluish color of the skin, particularly around the eyes and mouth.

Other symptoms of nitrate consumption include headache, dizziness, weakness or difficulty in breathing. Generally, healthy adults consume fairly large amounts of nitrate with few known health effects. In fact, most of the nitrate we consume is from our diets, particularly from raw or cooked vegetables. This nitrate is readily absorbed and excreted in the urine. However, prolonged intake of high levels of nitrate and that too taken in liquid form are linked to gastric problems due to the formations of nitrosamines. N-nitrosamine compounds have been shown to cause cancer in test animals.

Although there is no enforceable drinking water standard for livestock, animals too should not be allowed to drink water with more than 100 mg/l NO3-N or Nitrate. This is especially true of young animals. They are affected by nitrates the same way as human babies. Older animals may tolerate higher levels.

However, it is difficult to determine the toxicity of nitrate in animals because it depends on the rate at which the substance is consumed. A few hundred milligrams of nitrate may cause poisoning if consumed in a few hours. But spread over a whole day, 1,000 mg nitrate may cause no signs of toxicity.

Common symptoms include abdominal pain, diarrhea, muscular weakness or poor coordination. Affected animals will have blood that is a chocolate-brown color.

Nitrate also exists in animal feeds and fodder. Drought-stressed forage plants commonly have high nitrate levels. These feeds can have an additive effect when consumed with high nitrate drinking water.

Nitrate is listed as the second greatest chemical threat to surface and groundwater after pesticides. Another fact is that increasing nitrate levels in water is a potential source of several environmental stresses to aquatic organisms, because nitrate is known to be toxic to crustaceans, insects, amphibians and fish.

Today, it is acknowledged that human and animal wastes, industrial effluents, use of agrochemicals and seepage of sewage through drainage system are the main sources of nitrate contamination of ground water.

Thus Nitrates cannot be washed away or wished away. Nor will boiling the water rid it of nitrate content. If you boil water, the nitrates hardens and solidifies and this is more dangerous. Then what is the solution?.

The traditional three pot method can be implemented at the house level to get rid of the nitrates. It involves placing a pot containing sand on the top. Beneath it comes a pot containing charcoal and the last pot will be empty and this collects the filtered water.

Another way would be to dilute the nitrate-polluted water by mixing it with water from another source with low nitrate concentration. Though blended water is not safe for infants it is frequently used for livestock.

The best way is the natural way. Let water seep in to the soil and more the water that enters the ground, more will the nitrate dissolve. Studies have shown that both rainwater harvesting and modifies drain systems can dilute nitrates substantially. Beside, recharging of ground water can not only raise the water table but also dissolve to different extents all chemicals, including nitrates. 

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.