Events & Issues

New Delhi, 4 November 2013

Quality Drinking Water

NEW CENTRE GIVES HOPE

By Dhurjati Mukherjee

Cabinet decision’s which are not ‘political’ in nature rarely get to the public domain, through the media. Such is the case of the Cabinet recently approving the setting up an international Centre for drinking water quality, which would cater to the entire S Asian region. Though it is more important an event than the National Water Policy announced, few would be aware of it. The Centre, which is to be set up in Kolkata will conduct extensive research and training in the area and offer its advice to all the South Asian neighbours about water-related issues.

The Union Government is expected to provide Rs 174 crores to set up the new institution, land for which has already been earmarked. It shall conduct research on drinking water technologies, health impacts of water contamination with special emphasis on arsenic and fluoride and the chemistry of sediments and coordinate with other scientific institutions and universities, already working in these areas. 

As is well known, vast tracts of West Bengal, the rest of eastern India and Bangladesh have unacceptably high levels of arsenic in their groundwater. An estimated four to five million people are exposed to excess arsenic in W Bengal and six other States. Fluoride contamination in groundwater is more severe in 19 States with 10 million-odd Indians exposed to it. 

Apart from these, a recent study conducted by the Indian Council of Medical Research (ICMR) found that Salmonelia typhi, a water-borne bacterium that causes jaundice hepatitis and could eventually lead to gall bladder cancer was rampant in water sources of Kolkata. The bacterium infects the gall bladder, gets deposited there and often flourishes in the alkaline fluid generated from the organ. 

As per government estimates, over 50 million people – almost all in rural areas, lacked routine access to safe drinking water, in April 2012 though unofficial figures would be higher. Accordingly, the new Centre is expected to concentrate primarily in rural areas though its activities will cover urban drinking water issues too. Though cities and towns have municipal water supply, microbial contamination leads to outbreaks of water-borne diseases such as rotavirus infections among children and hepatitis A and hepatitis E among adults.

The problem is thus highly critical, not because of the enormity of the contamination effects but also because water-borne diseases have been multiplying. It may be mentioned here that consumption of polluted water from the Ganga contains traces of heavy metal deposits including molybdenum, mercury and lead, which can play merry havoc with the health of those (largely the poor and economically weaker sections of society) who perceive it as pure.

Apparently, the source of arsenic is of geological origin and has been manifest in the fluvial tracks of the Ganga-Brahmaputra-Barak valley. There are a number of hypotheses about its source and the probable reasons of occurrence in groundwater. Seven States, namely Jharkhand, Bihar, Uttar Pradesh, Assam, Manipur, Chhattisgarh and West Bengal have so far been reported to be affected by arsenic contamination in groundwater above the permissible limit of 50 mg/l.

Despite a number of precautionary measures having been initiated, especially in West Bengal, since the past three decades when arsenic contamination first surfaced in 1983, fresh surveys reveal that villages continue to be affected and that the number of people suffering from arsenic related diseases is not decreasing. Scientists as also social scientists thus are gravely concerned.  

Undoubtedly, the problem resolving areas seem to be inadequate and require scientific intervention. Moreover, advancement in understanding geochemical and mobilization processes, devising satisfactory removal filters, identification of shortfalls in operation and removal of arsenic techniques, delineation of risk free deeper aquifers as an alternate source of groundwater, developing surface water based water supply schemes in arsenic affected areas have been reported and these should lead towards evolving a comprehensive scientific framework in this regard.

Reports on arsenic toxicity leads to skin itching, weight loss, loss of appetite, weakness, lethargy and even chronic respiratory complaints, which have been observed in over 50 per cent cases. Apart from these, the other effects included gastrointestinal symptoms of anorexia, nausea, dyspepsia, pain in abdomen etc. Moderate to severe anaemia was also found in some cases.   

As regards fluoride contamination in groundwater is concerned, the most affected States are Rajasthan, Gujarat and Andhra Pradesh. While in Rajasthan and Gujarat all districts except one are affected, in Andhra Pradesh 17 bear the brunt. Other States where the problem is quite severe are Punjab, Haryana, Bihar, and Tamil Nadu. As per latest estimate, about 203 districts in 20 States across the country are affected with fluorine contamination. Around 62 million people in these States, including six million children below the age of 14, live under this ominous shadow.   

Rajasthan has been most severely affected by high fluoride. The distribution of fluoride was earlier found in 11 districts (Gupta, 1993).  As is well known, the State has an arid climate with variable annual rainfall. In Sirohi district, fluoride concentrations up to 16 mg L^-1 have been found in groundwater from dug wells and boreholes at depths between 25 m and 75 m during geochemical exploration for uranium (Maithani et. al., 1998).  It has been pointed out that “the association of fluoride-endemic areas with bedrock geology is often obscure” and, as such, it is difficult to discern “whether anomalies are related to primary bedrock or secondary enrichment in the sediments”.  

Fluoride poisoning and the biological response leading to ill-effects depend on the following factors: low calcium and high alkalinity in drinking water; total daily intake of fluoride; duration of exposure to fluoride; expectant mothers and lactating mothers being the most vulnerable groups as fluoride crosses the placenta as its no barrier and also enters maternal milk; derangement in hormonal profile either as a result of fluoride poisoning or as a cause, aggravating the disease.

Those suffering from fluorosis complain of fatigue and typically the bones of the backbone, neck, hands or legs of the affected person become fragile and lead to deformity. It becomes difficult to stand, run, and even walk or carry a load.   

Although concentrations of fluoride are likely to be higher in groundwater than in other water bodies, these concentrations in most groundwater are below the permissible limits that is, not considered detrimental to human health. However, aquifers with high fluoride concentrations have been recognized in a number of regions across the world. Endemic fluorosis is a problem in many of these regions.  

According to experts, “high fluoride groundwater are typically on Na-HCO₃ type with relatively low Ca concentrations (< 20 mg L^-1 or so) and with neutral to alkaline pH values (around 7-9)”. Fluoride problems have been found in groundwater from basement aquifers, particularly granites, where fluoride-rich minerals are abundant. Fluoride has also been found in volcanic zones where fluorine is derived from volcanic rocks and geothermal sources.  

Keeping in view the dimension of the problem of water contamination and its disastrous effect on human health, specially those living in rural areas and belonging to the poor and the impoverished sections, the new Centre would be a great blessing. But such a Centre should have been started long back by the Government to ameliorate the misery of the distressed. However, as the idiom goes its ‘better late than never’. ---INFA     

(Copyright, India News and Feature Alliance)