GUWAHATI, July 11 - The total number of the State�s habitations, where drinking water sources have been found to be contaminated by the presence of excess arsenic, has shot up to 4,118 in 18 districts as per the latest information available with this newspaper.
Similarly, the number of habitations in the State where drinking water sources have been contaminated with excess fluoride has also shot up to 1,171 in the same number of districts, as per the latest information available with this newspaper.
According to the information available with this newspaper, till April 1, 2015, the total number of arsenic-affected habitations in 20 districts of the State was 2,571. Till then, the safe limit of presence of arsenic in drinking water was considered to be 50 parts per billion (ppb), according to the Indian standard.
But the safe limit has been proposed to be lowered to 10 ppb, following a high-level meeting held by the Union Drinking Water and Sanitation Minister with the Inter-Ministerial Group (IMG) and involving eight arsenic-affected states of the country in the month of January this year, in line with the World Heath Organisation (WHO) recommendation.
This resulted in the rise in the total number of arsenic-affected habitations in the State to 4,118 in 18 districts so far. The sources covered under the water quality monitoring system of the State Government for the purpose, covered only the Government spot water sources.
In the case of fluoride contamination of drinking water sources, the fact remains that 746 habitations are found to be hit by this phenomenon recently, while 425 habitations are on the list of the affected habitations for quite a long time.
Experts here express their concern over the steps taken for quick and effective mitigation of the twin problem, which came into being following sinking of tubewells, or shifting the emphasis from surface water sources to groundwater sources to meet the drinking water needs of the people.
Experts here also lay much stress on conducting epidemiological survey, impact study and awareness generation. Without epidemiological survey, there is no way to know the disease burden, and it renders the medical intervention impossible, and thus the patients are forced to live without treatment.
Moreover, impact study can only tell which way huge spending in schemes are effective � it is like the tracer bullet for corrective direction, said the experts.
It needs mention here that as soon as arsenic contamination of drinking water sources were found, the West Bengal and Nepal governments conducted thorough epidemiological studies to check arsenicosis.
The genesis of chemical contamination of drinking water can be traced to the initiative of the United Nations International Children�s Emergency Fund (UNICEF) in the 1960s to take to groundwater sources in the developing countries in a bid to eliminate the possibility of water-borne diseases caused by bacteriological contamination of drinking water.
Till then, drinking water was solely drawn from surface water sources like ponds, lakes and rivers. Such contamination led to cholera, typhoid and diarrhoea-related deaths on a massive scale.