Guwahati, May 28: Testing of drinking water sources by the Assam public health engineering (PHE) department has revealed that Barpeta and Nagaon districts are the worst affected by arsenic and fluoride contamination.
Testing of drinking water sources by the department up to March 31, 2017, revealed 2,485 water sources in Barpeta were contaminated with arsenic while 401 in undivided Nagaon were laced with fluoride, which are highest among all districts of the state.
Though Hojai, which is badly affected by fluoride contamination, was recently carved out of Nagaon as a separate district, segregated figures of Hojai are yet to be compiled.
Though high fluoride contamination in groundwater has been a problem in Assam for more than two decades, it was only around 2005 that the first traces of arsenic were detected in the state.
According to a PHE department source, after testing water samples from 3,25,079 sources in the state, 10,301 sources were found to be contaminated by arsenic and 1,298 were found to be contaminated by fluoride.
Besides Barpeta, other districts affected by arsenic contamination are Jorhat, Nalbari, Baksa, Darrang and Bongaigaon districts. (See chart)
Prolonged arsenic contamination is known to cause cancer and skin diseases besides affecting reproductive health. Apart from Assam, arsenic-laced water is a serious problem in Bengal, Uttar Pradesh, Jharkhand, Chhattisgarh, Bihar and Manipur.
Similarly, apart from Nagaon, other districts in the state which are facing the problem of fluoride contamination are Dhubri, Karbi Anglong and Udalguri districts.
Consumption of water containing excessive fluoride causes dental and skeletal fluorosis and most of the fluorosis victims are children. The most pronounced symptoms of fluorosis are bent legs and discoloured and brittle teeth.
To supply arsenic-free water in the affected areas, 165 piped water supply schemes, mostly from safe surface water sources, were commissioned and 2,641 sanitary ring wells were constructed, a source in the PHE department said. "Similarly, in fluoride-affected areas of the state, 35 piped water supply schemes were installed and 861 sanitary ring wells were constructed," he said.
"Moreover, detailed project reports are being prepared to set up 124 piped water supply schemes in 3,705 arsenic-affected human habitations and 154 fluoride-affected human habitations of the state under the National Water Quality Sub Mission. After completion of these schemes, all the affected areas are expected get arsenic and fluoride-free water by 2021," he said.
The Centre has recently launched the National Water Quality Sub Mission to combat arsenic and fluoride to provide safe drinking water to about 28,000 affected habitations in the country by March 2021 with an outlay of Rs 25,000 crore. "Water filtration projects using nano technology are also being implemented in Jorhat, Barpeta, Dhubri, Baksa, Darrang, Goalpara, Morigaon, Nagaon and Nalbari districts with Rs 11.57 crore provided by Niti Aayog," the source said.