Arsenic contamination spreads wider in Assam

Though high fluoride contamination in groundwater has been a problem in Assam for two decades or so,it was only around 2005 that the first traces of arsenic were detected in the state. UNICEF initially carried out a rapid assessment survey along 25 km on both banks of the Brahmaputra; a joint programme involving UNICEF,IIT Guwahati and the state public health engineering department was conducted from 2005 to 2011,leading to the revelation made by the minister.

Under the programme,conducted in 76 blocks,56,000 water samples from as many locations were tested,and nearly 30 per cent of these had arsenic beyond the permissible limit of 10 ppb (parts per billion). From 4,500 locations (8 per cent),the content was more than 50 ppb. These locations are spread over all 19 affected districts,according to the list that minister Roy provided in the assembly.

The programme took into account only samples collected from government water sources. Tubewells set up by people themselves — in the absence of government schemes — were not covered.

People in affected areas have already been reporting skin pigmentation and various other ailments. The government has constituted a task force to look not only into arsenic contamination but also into overall water quality. Several districts already have high fluoride and iron contamination,while bacterial contamination too has been a cause for alarm.

“We at IIT Guwahati have been trying to give our ful support to the efforts to mitigate the problem,” said Prof Chandan Mahanta of IIT Guwahati,a member of the water quality task force (WQTF). Set up more than a year ago,the WQTF is supposed to meet every quarter,but has so far done so only twice.

“The contaminated water sources have been already discarded. A search for alternative surface water sources is on,” minister Roy said. At some places,hand-pumps have been replaced by shallow ring wells,he added.

Arsenic contamination,which is alarmingly high in several districts of adjoining Bangladesh and West Bengal,has been also reported from three other northeastern states — Arunachal Pradesh,Nagaland and Manipur. A K Singh of the North Eastern Regional Institute of Water and Land Management at Tezpur said in a recent study that six districts of Arunachal Pradesh,two of Nagaland and one of Manipur have reported arsenic contamination beyond permissible levels.

HIGHER THAN EVER

5 districts

Had arsenic contamination in groundwater in 2005

19 districts

In 2013; Assam currently has 27