|Fire brigade personnel install a pump set on the bank of the Teesta; (above) water is pumped into the Karala in Jalpaiguri on Friday. Pictures by Biplab Basak
Jalpaiguri, Dec. 2: Tests conducted by the state pollution control board have revealed that a combination of at least six pesticides had killed thousands of fish on the Karala river in Jalpaiguri on Monday.
The West Bengal Pollution Control Board’s Siliguri regional office had collected water samples from different points of the river in Jalpaiguri following the mass mortality of the fish.
The tests conducted at the board’s laboratory in Calcutta showed that the samples contained endosulfan1 and 2, methyl parathion, dieldrin, chlorphy-rifos, methyl malathion and DDT.
The board’s chairman, B.K. Dutta, said here today that the samples had higher levels of endosulfan and methyl parathion than all other pesticides.
“These two are highly toxic. The fish floated up dead in the river when a mixture of various pesticides was thrown into water early on Monday. The samples were collected from Babughat, Samajpara and Maskalaibari. Most of the pesticides found in the water samples are used by tea growers and other farmers,” he said.
Dutta said tests on water collected from the Karala on November 8 had shown no traces of the toxicants.
According to the board, there were strict restrictions on the use of endosulfan that used to be sold under the brand Thiodan.
Endosulfan can damage lungs in humans if swallowed raw and poses health hazards if it is inhaled or comes in contact with skin. The consequences of consuming fish killed with endosulfan depend on the extent of the contamination.
However, stakeholders of the tea industry said endosulfan was no longer used in tea gardens. “The Central Pesticides Directorate does not allow the use of endosulfan and DDT in tea gardens,” said S. Pathak, the chief adviser to the Tea Research Association in Nagrakata.
Endosulfan is available by the name of Endocel at many stores selling fertilisers and pesticides in Jalpaiguri. Dieldrin is sold by the name of Sulban.
A trader said endosulfan was mainly bought by farmers. “If someone buys pesticide from our shops and uses it for unscrupulous purposes, we have nothing to do. We do not keep a register of farmers who buy chemicals from us.”
The crop protection officer of the district agricultural department, Tapan Sarkar, ruled out that the use of pesticides by farmers along the Karala had polluted the water. “There are very small tracts of agricultural land along the river. Even if pesticides are used by the farmers, they would be of very small quantities that cannot have such an impact on the fish and other life in water.”