Bhubaneswar: Laboratory tests have confirmed presence of formalin, a water solution of formaldehyde, in fish samples collected from Unit IV market, the largest in Odisha's capital.

A 12-member team of Fisheries and Animal Resources Development Department (Fard) on Friday collected fish samples from the market after the state government ordered for tests in the wake of Assam government banning the import of fish due to presence of the carcinogenic chemical. The samples included prawn, rohu, mirkali, crabs and pomfret.

"The samples were collected from wholesale points, transport vehicles and other retail shops in the market. Out of the nine samples, one sample tested positive for formalin. A pomfret, which is a marine fish, tested positive. The trader concerned will be interrogated to ascertain the source of the fish," said fisheries secretary Vishal Gagan.

Gagan said that similar raids and tests would be conducted in other parts of the state.

"Task forces will be constituted in every district to prevent sale of formalin-laced fish. The testing kits will be provided by the Central Inland Fisheries Research Institute (CIFRI), Barrackpore," he added.

Earlier, both the Fard and the health department had received allegations about formalin-laced fish being sold in towns across the state. Traders either spray the solution or dip the fish in it to prevent decay.

Experts said the use of formalin in fish could cause various health hazards.

"Fish decomposes due to growth of bacteria and the use of this chemical inhibits the growth of bacteria. But consumption of formalin can cause irritation in nose, neck and eyes. It can also lead to vomiting and abdominal pain. Long time consumption may cause cancer as well," said retired professor of microbiology, Odisha University of Agriculture and Technology (OUAT), Bibhuti Bhusan Mishra.

However, the state government is yet to take a call on banning the import of fish from other states, especially Andhra Pradesh that is the largest supplier of fresh water fish to Odisha.

"We are planning to conduct laboratory test of large fish consignments from other states in collaboration with the Food Supplies and Consumer Welfare department to ascertain the presence of toxic substance," said a Fard official.

According to official statistics, the state produces around 6.8 lakh metric tonnes of fish annually, including 4.6 lakh metric tonnes of freshwater fish.

The state also imports around 20,000 metric tonnes of fish from Andhra Pradesh every year.

"The current domestic production of fish is sufficient to cater to the demand in the state. However, the shortfall arises as local fish from Odisha is also exported to other states," said an official.