Six persons were taken ill on Wednesday morning after inhaling chlorine that leaked from cylinders stored at an abandoned pumping station in Mullickghat.

Two civic officials, three fire department employees and a local resident complained of breathing problems after inhaling the gas and were rushed to SSKM Hospital and Calcutta National Medical College and Hospital.

?The pumping station had three large cylinders filled with chlorine. The valves of two had come loose, causing the leak,? said a fire department official. Hindustan Petrochemicals experts visited the site and replaced the valves. The cylinders were then shifted.

The pumping station, lying defunct for 15 years, used to release chlorine into the Hooghly for purification of water.

?We were not aware of the pumping station,? said mayoral council member Faiyaz Ahmed Khan. ?Efforts are on to trace other defunct stations.? Local parliamentarian Sudhanshu Seal, too, ?had no knowledge? about the closed facility.

Deputy commissioner (port) Ajay Ranade said: ?No major injury was reported.?

According to fire services divisional officer Bibhash Guha, a leak could have disastrous effects. ?When chlorine enters the respiratory system, it combines with water in our body and forms hydrochloric acid that burns tissues.?