The state-of-the-art transverse ventilation system in the newly-opened 9.2 km Chenani-Nashri tunnel on the Jammu-Srinagar highway may not be working effectively as commuters are complaining of high pollution levels, eye irritation and suffocation inside what has been labelled as one of India's infrastructural wonders.

Some of the commuters using the strategically-important tunnel in Jammu and Kashmir on a regular basis told media that they were also battling poor visibility caused by high pollution levels inside what is India's first and the world's sixth road tunnel that uses a hi-tech ventilation system to extract polluted air and maintain a constant flow of fresh air.

Balvinder Singh, a Delhi-based orthopaedic surgeon from Jammu, said he suffered breathing problems when he was inside the tunnel, built with Austrian technology at a cost of Rs 2,900 crore ($450 million) and inaugurated by Prime Minister Narendra Modi on April 2.

"The ventilation system inside the tunnel probably doesn't work effectively. As soon as we enter the tunnel during peak hours, the visibility starts plummeting. If we travel with the windows down, the pollution level rises. It causes breathing issues as well," the surgeon with Delhi's Safdarjung Hospital told media.

"It feels as if we are passing through a gas chamber," the surgeon said.

Anil Manhas, who works with the Jammu and Kashmir Education Department, uses the tunnel that has reduced the 41-km distance between Chenani in Udhampur to Nashri in Rambhan to just 11 km, slashing his travel time from two-and-a-half hours to a mere 10 minutes.

"I took it lightly when I used the tunnel for the first time. I had irritation in my eyes. It was also smoke-filled. This is happening regularly now and I think the ventilation system is not working. If this prevails for long... there are chances of vehicles meeting with accidents due to poor visibility," Manhas said.

Asked about the problem, National Highways Authority of India (NHAI) spokesperson Vishnu Darbari said since Infrastructure Leasing and Financial Services (IL&FS) had constructed the tunnel, only they would be able to answer queries about it.

But Ashutosh Chandwar, Vice President, IL&FS, contended that the problem has to do with claustrophobia caused by travel though such a long and confined space.

"I do not know why the passengers are feeling such problems... There is absolutely no possibility of it. Whenever there is pollution inside the tunnel, its ventilation system will automatically start and exhaust out the pollution. What people are suffering is phobia of travelling through a long tunnel," Chandwar told media.

He said the ventilation system of the tunnel was "well tested and can tackle every kind of pollution inside the tunnel".

Environmentalist Vivek Chattopadhyay said pollution levels inside such a long tunnel were bound to increase but could be controlled if the ventilation functions properly.

The Programme Manager at the Centre for Science and Environment said such problems occur in hilly terrain and assimilation of pollutants often occur as these do not disperse easily.

"The problem of poor visibility due to pollution levels inside the tunnel is genuine and it is commonly seen. The problem can be solved only if the ventilation system works effectively," Chattopadhyay told media.

Another problem commuters face on a routine basis is traffic congestion inside the tunnel.

"The traffic congestion due to the continuous flow of all kinds of vehicles is another major problem," said Bhushan, a Jammu resident who works with the state government.

The NHAI had earlier said vehicles below BS-III engines won't be allowed in.

However, the directive couldn't be executed considering the volume of trucks that ply daily carrying essentials between Jammu and Kashmir, Chandwar of IL&FS said.