The Society for Urban Environmental Protection (Suep) in January this year quoted a report of Harvard Centre for Risk Analysis in a press conference saying that CNG run vehicles emit Ultrafine particles which is more injurious to health than the pollution caused by diesel run vehicles, as it causes cancer. Though the matter is controversial, Suep said in its statement that it had reasons to believe that CNG pollution was taking place in Bangladesh.

The statement created anxiety amongst those involved in the CNG sector as well as the general public.

"There have been huge investments made in this sector through CNG-run vehicles, CNG filling stations and various other enterprises. I am concerned what might happen if CNG is proven dangerous for health," said Abu Sufian, owner of a CNG-run cab.

Suep in the same statement however, said the technology to measure emission of Ultrafine particles was not available in Bangladesh but it's study in January 2003 on ten taxicabs that had been converted into CNG vehicles, had found high volume of carbon monoxide and hydrocarbon. Suep assumed that the emission of Ultrafine particles would be high as well.

But DoE officials said there was very little possibility of CNG vehicles causing cancer. They said emission of Ultrafine particles is common in any fuel but CNG emits them less. Moreover, they said emission of more carbon monoxide and hydrocarbon from CNG-run vehicles is unthinkable.

"The Air Quality Management Project (AQMP) of DoE conducted a survey on 37 CNG-run vehicles and found only four of them were emitting carbon monoxide more than the expected level," said a high official of DoE. "Even that emission was only 4.5 percent whereas the standard is 4 percent," said a DoE official.

"The government has asked the DoE to clarify whether the statement claiming that CNG was causing cancer was true. We already had a meeting with experts on March 13. If necessary, we will arrange more discussions before conveying our opinion to the government," said Mohammed Reazuddin Ahmed, director technical of DoE.

A Source in the DoE said experts in the meeting mentioned CNG as a better fuel than diesel. Quoting a professor of Bangladesh University of Engineering and Technology, the source said Ultrafine particles are emitted when there is sulphur in the fuel and every petroleum product has sulphur except in the CNG available in Bangladesh.

The Suep statement caused a stir in agencies concerned and Petrobangla formed a three-member probe committee to investigate the matter. Headed by Professor AKM Kader, the committee was supposed to submit its report by mid-February but it has sought more time.

"We will submit the report by the end of March as it takes time to accumulate information and opinion from different organisations like the DoE and IUCN," said Professor Kader.