According to a study by Council of Scientific and Industrial Research (CSIR), vehicles that run on CNG emit dangerous Nano Carbon that causes cancer.
The limited-sized study was conducted in Delhi and CSIR alerted the central government regarding the health hazard it poses to humans and said it will also follow up.
Dr MO Garg, the Director General for CSIR said, "Natural gas is supposed to be a clean fuel when used in internal combustion engines, right? But, I don't think people realize that what you see (smoke) is perhaps better than what you don't see (no smoke from CNG vehicles)."
"We did a study with a professor of Alberta University, who have developed a device to measure and analyze particles emitted by vehicles. We have installed this machine on the exhaust of a natural gas-run DTC bus in Delhi."
"Can you imagine that we found nanocarbon particles coming out of from natural gas combustion. These particles are moving around in the atmosphere and going straight into your lungs through your nose. It then enters into your blood through membranes."
"These nanoparticles are rich in polynuclear aromatic, having huge surface area. They are also carcinogenic. I have been telling government that we need to look at this situation more seriously."