Is diesel harmful?

One query Pankaj,

do the diesel engines cause any problems to the passengers/driver in the long run? or is the emission of 'particulate matters' only harmful for the environment in general without causing any specific problems to the passengers/driver of the diesel car.

Sathanam.

Diesel is known to be environmentally friendly.

As per what I could gather from the net, diesel produces less CO emission as compared to petrol - the exhaust contains more soot and hence it is more visible than petrol exhaust.

Both Rohit and Pankaj are 50% correct when it's said that diesel emits less CO (Carbon Monoxide) than petrol. Also it emits less NOX (Nitrogen dioxide). Both are harmful fuels and in that sense diesel is cleaner than petrol. but diesel engines emit harmful "particulate matters" or "fine particulate matters" which are respirable and very very harmful for health.  In United States there are stringent emission standards for diesel powered vehicles. also we all know that diesel buses in Delhi which was the major cause of environmental pollution in Delhi is totally banned after Supreme Court Orders and now it is all converted to CNG.  Environment is far clean now as certified by reputed doctors and environmentalist.

My query was as to what extend the emissions from diesel powered car will affect the passenger/driver.

Santhanam

@Santhanam - I did not say that diesel is cleaner or less harmful than petrol, only that it has less CO emissions. However diesel exhaust has a lot of soot which is carcinogenic. So if not controlled this soot will pollute the air leading to all sorts of respiratory problems. In all diesel is a more efficient fuel (it has greater energy content per unit) and hence diesel engines are more efficient (the mixture is much leaner than with petrol) but they produce soot...so both fuel type will pollute if the air-fuel mixture is not close to ideal and means are not employed to control the emissions.