Air Pollution: Cigarettes Ten times worse than modern diesel engines Researchers from the Cancer Institute in Milan have discovered in an experiment that cigarette smoke pollutes the air ten times as badly as the exhaust gases of a modern diesel engine. The researchers started the experiment in the Italian Alps because there is very little fine dust in the air. In a garage a diesel engine was first run for 30 minutes and then three cars were burned. The evaluation of the results showed that the concentration of particulate matter in the smoke of cigarettes was ten times higher than in the diesel engine. Since cigarette smoke is very short-lived, it is mainly a pity for the closer environment, the researchers explained.