Environmental tobacco smoke produces fine particulate matter, the most dangerous element of air pollution. According to the new study, levels indoors can far exceed those outdoors because new engine models and lead-free fuels have cut the levels of particulate matter emissions from car exhausts.
In a study which was conducted in a garage in a small, Italian mountain town where there are very low levels of particulate matter air pollution. A turbo diesel engine was left idling for 30 minutes in the garage with the doors closed. Then, the doors were left open for four hours. The car was fueled with low sulphur fuel. Three filter cigarettes were also lit up sequentially, and left smoldering for another 30 minutes.
Results of the experiment show the diesel engine exhaust doubled the particulate matter levels found outdoors at its peak. The environmental tobacco smoke particulate matter reached levels 15-times higher than those measured outdoors. Thus researchers say air pollution emitted by cigarettes may be 10-times greater than diesel car exhaust.