Aug. 23, 2004 -- Three cigarettes can cause more air pollution than a diesel car's exhaust, according to an Italian study.
The study compared levels of air pollution particles produced by cigarettes with those coming from a late-model "eco-diesel" engine. The research team was led by Giovanni Invernizzi of the Tobacco Control Unit of Italy's National Cancer Institute.
Environmental tobacco smoke is a contributor of air pollution particles. These fine particles are a risk factor for chronic lung disease which can be debilitating and sometimes fatal. They can lead to conditions such as asthma, bronchitis, and emphysema, and are also a risk for lung cancer, write the researchers.
The test was conducted in the small, northern Italian mountain town of Chiavenna, which has unusually low outdoor levels of air pollution.
The experiment was conducted in a closed, private garage with six small vents, which were kept open during the experiment in accordance with Italian law.
The car they tested was a 2002 turbo diesel Ford Mondeo that met European gas exhaust standards. Low-sulfur fuel was also used.
The cigarettes were "MS" filter cigarettes produced by Italian State Monopoly. Each contained 1 milligram of nicotine and 11.2 milligrams of tar.
The researchers started the Mondeo and then let its engine idle for 30 minutes. After airing out the garage for four hours, the scientists lit three cigarettes -- one after another -- and let them smolder for a total of 30 minutes.
They measured air pollution levels every two minutes during the tests. They also measured pollution particle matter for an additional 90 minutes after the engine was turned off and the cigarettes had burned out. The car's exhaust and cigarettes were placed in the same position.
Researchers focused on fine particulate matter air pollution -- microscopic particles in the air that measure less than 2.5 micrometers in diameter, which is about the size of cigarette smoke particles.
The cigarettes produced 10 times as much particulate matter as the auto, comparing the first hour after starting the engine with the first hour after lighting the cigarettes.
"Since we utilized a room with a volume similar to that encountered in many offices and homes, the present data give cause for concern," write the researchers. "Environmental tobacco smoke is a major source of particulate matter pollution."
Newer vehicles have improved emission rates. "It has been estimated that older gasoline vehicles and light-duty diesel emission rates are on average 100 times higher than those of newer vehicles," write the researchers. Low-sulfur fuel also helps reduce particulate matter.
While smoking is restricted for health reasons in many countries, it's not always associated with air pollution.
"Even health personnel are often unaware of such risks," write the researchers, who suggest using their findings in antismoking campaigns. The research is published in the journal Tobacco Control.