New research provides evidence that the average cigarette is crawling with germs, including bacteria that cause respiratory disease.
But as one spokesman for a tobacco company pointed out, the authors of the new study aren't sure what, if any, hazard the germs pose. And exposure to bacteria is nothing new: Microbes surround us every day of our lives.
Still, the findings raise plenty of questions, said study lead author Amy R Sapkota. "Right now, we've just taken the first step to identify what's there. Now we need to figure out if they are impacting human health."
Hundreds of types of bacteria
Sapkota and colleagues looked for germs in four brands of cigarette: Camel, Kool Filter Kings, Lucky Strike Original Red and Marlboro Red. Previous research looked at specific types of germs, while the new study is all-encompassing, said Sapkota, assistant professor at the University of Maryland School of Public Health in the US.
The researchers found hundreds of types of bacteria in the cigarettes, including some that cause respiratory disease, lung and blood infections, foodborne illness, as well as infections that people get when they're in the hospital.
It's unclear how many of the germs can survive the heating process of smoking, said Sapkota. But it's possible that many germs might make it into the lungs because only the tip of a cigarette is extremely hot, potentially allowing germs elsewhere to stay cooler.
Sapkota said it's too early to tell if the germs make smokers sick or are even harmful to people who breathe in smoke. But it is clear that smokers have higher levels of bacteria in their respiratory tracts and higher rates of bacterial infection, she said. "But no one has ever looked to see if the cigarettes themselves could be a source of those bacterial infections."
May cause lung disease
John L Pauly, a Roswell Park Cancer Institute research scientist who has studied germs and cigarettes, said the new study and others raise questions about whether the bacteria in cigarettes could be responsible for disease in the lungs, such as chronic obstructive pulmonary disease. They may also cause disease in the mouth, he said.
It's also possible germs could cause chronic inflammation that could boost the likelihood of cancer, he said.
The source of the germs is unclear, but Pauly said they could appear during the preparation of tobacco. Sapkota agreed, adding that the cigarettes "could have been contaminated anywhere from seed to pack."
David Sutton, a spokesman for Altria Group, Inc., formerly known as Philip Morris USA, said it hasn't reviewed the new study. But "after an initial look at it, I would point out the authors' conclusion section: 'The overall public health implications of these findings are unclear at this time.'"
The study findings appear in an upcoming issue of the journal Environmental Health Perspectives. - (HealthDay News, December 2009)