E-cigarettes, suggested to minimize cigarette smoking is found to compromise the immune system in the lungs and generate some of the same potentially dangerous chemicals found in traditional nicotine cigarettes, says a team of researchers including an Indian-origin scientist.
“Our findings suggest that e-cigarettes are not neutral in terms of the effects on the lungs,” said Shyam Biswal, professor at the Johns Hopkins Bloomberg School of Public Health in the US.
E-cigarettes have gained popularity among current and former smokers as well as those who have never smoked, including teenagers as it is touted to pose little health risk for smokers, including those with chronic obstructive pulmonary disease (COPD).
“We have observed that they increase the susceptibility to respiratory infections in the mouse models,” Biswal noted.
In a study conducted on the mice, one group was exposed to e-cigarette vapour in an inhalation chamber in amounts that approximated actual human e-cigarette inhalation for two weeks, while the other group was just exposed to open air.
The researchers then divided each group into three subgroups. One received nasal drops containing Streptococcus pneumoniae, a bacteria responsible for pneumonia and sinusitis, among other illnesses, in humans. A second received nasal drops of the virus Influenza A, and the third subgroup did not receive either virus or bacteria.
The mice exposed to e-cigarette vapour were seen to have significantly impaired immune responses to both the viral and the bacterial infections, the researchers found.
The researchers also determined that e-cigarette vapour contains “free radicals,” known toxins found in cigarette smoke and air pollution. Free radicals are highly reactive agents that can damage DNA or other molecules within cells, resulting in cell death and the smoke contains 1014 free radicals per puff.
The findings appeared in the journal PLOS ONE.
“E-cigarette vapor alone produced mild effects on the lungs, including inflammation and protein damage,” says Thomas Sussan, lead author and an assistant scientist in the Department of Environmental Health Sciences at the Bloomberg School. “However, when this exposure was followed by a bacterial or viral infection, the harmful effects of e-cigarette exposure became even more pronounced… It’s 100 times lower than cigarette smoke, but it’s still a high number of free radicals that can potentially damage cells.”
The researchers believe this study, thought to be the first to examine animal response to e-cigarette inhalation, will serve as a model for future studies on the effects of e-cigarettes.
Since their introduction to the U.S. market in 2007, e-cigarettes have prompted debate as to their risk in general and relative to cigarettes.
The U.S. Food and Drug Administration last spring announced that it was going to begin regulating e-cigarettes. According to the U.S. Centers for Disease Control and Prevention, more than one-quarter million teenagers who reported never having smoked a cigarette reported using e-cigarettes in 2013.