E-cigarettes have for the first time been found to be harmful to the lungs in the same way as traditional nicotine cigarettes. Scientists at Johns Hopkins Bloomberg School of Public Health confirmed that e-cigarette vapours contain the same potentially dangerous chemicals. Research has also found that e-cigarette vapours contain free radical chemicals previously thought only to be found in tobacco cigarettes and air pollutants.Free radicals are highly reactive agents that can damage molecules within cells resulting in cell death. Cigarette smoke contains 1014 free radicals per puff. Though e-cigarette vapour contains far fewer free radicals than cigarette smoke -1 % as much -their presence in e-cigarettes still suggests potential health risks, the researchers said. For their study , researchers divided the mice into two groups: one was exposed to ecigarette 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 air. The researchers then divided each group into three subgroups. One received nasal drops containing Streptococcus pneumonia, 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 significantly more likely to develop compromised immune responses to both the virus and the bacteria which in some cases killed the mice, the researchers found. Experts say that both traditional cigarettes and ecigarettes are sources of nicotine. E-cigarettes contain less nicotine than cigarettes, but actual nicotine intake by e-cigarette users can approximate that of cigarette smokers.