New scientific evidence reported that those people who are exposed to passive smoke run a cardiovascular risk almost as high as those who smoke. People who do not smoke but inhale second hand smoke suffer a 30% increased risk of cardiovascular disease.

But the most alarming item is the speed with which passive smoking damages the cardiovascular apparatus. Trials that were discussed at the XVI World Congress of Cardiology showed that 30 minutes of exposure to tobacco smoke is enough for changes to occur in the arteries of the non-smokers.

"We know that just 30 minutes’ exposure to second hand tobacco smoke is enough to produce an observable change in the arterial function of non-smokers," said Dr Joaquín Barnoya, Research Director of the Cardiovascular Surgery Unit of Guatemala.

Passive tobacco smoke directly damages the endothelium, which is the internal wall of the arteries, responsible for their dilation and contraction.

Another significant advance in the understanding of the adverse effects of passive smoking is the finding that tobacco smoke contains substances whose destructive effect on the arteries of non-smokers is not known.

Health scientists found that cigarettes contain heavy metals like benzene or acrolein, which cause oxidative damage to arterial endothelium and the mitochondria, which is the cell breathing organ.

The researchers warn also that the longer the arteries of non-smokers are exposed to tobacco smoke, the more they will behave like the arteries of smokers.

Various trials have shown that passive smoking causes cardiovascular damage equal to 80% to 90% of the damage suffered by smokers.

In the United States alone 35,000 people die every year as a result of passive smoking. The World Health Organization estimates that by 2025, the deaths associated to tobacco will have tripled.