Wednesday, May 2, 2007

The dangers of secondhand smoke (1)

smoking hand
Secondhand smoke puts the heart under stress. A number of studies have linked exposure to secondhand smoke to a higher risk of death from heart attack. Some critics say that such a link does not strictly proof that secondhand smoke causes cardiac death. They may be right if we were forced to draw our conclusion only from a single study. But we are not. It is a puzzle of many pieces, and every day new pieces are added, closing gaps and uncovering missing links.

As to the heart issue, new facts have been found in Switzerland. In people exposed to environmental tobacco smoke (ETS) at home or at work, the heart rate variability is lower and the heart rate is higher than in persons not exposed. What does this mean? A healthy heart is able to adjust the speed of its beats to the situation, that is, beat faster in an effort and beat slowlier at rest. In addition, a higher heart rate at rest indicates that the heart is less fit and hence more likely to get sick.

Another puzzle piece: Secondhand smoke raises the level of a dangerous substance in the blood, C-reactive protein (CRP). CRP favours lesions in blood vessels, leading to atherosclerosis, stroke, angina pectoris and heart attacks.

Secondhand smoke not only is a poison in itself. It also increases the uptake of lead in pregnant women, as researchers in Krakow, Poland, have shown. This adds new evidence to the danger of tobacco smoke to the fetus. In addition, passive smoking has been linked to preterm delivery. - (Picture by Leo @ Flickr)

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