Second-hand smoke is also known as environment tobacco smoke (ETS) and it is a mixture of 2 forms of smoke coming from burning tobacco, namely sidestream smoke (smoke that comes from the end of a lighted cigarette, pipe, or cigar) and mainstream smoke (the smoke that is exhaled by a smoker).
Non-smokers are said to have involuntary smoking or passive smoking when they are exposed to second-hand smoke. The more they are exposed to, the higher the level of those harmful chemicals will be inhaled into the body.
Researchers from the Chinese PLA General Hospital in Beijing found that people regularly exposed to second-hand smoke might raise their risk of dying from various causes including heart disease and lung cancer, comparing to those who lived and worked in a smoke-free environment.
The findings of a long-term study based on 910 adults (439 men and 471 women) who were followed over a period of 17 years were published in the May 2012’s issue of journal ‘Chest’. At the outset, 44.2 percent lived with a smoker, while 52.9 percent inhaled second-hand smoke at work.
249 participants (150 men and 99 women) died over the following years. The risk of death from heart disease, stroke, lung cancer and emphysema were 2 to 3 times higher for people who were exposed to second-hand smoke.
11 percent of the 271 men exposed to second-hand smoke died of stroke, comparing to 6.5 percent of the 168 men who lived and worked in smoke-free surroundings. Though the study could not prove that second-hand smoke was the culprit, they did find evidence of dose-response relationship, which is key to building the case for a cause-and-effect relationship.
The study also revealed that second-hand smoke exposure is highly prevalent in China, the largest producer and consumer of tobacco in the world. In 2010, about one-third of the world’s cigarettes are consumed by China’s 301 million smokers.