Passive smoking is one of the causes of oral cancer, scientists say. Their study is published in Tobacco Control.
Malignant tumors of the mouth, lips and oropharynx is the cause of almost 230 thousand deaths in the world annually. Smoking is one of the most important risk factors for oral cancer.
A huge number of people are forced to inhale someone else's tobacco smoke, this phenomenon is called passive smoking. Passive smokers are about 33% of non-smoking men, 35% of non-smoking women and 40% of children.
Passive smoking has a lot of harmful effects on health. In 2009, the International Society for the Study of Cancer confirmed that second-hand exposure to tobacco smoke causes lung cancer. Passive smoking is known to increase the risk of laryngeal and pharyngeal cancer.
Scientists suggest that passive smoking can cause oral cancer. However, little research has been devoted to this issue. Based on the results of each of them separately, it is difficult to draw conclusions.
A new scientific paper is a meta-analysis and systematic review of all studies on the relationship between smoking and oral cancer. An international team of scientists analyzed data that covered nearly 7,000 people. Approximately half of them were passive smokers. The analysis showed that their risk of developing oral cancer is approximately 50% higher than that of people who did not breathe tobacco smoke. Exposure to tobacco smoke for more than 10 years almost doubled this risk.
In the conclusions of the study, the authors indicated that their work supports the idea that passive smoking is one of the causes of oral cancer. The dose-dependent effect (the longer the exposure, the higher the risk) also supports this hypothesis.
The authors of the study write that clarifying the harmful effects of passive smoking highlights the need to improve measures to prevent secondary exposure to tobacco smoke.