Can secondhand smoke cause cancer 3

Risk factors

Many different factors can interact in the development of lung cancer. First and foremost, harmful substances in the air we breathe contribute to the fact that the mucous membrane cells of the bronchi gradually transform into cancer cells. By far the most important risk factor for lung cancer
This is the space in the rib cage between the two lungs that houses the thoracic viscera - i.e. the heart, associated nerves, vessels and lymph nodes. The pleurs (pleura and lungs), which line the two pleural cavities with the lungs, form a partition between the mediastinum and the lungs. To the front and back, this space is bounded by the sternum and thoracic spine; from above and below it extends from about the level of the collarbone down to the diaphragm.
is smoking. But pollutants in the workplace and in the air are also considered risk factors. Diet, infections and occupational diseases (e.g. silicosis) and possibly hereditary predispositions also play a role. Even if there is no clear evidence for the latter so far, one can observe a familial accumulation of lung cancer.


90 percent of all lung cancer cases can be attributed to smoking. Numerous cancer-causing substances are contained in cigarette smoke. The risk of developing lung cancer is about 10-15 times higher for a smoker than for a never-smoker. This risk naturally increases with the number of cigarettes smoked every day and with the duration of smoking. Around every thirtieth smoker falls ill in the course of his life. For pipe and cigar smokers who do not inhale the smoke, the risk of lung cancer is significantly lower than with inhaled cigarette smoking, but still high compared to that of non-smokers. However, there is a subgroup of cigars and pipe smokers who inhale like cigarette smokers. The risk here is comparable to that of cigarette smokers. Even passive smokers (people who do not smoke themselves but stay in rooms where people smoke) have an increased risk of cancer: Passive smoking increases the risk of lung cancer by a factor of 1.3.


The work-related lung cancer risk is much lower than the risk of smokers. About one percent of all cases of lung cancer are caused by inhaling substances that people have to deal with in their workplace. Asbestos is responsible in over 90% of cases, but arsenic, beryllium, cadmium, chromium, nickel, aromatic hydrocarbons and diesel exhaust also play a role. These substances occur primarily in metal processing, in coal gas and coke production, in foundries or in rubber production. Workers in uranium mines are also at risk of lung cancer from contact with the naturally occurring, radioactive noble gas radon-radon
Radon is produced by the spontaneous radioactive decay of uranium and occurs practically everywhere in different concentrations.
elevated. Heavy air pollution - especially from diesel soot - can also increase the risk of lung cancer (1.5 times). Especially with smokers, pollutants - whether in the workplace or in the outside air - lead to an additional significantly increased risk of lung cancer.


A diet low in vitamins doubles the risk of developing lung cancer - especially among smokers. That is why it is important to eat fruits and vegetables regularly. Beta-carotene from leafy vegetables and carrots, for example, is said to have a protective effect against lung cancer. However, vitamins that are taken in the form of dietary supplements or high-dose preparations are not an alternative: In smokers, they do not seem to reduce the risk of cancer, but actually increase it. In relation to the harmful effects of smoking, however, the contribution of diet to the development of lung cancer is low overall.

Infections & Injuries

In general, scars in the lungs - due to previous inflammations or infections (e.g. as a result of tuberculosis or silicosis) or after injuries - are associated with an increased risk of cancer. This is because cancer tends to develop in those areas of the lungs that are scarred as a result of tuberculosis or other diseases. Here, too, smokers are at greater risk.

Genetic strain

Hereditary predisposition can also increase the risk of lung cancer. If one parent has bronchial cancer, the children's risk increases by two to three times.