Causes of Lung Cancer
The main cause of lung cancer is smoking which is responsible for nine out of ten cases. The more you smoke the higher your risk and the risk gets even higher the longer you smoke.
It’s an odd fact that if you smoke 20 cigarettes a day for 40 years then the risk of getting lung cancer is around eight times higher than if you smoke 40 a day for 20 years. The fact that the disease can actually be prevented makes it one of the most tragic forms of cancer.
How Cigarettes and Smoking cause Lung Cancer
It’s not surprising that smoking causes lung cancer. Cigarettes contain 4,000 chemicals, many of which are known carcinogens (substances which cause cancer). These chemicals are inhaled and slowly begin working on the cells in the lungs, air passages and windpipe.
But if a person stops’ smoking their risk decreases every year until, after about 15 years, their risk of developing lung cancer is no greater than someone who doesn’t smoke.
Filters and low tar cigarettes can reduce a person’s risk of getting lung cancer, as can smoking a pipe or cigar. But the risk is still far higher than for someone who doesn’t smoke because a huge amount of chemicals are still involved.
There has also been some suggestion that smoking cannabis can cause lung cancer but this is probably more likely to be due to the fact that many people roll the cannabis with tobacco.
Lung Cancer and Passive Smoking
Even people who don’t smoke can be at risk. In America, passive smoking accounts for approximately 3,000 deaths from lung cancer each year. If a non smoker lives with a smoker, inhaling their second hand smoking increases their chances of getting lung cancer by 25%. Working in a smoky bar or restaurant increases the risk by 17%.
In the UK, well known entertainer and life long non-smoker Roy Castle died from lung cancer. His death was attributed to the many years he played at clubs.
Environmental Causes of Lung Cancer
Exposure to asbestos can increase the risk of lung cancer by around ten times and if an exposed person smokes as well the likelihood of getting lung cancer is 50 times higher.
In some parts of the world a naturally occurring gas called radon (a by-product of uranium) which can pass through the soil into the foundations of buildings has been found to cause cancer. In America it’s the second leading cause of lung cancer killing around 22,000 people each year.
It has also been suggested that air pollution can cause lung cancer, although this has only been proved in a small amount of people who have been exposed to very large amounts of exhaust fumes in their working environment.
Uranium, chromium and nickel are all known factors in the development of the disease as well. But someone would have to be exposed to huge amounts to be put at risk of developing lung cancer.