What causes lung cancer? The four major risk factors
There is a one word answer to the question "what causes lung cancer".
The answer is - smoking.
Of course, there are other causes of lung cancer as well. Some of them
include exposure to asbestos, polluted air, radon, etc. Let's check out
some of the key lung cancer risk factors in more detail. This will provide
a more comprehensive answer to "what causes lung cancer".
Risk factor #1: Cigarette smoking
As noted elsewhere on this site, fully nine out of ten cases of lung
cancer develop because the patient is a smoker or has been a smoker.
Smoking has a very strong correlation with this dreaded disease. If you
are a smoker, that should be reason enough to quit smoking right now.
To give you some statistics, if you are a regular smoker who smokes one
pack of cigarettes a day, your chances of developing lung cancer is twenty
five times higher as compared to that of someone who is a non smoker.
If you smoke two packs a day, your probability of dying from lung cancer
is as much as one in seven. If you smoke cigars or pipes, your chances of
getting this disease are five times as much as that of someone who has
Cigarette smoking has as an accumulative effect on your lungs. With every
cigarette smoked, the risk of developing cancer goes up due to increased
cell damage within your lungs.
The good news is, the moment you stop smoking, your lungs begin the task
of repairing themselves. They replace unhealthy, tobacco-damaged cells
with normal, healthy cells. The risk of developing lung cancer begins to
decrease from the time you stop smoking. And it continues to drop over the
years, with each passing year. It is estimated that by the end of the
fifteenth year from the time you quit smoking, your chances of developing
lung cancer are no greater than that of someone who never smoked in his
Risk factor #2: Second hand smoke
This is closely related to smoking. Second hand smoke carries a high
concentration of carcinogens and other dangerous substances. If you
regularly inhale second hand smoke (this situation is also known as
passive smoking), you partake in many of the risks that accrue to smokers.
Some studies say that the risk of getting lung cancer increases by twenty
four percent for passive smokers as compared to those never exposed to
In America, there are an estimated three thousand deaths annually that are
attributed to second hand smoke.
Risk factor #3: Exposure to asbestos
Asbestos exposure is a known risk factor for mesothelioma (this is a
cancer that affects the lung's pleural linings).
In many countries, asbestos was a widely used construction material till
the 1960s. Asbestos was also present in many products used on a daily
basis. The risks associated with asbestos were not widely known then.
The problem with asbestos is that it releases fine silica fibers into the
air. When these fibers are inhaled, they get trapped within the lung
tissues and cause mesothelioma. In fact, mesothelioma does not develop in
anyone who has never been exposed to asbestos in one form or the other.
There are also key differences between smoker and non smokers. A non
smoker exposed to asbestos has a five times higher risk of developing lung
cancer compared to a non smoker who has not been exposed to asbestos. A
smoker exposed to asbestos has a fifty to ninety time greater risk as
compared to a non smoker who never went near asbestos!
Risk factor #4: Exposure to radon
Radon is a gas created by the radioactive decay of naturally occurring
uranium. According to estimates of the US Environmental Protection Agency,
about one in seven homes in America have unsafe levels of radon. Around
12% of all deaths from lung cancer are estimated to be due to radon
These are the major risk factors in developing lung cancer. Together, they
explain most of the lung cancer cases that occur and provide a more or
less complete answer to the question "what causes lung cancer".