Causes of lung cancer
Most cases of lung cancer
are caused by smoking, although people who have never smoked can also develop
the condition.
Smoking
Smoking cigarettes is the
single biggest risk factor for lung cancer. It's responsible for more than 85%
of all cases.
Tobacco smoke contains
more than 60 different toxic substances, which can lead to the development of
cancer. These substances are known to be carcinogenic (cancer-producing).
If you smoke more than 25
cigarettes a day, you are 25 times more likely to get lung cancer than a
non-smoker.
While smoking cigarettes
is the biggest risk factor, using other types of tobacco products can also
increase your risk of developing lung cancer and other types of cancer, such as
oesophageal cancer and mouth cancer. These products include:
- · cigars
- · pipe tobacco
- · snuff (a powdered form of tobacco)
- · chewing tobacco
Smoking cannabis has also
been linked to an increased risk of lung cancer. Most cannabis smokers mix
their cannabis with tobacco. While they tend to smoke less than tobacco
smokers, they usually inhale more deeply and hold the smoke in their lungs for
longer.
It's been estimated that
smoking four joints (homemade cigarettes mixed with cannabis) may be as
damaging to the lungs as smoking 20 cigarettes.
Even smoking cannabis
without mixing it with tobacco is potentially dangerous. This is because
cannabis also contains substances that can cause cancer.
Passive smoking
If you don't smoke,
frequent exposure to other people’s tobacco smoke (passive smoking) can
increase your risk of developing lung cancer.
For example, research has
found that non-smoking women who share their house with a smoking partner are
25% more likely to develop lung cancer than non-smoking women who live with a
non-smoking partner.
Radon
Radon is a naturally
occurring radioactive gas that comes from tiny amounts of uranium present in
all rocks and soils. It can sometimes be found in buildings.
If radon is breathed in,
it can damage your lungs, particularly if you're a smoker. Radon is estimated
to be responsible for about 3% of all lung cancer deaths in England.
Occupational exposure and
pollution
Exposure to certain
chemicals and substances used in several occupations and industries has been
linked to a slightly higher risk of developing lung cancer. These chemicals and
substances include:
- · arsenic
- · asbestos
- · beryllium
- · cadmium
- · coal and coke fumes
- · silica
- · nickel
Research also suggests
that being exposed to large amounts of diesel fumes for many years may increase
your risk of developing lung cancer by up to 50%. One study has shown that your
risk of developing lung cancer increases by about a third if you live in an
area with high levels of nitrogen oxide gases (mostly produced by cars and
other vehicles).