Some industrial processes produce dusts. These processes include drilling, polishing, crushing and sawing. Industrial dusts are often much smaller than the ordinary dust in the air. This means that they can avoid being trapped by the mucus in the air passages. Therefore these dusts can get into the lungs. This can cause serious diseases such as silicosis or pneumoconiosis of coal miners. It is because of diseases such as these that there are strict regulations about the conditions under which men and women work in industry. These regulations are being brought up to date all the time as our knowledge of industrial diseases grows.
Lung cancer kills more men today than any other type of cancer. The disease starts quietly and you may feel nothing at first. Often, by the time lung cancer is discovered, it is too late to treat it. People with this disease may suffer great pain before it finally kills them. Lung cancer is much more common in smokers than in non-smokers.
In this disease, cells in the lungs or in the air passages suddenly stop behaving normally. Instead they start to multiply rapidly. They form a lump or tumour. Doctors call this a carcinoma. The lump grows slowly at first and gradually blocks some of the air passages. It slowly invades the healthy parts of the lungs. One of the most dangerous things about lung cancer is that it starts quietly and secretly. The victim often feels nothing at first. Later a cough may start. Then breathing becomes more difficult. The cancerous lump is often widespread by the time it is discovered. By then it may be too late to save the patient.
No one knows yet exactly why the lung cells suddenly become cancerous. However, there are some clues. Lung cancer is rare in people who do not smoke.