Healthy Living

What Causes Lung Cancer?

Physical and environmental factors showing the highest potential for causing lung cancer

What Causes Lung Cancer?

Lung cancer is the unsuppressed growth of cells in the tissues of the lungs. Such a condition leads to a tumor (malignant) which may spread (by metastasis) to different organs of the body if not treated in time. Cancer of the lung at the primary stage is also known as carcinoma. The two types of carcinoma are NSCLC (non-small cell carcinoma) and SCLC (small cell carcinoma). 

Lung cancer is one of the leading causes of mortality among men and women around the world. Though there may be varying symptoms the common ones are:

  • Hemoptysis or coughing up blood
  • Frequent infections like pneumonia and bronchitis
  • Blockage of airways causing shortness of breath
  • Excessive coughing that persists and worsens with time
  • Fever and weakness (fatigue)
  • A dull pain in the chest which aches and is present for some time
  • Pain due to the presence of a cancer mass in structures such as the throat (difficulty in swallowing)
  • New occurrence of wheezing or coughing in a person who used to smoke or smokes at present

Family history, age, and exposure to certain hazards are some of the factors that increase the chances of developing cancer-related ailments. Some of these influences (similar forms of cancer in parents or close relatives) come through the genetic route, and can’t be avoided. Many other influences can be overcome by altering one’s lifestyle choices.

The following influences are widely acknowledged to be in the “high risk” category for triggering lung cancer:

Smoking tobacco

Nearly 80 percent of lung cancers in individuals are strongly connected to a deeply-ingrained habit of smoking. The danger of developing lung cancer is highest in people accustomed to smoking pipes and strongly-flavored cigars. The danger comes from inhaling too deeply and holding smoke within the lungs longer than usual. This allows tar and harmful smoke particles to coat lung tissue and block oxygen intake. Consisting of over 70 carcinogens (cancer causing agents), cigarettes are undoubtedly the prime cause of lung cancer. Chain smoking or smoking umpteen cigarettes each day for a long time can lead to this along with debilitating effects.

E-cigarettes, lower tar content, “mild” cigarettes, and menthol versions are equally capable of causing lung cancer. Non-smokers inhaling second-hand smoke are more prone to developing symptoms of cancer. Passive smoking is also an equally deadly contributor to lung cancer if such smoke is inhaled for a cumulatively long span of time.

Radon exposure

Exposure to radon, a toxic radioactive gas, is one of the major contributors inflating cancer mortality statistics. Radon affects smokers and nonsmokers alike. More than 21,000 people die every year in the US because of exposure to radon-contaminated rock, soil, and polluted water. Healthcare specialists say radon is most dangerous when it accumulates inside residences. Many residents get affected being oblivious of the fact that they may be residing on radioactive soil.


Mining, milling, textiles, insulation, and shipbuilding workers are at high risk for asbestos exposure. These workers are most vulnerable to lung cancer. Exposure to higher levels of asbestos causes mesothelioma. This is a rare kind of cancer that affects the pleural membrane encasing the lungs.

Mesothelioma is malignant and capable of spreading to other parts of the body. Homeowners are at greater risk when old HVAC insulation crumbles. The breakdown of asbestos in insulation material releases harmful particles that cause lung cancer. Smokers who work around asbestos and smoke have their risk multiplied many times that of the usual smokers. 

Cancer causing agents in industries

The following external factors can trigger lung cancer in people:

  • Exposure to radioactivity in nuclear installations, and in transporting radioactive wastes
  • Exposure to harmful elements such as mineral arsenate, white metal cadmium, silica, nickel, and derivatives of chromium; coal gas, pepper products, and mustard gas are also cancerous in high concentrations.
  • Exposure to harmful gases emitted in rubber factories and iron and steel foundries
  • Exposure to automobile exhausts and atmospheric pollutants in industrialized areas

Air pollution

Metropolitan areas having high traffic flows raise the risk of lung cancer substantially. Though atmospheric pollution is a risk factor lower than smoking, at least 5 percent of annual deaths are credited to this factor. Be it indoor or outdoor air pollution, there has been an increase in the rate of deaths caused by both factors. The burning of coal, dung, wood, or charcoal indoors (for heating or cooking) can also have detrimental effects.

Polluted water

Exceptionally high levels of mineral arsenate in water has been linked to the higher incidence of lung cancer. This problem has been tackled successfully in the U.S. Americans with access to safe drinking water and regulated public water supply systems are better protected from arsenite poisoning.

Use of radiation in treatment

Patients with Hodgkin's lymphoma find their cancer spreading within the lymphatic system. Such patients undergoing radiation treatment have developed lung cancer. Radiation treatment following breast cancer could also trigger lung cancer. 

Cancer in the family

Parents or grandparents having developed cancer, especially at a young age, increases the risk of cancer in the younger generations. Polluted environments, contaminated food, and bad lifestyle choices may activate cancer-susceptible genes to bring on lung cancer.

Previously Affected

Survivors of the NSCLC and SCLC types of cancers are known to be prone to cancer for a second time. Both these types of tumors have an over 5% average chance of recurring over time.

Excessive beta-carotene supplementation

Clinical studies show that active smokers taking bigger doses of beta-carotene are prone to developing lung cancer. Sources rich in beta-carotene such as carrots, crude palm oil, spinach, pumpkin, mangoes, cantaloupe, papaya and sweet potato among others should be avoided.

Though clinically unproven, the following factors can also trigger lung cancer:


Deep inhalation and heavy use of marijuana deposit the same amount of tar as regular smoking. The risk is reduced only in infrequent use.


The widespread use of talc in cosmetic formulations and in scented talcum powder is considered safe only if asbestos is completely eliminated, as it is under U.S. law.

It is important to seek medical advice if your condition is worsening or if you feel that you might have the illness.