What are they?

A risk factor is any agent that increases a person’s chance of developing a disease such as cancer. Each pathology has its associated risk factors. Even so, the risk factors do not ensure with total certainty the development of the disease, just as the absence of them does not exempt the possibility of suffering from it.

Lung Cancer Risk Factors


Between 80-90% of lung cancers occur in recent or former smokers. Depending on the number of cigarettes per day, smokers have between 10 and 20 times more risk of developing lung cancer than non-smokers. The light varieties of tobacco do not reduce this risk; only the fact of quitting smoking reduces it. Tobacco has so many adverse health effects that disease risk levels equal those of non-smokers about 15 years after leaving, depending on how long you’ve been using it.

Tobacco carcinogens are also found in the smoke given off by cigarettes. For this reason, people considered passive smokers – those who do not consume tobacco directly but are regularly exposed to the smoke of cigarettes consumed by those around them – also have the risk of lung cancer at the same level as people who regularly consume a low number of cigarettes.


It is a colourless and odourless radioactive gas that can accumulate inside homes or buildings. It is considered the first cause of lung cancer in non-smokers by the WHO and the second after tobacco in smokers. It is more present in rocky areas, such as the granitic ones (Galicia, west of Castilla y León, Extremadura, North of Madrid, etc.). The rooms that can accumulate the most radon are those closest to the land on which it is built, such as basements or ground floors. The only way to know if there is radon exposure is by measuring the gas inside homes with passive devices for no less than three months. Good ventilation of the rooms usually reduces the concentration of gas inside practically, but in some cases, isolation or risk reduction measures may be necessary.

asbestos or asbestos

It is a mineral found naturally in the environment. Asbestos fibres are strong and heat resistant, making them useful for various applications, including insulation, brakes, shingles, flooring, and many other products. When asbestos deteriorates or breaks down, it creates dust that, when inhaled or swallowed, asbestos fibres are deposited in the lungs or other organs, where they can irritate that, in turn, can lead to lung cancer, mesothelioma, laryngeal and ovarian cancer, or asbestosis (fibrosis of the lungs). It is mainly considered an occupational risk for factory workers in specific sectors: mining of said minerals, construction, shipbuilding, the automotive industry or the textile industry, etc. Domestic and environmental exposure near asbestos areas and factories is also described. In Spain, its use was prohibited in 2001, but the eradication of asbestos already installed is not regulated because it is a risk factor still present in our environment.


Arsenic is a substance that can be found as an odourless and tasteless white powder. It can be present in our environment in the air, water, or soil naturally or from agricultural or industrial processes, such as mining, metal smelting, or pesticide production. Consumption of specific groundwater may lead to exposure to arsenic in some countries or regions.

Waste areas often accumulate harmful substances, including arsenic. For this reason, the adjoining regions may present concentrations of this in higher amounts than usual. Arsenic can also be found in certain domestic woods due to chrome-plated copper arsenate (CCA) as a preservative for this material.

Exposure or ingestion of arsenic (through water or food treated with pesticides and not washed or cooked correctly) can cause numerous types of cancer such in the bladder, skin, lung, digestive tract, liver, kidney and lymphatic and hematopoietic systems.

Other work-related risk factors


It is a metal used in the minting of coins, the jewellery sector, marine engines or in the robotics sector. The quantities in which it can be found in everyday objects are regulated by the European Union. The most significant risk is exposure to gases and compounds generated in obtaining this metal and its alloys.

Oil and byproducts

It is a substance that is not only used in fuels but also most plastic products, tires, detergents, paints and other substances such as solvents, varnishes, fertilizers or insecticides. It is insoluble and, therefore, difficult to clean and remove. Leaks and spills of these products seriously harm the affected ecosystem. The combustion of oil produces harmful residual particles and polluting gases that are harmful to both the environment and health.

other substances

Numerous substances can increase the risk of lung cancer. Some of them are chemical and radioactive products, gases from the combustion of coal or firewood, dust particles in suspension in the mining industry, gases that emanate from metal welding, arsenic or chromium.


Like other diseases, the risk of developing lung cancer increases with age. This may be due to the accumulation of risk factors over the years and to the fact that cell repair mechanisms lose effectiveness due to ageing.

Genetic factors

Being in a family environment with a history of lung cancer should keep the rest of the members on alert due to their predisposition to develop this disease, especially if there are cases in which the disease develops at an early age.

Other diseases

Diseases that may not be aggressive at first or chronic may mean a higher risk of lung cancer. Some of them are COPD –chronic obstructive pulmonary disease–idiopathic pulmonary fibrosis, or scleroderma.

Environmental pollution

Pollutants suspended in the air we breathe can cause diseases such as lung cancer or COPD. Large cities and areas close to highways with considerable traffic have a higher rate of pollution.