Pathologies related to air pollution


The main components of air pollution in developed countries are:

  • Nitrogen dioxide (from the combustion of fossil fuels)

  • Ozone (from the effect of sunlight on nitrogen dioxide and hydrocarbons) 

  • Solid or liquid suspended particles 

  • Sulfur oxides

(See also Overview of Environmental Lung Disorder.)

Indoors, an additional source of air pollution is secondhand smoke, such as burning biomass (eg, wood, animal waste, crops) in developing countries (eg, for cooking and heating).

High levels of air pollution can adversely affect lung function and the onset of asthma and exacerbations of chronic obstructive pulmonary disease and increase the risk of lung cancer. Air pollution also increases the risk of acute cardiovascular events (eg, myocardial infarction) and the development of coronary artery disease. Residents of heavily trafficked areas are particularly at risk, especially when thermal inversion causes air to become stagnant.

All so-called major air pollutants (nitrogen oxides, sulfur oxides, ozone, carbon monoxide, lead and particulates), except carbon monoxide and lead, cause hyperreactivity of the airways. Long-term exposure may increase respiratory infections and respiratory symptoms in the general population, particularly in children, and may decrease lung function in children.

Ozone, which is the main component of smog, is a strong respiratory irritant and oxidant. Ozone levels tend to be highest in the summer, late morning and early afternoon. Brief exposure can cause dyspnoea, chest pain, and airway reactivity. Children who regularly engage in outdoor activities on days when ozone pollution is high have a higher chance of developing asthma. Long-term exposure to ozone causes a mild and permanent reduction in respiratory function.

Sulfur oxides, produced by the combustion of fossil fuels, since they have a high sulfur content, can create acid aerosols with high solubility, which can be deposited in the upper airways. Sulfur oxides can induce inflammation of the airways, possibly increasing the risk of chronic bronchitis and bronchoconstriction.

Air pollution particulate matter is a complex mixture, derived from the combustion of fossil fuels (especially diesel). The particles can have local and systemic inflammatory effects, suggesting an explanation for their impact on both lung and cardiovascular health. The so-called PM 2.5 (particulate matter with diameter <2.5 μm) is capable of producing a greater inflammatory response than larger particles. The data indicate that particulate air pollution increases death rates across all causes, particularly for cardiovascular and respiratory diseases.

Air pollution data has raised concerns about the potential health effects of even smaller particles, so-called nanoparticles, which are particles produced through a controlled engineering process and ultra-fine particles. Some nanoparticles and ultrafine particles can induce oxidative stress, airway inflammation and toxicity in animal models and have been associated with increased respiratory symptoms in patients with asthma; however, direct causality has yet to be reported.


Inside closed environments, pollution can be up to 5 times higher than outside, precisely because everything that enters the house stagnates. Adding to these substances are chemicals such as formaldehyde released from furniture glues and some fabrics such as carpets. The stoves themselves introduce atmospheric particulate matter, scented candles, deodorants, floor and surface cleaners into the air. Unfortunately, we are constantly threatened by everything around us.

It is essential to run for cover with a unique and definitive solution such as an air purifier and surface sanitizer. Deciding today to change the air in your home and office can really make a difference in terms of quality of life and health protection.