Air pollution causes respiratory diseases primarily by irritating and inflaming the airways and lung tissue.
Here's a breakdown of the process:
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Irritation and Inflammation: Air pollutants, such as particulate matter (PM), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), directly irritate the lining of the respiratory tract. This irritation triggers inflammation, a natural immune response that involves swelling and increased mucus production.
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Damage to Lung Tissue: Prolonged exposure to air pollutants can damage the cells and tissues within the lungs. This damage can impair lung function and make individuals more susceptible to respiratory infections.
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Exacerbation of Existing Conditions: Air pollution can worsen pre-existing respiratory conditions like asthma and chronic obstructive pulmonary disease (COPD). For example, high pollution levels can trigger asthma attacks, leading to increased hospital admissions for individuals with these conditions. The reference text states that people with lung conditions are admitted to the hospital more when pollution levels are high.
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Impaired Lung Development: In children, exposure to air pollution can hinder lung development, leading to reduced lung function later in life.
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Increased Susceptibility to Infections: Air pollution can weaken the immune system's ability to fight off respiratory infections, making individuals more vulnerable to illnesses like bronchitis and pneumonia.
Specific Pollutants and Their Effects:
| Pollutant | Source | Effect on Respiratory Health |
|---|---|---|
| Particulate Matter (PM) | Combustion (vehicles, power plants, fires), dust | Deeply penetrates lungs, causing inflammation, irritation, and contributing to asthma, bronchitis, and cardiovascular problems. |
| Ozone (O3) | Formed from reactions of pollutants in sunlight | Irritates airways, causing coughing, shortness of breath, and can worsen asthma. |
| Nitrogen Dioxide (NO2) | Vehicle emissions, industrial processes | Irritates airways, increases susceptibility to respiratory infections, and can worsen asthma. |
| Sulfur Dioxide (SO2) | Burning fossil fuels (coal, oil) | Irritates airways, causing coughing, wheezing, and shortness of breath; can worsen asthma and COPD. |
In summary, air pollution causes respiratory diseases by directly damaging lung tissue, triggering inflammation, impairing lung development, exacerbates existing conditions, and weakening the immune system, all of which contribute to a higher risk of respiratory illness.
