Which respiratory disease is linked to long-term air pollution exposure, and which pollutant is primarily responsible?

• A. Pneumonia; Nitrogen dioxide.
• B. Emphysema; Methane.
• C. Lung cancer; Carbon monoxide.
• D. Chronic bronchitis or aggravated asthma; PM2.5 and ozone are major contributing pollutants.

Answer: (D)

Long-term exposure to air pollution mainly harms the lungs by causing ongoing airway inflammation and damage. Fine particles, PM2.5, can reach deep into the lungs and even enter the bloodstream, provoking persistent inflammation, mucus production, and structural changes that underpin chronic bronchitis. Ozone, a reactive gas formed from other emissions in sunny conditions, irritates the airways and exacerbates inflammation, making asthma symptoms worse and contributing to chronic bronchitis over time. Because of their ability to penetrate the respiratory system and drive lasting inflammatory responses, chronic bronchitis and aggravated asthma are the disorders most strongly linked to long-term air pollution, with PM2.5 and ozone identified as major contributing pollutants.