What harms our breathing
The respiratory system moves air in and out and lets oxygen enter the blood while carbon dioxide leaves. Many everyday things can damage it. The most common threat is cigarette smoke, which contains three dangerous substances: nicotine (an addictive drug that speeds up the heart), tar (a sticky substance that paralyses the cilia and can cause lung cancer), and carbon monoxide (a gas that binds to haemoglobin so the blood carries less oxygen).
Remember
- Nicotine addicts and raises heart rate.
- Tar damages cilia and triggers cancer.
- Carbon monoxide steals space on haemoglobin.
Diseases and pollution
Long-term smoking and dirty air cause several diseases. In chronic bronchitis the bronchi become inflamed and produce too much mucus. In emphysema the thin walls of the alveoli break down, so the surface for gas exchange shrinks and breathing becomes hard. Lung cancer is the uncontrolled growth of lung cells. Asthma narrows the airways and makes wheezing.
Air pollution matters too. During a haze, fine dust called particulate matter (PM2.5) is small enough to reach the alveoli. Vehicle exhaust adds carbon monoxide. These irritate the airways and worsen breathing problems.
Remember
- Do not smoke and avoid second-hand smoke.
- Exercise regularly to strengthen the lungs.
- Wear a mask and stay indoors during heavy haze.
The cilia that line the trachea normally sweep mucus, dust and germs upward, away from the lungs. Keeping them healthy keeps the whole system clean.