Any substance that is breathed in affects what happens to the lungs. Many of these substances can be hazardous and threaten the lungs’ ability to work properly. Such hazards may include:

1. Cigarette Smoking

The major cause of chronic obstructive pulmonary* disease (COPD), emphysema, chronic bronchitis and lung cancer is cigarette smoking. When someone inhales cigarette smoke, irritating gases and particles cause one of the lungs’ defenses, the cilia, to slow down. Even one puff on a cigarette slows the cilia, weakening the lungs’ ability to defend themselves against infections.

*The term “pulmonary” refers to the lungs.

Cigarette smoke can cause air passages to close up and make breathing more difficult. It causes chronic inflammation or swelling in the lungs, leading to chronic bronchitis.

And cigarette smoke changes the enzyme balance of the lungs, leading to destruction of lung tissue that occurs in emphysema.

2. Triggers of Asthma

Asthma, the reversible blocking of the small air passages of the lungs, has many possible triggers and can be life-threatening. Infections, lung irritants, cold weather, allergies, overexertion, excitement, inherited factors, even work place chemicals and other irritants, play a part in this disease.

3. Tuberculosis (TB)

Tuberculosis is caused by a bacterium spread by the coughing or sneezing of a person who has active TB germs in his or her mucus (sputum). Most people who develop TB today were infected years ago when the disease was widespread. But outbreaks involving newly infected people are becoming more common in high-risk populations.

Years or decades later, if the natural defense systems of people’s bodies begin to weaken, the barriers they built up around the germs begin to crumble, and the TB germs escape and multiply. Such waiting-to-attack infection can become real illness when a person’s defenses are weakened by HIV (Human Immunodeficiency Virus) infection or other chronic illnesses such as cancer.

4. Occupational Hazards

Substances you breathe at work can cause lung disease, too. Workers who are exposed to occupational hazards in the air, dusts like those from coal, silica, asbestos, or raw cotton and metal fumes or chemical vapors, can develop lung disease, including occupational asthma.

5. Virus, Fungus, Bacterium (other than TB)

Hundreds of germs like these are carried in the air at all times. If they are inhaled into the lungs, the germs can cause colds, influenza, pneumonia, and other respiratory infections. When these germs lodge in your lungs, your breathing can be disrupted and you can become ill. Some of these illnesses can be prevented with vaccination.

6. Air Pollution

Particles and gases in the air can be a source of lung irritation. Do whatever you can to reduce your exposure to air pollution. Refer to radio or television weather reports or your local newspaper for information about air quality. Local officials use a simple scale called the Air Quality Index (AQI) to report and forecast on smog levels and other outdoor air pollution. The AQI is broken up into 5 distinct levels that are color coordinated. The last four levels have cautionary statements.

On days when the ozone (smog) level is moderate, an AQI of 51 – 100, unusually sensitive people should consider limiting prolonged outdoor activity.

On days when the ozone level is unhealthy for sensitive groups, an AQI of 101-150, active children and adults, and people with chronic heart and lung disease should limit prolonged outdoor exertion.

On days when the ozone level is unhealthy, an AQI of 151-200, sensitive groups should avoid prolonged outdoor activities while everyone else should limit or restrict prolonged physical activity to early morning or evening since smog is increased in sunlight.

When pollution levels are dangerous, an AQI of greater than 200, sensitive people should avoid all outdoor activities while everyone else should avoid prolonged outdoor exertion.

Air pollution can be a problem indoors, too. Check your home for irritants that you can control like dust, household chemicals, and cigarette smoke. You may also want to test your home for the presence of the gas, radon, which is the second leading cause of lung cancer.