What substances in cigarette smoke causes lung cancer?

There are many harmful substances in cigarette smoke, but the one that is most strongly linked to lung cancer is tar. Tar is a thick, sticky substance that forms when cigarette smoke condenses. It contains many different chemicals, some of which are known carcinogens (substances that can cause cancer). These chemicals damage the DNA in cells, which can lead to the development of cancer.

Other harmful substances in cigarette smoke that can contribute to lung cancer include:

- _Carbon monoxide: This gas reduces the amount of oxygen that can be carried by the blood, which can damage the heart and lungs.

- _Formaldehyde: This is a known carcinogen that is used to preserve dead bodies.

- _Ammonia: This is a poisonous gas that is used to make fertilizer.

- _Hydrogen cyanide: This is a deadly gas that is used in chemical warfare.

- _Arsenic: This is a poison that is used to kill rats.

- _Lead: This is a poisonous metal that can damage the brain and nervous system.