What substance leads to cellular changes and loss of elasticity in lung tissue due to smoking?

The substance that leads to cellular changes and loss of elasticity in lung tissue due to smoking is tar. Tar is a sticky, black substance produced when tobacco is burned, and it contains numerous harmful compounds that can damage lung tissue and the airways. When inhaled, tar coats the lungs, leading to inflammation, increased mucus production, and damage to the alveoli, which are the tiny air sacs responsible for gas exchange. Over time, this damage contributes to chronic obstructive pulmonary disease (COPD) and emphysema, conditions characterized by decreased lung elasticity and respiratory difficulties.

While nicotine, tobacco, and carbon monoxide are all harmful components of cigarette smoke, they do not specifically cause the cellular changes and loss of elasticity in lung tissue in the same manner that tar does. Nicotine primarily affects the central nervous system and is responsible for the addictive properties of smoking. Tobacco itself is the raw plant material and is associated with multiple health risks, but it is the tar produced during combustion that has the most direct and severe impact on lung tissue. Carbon monoxide, a colorless gas produced by burning tobacco, can affect oxygen transport in the blood but is less directly involved in causing structural changes in lung tissue compared to tar.