Causes damage to the alveoli and increases the production of mucus in the mouth, throat, and lungs.

The answer is : Tar

Tar is some sort of residual substance that we commonly found in tobacco products, which could cause the symptoms you've mentioned above

not only that, Tar is a highly carcinogenic substance, which mean that it generate high risk of cancer it get into our system

The back of the package where the nutrition label is