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

Hello user•tape measure•calipers•mri/ct scans •air displacement plethysmography •body fat scale•hydrostatic weight hope this : ))