why is the tar contained in tobacco smoke so harmful?

[Anna]

this is for a studyguide which i left the book at school. i know smart right.. lol anyways i need a good simple answer.

 

[kassi]

In solid form, tar is the brown, tacky substance that is left behind on the end of the cigarette filter. It stains a smoker's teeth and fingers brown and coats everything it touches with a brownish-yellow film.

Tar in cigarette smoke paralyzes the cilia in the lungs and contributes to lung diseases such as:

Emphysema
Bronchitis
Lung Cancer