Which is the main ingredienyt of cigarette which causes emphysema and cancer?

Answer 1

It is mostly just the tobacco. First, tobacco is often allowed to ferment, and the fermentation can create carcinogens. Then there may be carcinogenic additives. Then there is the smoke that is produced by burning the tobacco and the paper. Burning things often create carcinogens.

Answer 2

The Nicotine and the Tar

Nicotine does not directly cause cancer, but is instead the addictive compound recognized by nicotinic receptors. While nicotine is not mutagenic, the addiction created by the bodies craving for results in the uptake of carninogens. Tar is a generalized term for any substance that coats. In this case Tar is a residue formed by the burning of tobacco. Tar coats the alveoli of lungs, thereby decreasing air exchange and contains several mutagens.

Benzo(a)pyrene [B(a)P] diolepoxide (BPDE) is the substance found in cigarette smoke which causes mutations in the P53 gene. P53 is one of the "gatekeepers" of the genome and if mutations occur that affect its function, the cell can lose proofreading ability during replication thereby allowing cancerous cells to form. BPDE is formed by the burning of tobacco (heat activated), and is also found when wood is burned, or steaks are overcooked.

Answer 3

The honest answer is that they don't know. Medical conditions like cancer and emphysema are multifactorial, i.e. there are several or many contributing factors and not a single 'cause'. Why don't all smokers contract these conditions? What 'causes' a non-smoker to contract these conditions?

Answer 4

tar

causes of perhaps all diseases in the lungs

Answer 5

The whole thing causes cancer. The tobacco is not pure tobacco and has chemicals added to it. The smoke has the chemicals which everyone around you also breathe in called secondary smoke.