whats in tobacco that gives us cancer?

Answer 1

Ingredients in Tobacco

Cigarettes, cigars, and spit and pipe tobacco are made from dried tobacco leaves, as well as ingredients added for flavor and other properties. More than 4,000 individual chemicals have been identified in tobacco and tobacco smoke. Among these are more than 60 chemicals that are known CARCINOGENS (cancer-causing agents).

There are hundreds of substances added to cigarettes by manufacturers to enhance the flavor or to make the smoking experience more pleasant. Some of the compounds found in tobacco smoke include ammonia, tar, and carbon monoxide. Exactly what effects these substances have on the cigarette consumer’s health is unknown, but there is no evidence that lowering the tar content of a cigarette improves the health risk. Manufacturers do not provide the public with information about the precise amount of additives used in cigarettes, so it is hard to accurately gauge the public health risk. -

Answer 2

There are about 4000 additives to tobacco, around 60 of which are known carcinogens. Some of these chemicals come from pesticides the tobacco leaf is sprayed with as it's growing to improve yield, some are by-products of the manufacturing process, and some are added during manufacture.
Whilst some chemicals are added to make the tobacco burn better, some are there purely to increase nicotine absorption to the bloodstream (possibly to make tobacco even more addictive) and some have an anaesthetising effect that stops smokers coughing.

There's a list here of the additives,
http://quitsmoking.about.com/cs/nicotineinhaler/a/cigingredients.htm

and this link lists the known carcinogens in cigarettes.
http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/dc/caz/suba/smok/cig.jsp

Answer 3

tar is the culprit.

Answer 4

tar