eli5: If tobacco is a leaf, why does it have so many substances known to cause cancer?

Question

* Source is the packaging I’ve just read for a pack of tobacco in the UK which says it has 70 cancer causing substances

In: 2

Answer 1

Just 70? They’ve cut down, then.

The tobacco in cigarettes has been treated with a raft of additives before packaging, and that is where most, but not all, of the substances come from.

IF you look on a package of decent cigars, you will not find as many. Because cigars are simply tobacco leaves, rolled into other tobacco leaves, and sold. There is no “processing” of the leaf to speak of, not add chemicals to it.