If I may offer some small clarification:
There are
599 officially listed additives in *cigarettes*, as released by Big Tobacco in 1994 as part of the ongoing settlement. Per Wikipedia, "It applies, as documented, only to American manufactured cigarettes intended for distribution within the United States by the listed companies." Recent federal legislation has granted far-reaching oversight (in the US) to the FDA.
One thing to understand is that this list of additives was the product of decades of intense, private research by Big Tobacco (the 5 major US companies) to make their product sell--and keep selling. They are all approved (in varying amounts of course--cf. arsenic, for example) as food additives already; but why so many? Because there is an exacting science that goes into your cigarette that reaches far beyond taste and aroma--how long it burns, how evenly it burns, evenness of color, consistency of packing, shelf stability, ease of processing,
et cetera, ad nauseum. For example, the largest industrial consumer of chocolate is the tobacco industry--far surpassing the candy and soft drink industries.
Perhaps most importantly, at least from the companies' perspective, is how addictive they could make cigarettes. If independent studies are to be believed, seven times more addictive than heroin--and that's chemically, not taking into account the effects of advertising and social acceptance.
Now, let's look at pipe tobacco. Although 599 additives are approved and accounted for, it's my understanding that the majority of those additives are not used for tobacco destined for the pipes; that the main additives are alcohol, citric acid, sugars and "candy" flavors, e.g. chocolate, cherry, etc. I'd love to get input from the blenders that participate in the forums (calling Messers Ouellette, Pease and Tarler!) as to the journey the leaf takes from plant to package. Perhaps Kevin, with his Tobacconist University Certification, can shed some light on the processing end regarding pipe and cigar manufacture.
I'm very comfortable combusting and imbibing a bit of alcohol and sugar along with my tobacco; it's been exactly (today, in fact) one year since I stopped smoking cigarettes, and the acrid, chemically smell of them no longer holds any appeal to me whatsoever. I've moved on to a better, more flavorful product, that I would like to think is marginally better for me. I hold no illusions, however, and realize that excessive use of anything is not good for the body, and burning vegetable matter is on the long list of verbotens for soft tissue, but I'll take my chances here. And enjoy them.
And for your perusal, should you desire to research the topic independently:
Tobacco.org
Dave Hitt's wonderfully informative site
WHO's Tobacco-Free Initiative (the main organizing body behind worldwide anti legislation)
Everything you never wanted to know about The Settlement
Tobacco U
And, finally, I couldn't resist:
http://www.youtube.com/watch?v=MRt6I8ffu7s&feature=related