"Smoking is the most significant of these, causing around a quarter of all cancers globally."
Except for that the research shows that smoking doesn't cause cancer, except maybe for tobacco. And even the surgeon general now apparently admits that most cancers that tobacco users suffer from probably aren't from tobacco.[1]
No, of course not, I only cited the UMASS pamphlet because it's the most well written summary of the information. But every other source from the NY Times to Wikipedia says basically the same thing, e.g. http://www.nytimes.com/2006/12/01/opinion/01proctor.html
I read that NYT link and it seems to say the opposite - that smoking does cause cancer.
"What few experts will dispute is the magnitude of the hazard: the World Health Organization estimates that 10 million people will be dying annually from cigarettes by the year 2020 — a third of these in China. Cigarettes, which claimed about 100 million lives in the 20th century, could claim close to a billion in the present century."
Only a third of the people who die from smoking die from cancer. And again, it doesn't seem to be the tobacco but rather the radioactive material and the additives. Cigarette smokers in other countries have vastly lower rates of cancer.
Smoking causes cancer not because of "tobacco" or smoking or not "THC" (your cite) but because of free radicals that are released during the process of burning these carbohydrates that are - especially - joined to additives, such as benzoates and their chemical brothers. They then incorporate in your lung's DNA: Essentially, smoking _anything_ that burns at these high degrees of temperature will most likely create molecules in a state that replace your default circular ribonucleic acids. And that are the agents of cancer. And, btw, (because of my utter ignorance to this health issue that will most likely kill me) I am a smoker, too...
Well, yes, but have you looked at the incident rates? And, mainly, cigarettes are far more dangerous than anything else not because of tobacco, but because of chemical additives such as phenolic acids the tobacco industry use as "perfumes" to make them smell and taste better. Those additives are far more carcinogenic than tobacco because of their circular nature making our cell machinery believe they are actual C/G/T/A's.
Really? “Smoking”, like nearly all uses without further clarification in the media, refers of course to the smoking of tobacco. No need at all to start a stupid holy war because of that. There seems to be little doubt in the scientific community that smoking tobacco causes most lung cancer.
This is not a proper scientific observation, but it's my strong impression that tobacco smoking plus anything else is a major cause of cancer.
I.e. it's not the smoking per se that gets you (in this way, it does a lot of other types of damage), but doing it in combination with any of the following examples is a bad idea:
Living in a polluted city. One researcher told me around 1980 that Kansas wheat farmers will have some lung diseases from that occupation, but they stay relatively cancer free. Whereas jogging in the Boston urban area was none too good for your lungs.
Radon. The initial study that got everyone upset about it (note that it's no longer a "big" thing) was based on uranium miners. Who got not only a big radon dose but who were mostly heavy smokers.
I forget if birth control pills + smoking = cancer, but as I recall the combination of the two is rather unhealthy.
Anyway, the point here is that tobacco smoking may be more of a cancer promotion cause than a cause per se. Needless to say, determining that through epidemiology is hard and it's not like it changes the public health message.
Although Norvig's assumption that Fisher probably died of colorectal cancer because of smoking is not necessarily true - after all, prostate cancer and then colorectal cancer are the most prevalant cancer in males (and not lung c., as you die of it), and col. c. is one of the four most deadliest cancers. Oh well, only my smoker-addiction can keep up this argument to keep me doing it, I guess. ;)
Except for that the research shows that smoking doesn't cause cancer, except maybe for tobacco. And even the surgeon general now apparently admits that most cancers that tobacco users suffer from probably aren't from tobacco.[1]
[1] http://www.erowid.org/plants/cannabis/cannabis_health2.shtml