I'd have to dig for the source, but I found a source on the internet, which seemed incredibly credible for being a college professors wordpress blog. Basically

I'd have to dig for the source, but I found a source on the internet, which seemed incredibly credible for being a college professors wordpress blog. Basically, since 2005, the nitrotesimne levels in US Style smokeless tobacco has declined by more than 75% due to changes in manufacturing (largely), and from say, 80mg to 5mg, in the 1975-2016 period. Tobacco Specific Nitrosamines are widely acknowledged to be the single largest cancer causing agent in oral tobacco. (https://en.wikipedia.org/wiki/Tobacco-specific_nitrosamines https://en.wikipedia.org/wiki/Tobacco-specific_nitrosamines) https://rodutobaccotruth.blogspot.com/2016/07/is-snus-safer-than-dip-or-chewhealth.html https://rodutobaccotruth.blogspot.com/2016/07/is-snus-safer-... https://rodutobaccotruth.blogspot.com/2012/10/more-evidence-that-smokeless-tobacco.html https://rodutobaccotruth.blogspot.com/2012/10/more-evidence-... https://rodutobaccotruth.blogspot.com/2012/01/informative-study-on-tobacco-specific.html https://rodutobaccotruth.blogspot.com/2012/01/informative-st...