...And the fertilizer used by US tobacco farmers

One factor in the difference between India and the United States may be the extensive use of apatite as fertilizer for tobacco in the United States, because it starves the plant for nitrogen, thereby producing more flavorful tobacco; apatite is known to contain radium, lead 210, and polonium 210. This would also account for increased concentration of these elements compared to other crops, which do not use this mineral as fertilizer.

http://en.wikipedia.org/wiki/Health_effects_of_tobacco_smoking#Radioactive_carcinogens

Bottom line is none of this changes the well documented cancer risks associated with tobacco, it has long been known that tobacco contains radioactive isotopes, it just grabs attention because it raises the bogey man of radiation. Radioactive isotopes may be part of the reason for the cancer risk, but if you look at the radiation exposure variation due to things like diet, location, altitude, etc I suspect that the contribution from tobacco-borne polonium would end up being significant.

Claims such as: "causes as much radiation exposure as 300 chest X-rays a year, is responsible for 1% of all U.S. lung cancers, and more than 1,600 U.S. deaths and over 11,000 deaths worldwide every year."

have to be examined VERY carefully - such statistics are highly dependent on what numbers you use, where you get them from, the manner in which you apply them, and the assumptions you make... Remember when Cassini was getting ready for launch there were claims made that the RTG's contained enough plutonium to kill every single human on earth.... IF you make outrageous assumptions that claim was true, but the assumptions required to make it true are insane....

Statements like: "this is one of the most deadly substances known to science - 250,000 times more toxic than hydrogen cyanide " are pointless and alarmist- serving only to obscure the facts, not clarify them.