>>981987
How about this study…
https:// www.ncbi.nlm.nih.gov/pmc/articles/PMC2270238/
Journal of the Royal Society of Medicine
v.101(3); 2008 Mar
"Low levels of Po-210, which emits the same kind of alpha-radiation as radon, contaminate tobacco.3 Po-210 is relatively long-lived fallout from the decay of radon in the atmosphere close to tobacco plants. This in turn comes from the decay of uranium-contaminated calcium phosphate fertilizer used on tobacco fields. Sub-microscopic particles of Po-210 in the air are trapped on sticky hairs on the leaves of tobacco plants. These hairs are very hydrophobic, and once trapped the radioactivity does not wash off in the rain. Other crops are not affected. Owing to the recognition of the carcinogenicity of low levels of radon in smokers, it appears possible that low levels of Po-210 in cigarettes could be responsible for some lung cancers currently attributed to radon. This is of significance because steps could be taken to moderate uranium contamination of tobacco fields and reduce Po-210 levels in cigarette smoke."
"Uranium has a very long half-life and will accumulate in the soil with repeated applications of fertilizer. As a result, modern cigarettes may contain higher levels of Po-210 than those measured 40 years ago.3 Measurements of Po-210 in the cigarettes of today are needed. Additional measurements of Po-210 in autopsy specimens of smokers and controls are also required to better understand the levels and distribution of Po-210 in the bronchial tree. Smokers are killed by alpha-radiation, whatever its origin. Arguably, a significant part of this mortality is a result of Po-210 in tobacco. Technology to reduce Po-210 in cigarette smoke was available in 19678 and presumably could be improved. Now may be the time to apply it."