Is organically grown tobacco safer than conventionally grown tobacco?

I ask this question because Dr. Everett Koop stated that 90% of cancer caused by smoking is due to the radionuclides like polonium 210 and lead 210 content of the tobacco. But this is due to the intensive use of fertilizer that contains these contaminants in large amounts. So if these fertilizers are not used by organic farmers, would the tobacco not have little or no radioactive elements in it as a result, resulting in a tobacco that is 90% safer?