Thanks RC and Grayling Skies.
I've been studying this situation for several years and the deeper I look the more questions I have.
When Thallium was first discovered it was claimed that Thallium was in minute amounts in most areas of the world.
Subsequently, there seems to different points of view regarding the amount of thallium in the earth's crust, from a few ppb to a few ppm per KG.
I have not been able to determine if the use of nuclear tools (bombs, power plants, munitions, medicines), via decay has contributed to the amount of Thallium (stable 203 & 205) that seems to be way more prevalent than what is considered as being normal.
Because I have been unable to find answers I felt that perhaps those individuals who frequent this website might be able to shed some light on this opaque matter.
Those interested in discussing this issue deeper can contact me at
jcummins1@bellsouth.net