Treatment of tobacco and tobacco smoke with chelating agents to remove Pb-210 and Po-210

Abstract

This invention relates to the treatment of tobacco and tobacco smoke with chelating agents to reduce the concentration of Pb-210 and Po-210. Chelating formulations such as the tetrasodium salt of ethylenediaminetetraacetic acid in aqueous solution with a wetting agent are sprayed onto the tobacco during growth and/or the chelating formulations are used to soak or wash the tobacco after harvest but before curing the tobacco. Pb-210, Po-210 and other metals are removed from tobacco smoke by applying chelating agents to the surface of the tobacco and/or the filter material.

1 . We claim the treatment of tobacco, before the tobacco is cured, with chelating agents such as triethanolamine, ethylenediaminetetraacetic acid, EDTA, the disodium salt, Na 2 EDTA, the tetrasodium salt, Na 4 EDTA, and the pentasodium salt, Na 5 DPTA, to remove the Pb-210 and the Po-210, where the tobacco is washed by soaking or spraying with an aqueous solution of the chelating agent that may or may not include a wetting solution such as dioctyl sodium sulfoccinate and where the aqueous solution of the chelating agent may also include chemicals to control the pH of the solution and where after soaking or spraying the tobacco with the chelating solution, the tobacco may or may not be rinsed with water.  
   
   
       2 . We claim the process of removing Pb-210 and Po-210 from tobacco as in  claim 1 , where tobacco is treated after harvesting but before curing.  
   
   
       3 . We claim the process of removing Pb-210 and Po-210 from tobacco as in  claim 1 , where the tobacco treated is the tobacco plant before harvest where the chelating solution is sprayed onto the plants.  
   
   
       4 . We claim the treatment of smoke and combustion products of burning tobacco with chelating agents to remove Pb-210 and Po-210 and other metals, where the chelating agents that can be used include but are not limited to triethanolamine, ethylenediaminetetraacetic acid, EDTA, the disodium salt, Na 2 EDTA, the tetrasodium salt, Na 4 EDTA, and the pentasodium salt, Na 5 DTPA.  
   
   
       5 . We claim the process of removing Pb-210, Po-210 and other metals from smoke and combustion products of burning tobacco as in  claim 4 , where a residue of one or more chelating agents are applied to the surface of the cured tobacco so that the volatized and particle borne Pb-210, Po-210 and other metals produced by the burning tobacco can react with chelating agents on the surface of the unburned tobacco removing Pb-210, Po-210 and other metals from the smoke and combustion products being drawn through the unburned tobacco.  
   
   
       6 . We claim the process of removing Pb-210, Po-210 and other metals from smoke and combustion products of burning tobacco as in  claim 4 , where one or more chelating agents are applied to the surface of filter materials or otherwise incorporated into the filter material, where the chelating agent or combination of agents on the surface of the filter material and/or made part of the filter material would serve to remove Pb-210, Po-210 and other metals from the tobacco smoke and combustion products drawn through the filter, where the filter may or may not be directly attached to the tobacco being smoked.