Systematic Studies on the Breakdown of p,p'-DDT in Tobacco Smokes

These studies, on the pyrolysis of DDT, can be divided into two sections. Section 1 deals with the pyrolysis of p,p'-DDT in a nitrogen atmosphere at 900°C and subsequent isolation and identification of CH₂Cl₂, CHCl₃, CCl₄, CHCl = CCl₂, CCl₂ = CCl₂, chlorobenzene, CCl₃- CCl₃, a,p-dichlorotoluene, p,p'-dichlorobiphenyl, bis-(p-chlorophenyl)methane, cis-p,p'-dichlorostilbene, bis-(p-chlorophenyI)chloromethane, p,p'-DDM, p,p'-DDE, trans-p,p'-dichlorostilbene, p,p'-TDE, and p,p'-DDT. Mechanisms for the formation of these compounds are proposed, and on that basis prediction is made on the formation of DDT degradation products when DDT-treated tobacco is smoked. Section 2 deals with pyrolytic degradation of DDT incorporated in tobacco. Methyl chloride, bis-(p-chlorophenyl)methane, p,p'-dichlorobenzophenone, p,p'-DDM, trans-p,p'-dichlorostilbene, p,p'-DDE, p,p'-TDE and p,p'-DDT were identified as the pyrolysis products. Based on the type and nature of pyrolysis products obtained, eight conclusions are made.