Analysis of mainstream cigarette smoke constituents prioritized by the World Health Organization in a core collection of tobacco accessions: variability and correlations
Among the different strategies proposed for tobacco regulation, the WHO study group on Tobacco Product Regulation (TobReg) has proposed mandating ceilings on smoke constituents. These constituents were selected according to their potential toxicity, their variability among brands and the potential for the constituents to be lowered with the up to date technologies.
To assess the potential use of the natural diversity of tobacco plants to reduce the proposed constituents, we evaluated the variability of different leaf and smoke constituents in a core collection of tobacco accessions, representative of genetic diversity available before intensive modern breeding. A panel of 145 tobacco varieties from the Imperial Tobacco collection was grown in the field with three repeats and a split-splot design. After curing, handmade cigarettes were prepared to analyse smoke constituents. A statistical approach, taking into account multiple factors linked to the growing environment and weight of tobacco actively burnt during puffing, was designed to identify potential differences between varieties.
Significant differences were found for some constituents between tested varieties, but for others, low variability and inverse correlation are major bottlenecks. The WHO strategy on ceiling cannot be implemented in the state of art, even if some elements can be treated individually.