Novel approach for selective reduction of NNN in cigarette tobacco filler and mainstream smoke.

Research conducted during past decades to reduce the level of the tobacco specific nitrosamine N-nitrosonornicotine (NNN) and its precursor nornicotine in tobacco yielded identification of three tobacco genes encoding for cytochrome P450 nicotine demethylases converting nicotine to nornicotine. We carried out trials to investigate the effect of using tobaccos containing three non-functional nicotine demethylase genes on the selective reduction of NNN in cigarette tobacco filler and mainstream smoke. Our results indicate that the presence of non-functional alleles of the three genes reduces the level of nornicotine and NNN in Burley tobacco by 70% compared to the level observed in currently available low converter (LC) Burley tobacco varieties.

Tobacco-specific N-nitrosamines NNN and NNK levels in cigarette brands between 2000 and 2014.

The evolution of the levels of tobacco-specific N-nitrosamines (TSNA), N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in mainstream (MS) cigarette smoke is investigated based on smoke and tobacco chemistry data of cigarette brands sold by Philip Morris International (PMI) between 2000 and 2014. A total of 315 cigarette samples representing a wide range of product and design characteristics manufactured by PMI between 2008 and 2014 were analyzed and compared to a previously published dataset of PMI brands manufactured in 2000. The data indicate that there is a substantial reduction of NNN and NNK levels in tobacco fillers and MS cigarette smoke per mg of tar and per mg of nicotine using Health Canada Intense (HCI) machine-smoking regime.