For electronic cigarettes used, we do not find any details in the text of the publication nor in the protocol yet published separately. We only know that the participants received their e-cigarettes by mail with cartridges of liquid concentrates to 16 mg/ml of nicotine that they could use at will.
We asked these details by email to Professor Bullen. It shows that the model distributed to participants is more than 3 years, that they had only one cigarette and that emergency charger was distributed in a second time. As for the cartridge, the capacity was only 0.5 ml, 8mg of nicotine which is at most 5 cigarettes. Above all, participants used an average cartridge per day, which is ridiculously low compared to the use of today vapoteurs. Professor Bullen recognizes, moreover, that “this is a limitation of the study and one of the potential explanations for the observed effects. He says the rest at the end of its publication, with the devices distributed vapoteurs could only get 20% of doses of nicotine they got with the cigarette.
Today vapoteurs have much more powerful devices, and kits containing two e-cigarettes to get them through the day without having to recharge. Above all, they have cartridges or much larger tank, allowing them again to take a day or make a one time their device. Thus, they actually consume nicotine they do not need suffer from the lack of signs. The fact that the participants of the study Bullen used only 8 mg of nicotine per day confirms that they were not satisfied by the material that had been given them or by the explanations that had been given them.