The tar delivery of cigarettes is routinely measured with a machine and, with the exception of the United States, stated on every packet as a legal requirement in almost every country in the world. It is accompanied by measurement of nicotine and often carbon monoxide.
Yet these measurements are now known to be misleading for two reasons. Firstly, human smoking patterns vary greatly and are not mimicked by the machine. Secondly, modern cigarette design encourages over-inhalation, which may lead to the smoker taking in much greater amounts of tar and nicotine than are measured by the machine.
The tobacco industry has also modified cigarette design, making the modern cigarette at least as dangerous as its predecessor, despite a dramatic lowering of tar delivery.
Tar measurement and labelling has served the tobacco industry well, say the authors. It has underpinned claims that cigarettes were light or ultralight and has seemingly, and falsely reassured many smokers who might otherwise have quit the habit.
They believe that machine measured figures for tar, nicotine, and carbon monoxide should be removed from the packet, and a realistic measure must be established for regulatory purposes.
The current health warnings deal qualitatively with the risks of smoking very well, and misleading figures on the packet can only do harm, they conclude.