Comparing the cancer potencies of emissions from vapourised nicotine products including e-cigarettes with those of tobacco smoke

William E Stephens
Tobacco Control 2018;27:10–17
doi: 10.1136/tobaccocontrol-2017-053808

Vapourised nicotine products, such as electronic cigarettes (e-cigarettes), are rapidly growing alternatives to tobacco, acting as a method of nicotine delivery without the combustion of tobacco. Despite this, understanding of their safety is still under debate. Dr William Stephens, from the University of St Andrews, conducted a quantitative analysis to compare the relative cancer potencies between a number of nicotine products, including tobacco smoke, e-cigarette vapours and heat-not-burn (HnB) devices. Most e-cigarette emissions studied demonstrated a mean lifetime cancer risk of <1% of tobacco smoke. However, some devices produced higher potencies, particularly under conditions of a higher voltage. When compared with nicotine inhalers, the relative risks for e-cigarettes and tobacco cigarettes were 11 and ~2700, respectively. HnB devices demonstrated lower cancer potencies than tobacco smoke by at least one order of magnitude, but higher than those found in most e-cigarettes. Dr Stephens concluded that, ensuring the e-cigarettes were used under optimal conditions (such as enabling lower device settings) the emissions produced are likely to have a lower carcinogenic potency than that found in tobacco smoke.