An e-cigarette is nothing but an ‘Electronic Nicotine Delivery System,’ a battery-operated device used to ‘Vape’ a flavoured solution called an ‘e-liquid’ containing varying concentrations of nicotine, flavouring agents, and vaporisers. Here, it must be noted that ‘Nicotine’ is considered one of the most addictive substances. The age of first exposure and administered dosage add to the potential risk to a person addicted to it throughout life3,10. There is strong evidence that e-cigarette use by non-smokers increases the risk of smoking conventional tobacco by about three times, thus acting as a gateway. Moreover, tobacco smokers who switch to e-cigarettes continue dual use and do not truly benefit from quitting tobacco smoking11-13. So far, nowhere on earth has the e-cigarette been approved as a smoking cessation product like pharmaceutical nicotine replacement products11.

Since the emergence of e-cigarettes in the mid-2000s, they have been promoted and marketed by the tobacco industries as safer alternatives to conventional cigarettes and/or an effective way to stop smoking. However, the majority of global research does not conclusively support this claim10-14. Thus, many countries around the globe, including India, have banned e-cigarettes and related products15.

These are new nicotine delivery systems commonly referred to as ‘Heat-Not-Burn’ (HNB) by the tobacco industry. The HNB tobacco products are non-combusted cigarettes consisting of an electronic source that heats the tobacco instead of burning it. The HNB device works with the same technology as e-cigarettes, only replacing the e-solution/e-liquid with dry processed tobacco as the source of nicotine. With the tobacco industry’s active marketing strategies of many popular brands, the sales of these products are on the rise, with the perception of being less toxic, as claimed by the tobacco industry. However, the evidence does not support the claimed 90-95 per cent reduction in harmful and potentially harmful substances and toxicity in the HNB16-19.

Moreover, there is strong evidence that studies conducted by the tobacco industry or by researchers funded by them are not free of conflict of interest and thus cannot be trusted. There is clear proof that the studies sponsored by the tobacco companies did not disclose the high concentrations of particulate matter, tar, acetaldehyde, acrylamide, acrolein metabolite, and formaldehyde in their studies on emissions from heated tobacco. The tobacco industry data investigated by independent researchers shows that there are 22 and seven harmful or potentially harmful substances that were more than 200 per cent and 1000 per cent higher than in reference cigarette smoke17. Furthermore, no statistically detectable differences were found between users of heated tobacco and conventional cigarettes for 23 of the 24 biomarkers of potential harm. The studies performed by the tobacco industry on both animals and humans also showed that there was no evidence of improvement in pulmonary function or inflammation in smokers who switched to heated tobacco. Moreover, there is a possibility of hepatotoxicity, cardio-toxicity, and adverse effects on the cardiovascular system due to heated tobacco17,18.

Evidence from independent researchers showed that substantial amounts of carcinogenic tobacco-specific nitrosamines, as well as toxic and irritant substances and potential carcinogens17,18, were emitted from the HNB tobacco products. Almost equal proportions of nicotine and tar were found, and acenaphthene quantity, a potentially carcinogenic substance, was nearly three times higher than that of conventional cigarettes. It was also found that the release of formaldehyde cyanohydrins was of great concern due to its high level of toxicity at very low concentrations17-19. In vitro studies have reported that emissions from heated tobacco cause damage to human bronchial epithelial cells, potentially increasing oxidative stress, inflammation, infections, airway remodelling, and epithelial-mesenchymal transition-related changes in the airways17,18. Experimental animal studies have found that there is decreased blood vessel function due to exposure to heated tobacco, which is comparable to that induced by cigarette smoke. Studies have also reported that the users of heated tobacco are required to smoke at a rapid pace, which could lead to an increase in the intake of carbonyls which are potentially carcinogenic, and nicotine, which may induce nicotine dependence16-18. There is no convincing evidence that heated tobacco products are an efficient smoking cessation aid. Dual use, as observed with other harm-reduction products such as e-cigarettes and snuff/snus, also occurs. Studies have reported heated tobacco use by non-smokers in about 45 per cent of cases. However, there are limited data on the health effects of long-term use among switching smokers, dual users, as well as novice exclusive users16,17,19,20. In contrast, the e-cigarettes and the HNB tobacco products market is growing exponentially around the globe. Currently, the largest share of revenue from the sale of heated tobacco products is reported from the Asia-Pacific region, with use concentrated in the 18-39 yr age group16.

Given the potential threat to public health at the population level, the Government of India banned e-cigarettes and related products by promulgating the PECA 2019 (The Prohibition of Electronic Cigarettes [Production, Manufacture, Import, Export, Transport, Sale, Distribution, Storage and Advertisement] Act, 2019). However, despite the comprehensive ban, e-cigarettes and related products are still easily accessible, especially to young people, leading to continuing public health challenges in the country15,16.