A first-ever Indian study has found that Electronic Nicotine Delivery System (ENDS), also known as e-cigarettes, pose much less a health risk than combustible cigarettes and could be an ideal tool to reduce or give up smoking.

Published in the Indian Journal of Clinical Practice (IJCP), the study, involving a "systematic review of 299 published scientific literatures", was conducted by Prof R.N. Sharan and his team from the North-Eastern Hill University, Shillong. It compared the toxicities of nicotine, other chemicals and metal ions produced during cigarette smoking and use of e-cigarettes.

According to the team, "despite increasing awareness and regulatory measures to discourage cigarette smoking, the tobacco burden across the world has not shown significant decline over the years". In such a scenario, alternatives for tobacco harm reduction like ENDS or e-cigarettes, need to be evaluated.

Prof Sharan told IANS: "This up-to-date systematic review and meta-analysis is the first attempt by experts in India to audit the health and safety aspects of conventional cigarette smoking and ENDS in order to objectively evaluate the suitability of ENDS as a less harmful alternative to conventional smoking."

The study authoritatively concluded that newer generation ENDS was an efficient means of meeting the nicotine demand, and could help the cigarette smoking population quit the addiction and prevent tobacco harm reduction. Among the key findings, the experts concluded that toxic chemicals such as carcinogens and other toxicants were found in significantly higher quantities in conventional cigarette smoke as compared to the vapour from an e-cigarette.

"For instance, metal ion Cadmium, which is a Class 1 carcinogen, a respiratory, reproductive and developmental toxicant, was found to be over 1,369 times higher in cigarette smoke than ENDS vapour. Similarly, Lead and Chromium, which are Class 2a probable carcinogens, were over 12 and 13 times, more respectively in cigarette smoke."

Cigarette smoke was also found to have "significantly higher levels of Class 1 carcinogens such as formaldehyde (over 8 fold), benzene (22 fold) and NNK (over 92 fold), and Class 2a probable carcinogens, including acetaldehyde (over 91 fold), Propanediol (over 53 fold) and Isoprene (over 17 fold), among others, in comparison to vapour of e-cigarette."

On the other hand, however, the study also found that Nickel, a Class 2b possible carcinogen, was four-fold more in e-cigarette vapour than in cigarette smoke. The researchers also found that the risk of acute toxicity from direct ingestion of nicotine was highly unlikely to arise due to e-cigarette use, as ENDS delivered about 1mg of nicotine in blood (equivalent or lower to a cigarette), whereas it's known toxic level was in the range of 30-60 mg.

Speaking about the possible risks arising from the physical makeup or design of ENDS devices, the study warned that, "Poor materials and build quality, lack of quality control and improper use of ENDS can give rise to a potential accident hazard called "thermal runaway" in lithium rechargeable batteries.

However, the experts added that "with technological advancement and optimisation of safety features, these concerns can be adequately addressed." Finally, the authors of the study found that "ENDS usage was higher among former smokers than non-smokers by nearly 4.13 fold, signifying that they could potentially become a useful aid in smoking cessation.

"Also, use of ENDS was found to be 7.53 times higher in smokers than in non-smokers, which indicates that, contrary to perception, e-cigarettes are less likely to be a gateway to nicotine use but are more likely used by smokers to reduce tobacco harm or quit smoking.

The team comprised Dr. Sambuddha Das and Dr. Yashmin Choudhury from Assam University, and Dr S. Thangminlal Vaiphei from Central University of Rajasthan. Prof Sharan, who is a former President of the Indian Society for Radiation Biology, said: "Through this study, we have called for rational policy-making with the objective of maximising benefits and minimising potential risks by extending the benefits of ENDS to smokers who choose to use them as smoking cessation tools, while preventing the misuse of ENDS by never smokers, adolescents and children."