Raising strong objection against the latest study claiming that common e-cigarette "vapours" contain lead and other toxic metals and may raise major health issues, an expert argued that the sample size used in the research was not appropriate.

The study led by scientists at Johns Hopkins Bloomberg School of Public Health, and published in the journal Environmental Health Perspectives, examined e-cigarette devices owned by 56 users and found significant number of these generated aerosols with potentially unsafe levels of lead, chromium, manganese and/or nickel. Inhaling these metals for a longer term has been linked to lung, liver, immune, cardiovascular and brain damage, and even cancers, the study claimed.

"Several shortcomings were found in a similar study conducted by the same institute last year, including overestimating normal levels of exposure, not factoring in exposure to metals from daily activities, small sample size of products tested," Samrat Chowdhery, Director, Assocation of Vapers India (AVI), said in a statement. The previous study blew up the significance of exposure levels since patients who use inhalers are also exposed to metals. "These studies have also found a large variance in exposure levels among the users tested, which indicates harm can be significantly reduced with the use of quality products," Chowdhery said.

"This would be possible if the government brings in safety standards and regulates electronic cigarettes, instead of banning them. An evidence-based ENDS (Electronic Nicotine Delivery Systems) policy will help save millions of lives in this country," he added. An e-cigarette is a battery-operated device that uses a liquid that may contain nicotine, as well as varying compositions of flavourings, propylene glycol, vegetable glycerin, and other ingredients.

Experts have since long argued its benefits over tobacco cigarette, in which there is combustion, a burning of an organic material, which generates temperature up to 900 degrees Celsius, and thus produces all the harmful material. Conversely, e-cigarettes contains neither combustion nor tobacco, but only the burning of the liquid, made up of ingredients approved for food and contains minimal burning, which is 100-1000 times lower compared to a tobacco cigarette.

According to various media reports, the Union Health Ministry had recently ruled out acceptability of e-cigarettes in the light of research findings by experts who concluded that they have cancer-causing properties, are highly addictive, and do not offer a safer alternative to tobacco-based smoking products. Some states in India, including Jammu and Kashmir, Karnataka, Punjab, Maharashtra and Kerala, have prohibited the sales of e-cigarettes, while tobacco cigarettes remain legal.