Whether you're a smoker or not, you've no doubt heard the rumours. Some might call it science.
Over the decades it has been no secret that passive smoking is one of the biggest risks associated with cancer. It has been one of the most compelling debates around the recent issues plaguing cigarette smokers and their right to smoke in public; should unsuspecting members of the public be at risk as well?
According to the UK's National Health Service (NHS), second-hand smoke contains more than 4000 chemicals that are known to cause cancer. Frequent exposure to this smoke, which can last in the air for up to 2.5 hours, increases the risk of lung cancer and heart disease and can be particularly debilitating if continually exposed, news.com.au reports.
But there could be hope on the horizon for smokers and nonsmokers alike, after an evidence review on e-cigarettes and heat-not-burn products (like the IQOS) published by Public Health England (PHE) provided some compelling research that found e-cigarettes are saving thousands of lives each year.
Not only did the report conclude that vaping poses only a small fraction of the risks of smoking and switching completely from smoking to vaping conveys substantial health benefits, but it found that "there have been no identified health risks of passive vaping to bystanders".
That's right; those big clouds of smoke you see spewing out of electronic cigarettes are, in fact, safe.
"In many countries British American Tobacco provides a range of products for smokers seeking a harm reduced alternative," a spokesman for British American Tobacco Australia told news.com.au.
"Increasingly, the global evidence base supports making these products available. This is witnessed by the progressive approach to tobacco harm reduction by law makers in Europe, the United States, Canada and New Zealand.
"Australia's prohibitionist approach stands in stark contrast."
The science behind the research is as follows: When a smoker puffs on a normal cigarette at least 7000 chemicals are released due to the massive combustion caused by the cigarette's burn.
Because this is absent in vapour, the chemicals are "mostly at levels less than 1 per cent of those in tobacco smoke", according to Australian Tobacco Harm Reduction Association chairman Dr Colin Mendelsohn.
"The life of the chemicals from vaping is much smaller than smoking, in other words it disappears very quickly," Dr Mendelsohn, also conjoint Associate Professor at UNSW's School of Public Health and Community Medicine, told news.com.au.
"Cigarette smoke hangs around for ages whereas the chemicals in a vape, because it's liquid-based droplets, dissipates quite quickly."
Dr Mendehlson confirmed research has identified very low levels of chemicals in the air from vaping. Studies of vaping in homes found no discernible effect on air quality, and concentrations of vaping chemicals in vape shops were well below occupational exposure limits and nicotine was undetectable.
"The bottom line is that there is no identified health risk to bystanders."
Heated tobacco products, which heats tobacco instead of burning it, is also a safer alternative to the average cigarette, scientists claim.
"In fact cigarette company Phillip Morris, which has boldly claimed it is working towards a "smoke-free future", says five million smokers have already made the switch.
"IQOS does not produce smoke (first or second-hand) because it does not burn or combust tobacco," a spokesman told news.com.au.
"Unlike cigarettes, which ignite and burn at temperatures between 600-800 degrees, IQOS heats tobacco to only 300 degrees, which releases an aerosol instead of smoke.
"While the inhaled aerosol delivers nicotine to the user, the burning (or combustion) of the tobacco does not take place, and the aerosol that is generated contains significantly lower levels of harmful or potentially harmful constituents than cigarette smoke."
The company told news.com.au that a clinical study to determine the impact of IQOS aerosol on nearby non-users was underway but "has not yet been completed".
"That said, we have conducted extensive indoor air quality research. Our study looked at 18 markers of air quality associated with cigarette smoke, including carbon monoxide, benzene, and nitrous oxide.
"We measured the background levels in the room, then tested the levels associated with cigarette smoke and IQOS aerosol.
"Unsurprisingly, exposing the room to cigarette smoke resulted in much higher levels of harmful chemicals in the air. After the IQOS was used, however, only two of the 18 markers could be detected. These were nicotine, at a level 250 times lower than European Union indoor occupational air quality standards, and acetaldehyde at a level 40 times lower than European Union indoor exposure limits.
"Globally, nearly 5 million people have already stopped smoking and switched to IQOS, with approximately 10,000 smokers switching every day."
PHE's evidence review came just a few weeks after a US National Academies of Sciences, Engineering and Medicine report that concluded "e-cigarettes are likely to be far less harmful than combustible tobacco cigarettes".
"Our new review reinforces the finding that vaping is a fraction of the risk of smoking, at least 95 per cent less harmful, and of negligible risk to bystanders," said Professor John Newton, Director for Health Improvement at PHE.
"Yet over half of smokers either falsely believe that vaping is as harmful as smoking or just don't know.
"It would be tragic if thousands of smokers who could quit with the help of an e-cigarette are being put off due to false fears about their safety."
Dr Mendehlson says that while there is still research needed to investigate the harm done by vaping, there "is enough scientific evidence available now to make rational decisions".
"People have strong perfumes, they fart in public, they have body odour, we don't have rules against that.
"A blanket ban on vaping is really an over-reaction."