Evidence of vaping risks mounting
Vaping is touted as the lesser of two evils for smokers trying to quit — but a New Zealand scientist says there’s much about ecigarettes’ longterm effects we still don’t know. Jamie Morton reports.
THE most advanced study of its kind in the world, using human trials and 3D computer models to get a precise look at what vaping does to our lungs, has been launched in Auckland.
Worldwide sales of ecigarettes have boomed over the past decade, and today an estimated three in 100 New Zealanders use them at least once a day.
The Ministry of Health’s Vaping Facts website advises ecigarettes are less harmful than smoking but points out they have not been around long enough for the longterm effects to be known.
University of Auckland bioengineer Kelly Burrowes said given they were being promoted here as a tool to reach New Zealand’s Smokefree 2025 targets, regulators and healthcare providers needed to know the devices actually reduced harm caused by smoking and did not just pose further risks.
There was mounting evidence there were indeed risks.
One recent animal study showed an increase in lung cancer development as a result of exposure to nicotinecontaining ecigarette aerosol, while another pointed to emphysemalike changes in lungs after use.
Dr Burrowes also highlighted a 2019 outbreak that hospitalised about 3000 people in the US, thought to be the result of vitamin E acetate being added to THCcontaining vaping liquids.
Vaping devices work by using heat to aerosolise a liquid, typically consisting of propylene glycol, glycerol, flavourings and nicotine, which is then inhaled and puffed out.
‘‘All of the chemicals used are generally regarded as safe for oral ingestion but their impact on the lungs, and the rest of the body, when inhaled is unknown,’’ she said.
‘‘In addition, analysis of the chemicals in electronic cigarette aerosol have shown a much larger range of chemicals than those in the liquid.’’
In earlier research, Dr
Burrowes and her team have identified about 50 different chemicals, including heavy metals that most likely come from the metal heating coil and welding material in the devices.
Some studies have also shown carcinogenic chemicals within the aerosol, including formaldehyde and acrolein, created as byproducts through the heating process.
‘‘You may have seen the value of ‘95% safer’ being used, especially by retailers,’’ she said.
‘‘This quantification is completely unfounded because the data required to make this quantification are not yet available.’’
That metric came from a study that estimated the relative harm of various nicotinecontaining products, using scoring from a selected panel of experts.
‘‘While the scores provided by the panellists were informed by knowledge, they are fundamentally value judgements and are not an exact science.’’
However, the devices have shown promise in quitsmoking studies and some research has also indicated smokers with chronic obstructive pulmonary disease could experience improvements in lung function if they switched to vaping.
Dr Burrowes said on the weight of evidence so far, she felt vaping products were probably useful aids for quitting cigarettes but they should only be used as an intermediate step.
Her new study, supported by a new Marsden Fund grant, sought to find out exactly what went into vaping aerosols, where these chemicals travelled in the body and what effect they had on everything from cells to whole organs.
With more than 400 vaping brands and 8000 flavours, not to mention other factors such as different device settings, getting a good overall picture was not easy.
But her team had already developed a device that acted as a control for those variables and it would be used to gain the data needed to build rich new models.
The first stage of the project used sophisticated methods, such as gas chromatographymass spectrometry, to measure the inhaled chemicals, alongside other measurements of particle sizes.
Investigating how the aerosol made its way into our lungs would be similarly challenging, she said.
For this, the team would test its computer models and actual particle flows against 3Dprinted models of a human airway tree.
The next steps would involve looking at how cells, tissues and lungs responded, by observing 20 healthy young volunteers before and immediately after vaping.
The scientists expected that, like cigarette smoke, vaping triggered an inflammatory response in the lungs that changed their function and density, and their mechanics, over time.
‘‘There is currently no way to link from changes occurring at the cellular level to the impact on how the lungs work as a whole to really understand the impact of vaping a our models will be the first in the world to do this.
‘‘Electronic cigarettes could have a significant positive impact on our society through smoking reduction but their net health impact depends on risks that are poorly understood, as well as their benefits.’’