From the ATHRA FAQ - that can be found here: 
What is tobacco harm reduction?
Safety and health
Are e-cigarettes less harmful than smoking?
Is it fair to say that vaping is likely to be at least 95% lower risk than smoking?
Additional information on PubPeer
Is vaping harmful to bystanders?
Should public vaping be banned?
What about the unknown long-term risks?
But it took decades to find out that smoking was harmful
Don’t the recent US cases of severe lung injury prove that vaping is very harmful?
Does vaping cause popcorn lung?
How common is child poisoning?
What about fires and explosions?
Does vaping help people quit smoking?
Is vaping a popular quitting aid?
Should vapers continue to vape after quitting smoking?
Is there a ‘youth vaping epidemic’ in Australia?
Is there a youth vaping ‘epidemic’ in the US?
Is vaping a gateway to smoking?
Should flavours be banned to stop youth vaping?
Does nicotine damage the developing adolescent brain?
What can be done to protect young people?
Is vaping being taken up by non-smokers?
Does vaping ‘renormalise’ smoking?
Isn’t most vaping ‘dual-use’ of e-cigarettes and cigarettes?
Is vaping cheaper than smoking?
The tobacco industry
Is vaping a tobacco industry ploy to keep people smoking?
Regulation of vaping
How should vaping be regulated?
How should vaping products be taxed?
Who should regulate vaping products?