With multiple fatalities confirmed in the U.S. this year, health concerns about e-cigarettes are growing around the world.

E-cigarettes are referred to by many different names. They are sometimes called "e-cigs," "vapes," and "electronic nicotine delivery systems."

The number of "vapers" has been increasing rapidly – from about seven million in 2011 to 41 million worldwide in 2018. And the number of adults who vape will reach almost 55 million by 2021, according to market research company Euromonitor International.

Vapers may believe vaping is less harmful than smoking regular cigarettes, or see e-cigs as a way to help them quit smoking tobacco. 

But can e-cigarettes really do all of that?

Users inhale this aerosol into their lungs, while bystanders can also breathe in the vapor when the user exhales into the air. 

So, are e-cigarettes safe? 

Well, the good news is, e-cigarettes are less harmful and almost certainly less lethal than conventional cigarettes since they contain fewer toxic chemicals.  

However, they can still harm your body. 

Firstly, most e-cigarettes contain nicotine, which is not only highly addictive but also dangerous to an adolescent's brain development and pregnant women and their developing babies. 

Besides nicotine, e-cigarette aerosol can also contain cancer-causing chemicals and tiny particles that reach deep into the lungs. 

E-cigarettes have been associated with people's desire to quit smoking ever since they hit the market. But, can they really help you quit? 

Some evidence has suggested that e-cigarettes may work as a cessation aid for some people, but the nicotine they contain makes them addictive. 

As the worldwide backlash intensifies against the claim that the technology is less harmful than smoking tobacco, countries including the U.S., India and Brazil have announced different levels of bans on e-cigarettes.  

And China has banned the sales of e-cigarettes to minors as well as selling them online or putting up any e-cigarette advertisements online.

So, if you've never smoked tobacco or its variants including e-cigarettes, it's best not to start. 

On-camera reporter: Guo Meiping

Scriptwriter: Guo Meiping  

Cover image: Liu Shaozhen

Executive producer: Guo Meiping  

Producer: Si Nan  

Supervisor: Zhang Shilei