(CBS) - There were some new developments this week in the controversy surrounding the growing use of electronic cigarettes, or "e-cigarettes." These devices allow consumers to inhale nicotine and other products via an electronically-produced vapor, rather than smoke.
On Monday, the American Heart Association (AHA) called for e-cigarettes to come under tougher national regulations and to be subject to the same laws and restrictions applied to traditional tobacco products.
And on Tuesday, the World Health Organization (WHO) said it will call for a ban on the indoor use of e-cigarettes in public spaces and in workplaces -- as well as prohibiting unproven health claims about the devices, and halting advertising and sales targeted to children.
In a background report, the WHO notes e-cigarettes have grown in less than a decade's time into a global industry -- with estimated revenues of $3 billion, nearly 470 brands and a growing stake from the international tobacco industry.
The report, which is scheduled to be released in October at a WHO meeting in Moscow, also says e-cigarettes are now being marketed in nearly 8,000 different flavors -- which the organization says adds to concerns the devices will "serve as a gateway" to nicotine addiction and, ultimately, tobacco smoking by young people.
"Experimentation with e-cigarettes is increasing rapidly among adolescents," the report says, "with e-cigarette use in this group doubling from 2008 to 2012."
Proponents of the e-cigarette industry have been pushing back.
The Tobacco Vapor Electronic Cigarette Association (TVECA) is an industry group that represents manufacturers and distributors in the United States and throughout the European Union.
TVECA notes that, "after eight-plus years on the market, (and) billions and billions of uses by millions and millions of Americans," none of more than 35 clinical studies focusing on e-vapor products have found any ingredients or byproducts at any level harmful to humans.
TVECA co-founder Thomas Kiklas also pointed to a 2009 FDA study - which he says determined e-cigarettes and similar devices are "over 1,400 times less harmful than traditional tobacco products and do not pose any threat of harm to any consumer."