Scientists from the Roswell Cancer Park Institute in Buffalo, NY, have announced the findings of two studies respectively looking at evidence on “thirdhand” exposure to nicotine from e-cigarettes and the accuracy of e-cigarette product labels.

Sales of e-cigarettes (“electronic cigarettes”) – where nicotine and other cigarette-associated substances are inhaled in a vapor through a battery-operated device – have doubled each year since 2008 in the US. E-cigarettes are not currently regulated by the US Food and Drug Administration (FDA).

Over the past couple of years, various studies have analyzed to what extent e-cigarettes may or may not be harmful to both the smoker and other people.

Medical News Today reported on a 2012 study finding that, although e-cigarettes contribute less to indoor air pollution than traditional tobacco cigarettes, they are “not entirely emission-free,” and so bystanders may be exposed to the released vapor.

That study also criticized the labeling of e-cigarettes, commenting that the inadequate or vague information on the content of the products made it difficult for smokers to know the potential dangers of the contained substances.