As debate over whether vaping is a healthier alternative to smoking rages on, a team from Lawrence Berkeley throw a little more fuel onto the fire, finding that the hotter an e-cigarette gets, the more likely it is to release irritants – and a couple of carcinogens to boot.

The indoor environment group at LBNL has been working on tobacco chemistry and exposure in indoor environments for about 30 years, but with the increasing popularity of e-cigarettes, they started looking at the chemical composition of both direct and passive (exhaled vapor) emissions. In particular, they focused on the effect of heating on the composition – as well as how the design of the device and nature of liquids can affect the levels of chemicals in the vapor. The overall objective? To assess the impact of the vapor on indoor air quality and estimate the health outcomes of exposure for both users and non-users.