Most current studies that look promising regarding the safety of ecigs are:
At first
See a recent review of Zachary Cahn & Michael Siegel. (Electronic cigarettes as a harm reduction strategy for
tobacco control: A step forward or a repeat of past mistakes?; Journal of Public Health Policy, 2010-12-09)
It is an examination of scientific evidence about the safety and effectiveness of electronic cigarettes based on 16 laboratory studies that identified the components in electronic cigarette liquid and vapor. The researchers found that carcinogen levels in electronic cigarettes are up to 1,000 times lower than in
tobacco cigarettes.
They state: "Few, if any, chemicals at levels detected in electronic cigarettes raise serious health concerns……Although the existing research does not warrant a conclusion that electronic cigarettes are safe in absolute terms and further clinical studies are needed to comprehensively assess the safety of electronic cigarettes, a preponderance of the available evidence shows them to be much safer than
tobacco cigarettes and comparable in toxicity to conventional nicotine replacement products."
Second
You can find links of recent in vitro studies with encouraging results on the site of Flavourart, Italy;
The first study was done by 2 biotechnologists to evaluate the cytotoxicity of inhaled vapor (Flavourart’s Heavenjuice with a mix of their flavours Virginia and Perique black) towards fibroblasts (cells of the respiratory epithelia). None of the results with the mentioned Flavourart mix were cytotoxic on fibroblasts.
The second study, by a biotechnologist and a chirurg, specialised in allergology and immunology, was done on blood cells (monocytes/macrophages.) The aim was to test whether there was a pro-sensitising effect caused by the Flavourart Heaven juice with mix of Virgina and Perique black. The cells treated with the mentioned Heavenjuice mix seem to show no pro-sensitising effect.
The third study/report is on heavy metals. The results are far under the limits.
See for further introduction and details also my post of 12-12-2010 in above thread E-liquid lab/toxicology reports;
http://www.e-cigarette-forum.com/fo.../2716-e-liquid-lab-toxicology-reports-10.html