The use of e-cigarettes every day nearly doubles the risk of a heart attack, according to a new survey.

The survey of 70,000 people found that using both e cigarettes and normal ones, the most common thing to do , appears to be more dangerous than using either one alone.

Lead author and director of university of California's centre for tobacco research Stanton Glantz told Tim Dower the combination of normal smoking and e-cigarettes is dangerous.

" e-cigarettes are not as bad as smoking, that about triples the risk, but smoking them both multiplies the risk."

LISTEN ABOVE AS STANTON GLANTZ SPEAKS TO MIKE HOSKING