Smoking a shisha pipe is as bad for people as smoking tobacco, the Department of Health and the Tobacco Control Collaborating Centre has found.People who smoke shisha, or herbal tobacco, can suffer from high carbon monoxide levels, its research revealed.
It found one session of smoking shisha resulted in carbon monoxide levels at least four to five times higher than the amount produced by one cigarette.
High levels of carbon monoxide can lead to brain damage and unconsciousness.
Shisha is a water-pipe, popular in many Arab countries, in which fruit-scented tobacco is burnt using coal, passed through an ornate water vessel and inhaled through a hose.
The Department of Health said it was difficult to know exactly how much carbon monoxide one cigarette produced, due to the differences in smokers' inhalations.
CO LEVELS - PARTS PER MILLION
Normal level: 3 ppm
Light smoker: 10-20 ppm
Heavy smoker 30-40 ppm
Faulty boiler/fire levels: Upwards of 100 ppm
Severe symptoms: 100 ppm
Lethal levels: More than 300 ppm
The study found shisha smokers had 40-70 ppm of CO in their breath - affecting 8-12% of their blood.
Dr Hilary Wareing, director of the Tobacco Control Collaborating Centre, told the BBC's Asian Network she was shocked by the results of the research.
"Our mouths opened at the level of harm - none of the tests we did showed anything other than shisha is hazardous to health."
Paul Hooper, regional manager at the Department of Health, said the findings made the dangers of shisha a "major issue".
He said many people regard shisha "as not even smoking".