'Shisha' more harmful than cigarettes: WHO

World health experts warn that a session of smoking "shisha" equates to smoking 20 to 30 cigarettes at once, and heating the pipe also adds toxins.

A man smokes a pipe in a cafe at the Souq Waqif in Doha, State of Qatar, Wednesday, Nov. 29, 2006. (AAP Image/Tracey Nearmy)

Smoking water pipes can be more harmful than cigarettes, world health experts have warned.

A single puff from a water pipe nearly equals the volume of smoke inhaled from an entire cigarette, while one session of "shisha" can equal smoking 20 to 30 cigarettes in one go, a conference has been told.

Moreover, smoke from charcoal used to heat the tobacco contains toxins.

Smoking the water pipe - variously known as a hubbly-bubbly, hookah, shisha or nargileh - has long been popular in the Middle East and North Africa but has a growing fan base elsewhere.

The water pipe's popularisation has become a major worry for anti-tobacco campaigners as it is overlooked by regulators. Additionally, aromatic flavourings added to the tobacco appeal to younger smokers.

"A single puff from a water pipe is nearly equal to the volume of smoke inhaled from an entire cigarette," said The Tobacco Atlas, launched at the World Conference on Tobacco OR Health in Abu Dhabi.

And World Health Organisation tobacco expert Edouard Tursan d'Espaignet said "one session of shisha (water pipe) can be equal to smoking 20 to 30 cigarettes in one go, which can be very dangerous".

Gemma Vestal of the WHO's Tobacco Free Initiative says although shishas have previously been the domain of older males, "younger people between 18- and 24-years old living in cities and educated" are increasingly smoking them.

And Ghazi Zaatari, chair of pathology and laboratory medicine at the American University of Beirut, says aromatic flavourings are giving younger smokers a "smoother and more tolerated" alternative to the taste of traditional tobacco.

WHO says harmful effects include impact on the "respiratory system, cardiovascular system, oral activity and teeth".

In addition to the dangers of lung cancer, data also suggest probable associations with oral, oesophageal, gastric, and urinary bladder cancer, as well as chronic bronchitis, cardiovascular disease, stroke as well as other illnesses.