Hubbly-bubbly, hookah or shisha - whatever name it goes by, puffing on a Turkish waterpipe is the latest trend to hit British bars and cafes. The flavoured tobacco, which is smoked via a long pipe connected to a vessel filled with water, is particularly fashionable among young people, with the number of specialist bars rising 210 per cent since 2007. But the World Health Organisation has warned that a one-hour shisha session can be as harmful as smoking 100 cigarettes.