When water does not clear the smut from the smoke.

Water-pipe (shisha) smoking is increasingly popular among young people in Europe and North America. The proponents claim that smoking water-pipe is much 'cleaner' than cigarettes. Although, a recent analysis of toxicant yields during 1-2 h water-pipe smoking resulted comparable to 100-200 cigarettes. We report a case of a 25-year-old patient with elevated haemoglobin, impaired concentration and reduced physical performance. Molecular investigations for JAK2 mutations and BCR-ABL fusion transcripts were negative and the arterial blood gas analysis revealed an elevated carboxyhaemoglobin of 6.1%. In a follow-up visit, the patient disclosed excessive shisha smoking. Secondary polycythaemia was diagnosed caused by chronic carbon monoxide poisoning. After cessation of shisha smoking all blood values returned to normal ranges within 6 weeks. Owing to the increasing popularity of water-pipe smoking and the anticipated health risks, our report should help to enhance awareness and advocate more information in tobacco prevention programmes on its potential toxicities.