Researchers believe that certain compounds used with Henna products are causing instances of leukemia. Researchers in the Gulf found a much higher than usual incidence of types of leukemia in local women – elsewhere, most sufferers are men. One possible reason - the popular local custom of using henna to create elaborate skin decorations.
They believe that it is not the henna itself that is the problem, but the compounds used as a solvent for the henna powder. Benzene, which is known to cause cancer, is banned for this purpose in many countries, but is still widely employed.
"The majority of the females in UAE routinely use henna to stain their nail, hands, feet and to decorate a large area of the skin of their arms and legs for cosmetic reasons," said the study, by a team from hospitals in the United Arab Emirates, published in the Leukaemia and Lymphoma journal.
"To our knowledge, the henna used at different henna salons in the UAE are actually mixed with benzene and other petroleum products in addition to many other chemical additives for colour enhancement.
One popular type of liquid used to give a henna effect in tourist resorts around the world, so-called "black henna", is in fact not made of henna and often contains a substance called para-phenylenediamine which can cause allergies and scarring.
The Gulf, where henna application is a viewed as a cosmetic art form, uses real henna, but local authorities acknowledge that clinics often use pre-prepared pastes that have been mixed with benzene.
The journal study found that acute myeloid leukaemia was 93 per cent more common in Emirati women than Emirati men, and 63 per cent higher than in expatriate women. Normally, its incidence is higher in men.
"Benzene has always been known as a cancerous substance," said Dr Sherief Islam, one of the authors of the study. "It can be used as a solvent – in fact, if it's used in industrial paint there are strict health regulations about applying it."