Heavy metals in hookah tobacco

Hookah smoking is coming under the microscope as scientists and health authorities realise that they don't know very much about the health hazards associated with this form of tobacco consumption. The World Health Organization recognises that hookah smoking is no safer than cigarette smoking, contradicting the beliefs of many hookah smokers that passing the smoke through water purifies it before it is inhaled. In practice, many harmful chemicals are poorly soluble or insoluble in water, so this operation is less than perfect.

A recent study reported in separationsNOW.com found that some toxic furans in hookah smoke elude capture by the water reservoir and pass through to the smoker. These are in addition to various carcinogens, nicotine and carbon monoxide which are also known to be in hookah smoke. Bearing in mind that hookah devotees smoke for longer periods than typical cigarette smokers, the potential risks are high.

Now, a new study has focussed on the metals in hookah tobacco. Joseph Caruso and colleagues from the University of Cincinatti recognised that tobacco plants accumulate metals from the soil as they grow, so they might also cause a problem. They used ICPMS to measure the levels of 18 metals in tobacco, as reported in Analytical Methods.

They found that the levels of the metals are low and those of four of the more toxic metals (As, Cd, Cr, Pb) in a typical smoking portion of hookah tobacco are actually lower than those in a typical cigarette. So, metals may not be one of the health factors to fear for hookah smokers. However, "the most important measure regarding the toxic metals is the amount reaching the smoker’s respiratory system from the smoke. This project is now ongoing in these labs," said Caruso.