Cannabis more toxic than tobacco
Cannabis smoke contains more toxins than tobacco smoke, study finds
Wednesday, 19, Dec 2007 09:32
Smoke from cannabis contains more toxic chemicals than from tobacco, Canadian researchers have revealed.
Scientists at Health Canada found that directly-inhaled cannabis has 20 times as much ammonia and five times more hydrogen cyanide than tobacco smoke.
Cannabis is the most frequently used drug in the UK with around 2.7 million (8.7 per cent) of 16 to 59-year-olds saying they used it in 2005-06.
Nitrogen oxides, which affect the circulatory and immune systems, were five times as concentrated in cannabis smoke, the New Scientist reports.
Toxins in cannabis smoke were measured using machines that collect the smoke and analyse its contents.
The findings add to the health dangers of cannabis, which was already known to be more harmful to the lungs than tobacco smoke as cannabis smokers inhale the drug one-third more deeply and hold it in their lungs for up to four times as long as cigarette smokers do.
Secondhand cannabis smoke was also found to be more harmful than tobacco smoke, although cigarette smoke contained higher levels of polycyclic aromatic hydrocarbons - which can affect reproduction and cause tumours in animals.
"This study highlights that cannabis contains similar carcinogens to tobacco, in particular volatile organic compounds," British Lung Foundation spokesman Stephen Spiro told the New Scientist.
"That these exist in similar or even greater proportions to tobacco smoke is a great worry."