Their report, The Impact of Cannabis on Your Lungs, reports that:
88 per cent of people think a typical tobacco cigarette puts you at greater risk of developing lung cancer than a typical cannabis cigarette.
As the BLF report points out, the evidence points the other way. This paper from 2008, for example, suggests that one joint of cannabis being similar to 20 cigarettes for risk of lung cancer.
The BLF conclude by recommending:
that public health education programmes be implemented to dispel the myth that smoking cannabis is relatively safe, and to highlight the adverse respiratory effects of smoking cannabis mixed with tobacco.
I have to say I’m a little bit disappointed by that recommendation, which doesn’t square with our understanding of the evidence for what is effective in drug prevention. As Claire’s paper on effective prevention in school based programmes points out knowledge is not sufficient to change behaviours.
Rather we need young people to develop skills that will enable them to manage social situations where the drug is available, to understand that their peers haven’t smoked the drug as much or as often as they might think, and to develop their character and values in relation to health decisions.