Cannabis users warned they face higher lung cancer risk

According to a report by the British Lung Foundation, seven in eight people believe smoking cigarettes is worse than cannabis but in fact the risk of developing lung cancer is 20 times greater from a cannabis joint than a legal tobacco cigarette.

The study claims there is an alarming gap between the public perception of cannabis as a relatively safe drug and the serious and even fatal impact it can have on the lungs of people who smoke it.

Dame Helena Shovelton, chief executive of the charity, said the problems was not confined to a comparatively few cannabis users.

“It is alarming that, while new research continues to reveal the multiple health consequences of smoking cannabis, there is still a dangerous lack of public awareness of quite how harmful this drug can be,” she said.

“Young people in particular are smoking cannabis unaware that, for instance, each cannabis cigarette they smoke increases their chances of developing lung cancer by as much as an entire packet of 20 tobacco cigarettes.”

According to the survey, nearly seven per cent of adults aged between 16 and 59 in England and Wales have used cannabis in the past year – approximately 2.2 million people.

This makes cannabis the most commonly used illicit drug in the UK.

Dame Helena added: “This is not a niche problem – cannabis is one of the most widely-used recreational drugs in the UK, with almost a third of the population having tried it.

“We therefore need a serious public health campaign – of the kind that has helped raise awareness of the dangers of eating fatty foods or smoking tobacco – to finally dispel the myth that smoking cannabis is somehow a safe pastime.”

The charity said its report is the most comprehensive review of research yet compiled on the subject of cannabis use.

More than 1,000 survey respondents were asked which, out of smoking a typical cannabis cigarette and smoking a typical tobacco cigarette, either from a packet or a roll-up, increases the risk of developing lung cancer the most.

A total of 88 per cent said tobacco cigarettes posed the greatest risk.

Almost a third of the those surveyed said smoking cannabis is not harmful to health, but the figure rose to almost 40 per cent among those who were aged under 35.

But evidence suggests smoking one cannabis cigarette a day for a year increases the risk of lung cancer by eight per cent, according to the charity’s report.

By comparison, smoking 20 tobacco cigarettes a day for a year increases the risk of lung cancer by seven per cent.

Smoking a cannabis cigarette therefore increases the smoker’s risk of lung cancer by as much as 20 tobacco cigarettes.

The average puff on a cannabis cigarette is two-thirds larger and is held for four times longer than the average puff on a tobacco cigarette.

As a result, someone smoking a cannabis cigarette inhales four times as much tar as from a tobacco cigarette and takes on board five times as much carbon monoxide.

The strength of herbal cannabis in the UK, as measured by the percentage content of tetrahydracannabinol, which is the principal psychoactive ingredient of cannabis, almost doubled to 10.4 per cent between 1995 and 2007, the report claims.

The increasing strength of cannabis means a series of studies conducted with people who have used cannabis in previous decades may not be as accurate, it says.

The report calls for a public health education programme to raise awareness of the impact smoking cannabis has on the lungs and wider health.

It said more research is also needed to find out more about the impact on health of using the drug.