Last summer, 41-year-old David Bradley systematically shot dead four members of his family as they entered the house, one by one, over a five hour period. Later he carried an arsenal of weapons to the nearest police station in a rucksack, pausing only for a cigarette outside, then calmly handed himself in to the waiting officers.
“He said that he had felt ‘jaded and weird’, the hot weather was getting to him, and he had ‘started to flip’,” said Det. Supt. Steve Wade, who led the murder inquiry. Bradley was a heavy cannabis smoker, and may have fallen victim to one of the emerging side effects of the drug: cannabis psychosis. High doses of tetrahydrocannabinol -the psychoactive substance in cannabis - have been reported to produce psychotic symptoms, such as visual and auditory hallucinations, delusional ideas, and thought disorder in normal volunteers, according to an Australian National Drug Strategy report.
Recently declassified to a class C drug, cannabis has become normalised and increasingly accepted in today’s youth society, treated as a social aid much like cigarettes and alcohol. But although we could not claim ignorance of the liver damage that excessive drinking can result in, and the carcinogenic properties of cigarettes, very little indeed is known about the long term health consequences of cannabis smoking.
It can only be assumed that inhaling marijuana smoke would have the same lung-tarnishing side-effect as tobacco smoke, but to the same extent? Or perhaps, frighteningly, to a far greater extent. Cannabis smokers tend to ‘breath-hold’ - keeping the smoke in their lungs for as long as possible in order to heighten the effects of the drug – far longer than a tobacco smoker would.
What exactly is the inhaler subjected to? Alongside the psychoactive ingredient, delta-9-tetrahydrocannibinol, or THC, the smoke contains more that 400 chemicals. The breath-holding technique, coupled with the increased tar content of cannabis, means smokers take in four times the amount of tar as regular smokers.
Additionally, the tar phase of cannabis smoke contains higher concentrations of polycyclic aromatic hydrocarbons (PAHs) than tobacco smoke. As PAHs are carcinogenic, the lung cancer risk gets even higher. A recent study by the British Lung Foundation found that just three cannabis joints a day cause the same damage as 20 cigarettes.
In the light of declassification and given the emerging knowledge of the drug’s dangers, health care professionals are calling for a wide-ranging study into its long term effects on the human body.
Dr. Onn Min Kon, consultant physician in the chest medicine department of St Mary’s Hospital, London, believes that a 20 or 30 year study, similar to 20th century tobacco smoking studies, is now called for, having seen what he likens to the lungs of 65 year old tobacco smokers in 25 year old cannabis smokers.
“We don’t have a very big longitudinal study like we have for tobacco smokers that clearly shows that smoking cannabis results in lung disease or cancer,” he says.
“The reason is that you have to follow people up for a very long period of time. And you need large numbers. How did we prove tobacco smoking is bad for you? We found out over a course of twenty to thirty years and this was after people started to have problems. The first evidence you have is patients coming in who have terrible lung disease and lung cancer.
“The group they followed was doctors because doctors are really easy to track down, as they have to register with the General Medical Council every year. So they tracked down these people and they found death certificates. People don’t smoke cannabis like they smoke cigarettes. The exposure is likely to be less and you can’t declare it. There’s no way. It’s illegal.
“The majority of cannabis smokers start when they’re young and they stop; tobacco smokers start and they don’t stop. It is addictive, so some people get hooked. Therefore it may not be as easy as it was with tobacco.”
One of the strongest arguments in favour of cannabis is its medicinal use. It is thought that the drug can suppress the nausea associated with cancer treatment, increase appetite and prevent weight loss in AIDS sufferers, relieve eye pressure in glaucoma, and ease muscular spasms, tremors and bladder incontinence in victims of multiple sclerosis (MS).
Medicinal users do not have to smoke the drug in order to gain the palliative benefits of THC, as it can be administered in tablet form or mixed into food. But smoking the drug provides the fastest route into the bloodstream, and thereby the brain, speeding the relief. As cannabis is not water-soluble, it is impossible to inject.
62 year old Wendy Jardine-Brown was diagnosed with MS ten years ago, and smokes marijuana regularly in order to manager her symptoms. In support of clinical trials on the drug, she says: “On a selfish level, I’d like it to be legalised, because I don’t like having to engage in criminal behaviour to get it. On a level where I’m considering society, I’m not convinced that the declassification had anything to do with the health risks at all and far more to do with the criminals smuggling it. It would be far more informative to have the risks and benefits laid out for us rather than a blanket ban.
“At the end of the day, the MS will get me a long time before the lung cancer does, or at least I think so. What I’m more worried about is kids smoking the pot recreationally – what if they have lung cancer as early as their 30s and 40s? As someone who has suffered from a debilitating disease I wouldn’t wish it on anyone, especially when it could be avoided entirely with a little more knowledge.”
