From: BMJ Specialty Journals

Emphysema linked to smoking marijuana

Large lung bullae in marijuana smokers 2000;55:340B2

Regular smokers of cannabis or pot may run the risk of developing the crippling lung disease emphysema, reports a study in Thorax.

The study reports four cases of the early stages of the disease in four young men aged 27, 35, 44 and 46 who smoked cannabis regularly. Examination showed that large areas of both lungs in each of the men had simply disappeared and been replaced with cysts. This is a form of emphysema, a disease that gradually diminishes the surface area of the lungs. It is usually associated with heavy cigarette smoking.

Each of the men described had been or were current smokers, but the amount smoked was minimal in three of them: two cigarettes a day in one, half an ounce of tobacco in another. One man smoked only cigars. But all of them had been, or continued to be, heavy cannabis users. The 27 year old had smoked several pipes of pot a day for several years; both the men in their 40s smoked two or three joints a day, while the man in his 30s had smoked two joints a week for about 20 years.

The common perception of cannabis, say the authors, is that it is harmless. But other than the mind altering substances in pot, smoke from both cigarettes and joints is the same, only more tends to enter the lungs in pot smokers, because of the long drags on joints. The physical effects on the lungs of smoking three to four joints a day are equivalent to those produced by smoking a pack of cigarettes a day, say the authors.


Dr Martin Johnson, Department of Respiratory Medicine, Glasgow Royal Infirmary, Glasgow, Scotland

This article comes from Science Blog. Copyright 2004