Ask the Doctor
August 20, 2013

Risk of smoking marijuana

Dear Doc,

Does smoking marijuana/weed carry any risk of lung cancer?


Dear Leroy,

Many who smoke marijuana (ganja, weed) are usually quick to claim that there are medicinal benefits from smoking it. In their assessment, every benefit that can be attributed to smoking is a license to smoke marijuana. The question of a lung cancer risk to marijuana smoking is more complicated than it looks.{{more}}

Because marijuana smoking is an illegal activity in most countries, it means that it is difficult to find a group of persons who smoke marijuana only. What this means is that you will not be able to claim that the cancer is due to either marijuana or tobacco when both are used. There is also the situation where it will be difficult to find individuals in significant numbers who smoke marijuana alone that are willing to come forth and be part of a study.

What we must never forget is that any tissue that receives repeated irritation from an object or chemical that results in repeated and increased cell multiplication has the potential for a cell that is abnormal to develop. There are substances that can be carcinogenic (trigger cancers to develop) by virtue of a specific action and others that can act indirectly. Smoke from any source can possibly act indirectly to trigger cancer development.

It will be difficult to find a professional that would refute that marijuana smoking has the potential to trigger cancer development.

Be it tobacco, marijuana or any of the cannabis family, it must be noted that inhalation of smoke carries the risk of lung cancer.


SVG Cancer Society,

P.O. Box 709, Kingstown.