We reported in this blog around a year ago that one of the hazards of smoking marijuana was the possibility that the smoker would also inhale spores of the Aspergillus fungus (among others). Just like any other plant material after harvest and before it is fully dried out marijuana is an ideal food for Aspergillus - the fungus grows quickly and will sporulate once the food supply starts to decline. Those spores are extremely tiny and will penetrate the deepest parts of the smokers lungs.
Health effects of this can start with the development of allergies, increase asthma symptoms, cause severe asthma by fungi growing within the lungs, allergic bronchopulmonary aspergillosis (ABPA) and so on. All of these can happen to people who have completely healthy immune systems - these are not invasive infections but are chronic debilitating illnesses with no cure yet devised. People who do have a poor immune system i.e. transplant recipients, people being treated for some types of cancer, people on high doses of steroids are much more at risk of an invasive infection, so inhaling spores is a very bad idea!
Marijuana is particularly prone to fungal growth as it is often grown and prepared by amateurs who have limited idea of the dangers Aspergillus can bring or how to avoid them. Storage is also an issue - if it becomes damp the fungus can grow all over again. Up until now there has been no known effort to establish the levels of Aspergillus in marijuana.
News this week is that a laboratory has been set up on California, USA to advise users of this material on the levels of contamination in samples of the drug that the users bring in. Legality aside this can only be a good thing for the marijuana users of that area, perhaps partially akin to the handing out of free sterile syringe needles to IV herione accicts?