Marijuana that contains fungus can be dangerous'even fatal'to users with compromised immune systems, particularly a fungus in a group known as Aspergillus. To ensure your pot is fungus-free, have your dispensary check a sample under a 30-magnification microscope, urges Stephen DeAngelo of the Harborside Health Center in Oakland, Calif. Unfortunately, there's no simple way to screen for this hazard on your own.
