Candidates for organ transplant are thoroughly screened, and illicit substance use is usually disqualifying. But cannabis is well established as a medicine (as it has been for millennia) and should not prevent patients from receiving a necessary transplant. Doctors at a pediatric hospital in Delaware recently described the thought process around allowing or prohibiting cannabis use.
Organophosphates are a class of insecticides like chlorpyrifos and soman. Sarin, used as a chemical weapon, is also an organophosphate. Many of these are neurotoxic, owing to their ability to amplify the neurotransmitter acetylcholine, which paralyzes insects and causes their death. A recent study from medical researchers in Maryland and Pennsylvania described the human toxicity in detail and explained why cannabinoids may be protective for humans.