Not all medical knowledge is equal. Look at the WHO ran by Bill gates who didn't even goto medical school. Cannabis actually can even act as an antihistamine, it actually alleviates my allergies. I'm not doubting there research. But there is research also that proves you can only be effected by cannabis sativa in an allergic way, would be threw touching of the cannabis. Which some people who inhale may not realize they did by mistake. And assuming it came from inhalation, but actually came from physical contact.