Hi John, I read your questions and I noticed that there was no clear answer regarding Marijuana smoking. I have done alot of research as I also do have bladder cancer and was a non-smoker. But, did occassionally partake in marijuana smoking. It definately has an affect on bladder cancer in my opinion. Bladder cancer has become more common in young people these days as they smoke more of it. My urologist told me that it would escalate the cancer and continue to have a negative affect if you were to continue smoking weed. So, stay away from any kind of smoking or smoking atmosphere. Second hand smoke is actually even worse from my research. You won't get straight answers on this subject as it really has not been focused on for some odd reason. Good luck, Tom