I was intrigued by this and I asked him why he was so concerned about whether I smoked cigarettes or not. What he told me blew me away.
He told me that 90% of all bladder cancers that he saw were caused by smoking cigarettes. He said that when you smoke the toxins from the smoke enter your bloodstream. These toxins are then filtered out by the kidneys and mixed with urine. The toxins then sit in the bladder until they are excreted.
Because of this there is in effect a toxic mixture sitting in the bladder. The longer it sits there the more time it has to cause damage.
When you see this it makes sense to stop smoking. It makes sense to stop introducing carcinogenic substances into your body. It makes sense to quit smoking as soon as possible.