This is why I bike rather than run. Crashing is your primary risk there but otherwise, it's stupendously hard+ to hurt yourself unknowingly.
I'm not fully aware of all of the possible long term risks to cycling but I know pollution from cars comes up a lot. I believe the prevailing consensus is that the benefits still outweigh the harm done.
+: May be overstating it. You can hurt your wrists through a bad fit and your knees through using too high a gear. In both cases, your body will probably let you know about it soon though.
I bike and run, and like you appreciate how gentle cycling is on one's body. With that said, I don't worry about getting killed while running the way I do while cycling (i.e. by cars).
I'm not fully aware of all of the possible long term risks to cycling but I know pollution from cars comes up a lot. I believe the prevailing consensus is that the benefits still outweigh the harm done.
+: May be overstating it. You can hurt your wrists through a bad fit and your knees through using too high a gear. In both cases, your body will probably let you know about it soon though.