Maybe that's why the death count is not that high?
I don’t believe that there are that many Heroin smokers.
It is most often injected and next most common is snorting followed by smoking (last I read).
In the past at least it was too expensive to smoke (too much of your expensive drug lost to smoke that did not get you high).
What may be happening is that some heroin is being added to marijuana as are a lot of different drugs to increase the high.