And all this may be true, and it may also be true that heroin isn't as damaging to the organs as, say alcohol. Still, to me it's a kind of pointless argument only because the 'clean, controlled, safe heroin' is to be found practically NOWHERE. [It's like when people start geeking out on too many popular science tv shows about physics. Yes, ok so we get that time travel is theoretically possible if you can do XYZ. Trouble is, XYZ is so phenomenally difficult to achieve, that at this stage of history it's not exactly a pressing conCERN.]
So 'clean heroin' might not be as problematic. But the real actual heroin that real actual people buy and use most totally is.
I get what Pergamos is saying. However, as I've suggested, being pedantic about the qualities of a particular molecule doesn't explain much about or help the daily reality of being an addict or being in the orbit of addicts as Nigel and myself have (and probably a whole bunch of other people here on PD.)
If you go back to Nutt's research that was linked a few posts ago, he most certainly included 'secondary harm' in his work. Harm is harm. Anyone who doesn't believe me, should invite an opiate addict to live in their home for a few months.