the meaning of it

[chance22]

In Isaac Asimov's The Never-ending Fight, it writes: There is indeed something to this if it is only the practitioner's body and health and life that is involved and no one else's. But what of the smoker whose effluvium damages the lungs of non-smokers forced to breathe his or her reeks ? What of the drinker who drives and kills? What of the addict who lures others into addiction? What of the sociopath who directly harms others as his or her path to joy? By and large, then, society demands that these harmful physical practices be controlled insofar as it can be done humanely.
(But, in that case, why should we not be at least as deeply concerned with the pernicious effects of superstition)

My question is: what does the underlined word "it" refer to? The control? What's the meaning of "humanely" in this sentence? I can't get the opinion and the logic with regard to the following sentence. Could you paraphrase or explain it? Thank you.

[SoothingDave]

"It" refers to the control. "Humanely" means what it normally means. In the example of smokers, that we should have them smoke outside, far away from any innocents who may breathe in their smoke. But maybe we are "humane" and provide a cover for them for when it rains. Or maybe a place inside and well-ventilated to smoke when it's freezing cold.