In addition to the quick decay of much of the smog described by Retric, you also have a huge benefit purely from dilution. The world is really big, and most humans live clustered in <1% of its area. So even if every coal-burning plant on the planet were to implement this tech fully, it would decrease the worldwide human exposure by a couple orders of magnitude.
The effect is even more extreme when you consider the vertical dimension; probably at least another order of magnitude, but hard as a layman to estimate.
The effect is even more extreme when you consider the vertical dimension; probably at least another order of magnitude, but hard as a layman to estimate.