As noted in that article the issue there is people using low quality coal for heat and those aplliances have no pollution control. Very few people in the US use coal for heat, I should know.
The majority of those that do like myself use anthracite which emits no soot.
Little bit of history lesson here. Anthracite is the highest rank of coal and is nearly pure carbon. In Northeastern Pennsylvania is located the largest and one of the few deposits of this coal. It was this coal that was used for heat in the major cities up and down the east coast into the 40's and 50's. That is why you never see a picture like those from China or even London in the 50's. The only thing that would be even remotely close is some places in the Pittsburgh area but that was becsue of all the steel mills.