Entirely missing the point. It isn't "poor country has unclean air", it is "mass producer has unclean air". There are no technologies that rich countries are hoarding and using to clean their air that is too costly for poorer nations. If you moved all of this production back to developed countries, their air won't be clean either.
Just because China took the hit of having unclean air in order to manufacture stuff for the world's needs so it could raise its population from poverty, doesn't mean that they don't have enough money to get any rich country tech that can clean the air. No technology can work effective enough at the rate that China manufactures shit that all developed countries use without realising where it's sourced from.
