If someone is flooding the area around them with high PM2.5 thus that everyone nearby has respiratory problems, but the overall rate of PM2.5 across all of the US is very low (because generally, it actually is) then your proposed scheme would ensure that areas (generally cities) are going to be completely unlivable, but there'd be no reason to change because overall the tax would remain low.

In fact they'd have no reason to improve anything provided that their projection for the cost of improvement looked marginally more expensive then just paying projected future cost of the tax.