Its not a problem as the exhaust is dumped way up high by the tall stacks. And remember the particular complication with our Septic Air is lack of dispersion or 'the solution to the pollution is dilution'. That is no air movement down under the inversion. Think of it as a warehouse with a 14 foot ceiling and all being forced to use and breath the same enclose or locked in air. And some jackass over a ways is burning tires. 
Also all coal burning home heating appliances which are EPA certified are tested using high grade coal not being produced in Alaska. Thus as everyone is trying to heat cheap they are all burning cheap local low grade coal which cannot burn clean.