I was expecting something a lot worse than the data they show. Excluding a few days each year that were overwhelmed by wildfire smoke sounds reasonable when you are trying to measure the impact of your vehicle and commercial emissions rules. There are other statistics available for total air quality, obviously, as the authors were able to find the data.

The EPA approves about a third of all exclusion requests, which means that in summer 2023 out of 3000 counties in the US, 150 requests were approved to exclude a county's measure for a certain day, which is about 0.06% of measurements.

I'm not saying it's not worth knowing this, but the idea that the law is terribly flawed or that there is rampant abuse or that the EPA is complicit in some coverup is ridiculous.

The real takeaway is that while we're successfully curbing some sources of pollution with existing laws, other sources of pollution are becoming more of a problem.