[burger]

I read this paper, and I don't doubt that air pollution makes thing worse.  But this analysis has a fatal flaw: rural counties tend to have better air quality all things being equal: https://www.cdc.gov/mmwr/volumes/66/ss/ss6613a1.htm   And rural counties were later than urban areas to get the virus, so their death rates will lag: https://www.nytimes.com/interactive/2020...cases.html  I suspect you can probably explain much of the differences between areas in deaths by population. 

This paper is not published yet and shouldn't be.  I think we're going to see a lot of retractions and/or fatal critiques of papers that are being put out now.

Someone should go back and do this analysis once we have final death rates and after accounting for the timing of when social distancing measures were implemented and the timing of the first case in each county.

[burger]

I read this paper, and I don't doubt that air pollution makes thing worse.  But this analysis has a fatal flaw: rural counties tend to have better air quality all things being equal: https://www.cdc.gov/mmwr/volumes/66/ss/ss6613a1.htm   And rural counties were later than urban areas to get the virus, so their death rates will lag: https://www.nytimes.com/interactive/2020...cases.html  I suspect you can probably explain much of the differences between areas in deaths by population. 

This paper is not published yet and shouldn't be.  I think we're going to see a lot of retractions and/or fatal critiques of papers that are being put out now.

Someone should go back and do this analysis once we have final death rates and after accounting for the timing of when social distancing measures were implemented and the timing of the first case in each county.