Table A.1.

Data Sources

	Source	Access link
COVID-19 incidences	Johns Hopkins University COVID-19 Resource Center	GitHub Repository: CSSEGISandData/COVID-19 Full address: https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data/csse_covid_19_time_series
Air Pollution and Meteorological data	US EPA – AQS API	API documentation: https://aqs.epa.gov/aqsweb/documents/data_api.html Data files: https://aqs.epa.gov/aqsweb/airdata/download_files.html
Demographic data	2014-18 release of the American Community Survey	Module documentation: https://walker-data.com/tidycensus/ Full address: https://www.kaggle.com/headsortails/covid19-us-county-jhu-data-demographics