aqi_pm25_facilities

This repository contains the data and code used to calculate the peak and mean PM2.5 AQI values referenced in Alleen Brown's article for The Appeal on the impact of Canadian wildfire smoke on people incarcerated in prisons, jails, and other carceral facilities in Delaware, New Jersey, New York, and Pennsylvania.

Data Sources

• Facility Data: The vast majority of the facility data comes from the Department of Homeland Security's Homeland Infrastructure Foundation-Level Data (HIFLD).
• AQI Data: Data on the Air Quality Index for 2.5mm particulate matter comes from the Environmental Protection Agency's AirNow program.

Methodology

The EPA collects data on particulate matter pollution from hundreds of monitoring sites across the country, most of which are run by state or local agencies. To calculate the peak and mean AQI values, we first determined the monitoring site closest to each facility, excluding facilities with no monitoring sites closer than 25 miles. Then we calculated the peak AQI on June 7, 2023, (when pollution caused by the fires was at its worst) by determining the highest 1-hour average value at each monitoring site. We also calculated an average value for the entire 24-hour period, as this is the figure the EPA uses to report the official AQI each day.

The EPA underlines in its guidelines for data use that AirNow data is preliminary and has not been fully validated. A separate database, called the Air Quality System, contains more finalized air quality information — however it can take more than six months from when the data is collected for it to appear in the system. AirNow remains the agency’s source for real-time air quality information.

Data Products

We created two data products from our analysis:

• pm25_aqi_by_facility.csv: A CSV file containing data about each facility
• pm25_aqi_by_facility.geojson: The same exact data but in GeoJSON format with polygons added for each facility

These datasets contain the following fields:

Field	Data Type	Description	Source
facility_name	`str	The facility's name	HIFLD
facility_address	str	The facility's address	HIFLD
facility_city	str	The city in which the facility is located	HIFLD
facility_state	str	The state in which the facility is located	HIFLD
facility_zip	str	The ZIP code for the facility	HIFLD
facility_latitude	float	The latitude of the facility's centroid	HIFLD
facility_longitude	float	The longitude of the facility's centroid	HIFLD
facility_type	str	The type of facility (e.g., state, local, county, juvenile)	HIFLD
facility_capacity	str	The maximum number of people a facility is rated to house	HIFLD
facility_status	str	Whether the facility is open or closed (we only include open facilities in the dataset, so this is somewhat superfluous)	HIFLD
facility_data_source	str	The URL for the data use originally used by HIFLD to compile the data	HIFLD
facility_data_source_date	datetime	The date on which the data source was first accessed	HIFLD
facility_data_edit_date	datetime	The date on which the data was last edited	HIFLD
monitoring_site_name	str	The name of the nearest PM2.5 AQI monitoring site	AirNow
monitoring_site_state	str	The state in which the nearest monitoring site is located	AirNow
monitoring_site_county	`str	The county in which the nearest monitoring site is located	AirNow
monitoring_site_latitude	float	The nearest monitoring site's latitude	AirNow
monitoring_site_longitude	float	The nearest monitoring site's longitude	AirNow
peak_pm25_aqi	int	The peak PM2.5 AQI measured by the nearest monitoring site on June 7, 2023	AirNow
mean_pm25_aqi	int	The mean PM2.5 AQI measured by the nearest monitoring site on June 7, 2023	AirNow
geometry (GeoJSON file only)	polygon	A polygon representing the boundaries of the facility	HIFLD

Questions

If you have any questions about this data or our analysis, please reach out to Alleen Brown or Ethan Corey.