Air Quality Monitoring Readings

The City of Detroit has installed seven Teledyne T640x air quality monitors at fixed locations across the city to measure real-time particulate matter (PM) in ambient air. The measurement and collection of public real-time and historical air pollution data provides additional information for the public, organizations, and local and state regulators to make informed air quality decisions, educate the public regarding the interaction of air quality, regulations and health, and provide necessary data to manage and regulate air quality in the region. This air quality monitoring project seeks to supplement existing monitoring efforts in Detroit from the State of Michigan Department of Environment, Great Lakes, and Energy (EGLE), Wayne County, and citizen and community group monitors, and aims to collectively provide coverage across every Detroit City Council district. This database presents the locations of the monitors, hourly averages for PM10 (PM less than 10 micrometers in aerodynamic diameter/particle size), PM2.5 (PM less than 2.5 micrometer particle size), PMcoarse (PM between particle size 2.5-10 micrometers), the air quality index (AQI) calculated for both PM10 and PM2.5, and representative meteorological data for each monitor (wind speed, direction, and temperature) from the closest Michigan Department of Environment, Great Lakes, and Energy (EGLE) meteorological station. The T640x option is an approved Federal Equivalent Method (FEM) for PM2.5, PM10 and PMcoarse, designating the method as acceptable for use in state or local air quality surveillance systems. The database will be updated daily with historical data available for download, while the live data dashboard showing current data is updated hourly. The AQI is EPA’s tool for categorizing and communicating air quality into levels of health concern, with specific information for which groups of people may be affected and preventative measures to reduce exposure.[1] Historical AQI data present an AQI for the 24-hour period prior- for example the AQI at the end of a given day will give a representative value for the air quality over the full course of the day. Real-time AQI reporting is calculated using EPA’s NowCast methodology, which uses an algorithm that relates hourly readings from air quality monitors to the AQI using a weighted average of the previous 12 hours.[2] For the historical data download, note that for past dates the AQI value should be used instead of the NowCast AQI, as noted it will give a representative value for the full day. Both real-time and downloaded data is preliminary and subject to change, and monthly QA/QC reports will be posted that will include any data corrections made for periods of calibration or maintenance. *Data Flag – Monitoring Station 1 (DPD 6th Precinct) used a replacement Teledyne T640 from 7/2/25 until 10/21/25. While the Teledyne T640 still measures PM2.5, PM10 and PMcoarse, only the PM2.5 measurments meet FEM requirements. A [visualization of the Air Quality Monitor Readings] is available from the open data Analytics Hub [1] U.S. EPA. Technical Assistance Document for the Reporting of Daily Air Quality- the Air Quality Index (AQI). EPA-454/B-24-002. May 2024. [https://document.airnow.gov/technical-assistance-document-for-the-reporting-of-daily-air-quailty.pdf]. [2] Id at 16.