The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as state, local, and tribal air pollution control agencies. Its component data sets have been collected over the years from approximately 10,000 monitoring sites, of which approximately 5,000 are currently active. OAR's Office of Air Quality Planning and Standards (OAQPS) and other internal and external users, rely on this data to assess air quality, assist in Attainment/Non-Attainment designations, evaluate State Implementation Plans for Non-Attainment Areas, perform modeling for permit review analysis, and other air quality management functions. Air quality information is also used to prepare reports for Congress as mandated by the Clean Air Act. This data covers air quality data collected after 1980, when the Clean Air Act requirements for monitoring were significantly modified. Air quality data from the Agency's early years (1970s) remains available (see OAR PRIMARY DATA ASSET: Ambient Air Quality Data -- Historical), but because of technical and definitional differences the two data assets are not directly comparable. The Clean Air Act of 1970 provided initial authority for monitoring air quality for Conventional Air Pollutants (CAPs) for which EPA has promulgated National Ambient Air Quality Standards (NAAQS). Requirements for monitoring visibility-related parameters were added in 1977. Requirements for monitoring acid deposition and Hazardous Air Pollutants (HAPs) were added in 1990. Most monitoring sites contain multiple instruments. Most also report meteorological data, including wind speed and direction, humidity, atmospheric pressure, inbound solar radiation, precipitation and other factors relevant to air quality analysis. The current system of sites represents a number of independently-defined monitoring networks with different regulatory or scientific purposes, such as the State and Local Air Monitoring System, the National Air Toxics Trends sites, the Urban Air Toxics sites, the IMPROVE visibility monitoring network, the air toxics monitoring sites for schools, and others. (A complete list of air quality monitoring networks is available at https://www.epa.gov/???). Efforts are under way through NCore Multipollutant Monitoring Network (https://www.epa.gov/ttnamti1/ncore/index.html) to streamline and integrate advanced air quality measurement systems to minimize costs of data collection. Measurements and estimates from these networks are collected across the entire U.S., including all states and territories, with emphasis on documenting pollutant exposures in populated areas.Sampling frequencies vary by pollutant (hourly, 3- and 8-hour, daily, monthly, seasonal, and annual measurements), as required by different NAAQS. Some 50,000 measurements per day are added to the EPA's central air quality data repository, the Air Quality System (AQS). All data, including meteorological information, is public and non-confidential and available through the AQS Data Mart (https://www.epa.gov/ttn/airs/aqsdatamart/). Generally, data for one calendar quarter are reported by the end of the following quarter; some values may be subsequently changed due to quality assurance activities.

This indicator shows how many days per year were assessed to have air quality that was worse than “moderate” in Champaign County, according to the U.S. Environmental Protection Agency’s (U.S. EPA) Air Quality Index Reports. The period of analysis is 1980-2024, and the U.S. EPA’s air quality ratings analyzed here are as follows, from best to worst: “good,” “moderate,” “unhealthy for sensitive groups,” “unhealthy,” “very unhealthy,” and "hazardous."[1]

In 2024, the number of days rated to have air quality worse than moderate was 0. This is a significant decrease from the 13 days in 2023 in the same category, the highest in the 21st century. That figure is likely due to the air pollution created by the unprecedented Canadian wildfire smoke in Summer 2023.

While there has been no consistent year-to-year trend in the number of days per year rated to have air quality worse than moderate, the number of days in peak years had decreased from 2000 through 2022. Where peak years before 2000 had between one and two dozen days with air quality worse than moderate (e.g., 1983, 18 days; 1988, 23 days; 1994, 17 days; 1999, 24 days), the year with the greatest number of days with air quality worse than moderate from 2000-2022 was 2002, with 10 days. There were several years between 2006 and 2022 that had no days with air quality worse than moderate.

This data is sourced from the U.S. EPA’s Air Quality Index Reports. The reports are released annually, and our period of analysis is 1980-2024. The Air Quality Index Report websites does caution that "[a]ir pollution levels measured at a particular monitoring site are not necessarily representative of the air quality for an entire county or urban area," and recommends that data users do not compare air quality between different locations[2].

[1] Environmental Protection Agency. (1980-2024). Air Quality Index Reports. (Accessed 13 June 2025).

[2] Ibid.

Source: Environmental Protection Agency. (1980-2024). Air Quality Index Reports. https://www.epa.gov/outdoor-air-quality-data/air-quality-index-report. (Accessed 13 June 2025).

Annual air trends report in the form of an interactive web application. The report features a suite of visualization tools that allow the user to: -Learn about air pollution and how it can affect our health and environment. -Compare key air emissions to gross domestic product, vehicle miles traveled, population, and energy consumption back to 1970. -Take a closer look at how the number of days with unhealthy air has dropped since 2000 in 35 major US cities. -Explore how air quality and emissions have changed through time and space for each of the common air pollutants. -Check out air trends where you live. Users will also be able to share this content across social media, with one-click access to Facebook, Twitter, Pinterest, and other major social media sites.

This United States Environmental Protection Agency (US EPA) feature layer represents monitoring site data, updated hourly concentrations and Air Quality Index (AQI) values for the latest hour received from monitoring sites that report to AirNow.Map and forecast data are collected using federal reference or equivalent monitoring techniques or techniques approved by the state, local or tribal monitoring agencies. To maintain "real-time" maps, the data are displayed after the end of each hour. Although preliminary data quality assessments are performed, the data in AirNow are not fully verified and validated through the quality assurance procedures monitoring organizations used to officially submit and certify data on the EPA Air Quality System (AQS).This data sharing, and centralization creates a one-stop source for real-time and forecast air quality data. The benefits include quality control, national reporting consistency, access to automated mapping methods, and data distribution to the public and other data systems. The U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, National Park Service, tribal, state, and local agencies developed the AirNow system to provide the public with easy access to national air quality information. State and local agencies report the Air Quality Index (AQI) for cities across the US and parts of Canada and Mexico. AirNow data are used only to report the AQI, not to formulate or support regulation, guidance or any other EPA decision or position.About the AQIThe Air Quality Index (AQI) is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles (often referred to as "particulate matter") are the two pollutants that pose the greatest threat to human health in this country.A number of factors influence ozone formation, including emissions from cars, trucks, buses, power plants, and industries, along with weather conditions. Weather is especially favorable for ozone formation when it’s hot, dry and sunny, and winds are calm and light. Federal and state regulations, including regulations for power plants, vehicles and fuels, are helping reduce ozone pollution nationwide.Fine particle pollution (or "particulate matter") can be emitted directly from cars, trucks, buses, power plants and industries, along with wildfires and woodstoves. But it also forms from chemical reactions of other pollutants in the air. Particle pollution can be high at different times of year, depending on where you live. In some areas, for example, colder winters can lead to increased particle pollution emissions from woodstove use, and stagnant weather conditions with calm and light winds can trap PM2.5 pollution near emission sources. Federal and state rules are helping reduce fine particle pollution, including clean diesel rules for vehicles and fuels, and rules to reduce pollution from power plants, industries, locomotives, and marine vessels, among others.How Does the AQI Work?Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy-at first for certain sensitive groups of people, then for everyone as AQI values get higher.Understanding the AQIThe purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:Air Quality Index(AQI) ValuesLevels of Health ConcernColorsWhen the AQI is in this range:..air quality conditions are:...as symbolized by this color:0 to 50GoodGreen51 to 100ModerateYellow101 to 150Unhealthy for Sensitive GroupsOrange151 to 200UnhealthyRed201 to 300Very UnhealthyPurple301 to 500HazardousMaroonNote: Values above 500 are considered Beyond the AQI. Follow recommendations for the Hazardous category. Additional information on reducing exposure to extremely high levels of particle pollution is available here.Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:"Good" AQI is 0 to 50. Air quality is considered satisfactory, and air pollution poses little or no risk."Moderate" AQI is 51 to 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms."Unhealthy for Sensitive Groups" AQI is 101 to 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air."Unhealthy" AQI is 151 to 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects."Very Unhealthy" AQI is 201 to 300. This would trigger a health alert signifying that everyone may experience more serious health effects."Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected.AQI colorsEPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on.Air Quality Index Levels of Health ConcernNumericalValueMeaningGood0 to 50Air quality is considered satisfactory, and air pollution poses little or no risk.Moderate51 to 100Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.Unhealthy for Sensitive Groups101 to 150Members of sensitive groups may experience health effects. The general public is not likely to be affected.Unhealthy151 to 200Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.Very Unhealthy201 to 300Health alert: everyone may experience more serious health effects.Hazardous301 to 500Health warnings of emergency conditions. The entire population is more likely to be affected.Note: Values above 500 are considered Beyond the AQI. Follow recommendations for the "Hazardous category." Additional information on reducing exposure to extremely high levels of particle pollution is available here.

Part of What Works Cities Certification is reporting our city's annual average concentration of PM2.5 (fine particular matter) does not exceed 10 milligrams per cubic meter.The information is sensor data from the Triple Oak Site (Site Number 0021) and Millbrook School (Site Number 0014).Please look to the Dataset Schema section below for descriptions of columns and data types. US Environmental Protection Agency. Air Data App Map [internet database] available at https://www.epa.gov/outdoor-air-quality-data/interactive-map-air-quality-monitors. Accessed January 10, 2023. US Environmental Protection Agency. Air Quality System Data Mart [internet database] available at http://www.epa.gov/ttn/airs/aqsdatamart. Accessed January 10, 2023.

The AQS Data Mart is a database containing all of the information from AQS. It has every measured value the EPA has collected via the national ambient air monitoring program. It also includes the associated aggregate values calculated by EPA (8-hour, daily, annual, etc.). The AQS Data Mart is a copy of AQS made once per week and made accessible to the public through web-based applications. The intended users of the Data Mart are air quality data analysts in the regulatory, academic, and health research communities. It is intended for those who need to download large volumes of detailed technical data stored at EPA and does not provide any interactive analytical tools. It serves as the back-end database for several Agency interactive tools that could not fully function without it: AirData, AirCompare, The Remote Sensing Information Gateway, the Map Monitoring Sites KML page, etc.

AQS must maintain constant readiness to accept data and meet high data integrity requirements, thus is limited in the number of users and queries to which it can respond. The Data Mart, as a read only copy, can allow wider access.

The most commonly requested aggregation levels of data (and key metrics in each) are:

Sample Values (2.4 billion values back as far as 1957, national consistency begins in 1980, data for 500 substances routinely collected) The sample value converted to standard units of measure (generally 1-hour averages as reported to EPA, sometimes 24-hour averages) Local Standard Time (LST) and GMT timestamps Measurement method Measurement uncertainty, where known Any exceptional events affecting the data NAAQS Averages NAAQS average values (8-hour averages for ozone and CO, 24-hour averages for PM2.5) Daily Summary Values (each monitor has the following calculated each day) Observation count Observation per cent (of expected observations) Arithmetic mean of observations Max observation and time of max AQI (air quality index) where applicable Number of observations > Standard where applicable Annual Summary Values (each monitor has the following calculated each year) Observation count and per cent Valid days Required observation count Null observation count Exceptional values count Arithmetic Mean and Standard Deviation 1st - 4th maximum (highest) observations Percentiles (99, 98, 95, 90, 75, 50) Number of observations > Standard Site and Monitor Information FIPS State Code (the first 5 items on this list make up the AQS Monitor Identifier) FIPS County Code Site Number (unique within the county) Parameter Code (what is measured) POC (Parameter Occurrence Code) to distinguish from different samplers at the same site Latitude Longitude Measurement method information Owner / operator / data-submitter information Monitoring Network to which the monitor belongs Exemptions from regulatory requirements Operational dates City and CBSA where the monitor is located Quality Assurance Information Various data fields related to the 19 different QA assessments possible

Querying BigQuery tables

You can use the BigQuery Python client library to query tables in this dataset in Kernels. Note that methods available in Kernels are limited to querying data. Tables are at bigquery-public-data.epa_historical_air_quality.[TABLENAME]. Fork this kernel to get started.

Acknowledgements

Data provided by the US Environmental Protection Agency Air Quality System Data Mart.

Abstract

Dataset quality ***: High quality dataset that was quality-checked by the EIDC team

These are the standard time aggregations EPA calculates and stores (we do not have monthly data). All have data files grouped by parameter: Criteria Gases, and Particulates Each group has data listed by year, in reverse order, back to 1990.

Each table entry has the file name, linked to the file, the size of the (zipped) file, the number of data rows in the file, and the date the file was last modified. EPA will update these files twice per year; in the spring and fall (late May and November). Keep in mind, data collection agencies have up to 6 months to report their data.

The files are all comma separated text with a header. Each aggregate level has a different format.

Methodology

For site description data, each unique geographic location that contains monitors is called a "site" in AQS. Information about the geographic setting is store in the site record, which are presented here. A unique site is identified by the combination of state code, county code, and site number (within county). It can also be identified by the latitude and longitude.

For monitor description data, each parameter that is measured at a site is considered a "monitor" in AQS. (So a "monitor" does not necessarily correspond to a physical instrument/sampler.) AQS tracks administrative information about monitors including who operates them, the methods being used, the networks they belong to, etc. That information is available in this file. A unique monitor is identified by the combination of state code, county code, site number (within county), parameter code, and parameter occurrence code ("POC", used to differentiate when a parameter is measured more than once at a site).

For daily summary data, each daily summary file contains data for every monitor (sampled parameter) in our database for each day. These files are separated by parameter (or parameter group) to make the sizes more manageable.

This file will contain a daily summary record that is:

1) The aggregate of all sub-daily measurements taken at the monitor.

2) The single sample value if the monitor takes a single, daily sample (e.g., there is only one sample with a 24-hour duration). In this case, the mean and max daily sample will have the same value.

The daily summary files contain (at least) one record for each monitor that reported data for the given day. There may be multiple records for the monitor if:

• There are calculated sample durations for the pollutant. For example, PM2.5 is sometimes reported as 1-hour samples and EPA calculates 24-hour averages.

• There are multiple standards for the pollutant (q.v. pollutant standards).

• There were exceptional events associated with some measurements that the monitoring agency has or may request be excluded from comparison to the standard.

%3C!-- --%3E

Air Quality Index data as reported by the Environmental Protection Agency. The Air Quality Index is an indicator of overall air quality that takes into account all of the criteria air pollutants measured within a geographic area. More information on this data available at: https://www.epa.gov/outdoor-air-quality-data/air-quality-index-report

Context:

The Environmental Protection Agency (EPA) creates air quality trends using measurements from monitors located across the country. All of this data comes from EPA’s Air Quality System (AQS). Data collection agencies report their data to the EPA via this system and it calculates several types of aggregate (summary) data for EPA internal use.

Content:

Field descriptions:

1. State Code: The FIPS code of the state in which the monitor resides.

2. County Code: The FIPS code of the county in which the monitor resides.

3. Site Num:A unique number within the county identifying the site.

4. Parameter Code: The AQS code corresponding to the parameter measured by the monitor.

5. POC: This is the “Parameter Occurrence Code” used to distinguish different instruments that measure the same parameter at the same site.

6. Latitude: The monitoring site’s angular distance north of the equator measured in decimal degrees.

7. Longitude: The monitoring site’s angular distance east of the prime meridian measured in decimal degrees.

8. Datum: The Datum associated with the Latitude and Longitude measures.

9. Parameter Name: The name or description assigned in AQS to the parameter measured by the monitor. Parameters may be pollutants or non-pollutants.

10. Sample Duration: The length of time that air passes through the monitoring device before it is analyzed (measured). So, it represents an averaging period in the atmosphere (for example, a 24-hour sample duration draws ambient air over a collection filter for 24 straight hours). For continuous monitors, it can represent an averaging time of many samples (for example, a 1-hour value may be the average of four one-minute samples collected during each quarter of the hour).

11. Pollutant Standard:A description of the ambient air quality standard rules used to aggregate statistics. (See description at beginning of document.)

12. Metric Used: The base metric used in the calculation of the aggregate statistics presented in the remainder of the row. For example, if this is Daily Maximum, then the value in the Mean column is the mean of the daily maximums.

13. Method Name: A short description of the processes, equipment, and protocols used in gathering and measuring the sample.

14. Year: The year the annual summary data represents.

15. Units of Measure: The unit of measure for the parameter. QAD always returns data in the standard units for the parameter. Submitters are allowed to report data in any unit and EPA converts to a standard unit so that we may use the data in calculations.

16. Event Type: Indicates whether data measured during exceptional events are included in the summary. A wildfire is an example of an exceptional event; it is something that affects air quality, but the local agency has no control over. No Events means no events occurred. Events Included means events occurred and the data from them is included in the summary. Events Excluded means that events occurred but data form them is excluded from the summary. Concurred Events Excluded means that events occurred but only EPA concurred exclusions are removed from the summary. If an event occurred for the parameter in question, the data will have multiple records for each monitor.

17. Observation Count: The number of observations (samples) taken during the year.

18. Observation Percent: The percent representing the number of observations taken with respect to the number scheduled to be taken during the year. This is only calculated for monitors where measurements are required (e.g., only certain parameters).

19. Completeness Indicator: An indication of whether the regulatory data completeness criteria for valid summary data have been met by the monitor for the year. Y means yes, N means no or that there are no regulatory completeness criteria for the parameter.

20. Valid Day Count: The number of days during the year where the daily monitoring criteria were met, if the calculation of the summaries is based on valid days.

21. Required Day Count: The number of days during the year which the monitor was scheduled to take samples if measurements are required.

22. Exceptional Data Count: The number of data points in the annual data set affected by exceptional air quality events (things outside the norm that affect air quality).

23. Null Data Count: The count of scheduled samples when no data was collected and the reason for no data was reported.

24. Primary Exceedance Count: The number of samples during the year that exceeded the primary air quality standard.

25. Secondary Exceedance Count: The number of samples during the year that exceeded the secondary air quality standard.

26. Certification Indicator: An indication whether the completeness and accuracy of the information on the annual summary record has been certified by the submitter. Certified means the submitter has certified t...

This dataset was compiled from the EPA's Air Quality Index Daily Values Report. As of April 2024 the full 2023 AQI dataset for all CBSA's is not available, so I have compiled this to use in the meantime.

The EPA's definition of the Air Quality Index is below:

https://mayor.dc.gov/sites/default/files/dc/sites/mayormb/page_content/images/US-Air-Quality-Chart.png" alt="AQI">

This dataset includes the following fields:

1. Date the measure was taken
2. Overall AQI value
3. Main Pollutant
4. Name of site where the AQI value was measured
5. ID of site where the AQI value was measured
6. Source of overall AQI value
7. Ozone level 8 PM25 level
8. CO level
9. PM10 level
10. NO2 level
11. AQI category (good, moderate, unhealthy, etc.)
12. City name
13. State name

It contains data for the following metro areas:

• Ithaca, NY
• Chicago, IL
• Miami, FL
• Minneapolis, MN
• Charlotte, NC
• Dallas, TX
• Greensboro, NC
• State College, PA
• Richmond, VA
• Asheville, NC
• Athens, GA
• Boston, MA
• Baltimore, MD
• Detroit, MI
• Washington, DC
• New York, NY
• Philadelphia, PA
• Denver, CO
• Orlando, FL
• Cleveland, OH
• Portland, OR
• Phoenix, AZ
• Los Angeles, CA
• Kahului, HI
• Madison, WI
• Chapel Hill, NC
• San Francisco, CA
• Raleigh, NC
• Houston, TX
• Seattle, WA

These are the most populated cities in the CBSA's- the data points may include air quality metrics for other nearby areas.

The AirData Air Quality Index Summary Report displays an annual summary of Air Quality Index (AQI) values for counties or core based statistical areas (CBSA). Air Quality Index is an indicator of overall air quality, because it takes into account all of the criteria air pollutants measured within a geographic area. Although AQI includes all available pollutant measurements, you should be aware that many areas have monitoring stations for some, but not all, of the pollutants. Each row of the AQI Report lists summary values for one year for one county or CBSA. The summary values include both qualitative measures (days of the year having "good" air quality, for example) and descriptive statistics (median AQI value, for example).

Summary statistics for the current year are incomplete because data are still being reported and quality assured. Data for the current year are considered preliminary until May 1 of the following year. Therefore, comparing reported values for the current year with previous years may not be valid.

Content

This set includes daily reports of air quality index from various US Metro areas, as well as geographic data for the collection locations. This set has over 10 million rows.

Want a smaller set? I also have ANNUAL metrics available here. The yearly dataset is ~34k rows.

Acknowledgements

Data sourced directly from the Environmental Protection Agency Banner: Photo by Maxim Tolchinskiy on Unsplash

Inspiration

This data offers opportunities for historical evaluation and visualization. What trends do we see in air quality over the years? Are there any predictions to be make for future air quality based on recent trends?

Like this dataset? See my other datasets!

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.

Description:

*This dataset features air pollution data from the Environmental Protection Agency's (EPA) Air Quality System (AQS), recognized as the "gold standard" for outdoor air pollution measurements. The AQS collects data on ozone and particulate matter (PM2.5) from approximately 4,000 monitoring stations, primarily located in urban areas across the United States.*

*The dataset provides comprehensive air quality measures across the United States by offering detailed information about air quality metrics, geographic locations, and temporal trends.*

The dataset is structured with the following attributes:

Measure Information:

Includes unique identifiers, descriptive names, and types of air quality measures to help users understand the nature and format of the data.

Geographic Information:

*Provides standardized Federal Information Processing Standards (FIPS) codes for states and counties, alongside their human-readable names, allowing for geographic-level analyses.*

Temporal Data:

Contains "Report Year", enabling trend analyses over time.

Quantitative Metrics:

Features numerical values and associated units for air quality measures, indicating the magnitude and context of environmental conditions.

Data Source Details:

Includes information about data origins and a binary "Monitor Only" field to identify whether the data is exclusively derived from monitoring stations.

This dataset is ideal for studying environmental patterns, assessing public health impacts, and informing policy decisions related to air quality and environmental health.

Attribution:

This work uses data from the Air Quality Measures on the National Environmental Health Tracking Network, originally created and maintained by the Centers for Disease Control and Prevention (CDC).

https://www.epa.gov/aqs

LICENSE: The Data is available under the Open Database License (ODbL).

NO ENDORSEMENT: The CDC does not endorse this work or its conclusions.

DISCLAIMER: Please independently verify the data and it's derivation(s) before applying it to research or decision-making.

This dataset contains trends in days violating air quality standards by date for the Philadelphia-Camden-Wilmington Core-Based Statistical Area (CBSA).In order to convey the health impacts of air pollution to the general public, the US EPA has created a color-coded scale to identify pollutant levels in simple terms. This scale is referred to as the Air Quality Index (AQI). AQI levels are directly related to the federal air quality standards and pollutant concentrations in the air. The AQI reports pollutant levels for six different categories based on AQI: Good or green (0 to 50), Moderate or yellow (51 to 100), Unhealthy for Sensitive Groups or orange (101 to 150), Unhealthy or red (151 to 200), Very Unhealthy or purple (201 to 300), and Hazardous (301 to 500). Note that no day in 2000 or subsequent years has qualified as hazardous, so it is not present in the charts. Sensitive groups are defined as children, older adults, and those with breathing impairments. When the AQI reaches Code Orange or higher for any of the pollutants, an air quality standard violation has occurred.

Air quality standards have been revised a number of times since 1997, and the data in these charts is normalized to the current standard.

Background:

Looking at Chicago's gleaming skyline today, it's surprising to remember that not so long ago many of those buildings were black with soot from coal-fired furnaces and factories all over the city. Take a look back at old photos or films, though, and that skyline isn't so pristine.

During the Industrial Age belching smokestacks were looked at as a good thing – this meant the city that works was working! Eventually, though, we learned you can have too much of a good thing. Some days, pollution turned day into night, ruining clothing, blackening buildings, sickening Chicagoans and even stopping airplanes from taking off. Today, we can see a similar situation in countries like India, Iran, Pakistan and China where coal is still widely used.

The Chicago Tribune led the crusade against Chicago’s dirty air. The newspaper began reporting on the condition of the city's air as early as the 1870s. In one report, the author Rudyard Kipling is quoted as saying simply, "the air is dirt" after a visit to Chicago.

In 1959, Chicago established the Department of Air Pollution Control to investigate and regulate emission sources. Subsequent regulations, including the federal Clean Air Act of 1970, and more recent city and state legislation have helped further mitigate city-wide emissions. Today, Chicago air pollution levels are a small fraction of their historical levels.

Standands:

The US Environmental Protection Agency (EPA) defines “moderate” air quality as air potentially unhealthy to sensitive groups including children, the elderly, and people with pre-existing cardiovascular or respiratory health conditions.

AQI ratings are calculated by weighting 6 key criteria pollutants for their risk to health. The pollutant with the highest individual AQI becomes the ‘main pollutant’ and dictates the overall air quality index. Fine particulate matter (PM2.5) and ozone represent two of the most common ‘main pollutants’ responsible for a city’s AQI due to the weight the formula ascribes to them for their potential harm and prevalence at high levels.

PM2.5 pollution is fine particle pollution with a range of chemical compositions that measures 2.5 microns in diameter or less. The US EPA recommends that annual PM2.5 exposure not exceed 12 μg/m3. The World Health Organization (WHO), meanwhile, employs a more stringent standard, recommending that exposure remain below 10 μg/m3 annually.

learn more: https://www.iqair.com/usa/illinois/chicago

In this dataset we explore the pollution levels and learn EDA techniques in the process.

Air pollution directly affects human health endpoints including growth, respiratory processes, cardiovascular health, fertility, pregnancy outcomes, and cancer. Therefore, the distribution of air pollution is a topic that is relevant to all, and of direct interest to many students. Air quality varies across space and time, often disproportionally affecting minority communities and impoverished neighborhoods. Air pollution is usually higher in locations where pollution sources are concentrated, such as industrial production facilities, highways, and coal-fired power plants. The United States Environmental Protection Agency manages a national air quality-monitoring program to measure and report air-pollutant levels across the United States. These data cover multiple decades and are publicly available via a website interface. For this lesson, students learn how to mine data from this website. They work in pairs to develop their own questions about air quality or air pollution that span spatial and/or temporal scales, and then gather the data needed to answer their question. The students analyze their data and write a scientific paper describing their work. This laboratory experience requires the students to generate their own questions, gather and interpret data, and draw conclusions, allowing for creativity and instilling ownership and motivation for deeper learning gains.

NARSTO_EPA_SS_HOUSTON_TEXAQS2000_PM_SIZE_MASS is North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Houston, Texas Air Quality Study 2000 (TexAQS2000) Size-specific Particulate Matter (PM) Mass Concentration Data. This file reports size segregated mass particulate data collected with a micro-orifice uniform deposit impactors (MOUDI) sampler during the TexAQS2000 at the Houston Regional Monitoring (HRM) Site 3 and LaPorte Houston Supersite monitoring locations. Daily MOUDI sampling began on August 17, 2000 and ended on September 13, 2000. The MOUDI is a model 100 rotating micro-orifice uniform deposit impactor from MSP Corporation. The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended PM. The overall goals were to characterize the composition and identify the sources of PM in Southeastern Texas, to develop and test new methods for characterizing fine PM, and to collect data on the physical and chemical characterization of fine PM that can be used to support exposure and health effects studies. NARSTO, which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.

This report provides Air Quality Index annual summary information, including maximum AQI values and the count of days in each AQI category each county in Virginia for year 2023.

The US Environmental Protection Agency's (EPA) National Health and Environmental Effects Research Laboratory (NHEERL) in the Environmental Public Health Division (EPHD) is currently engaged in research aimed at developing a measure that estimates overall environmental quality at the county level for the United States. This work is being conducted as an effort to learn more about how various environmental factors simultaneously contribute to health disparities in low-income and minority populations, and to better estimate the total environmental and social context to which humans are exposed. This dataset contains the finalized non-transformed variables chosen to represent the Air, Water, Land, Built, and Sociodemographic Domains of the total environment. This does not represent the final variables for the EQI. The Transformed dataset was used to create the EQI. This dataset is for information purposes only for those who want to see the original non-transformed variables.Six criteria air pollutants and 81 hazardous air pollutants are included in this dataset. Data sources are the EPA's Air Quality system (https://www.epa.gov/ttn/airs/airsaqs/) and the National-scale Air Toxics Assessment (https://www.epa.gov/nata/). Variables are average pollutant concentrations or emissions for 2000-2005 at the county level for all counties in the United States. Data on water impairment, waste permits, beach closures, domestic water source, deposition for 9 pollutants, drought status, and 60 chemical contaminants. Data sources are the EPA's WATERS (Watershed Assessment, Tracking and Environmental ResultS) Database (https://www.epa.gov/waters/), the U.S. Geological Survey Estimates of Water Use in the U.S. for 2000 and 2005 (https://water.usgs.gov/watuse/), the National Atmospheric Deposition Program (http://nadp.sws.uiuc.edu/), the U.S. Drought Monitor Data (http://droughtmonitor.unl.edu/), and the EPA's National Contaminant Occurrence Database (https://water.epa.gov/scitech/datait/databases/drink/ncod/databases-index.cfm). Variables are calculated for the time period from 2000-2005 at the county level for all counties in the United States. Data represents traffic safety, public transportation, road type, the business environment and public housing. Data sources are the Dun and Bradstreet North American Industry Classification System (NAICS) codes; Topologically Integrated Geographic Encoding and Referencing (TIGER); Fatality Annual Reporting System (FARS); and Housing and Urban Development (HUD) data. This dataset contains the finalized variables chosen to represent the sociodemographic domain of the total environment. Data represents socioeconomic and crime conditions. Data sources are the United States Census and the Federal Bureau of Investigation Uniform Crime Reports. Variables are calculated for the time period from 2000-2005 at the county level for all counties in the United States.