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).

The datasets contains date- and state-wise historically compiled data on air quality (by pollution level) in rural and urban areas of India from the year 2015 , as measured by Central Pollution Board (CPCB) through its daily (24 hourly measurements, taken at 4 PM everyday) Air Quality Index (AQI) reports.

The CPCB measures air quality by continuous online monitoring of various pollutants such as Particulate Matter10 (PM10), Particulate Matter2.5 (PM2.5), Sulphur Dioxide (SO2), Nitrogen Oxide or Oxides of Nitrogen (NO2), Ozone (O3), Carbon Monoxide (CO), Ammonic (NH3) and Lead (Pb) and calculating their level of pollution in the ambient air. Based on the each pollutant load in the air and their associated health impacts, the CPCB calculates the overall Air Pollution in Air Quality Index (AQI) value and publishes the data. This AQI data is then used by CPCB to report the air quality status i.e good, satisfactory, moderate, poor, very poor and severe, etc. of a particular location and their related health impacts because of air pollution.

AQI: Alabama: Mobile: PM10 data was reported at 11.000 Index in 26 Dec 2024. This records a decrease from the previous number of 16.000 Index for 14 Dec 2024. AQI: Alabama: Mobile: PM10 data is updated daily, averaging 19.000 Index from Jan 1985 (Median) to 26 Dec 2024, with 4968 observations. The data reached an all-time high of 159.000 Index in 11 Nov 2004 and a record low of 0.000 Index in 01 Oct 2024. AQI: Alabama: Mobile: PM10 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants.

AQI: Alaska: Anchorage: SO2 data was reported at 0.000 Index in 05 Dec 1984. This stayed constant from the previous number of 0.000 Index for 04 Dec 1984. AQI: Alaska: Anchorage: SO2 data is updated daily, averaging 0.000 Index from Dec 1980 (Median) to 05 Dec 1984, with 881 observations. The data reached an all-time high of 41.000 Index in 07 Aug 1984 and a record low of 0.000 Index in 05 Dec 1984. AQI: Alaska: Anchorage: SO2 data remains active status in CEIC and is reported by United States Environmental Protection Agency. The data is categorized under Global Database’s United States – Table US.ESG.E001: Air Quality Index and Air Pollutants.

Data on India's Air Quality - state-wise air pollution due to PM 2.5, ozone and solid fuels, deaths due to pollution, and comparison with global peers.

Annual emissions of various air pollutants in the United States have experienced dramatic reductions over the past half a century. As of 2024, emissions of nitrogen oxides (NOx) had reduced by more than ** percent since 1970 to *** million tons. Sulfur dioxide (SO₂) emissions have also fallen dramatically in recent decades, dropping from ** million tons to *** million tons between 1990 and 2024. Air pollutants can pose serious health hazards to humans, with the number of air pollution related deaths in the U.S. averaging ****** a year.

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.

According to the monitoring data from the Embassy of the United States, there was on average 39 micrograms of PM2.5 particles per cubic meter to be found in the air in Beijing during 2023. The air quality has improved considerably since 2013.

Reasons for air pollution in Beijing

China’s capital city Beijing is one of the most populous cities in China with over 20 million inhabitants. Over the past 20 years, Beijing’s GDP has increased tenfold. With the significant growth of vehicles and energy consumption in the country, Beijing’s air quality is under great pressure from the economic development. In the past, the city had a high level of coal consumption. Especially in winter, in which coal consumption increased due to heating, the air quality could get extremely bad on the days without wind. In spring, the wind from the north would bring sand from Mongolian deserts, resulting in severe sandstorms in Beijing. The bad air quality also affected the air visibility and threatened people’s health. On days with very bad air quality, people wearing masks for protection can be seen on the streets in the city.

Methods to improve air quality in Beijing

Over the past years, the government has implemented various methods to improve the air quality in Northern China. Sandstorms, which were quite common 15 years ago, are now rarely seen in Beijing’s spring thanks to afforestation projects on China’s northern borders. The license-plate lottery system was introduced in Beijing to restrict the growth of private vehicles. Large trucks were not allowed to enter certain areas in Beijing. Above all, the coal consumption in Beijing has been restricted by shutting down industrial sites and improving heating systems. Beijing’s efforts to improve air quality has also been highly praised by the UN as a successful model for other cities. However, there is also criticism pointing out that the improvement of Beijing’s air quality is based on the sacrifice of surrounding provinces (including Hebei), as many factories were moved from Beijing to other regions. Besides air pollution, there are other environmental problems like water pollution that China is facing. The industrial transformation is the key to China’s environmental improvement.

This large vector dataset contains high resolution air pollution mapping of NO, NO2, O3, CH4, CO2, BC, PN2.5, and UFP concentrations in California between June 2015 and June 2019. The dataset consists of measurements collected using four Google Street View vehicles equipped with the Aclima mobile measurement and data integration platform from 2015-05-28 to 2019-06-07. Not all four cars were actively mapping over the entire time frame. Note that there may be gaps in the data when an individual car was not mapping due to operational, mechanical, or system difficulties. Dates of operation for each of the four cars: Car A: 2016-05-03 - 2019-04-30 Car B: 2016-05-03 - 2018-06-08 Car C: 2015-05-28 - 2019-06-07 Car D: 2015-06-24 - 2018-11-05 Data was collected in several geographic regions of California including the San Francisco Bay Area, Los Angeles, and the northern San Joaquin Valley. Mapping occurred in targeted neighborhoods or cities within these regions. The data set contains a table titled "California_Unified_2015_2019" which consists of the concentration of the pollutants Ozone (O3), Nitrogen Dioxide (NO2), Nitrogen Monoxide (NO), Methane (CH4), Carbon Dioxide (CO2), Black Carbon (BC), particle number less than 2.5 micrometers in size (PN2.5), and Ultrafine Particles (UFP) measured using four Google Street View cars equipped with fast time-response, laboratory-grade instruments. The data was collected at 1-Hz time resolution from 20150528 to 20190607 for roads in three regions of California - the San Francisco Bay area, Los Angeles, and the northern San Joaquin Valley. Specific areas mapped varied by region based on desired spatial data coverage and science questions. Each data point is geolocated with latitude and longitude as well as the identity and speed of the car. For details including methodologies, standards, data providers, metadata field definitions and descriptions, refer to the metadata.

Processed air pollution datasets originally obtained from the open data portal of the Madrid City Hall. The pollutants include:

• Fine particulate matter: PM_2.5
• Coarse particulate matter: PM₁₀
• Ozone: O₃
• Nitrogen monoxide: NO
• Nitrogen dioxide: NO₂
• Nitrogen oxides: NOx
• Sulfur dioxide: SO₂
• Carbon monoxide: CO
• Toluene: TOL
• Benzene: BEN
• Ethylbenzene: EBE

The period covered goes from the 1^st of January 2010 to the 30^th of April 2022. Each pollutant is recorded by a variable number of sensors, between 6 and 24 of them (additional information here). They cover Madrid city and surroundings (see this map). Additional information about the pollutants can be found here.

The specific datasets in HDF5 format are:

1. 01h_flat_raw.h5: Hourly raw data, one table per pollutant. The first column is the timestamp, which are in time-since-epoch. 108049 rows and between 7 and 25 columns.
2. 01h_35x30_norm_linear_J0.0.h5: Hourly mesh-grid data, normalized and linearly interpolated. Single table of shape: (108049, 35, 30, 11).
3. 01h_35x30_norm_nearest_J0.0.h5: Hourly mesh-grid data, normalized and nearest-neighbors interpolated. Single table of shape: (108049, 35, 30, 11).
4. 01h_35x30_raw_linear_J0.0.h5: Hourly mesh-grid data, linearly interpolated. Single table of shape: (108049, 35, 30, 11).
5. 01h_35x30_raw_nearest_J0.0.h5: Hourly mesh-grid data, nearest-neighbors interpolated. Single table of shape: (108049, 35, 30, 11).
6. 01h_35x30_stand_linear_J0.0.h5: Hourly mesh-grid data, standardized and linearly interpolated. Single table of shape: (108049, 35, 30, 11).
7. 01h_35x30_stand_nearest_J0.0.h5: Hourly mesh-grid data, standardized and nearest-neighbors interpolated. Single table of shape: (108049, 35, 30, 11).

This datasets are prepared to work with the framework published at https://github.com/iipr/air-quality

OpenAQ is an open-source project to surface live, real-time air quality data from around the world. Their “mission is to enable previously impossible science, impact policy and empower the public to fight air pollution.” The data includes air quality measurements from 5490 locations in 47 countries.

Scientists, researchers, developers, and citizens can use this data to understand the quality of air near them currently. The dataset only includes the most current measurement available for the location (no historical data).

Update Frequency: Weekly

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.openaq.[TABLENAME]. Fork this kernel to get started.

Acknowledgements

Dataset Source: openaq.org

Use: This dataset is publicly available for anyone to use under the following terms provided by the Dataset Source and is provided "AS IS" without any warranty, express or implied.

This pie chart displays news per publication date using the aggregation count. The data is filtered where the keywords includes Air-Pollution-Government policy.

Air Quality Index: Northern Thailand: Chiang Rai: Wiang, Muang,: PM2.5: High data was reported at 9.500 mcg/Cub m in 18 May 2025. This records a decrease from the previous number of 22.600 mcg/Cub m for 17 May 2025. Air Quality Index: Northern Thailand: Chiang Rai: Wiang, Muang,: PM2.5: High data is updated daily, averaging 22.300 mcg/Cub m from Mar 2024 (Median) to 18 May 2025, with 427 observations. The data reached an all-time high of 275.000 mcg/Cub m in 05 May 2024 and a record low of 6.000 mcg/Cub m in 21 Jul 2024. Air Quality Index: Northern Thailand: Chiang Rai: Wiang, Muang,: PM2.5: High data remains active status in CEIC and is reported by Air Quality and Noise Management Bureau. The data is categorized under Global Database’s Thailand – Table TH.ESG.E: Air Quality Index.

This chart provides a detailed breakdown of the threshold standards for various pollutants, categorized into low, medium, and high levels. Each threshold represents a specific concentration range, reflecting the potential environmental and health impacts associated with different pollutant levels. By reviewing this chart, residents can easily understand the current pollutant readings and compare them against the established thresholds to assess air quality and environmental conditions in their area. This transparency allows community members to stay informed about environmental quality and take appropriate precautions when pollutant levels approach or exceed higher thresholds. Additionally, the chart serves as an educational tool to raise awareness about the importance of maintaining sustainable environmental practices to protect public health and the ecosystem.This chart lives in the application: Air Quality Monitoring Stations Application Phase IIAnd lives in the dashboard: Air Quality Monitoring Dashboard City Wide

The table Air Pollution Facilities is part of the dataset Propublica Toxic Air Pollution Hot Spots, available at https://redivis.com/datasets/r24b-20p84dkxx. It contains 2120 rows across 71 variables.

Percentage of households that rated their indoor air quality and practices used to improve indoor air quality. The data is from the Households and the environment survey.

This bar chart displays news by source using the aggregation count. The data is filtered where the keywords includes Air-Pollution-Government policy.

The Canadian Environmental Sustainability Indicators (CESI) program provides data and information to track Canada's performance on key environmental sustainability issues. The Air quality indicators track ambient concentrations of fine particulate matter, ground-level ozone, sulphur dioxide, nitrogen dioxide, and volatile organic compounds at the national, regional and urban levels and at local monitoring stations. The national and regional indicators are presented with their corresponding Canadian Ambient Air Quality Standard when available. Canadians are exposed to air pollutants on a daily basis, and this exposure can cause adverse health and environmental effects. Information is provided to Canadians in a number of formats including: static and interactive maps, charts and graphs, HTML and CSV data tables and downloadable reports. See the supplementary documentation for the data sources and details on how the data were collected and how the indicator was calculated. Canadian Environmental Sustainability Indicators: https://www.canada.ca/environmental-indicators