About the World Air Quality Index project
aqicn.org - waqi.info

The World Air Quality Index project began in 2007, 18 years ago. Its core mission is to foster air pollution awareness by providing a unified, worldwide and real-time air quality information.

The project is now providing transparent air quality information for hundreds of countries, covering more than 500,000 air quality monitoring stations, via those two websites: aqicn.org and waqi.info.

The founding team is composed of several contributors in the domain of environmental sciences, data science, system engineering, HW and UI design.

The team has been expanding worldwide, with new key supporters from China, Singapore, India, Australia, USA and many countries in Europe.

The project is run on limited resources. Our web hosting and infrastructure have been highly optimised, costing approximately $500 per month, while being able to serve several million API requests per day over terabytes of data.

The income, mainly from online advertising and our GAIA air quality monitoring stations, is used to cover the continuous research and development efforts.

The project is constantly looking for support from more contributors.

It has now received active contributions from more than 16309 citizens from 138 countries

made in 北京

Contacting the World Air Quality Index team

If you would like to send us a message, please try to use one of the following dedicated contact channels:

If none of the above channels match your need, click here to send us a message (but, please, keep in mind that due to our limited team capacity we can not guarantee replying to all messages).

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If you wonder wether the values for PM10 and PM2.5 are reversed, then check out this Frequently Asked Question.


Credits

All the credits must go to the US Embassies in China for initially providing and publishing their PM2.5 air quality measurement, to the China MEP for the huge effort in providing PM2.5 for so many cities, and all the worldwide Environment Protection Agencies for their excellent work on monitoring and providing Air Quality information .

All this work is made possible thanks to the excellent work for the worldwide EPA (below list not exhaustive):


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We are looking for help to translate this website. More information, please check the translation page.


Common question & answers

  1. Air Quality Data sources All the Air Quality data seen on World Air Quality Index are the official data from each country respective Environmental Protection Agency (EPA). Data from each EPAs is measured using professional monitoring equipment. The full EPA source list used in World Air Quality Index is available from sources page.
  2. Seeing different readings from other websites : This is most likely normal, and due to the fact that different websites use different AQI scales present the data. At World Air Quality Index, we are using the US EPA scale, while other website might use different scales. Check this article for more information.
  3. I want to monitor the air quality in my area : As high-end professional stations can be really expensive (more than $10K per stations), the World Air Quality Index project / Earth Sensing Labs has designed specially optimized and affordable monitoring stations costing as low as $200. Please check the GAIA air quality monitoring station product page.
  4. I want to add a new station on the map : Provided your monitoring station is qualified (for instance if it is using BAM, TOEM or GAIA technology), then adding a new station on the map is not only simple and straightforward but also completely free. Please refer to this page for the full explanation: aqicn.org/publishingdata/
  5. Data quality & real-time validation : The data published on World Air Quality Index is real-time and therefore un-validated at the time of publication. In order to strengthen the quality, a set of real-time AI algorithms are used to detect abnormal data conditions (sparks, low reporting, etc.) and automatically 'disable' data reported from defective stations.
  6. Historical data access : We are currently investigating with several international institutions (WHO, UN, GEO) the possibility to setup a framework for accessing the historical Air Quality data. If you are from an international institution, organization or university and want to join this effort, then check our data platform page.
  7. API (Application Programming interface) : The World Air Quality Index project is offering a free API for maps, tiles and programmatic JSON access. Check the API page for more information.
  8. Contributing to the World Air Quality Index project : The project is always looking for more hands to support the activities: For instance, to write articles, to improve our applications, to create new data visualization, to improve the air quality forecast or to translate the website and app to news languages. Check the contribute page for more info.
  9. Funding : The World Air Quality Index project is independent from any government and any "profit" corporation. It has so far not received any funding from any public nor private entity. The limited income from online ads is used to cover infrastructure cost.
  10. Why choosing the U.S. EPA index to harmonize the data? This is mostly for historical reason: When we started in 2007, there was not so many alternative, and the US EPA was actually quite proactive at promoting the idea of clean air, so the choice was natural. Some alternatives, such as the European “Common Air Quality Index” could also have been a good option, but the EEA failed to promote their standard. This won't be a problem for long anyways, since we are now working on a improvement which will allow users to select any scale they want among a list of more than 80 scales!
  11. How many cities do you currently provide air quality data for and is the info available on your app in each of them? We are providing the data for 25,000 stations worldwide ~ that’s around 2,000 major cities in 70 countries. The info is available in the app for each of them, but not all of the cities have the “full” set of pollutant monitoring (e.g. PM2.5, PM10, Ozone, NO2, SO2, CO). For example, some only have PM10 or a composite AQI. We are also continuously increasing the coverage, targeting to get 10 to 20% more stations every year. The full list of cities and stations is available from this page.
  12. Media kit Our public media kit is available from the media kit page.
Any other question, please check the Frequently Asked Question: aqicn.org/faq/.

made in 北京


Air Quality Rankings

About the Air Quality and Pollution Measurement:

About the Air Quality Levels

AQI Air Pollution Level Health Implications Cautionary Statement (for PM2.5)
0 - 50 Good Air quality is considered satisfactory, and air pollution poses little or no risk None
51 -100 Moderate Air 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. Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
101-150 Unhealthy for Sensitive Groups Members of sensitive groups may experience health effects. The general public is not likely to be affected. Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
151-200 Unhealthy Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion
201-300 Very Unhealthy Health warnings of emergency conditions. The entire population is more likely to be affected. Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
300+ Hazardous Health alert: everyone may experience more serious health effects Everyone should avoid all outdoor exertion

To know more about Air Quality and Pollution, check the wikipedia Air Quality topic or the airnow guide to Air Quality and Your Health.

For very useful health advices of Beijing Doctor Richard Saint Cyr MD, check www.myhealthbeijing.com blog.


Usage Notice: All the Air Quality data are unvalidated at the time of publication, and due to quality assurance these data may be amended, without notice, at any time. The World Air Quality Index project has exercised all reasonable skill and care in compiling the contents of this information and under no circumstances will the World Air Quality Index project team or its agents be liable in contract, tort or otherwise for any loss, injury or damage arising directly or indirectly from the supply of this data.



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