History of Air quality index in Timeline
The Air Quality Index (AQI) is a tool used by government agencies to inform the public about current and projected air pollution levels. A higher AQI indicates greater pollution and increased health risks, particularly for vulnerable groups like children, seniors, and those with respiratory or cardiovascular conditions. During periods of high AQI, authorities often advise limiting outdoor physical activity and even staying indoors. In cases of wildfire smoke, mask usage outdoors and air purification indoors are also recommended.
1968: Debut of the Air Quality Index
The Air Quality Index (AQI) was introduced in 1968 by the National Air Pollution Control Administration. The goal was to increase public awareness about air pollution and encourage local officials to address pollution sources.
1990: Clean Air Act Mandates Regular Review of Air Quality Standards
The 1990 Clean Air Act in the USA mandated the EPA to review its National Ambient Air Quality Standards every five years. This ensures the Air Quality Index is consistently updated with the latest health information on pollutants.
2006: Common Air Quality Index (CAQI) Implemented in Europe
The Common Air Quality Index (CAQI) came into use in Europe in 2006.
2011: N Seoul Tower Illumination Reflects Air Quality
In 2011, the N Seoul Tower in South Korea was lit up on days when the air quality in Seoul was good, totaling 48 days that year.
2012: N Seoul Tower Illumination Reflects Air Quality
During the spring of 2012, the N Seoul Tower in South Korea was lit up in blue for 52 days, signifying good air quality days in Seoul, surpassing the 48 days in 2011.
2012: Structure and Components of CAQI Defined
In 2012, the CAQI structure, a scale of 0 to 100 representing good to poor air quality, was defined. It included hourly and daily versions, roadside and background indices, and mandatory pollutants (NO2, PM10, O3), along with optional ones (PM2.5, CO, SO2).
2012: CiteairII Project Evaluates and Describes CAQI
In 2012, the EU-supported project CiteairII evaluated the CAQI and explained its creation. They highlighted the goal of creating an index easy for the public to grasp, emphasizing air pollution's presence and sources, particularly traffic.
January 1, 2013: China's Ministry of Environmental Protection Starts Monitoring Air Pollution in Major Cities
On January 1, 2013, China's Ministry of Environmental Protection (MEP) began monitoring daily pollution levels in 163 major cities, considering six pollutants: sulfur dioxide, nitrogen dioxide, PM10, PM2.5, carbon monoxide, and ozone.
December 30, 2013: Hong Kong Replaces Air Pollution Index with Air Quality Health Index
On December 30, 2013, Hong Kong replaced its existing Air Pollution Index with a new index called the Air Quality Health Index, measured on a scale of 1 to 10+ and considering pollutants like ozone, nitrogen dioxide, sulfur dioxide, and particulate matter.
September 17, 2014: India Launches National Air Quality Index (NAQI)
India launched the National Air Quality Index (NAQI) in New Delhi on September 17, 2014, as part of the Swachh Bharat Abhiyan.
2014: India Revises Air Quality Index Measurement Parameters
In 2014, India transitioned from using three indicators to eight parameters for its air quality index, based on recommendations from IIT Kanpur and an expert group. Real-time monitoring systems were installed in major cities like Delhi and Mumbai.
November 2017: European Environment Agency Encourages Use of European Air Quality Index
In November 2017, the European Environment Agency started encouraging the use of the European Air Quality Index (EAQI) for informing the public about air quality.