Colour Codes for Air Pollution: What does Code Maroon, Purple, Red, Orange, Yellow, and Green air quality mean?

economictimes.indiatimes.com:

code orange air quality action day has been declared by the Pennsylvania Department of Environmental Protection, advising children, older adults, and individuals with respiratory issues to minimize outdoor activities. Additionally, residents are strongly urged to contribute to pollution reduction by refraining from open burning and the use of gas-powered lawn equipment. While authorities have alerted the residents in Pennsylvania, it is crucial to understand the meaning of different colour codes for the air quality index.

The Air Quality Index (AQI) is used by the Environmental Protection Agency (EPA) to assess and inform the public about the levels of pollutants in the air. It is categorized into six levels, each represented by a different colour, indicating the degree of concern. Public health officials may refer to the AQI by its colour or level. The AQI ranges from 0 to 500, with each number corresponding to the concentration of pollutants in the air. Green represents the lowest level of concern, indicating good air quality with an index below 50. Yellow signifies a moderate level of concern, except for individuals who are unusually sensitive or have underlying health conditions. Orange indicates «unhealthy for sensitive groups» with an index value of 101 to 150. During a Code Orange alert, older individuals, children, and people with health conditions are advised to stay indoors. Red represents an «unhealthy» level, posing serious health risks to sensitive groups and potentially causing irritation among the general public. In June, over 100 million people in the Northern U.S. experienced Code Red due to wildfires in Canada. Public