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  2. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    The most commonly used air quality index in the UK is the Daily Air Quality Index recommended by the Committee on the Medical Effects of Air Pollutants (COMEAP). [39] This index has ten points, which are further grouped into four bands: low, moderate, high and very high. Each of the bands comes with advice for at-risk groups and the general ...

  3. List of least-polluted cities by particulate matter ...

    en.wikipedia.org/wiki/List_of_least-polluted...

    Below is a list of 526 cities sorted by their annual mean concentration of PM2.5 (μg/m 3) in 2022. [1] [2] By default the least polluted cities which have fewest particulates in the air come first. Click on the arrows next to the table's headers to have the most polluted cities ranked first. Please note that constraints exist in this type of ...

  4. Air Pollution Index - Wikipedia

    en.wikipedia.org/wiki/Air_Pollution_Index

    AQI Mechanics An individual score is assigned to the level of each pollutant and the final AQI is the highest of those five scores. The pollutants can be measured quite differently. SO 2, NO 2 and PM 10 concentration are measured as average per day. CO and O 3 are more harmful and are measured as average per hour. The final AQI value is ...

  5. List of countries by air pollution - Wikipedia

    en.wikipedia.org/wiki/List_of_countries_by_air...

    The following list of countries by air pollution sorts the countries of the world according to their average measured concentration of particulate matter in micrograms per cubic meter (μg/m 3). The World Health Organization's recommended limit is 5 micrograms per cubic meter, although there are also various national guideline values, which are ...

  6. List of most-polluted cities by particulate matter concentration

    en.wikipedia.org/wiki/List_of_most-polluted...

    This list contains the top 500 cities by PM2.5 annual mean concentration measurement as documented by the World Health Organization covering the period from 2010 to 2022. The January 2024 version of the WHO database contains results of ambient (outdoor) air pollution monitoring from almost 5,390 towns and cities in 63 countries.

  7. Air pollution measurement - Wikipedia

    en.wikipedia.org/wiki/Air_pollution_measurement

    Urban air quality index (AQI) values are computed by combining or comparing the concentrations of a "basket" of common air pollutants (typically ozone, carbon monoxide, sulfur dioxide, nitrogen oxides, and both fine and coarse particulates) to produce a single number on an easy-to-understand (and often colour-coded) scale. [63]

  8. Pollutant Standards Index - Wikipedia

    en.wikipedia.org/wiki/Pollutant_Standards_Index

    The Pollutant Standards Index (PSI) is a type of air quality index used in Singapore, which is a number used to indicate the level of pollutants in air.Initially PSI was based on five air pollutants, but since 1 April 2014 it has also included fine particulate matter (PM 2.5).

  9. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    These sections require the EPA "(1) to list widespread air pollutants that reasonably may be expected to endanger public health or welfare; (2) to issue air quality criteria for them that assess the latest available scientific information on nature and effects of ambient exposure to them; (3) to set primary NAAQS to protect human health with ...