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  2. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    2 5 160 100 35 100 150 500 80 ... The PSI chart below is grouped by index values and ... Follow tips for keeping particle levels low indoors. PM 2.5 24-Hour AQI ...

  3. Air quality guideline - Wikipedia

    en.wikipedia.org/wiki/Air_quality_guideline

    The guidelines stipulate that PM 2.5 should not exceed 5 μg/m 3 annual mean, or 15 μg/m 3 24-hour mean; and that PM 10 should not exceed 15 μg/m 3 annual mean, or 45 μg/m 3 24-hour mean. [2] For ozone (O 3 ), the guidelines suggest values no higher than 100 μg/m 3 for an 8-hour mean and 60 μg/m 3 peak season mean. [ 2 ]

  4. National Ambient Air Quality Standards - Wikipedia

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

    Particulate Matter (PM) was listed in the 1996 Criteria document issued by the EPA. In April 2001, the EPA created a Second External Review Draft of the Air Quality Criteria for PM, which addressed updated studies done on particulate matter and the modified pollutant standards done since the First External Review Draft.

  5. Nearly everyone in the world breathes bad air. This is what ...

    lite.aol.com/politics/story/0001/20250212/1b...

    The tiniest of these — known as PM 2.5 because they are less than 2.5 microns in diameter — can get deep into human lungs and are mostly created by burning fuels. Coarser particles, known as PM 10, are linked to agriculture, roadways, mining or the wind blowing eroded dust, according to the WHO.

  6. Indoor air quality - Wikipedia

    en.wikipedia.org/wiki/Indoor_air_quality

    To eliminate most complaints caused by CO 2, the total indoor CO 2 level should be reduced to a difference of no greater than 700 ppm above outdoor levels. [90] The National Institute for Occupational Safety and Health (NIOSH) considers that indoor air concentrations of carbon dioxide that exceed 1000 ppm are a marker suggesting inadequate ...

  7. 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.

  8. Particulates - Wikipedia

    en.wikipedia.org/wiki/Particulates

    Average levels of PM 2.5 were measured using aqicn.org's World Air Quality Index data, and a formula developed by AirNow was used to convert the PM 2.5 figure into micrograms per cubic meter of air (μg ⁄ m 3) values. Among the 70 capital cities investigated, Baghdad, Iraq is the worst performing one, with PM 2.5 levels going up +31.6 μg/m 3.

  9. Nearly everyone in the world breathes bad air. This is what ...

    lite.aol.com/news/world/story/0001/20250211/1b...

    HANOI, Vietnam (AP) — Everyone loves a breath of fresh air. Unfortunately, too often our air is anything but fresh. While air quality varies dramatically from place to place and day to day, nearly the entire world — about 99% of the global population — is exposed to air at some point that doesn't meet the strict standards set by the World Health Organization, the agency has reported.