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  2. Particulate pollution - Wikipedia

    en.wikipedia.org/wiki/Particulate_pollution

    Particulate pollution is observed around the globe in varying sizes and compositions and is the focus of many epidemiological studies. Particulate matter (PM) is generally classified into two main size categories: PM 10 and PM 2.5.

  3. Particulates - Wikipedia

    en.wikipedia.org/wiki/Particulates

    Annual seasonal average particulate matter concentrations have been recorded as high as 279 μg/m 3 (micrograms per cubic meter). [citation needed] The World Health Organization's recommended annual mean PM 10 level is 20 μg/m 3, [296] which means that Ulaanbaatar's PM 10 annual mean levels are 14 times higher than recommended. [citation needed]

  4. National Ambient Air Quality Standards - Wikipedia

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

    Atmospheric particulate matter. PM 10, coarse particles: 2.5 micrometers (μm) to 10 μm in size (although current implementation includes all particles 10 μm or less in the standard) PM 2.5, fine particles: 2.5 μm in size or less. Particulate Matter (PM) was listed in the 1996 Criteria document issued by the EPA.

  5. 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.

  6. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    This index, reported by the Environmental Protection Department, is measured on a scale of 1 to 10+ and considers four air pollutants: ozone; nitrogen dioxide; sulfur dioxide and particulate matter (including PM10 and PM2.5). For any given hour the AQHI is calculated from the sum of the percentage excess risk of daily hospital admissions ...

  7. 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]

  8. Ambient air quality criteria - Wikipedia

    en.wikipedia.org/wiki/Ambient_air_quality_criteria

    PM 10 "Coarse Particulate Matter" 150 μg/m 3: 24 hour Average over 3 years Once per year US EPA [3] Legal United States Primary and Secondary PM 10: 125 μg/m 3: 24 hour 99th %ile 3 days/yr WHO [1] Guideline Global PM 10: 50 μg/m 3: 24 hour Mean None WHO [1] Guideline Global PM 10: 20 μg/m 3: Annual Mean None WHO [1] Guideline Global PM 10: ...

  9. NowCast (air quality index) - Wikipedia

    en.wikipedia.org/wiki/NowCast_(air_quality_index)

    PM 2.5 AQI of US monitors, calculated utilizing NowCast, courtesy US EPA PM2.5 AQI map, calculated utilizing NowCast, courtesy US EPA. The PM (particulate matter) NowCast is a weighted average of hourly air monitoring data used by the United States Environmental Protection Agency (USEPA) for real-time reporting of the Air Quality Index (AQI) for PM (PM 10 - particles less than 10 micrometers ...