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  2. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    The index is defined in both hourly and daily versions, and separately near roads (a "roadside" or "traffic" index) or away from roads (a "background" index). As of 2012, the CAQI had two mandatory components for the roadside index, NO 2 and PM 10, and three mandatory components for the background index, NO 2, PM 10 and O 3.

  3. 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.

  4. Particulate pollution - Wikipedia

    en.wikipedia.org/wiki/Particulate_pollution

    Worldwide, PM 10 concentrations of 70 μg/m 3 and PM 2.5 concentrations of 35 μg/m 3 have been shown to increase long-term mortality by 15%. [29] More so, approximately 4.2 million of all premature deaths observed in 2016 occurred due to airborne particulate pollution, 91% of which occurred in countries with low to middle socioeconomic status.

  5. National Ambient Air Quality Standards - Wikipedia

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

    The EPA is strengthening monitoring requirements for CO by calling for CO monitors to be placed in strategic locations near large urban areas. Specifically, the EPA has called for monitors to be placed and operational in CBSA's (core based statistical areas) with populations over 2.5 million by January 1, 2015; and in CBSA's with populations of ...

  6. 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).

  7. Particulates - Wikipedia

    en.wikipedia.org/wiki/Particulates

    On the other hand, Omaha, Nebraska is performing the best and has a decrease of −1.1 μg/m 3 in PM 2.5 levels. The cleanest city in this report is Zürich, Switzerland with PM 2.5 levels of just 0.5 μg/m 3, placed first in both 2019 and 2022. The second cleanest city is Perth, with 1.7 μg/m 3 and PM 2.5 levels dropping by −6.2 μg/m 3 since

  8. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    The conversion equations depend on the temperature at which the conversion is wanted (usually about 20 to 25 °C). At an ambient sea level atmospheric pressure of 1 atm (101.325 kPa or 1.01325 bar), the general equation is:

  9. 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 ]