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

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

    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. Air quality in the database is represented by the annual mean concentration of particulate matter (PM10 and PM2.5, i.e. particles smaller than 10 or 2.5 micrometers, respectively). [1 ...

  3. Chicago air quality unhealthy as Canadian wildfire emissions ...

    www.aol.com/chicago-air-quality-unhealthy...

    The air quality in Chicago has reached unhealthy levels as the city is affected by the smoke coming from the wildfires in Canada, where record-beating emissions are leading to the smoke travelling ...

  4. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    PM is most usually (but not always) expressed as mg/m 3 of air or other gas at a specified temperature and pressure. For gases, volume percent = mole percent 1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6 .

  5. Particulate pollution - Wikipedia

    en.wikipedia.org/wiki/Particulate_pollution

    In European countries, air quality at or above 10 micrograms per cubic meter of air (μg/m 3) for PM 2.5 increases the all-causes daily mortality rate by 0.2-0.6% and the cardiopulmonary mortality rate by 6-13%. [35] 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 ...

  6. Chicago's air quality ranks among worst in the world - AOL

    www.aol.com/news/chicagos-air-quality-ranks...

    Chicago had the worst air quality in the world Tuesday, according to IQAir.com, a tracking service. The city's air quality index is in the "very unhealthy" category for all age groups, reminiscent ...

  7. Air quality guideline - Wikipedia

    en.wikipedia.org/wiki/Air_quality_guideline

    The reports provide guidelines intending to give guidelines to reduce the health effects of air pollution. [2] 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]

  8. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    Various governmental agencies involved with environmental protection and with occupational safety and health have promulgated regulations limiting the allowable concentrations of gaseous pollutants in the ambient air or in emissions to the ambient air. Such regulations involve a number of different expressions of concentration.

  9. Canadian wildfire smoke causes air quality to deteriorate in ...

    www.aol.com/lifestyle/canadian-wildfire-smoke...

    Canadian wildfire smoke is once again causing air quality to reach unhealthy levels in major cities in the United States, but unlike last week when the thickest smoke blew over the Northeast, the ...