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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]
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 ...
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]
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.
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.
Types of atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM10, which are coarse particles with a diameter of 10 micrometers (μm) or less; fine particles, designated PM2.5, with a diameter of 2.5 μm or less; ultrafine particles; and soot.
Airborne particles are commonly either biological contaminants, particulate contaminants, gaseous contaminants, or dust. This diagram shows the size distribution in micrometres (µm) of various types of airborne particles.
Particulate matter (PM) in the atmospheric air or in any other gas cannot be expressed in terms of ppmv, ppbv, volume percent or mole percent. PM is most usually (but not always) expressed as mg/m 3 of air or other gas at a specified temperature and pressure.