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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 2008 to 2017. The 2018 version of the WHO database contains results of ambient (outdoor) air pollution monitoring from almost 2700 towns and cities in 91 countries.
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. PM 10, also known as coarse particulate matter, consists of particles 10 micrometers (μm) and smaller, while PM 2 ...
An air quality index (AQI) is an indicator developed by government agencies [1] to communicate to the public how polluted the air currently is or how polluted it is forecast to become. [2][3] As air pollution levels rise, so does the AQI, along with the associated public health risk. Children, the elderly and individuals with respiratory or ...
To analyse the air pollution trend, 480 cities around the world (Ukraine excluded) was mapped by air experts [277] to calculate the average PM 2.5 level of the first nine months of 2019 against that of 2022. [278]
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). The World Health Organization's recommended limit is 5 micrograms per cubic meter, although there are also various national guideline values, which are ...
Below is a list of 526 cities sorted by their annual mean concentration of PM2.5 (μg/m 3) in 2022. [1] [2] By default the least polluted cities which have fewest particulates in the air come first.
e. Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. [ 1 ] It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological ...
Earth is rounded into an ellipsoid with a circumference of about 40,000 km. It is the densest planet in the Solar System. Of the four rocky planets, it is the largest and most massive. Earth is about eight light-minutes away from the Sun and orbits it, taking a year (about 365.25 days) to complete one revolution.