List of countries by air pollution

The following list of countries by air pollution sorts the countries of the world according to their average measured concentration of particulate matter (PM2.5) in micrograms per cubic meter (μg/m³). The World Health Organization's recommended limit is 5 micrograms per cubic meter, although there are also various national guideline values, which are often much higher. Air pollution is among the biggest health problems of modern industrial society and is responsible for more than 10 percent of all deaths worldwide (nearly 4.5 million premature deaths in 2019), according to The Lancet. Air pollution can affect nearly every organ and system of the body, negatively affecting nature and humans alike. Air pollution is a particularly big problem in emerging and developing countries, where global environmental standards often cannot be met. The data in this list refers only to outdoor air quality and not indoor air quality, which caused an additional two million premature deaths in 2019.^[1]