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WHO: Air pollution levels rising in many of the world’s poorest cities

More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels that exceed World Health Organization (WHO) limits, according to the organization. While all regions of the world are affected, populations in low-income cities are the most impacted.

According to the latest urban air quality database, 98% of cities in low- and middle income countries with more than 100 000 inhabitants do not meet WHO air quality guidelines. However, in high-income countries, that percentage decreases to 56%.

WHO data
Source: WHO. Country groupings. Click to enlarge.

WHO Ambient Air Quality Guidelines
  Annual Mean 24-hour mean
PM2.5 10 μg/m3 25 μg/m3
PM10 20 μg/m3 50 μg/m3

In the past two years, the database—now covering 3,000 cities in 103 countries—has nearly doubled, with more cities measuring air pollution levels and recognizing the associated health impacts.

As urban air quality declines, the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma, increases for the people who live in them.

Global urban air pollution trends. WHO was able to compare a total of 795 cities in 67 countries for levels of small and fine particulate matter (PM10 and PM2.5) during the five-year period, 2008-2013. PM10 and PM2.5 include pollutants such as sulfate, nitrates and black carbon, which penetrate deep into the lungs and into the cardiovascular system, posing the greatest risks to human health. Data was then analysed to develop regional trends.

Key trends from 2008-2013:

  • Global urban air pollution levels increased by 8%, despite improvements in some regions.

  • In general, urban air pollution levels were lowest in high-income countries, with lower levels most prevalent in Europe, the Americas, and the Western Pacific Region.

  • The highest urban air pollution levels were experienced in low-and middle-income countries in WHO’s Eastern Mediterranean and South-East Asia Regions, with annual mean levels often exceeding 5-10 times WHO limits, followed by low-income cities in the Western Pacific Region.

  • In the Eastern Mediterranean and South-East Asia Regions and low-income countries in the Western Pacific Region, levels of urban air pollution has increased by more than 5% in more than two-thirds of the cities.

  • In the African Region urban air pollution data remains very sparse, however available data revealed particulate matter (PM) levels above the median. The database now contains PM measurements for more than twice as many cities than previous versions.

Most sources of urban outdoor air pollution are well beyond the control of individuals and require action by cities, as well as national and international policymakers to promote cleaner transport, more efficient energy production and waste management, WHO said.

More than half of the monitored cities in high-income countries and more than one-third in low- and middle-income countries reduced their air pollution levels by more than 5% in five years.

During the World Health Assembly, 23-28 May, Member States will discuss a road map for an enhanced global response to the adverse health effects of air pollution.

WHO’s Air Quality Guidelines offer global guidance on thresholds and limits for key air pollutants that pose health risks. The Guidelines indicate that by reducing particulate matter (PM10) pollution from 70 to 20 micrograms per cubic meter (μg/m), air pollution-related deaths could be reduced by roughly 15%.

The WHO urban air quality database builds on well-established, public air quality monitoring systems as a source of reliable data in different parts of the world.

The primary source of data include official reporting from countries to WHO, and official national and sub-national reports and web sites containing measurements of PM10 or PM2.5. Measurements reported by the following regional networks were used: the Clean Air Asia for Asia and the European Environment Agency for Europe’s Air Quality e-Reporting database. In the absence of data from the previous sources, data from UN and development agencies, peer-reviewed journal articles and ground measurements compiled in the framework of the Global Burden of Disease project were used.

Annual mean concentrations of particulate matter (PM10 and/or PM2.5) based on daily measurements, or data which could be aggregated into annual means, were included in the database. In the absence of annual means measurements covering a more limited period of the year were exceptionally used.



One of the worst things in poorer countries is burning dung for cooking and heat. Next is burning wood in an uncontrolled manner. Then comes burning coal for heat in poorly designed furnaces. All of these were sort of OK in sparsely populated areas but not in densely populated urban areas. The long term solution is probably women's education and a lower birth rate. Good luck.


Yes, because poor people shouldn't procreate?

That was Soo Margret Sanger... Move on and get off your high horse, just capture more carbon to pick up their slack. Drive more ev miles, put solar on your roof, be proactive not imposing your view on the rest of the world.



I have debated whether your comments were worth answering. All I suggested was improving education and especially women's education which generally improves all aspects of life. I did not suggest any forced action. If there was better education in some of the poorer countries there would be less poverty, more purpose to life, and eventually less war. Maybe, with a bit more education and wealth, there would be less uncontrolled burning of dung, wood, and coal and less pollution. Maybe you need to relocate your head or at least think a little more before answering in the manner of your post.


The arrival of nearby cement factories, CPPs and many ICEVs, specially poorly maintained diesel units, have certainly contributed to increased pollution in most large poor cities?

Huge human population growth have also contributed to related pollution rise, in many large Asian, African and So-American cities

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