What is the current state of air quality around the world?
The world’s population does not have equal access to clean air.
When characterizing air quality for its potential impact on people’s health, scientists are most interested in the levels of pollution close to areas with large numbers of people. They therefore estimate average concentrations of fine particulate matter (PM2.5) and ozone that are population-weighted. This means that greater weight, or emphasis, is given to air pollution concentrations in areas of high population density, where the most people live. These weighted numbers make it easier to compare average pollution concentrations across countries.
Map of fine particle levels
Global map of population-weighted fine particulate matter concentrations in 2015.
The first map shows population-weighted concentrations of fine particulate matter around the world in 2015. The highest concentrations were in North Africa and the Middle East. Among individual countries in those regions, Qatar had the highest levels (107 µg/m3), followed closely by Saudi Arabia (106 µg/m3) and Egypt (105 µg/m3). These high concentrations are mainly due to windblown mineral dusts from deserts (arising from both natural and human activities), although emissions from combustion processes (the burning of fuels or other materials) also play a part.
In other regions, most notably Asia and western sub-Saharan Africa, high levels of fine particulate matter were observed that were due to human activity, mostly involving combustion. The emission sources include the burning of solid fuels (for example, wood or dried dung) in people’s homes for cooking and heating, coal-fired power plants for electricity, burning of agricultural wastes (for example, corn stubble in fields), industrial activities, and transportation (emissions from cars, buses, trucks, trains, and ships).
All these sources contributed to the high particle concentrations (population-weighted) seen in 2015. Bangladesh (89 µg/m3), Nepal (75 µg/m3), India (74 µg/m3), and China (58 µg/m3) experienced some of the highest concentrations in Asia. In sub-Saharan Africa, Mauritania had very high levels (85 µg/m3).
Current ozone levels
People across the globe are also exposed — to varying degrees — to ozone in the air they breathe. While less variable than fine particle levels, ozone concentrations (calculated as seasonal averages, primarily during the warmer months when ozone levels are highest) were relatively high in the United States, China, and some countries of western and central sub-Saharan Africa, the Middle East, and South Asia, as shown in the second map.
Map of ozone levels
Global map of population-weighted ozone concentrations (seasonal averages) in 2015.
You can explore patterns and trends in fine particulate matter and ozone pollution levels using the interactive tools in Explore the Data. Compare results among individual countries and regional groupings. See the How To page for more detailed instructions.