IQAir's 2018 World Air Quality Report

First of its kind, IQAir's 2018 report on PM2.5 air pollution from over 3000 Cities.

IQAir’s 2018 World Air Quality Report

This comprehensive report is the first of its kind to reveal 2018 particulate matter pollution (PM2.5) with measurements from over 3000 cities around the world. The data was compiled from both governmental public monitoring sources in addition to public IQAir AirVisual monitoring stations.

Simultaneously IQAir published an interactive air pollution city ranking which provides a clear month-by-month overview of PM2.5 air pollution at a global, regional, country and city level. Live air pollution data for more than 10’000 locations around the globe can be accessed on the AirVisual website or with the free AirVisual App (AndroidGoogle Play & Apple iOS).

Excecutive Sumary

Air pollution is the greatest environmental risk to health today, estimated to contribute to 7 million premature deaths(1) every year. Polluted air presents the world’s 4th leading contributing cause of early deaths, and burdens the global economy with an estimated annual cost of $225 billion (USD)(2).

The city ranking shows Asian locations dominating the highest 100 average PM2.5 levels during 2018, with cities in India, China, Pakistan and Bangladesh occupying the top 50 cities. Numerous cities within the Middle East region also rank highly, with Kuwait City, Dubai and Manama all exceeding the WHO guideline by over 500%. At a country level, weighted by population, Bangladesh emerges as the most polluted country on average, closely followed by Pakistan and India, with Middle Eastern countries, Afghanistan and Mongolia also within the top 10. Southeast Asia’s most polluted cities during 2018 were the capitals Jakarta and Hanoi, with a number of Thai cities also ranking highly in this region. Public awareness of local pollution levels in these countries has grown considerably during 2018, as well as in South Korea and Pakistan. Public engagement with air pollution also increased in the United States and Canada, particularly during the severe wildfires which punctuated part of the region’s generally low PM2.5 levels during August and November.

Why PM2.5? The report focuses on PM2.5 as a representative measure of air pollution. PM2.5 refers to particulate matter (ambient airborne particles) which measure up to 2.5 microns in size, and has a range of chemical makeups and sources. PM2.5 is widely regarded as the pollutant with the most health impact of all commonly measured air pollutants. Due to its small size PM2.5 is able to penetrate deep into the human respiratory system and from there to the entire body, causing a wide range of short- and long-term health effects. Particulate matter is also the pollutant group which affects the most people globally. It can come from a range of natural as well as man-made sources. Common sources of PM include combustion (from vehicle engines, industry, wood and coal burning), as well as through other pollutants reacting in the atmosphere. The WHO recommends an annual mean exposure threshold of 10 μg/m³ to minimize the risk of health impacts from PM2.5, whilst advising that no level of exposure has been shown to be free of health impacts(3).

To relate exposure to potential health impacts, this report refers to the United States Air Quality Index (US AQI). The US AQI color scale is used, supplemented by the WHO guideline. The US AQI is one of the most widely recognized AQI systems available. The US AQI converts pollutant concentrations into a col