Ranking of world cities by air quality 2021
• The air we breathe is taken for granted, but pollution levels have been rising over the years, an inevitable consequence of globalization. According to HouseFresh, 7 million people (600 of them children) die prematurely each year due to air pollution. Poor air quality has been linked to respiratory disease, leukemia, heart disease, strokes and breast cancer.
• Air pollution is not only something we can see and smell. Emissions from vehicles, mining, chemical production and power generation all play a role in the release of hazardous substances into the environment. Even natural phenomena such as volcanic eruptions and the decomposition of methane from the decomposition of organic matter affect air quality.
Methodology for creating a list of cities with the cleanest and dirtiest air
• In 2020, the Swiss company IQAir produced the World Air Quality Report, which was based on the amount of particulate pollutants (known as PM2,5). However, on September 22, the WHO halved the target value of PM2,5 concentration in µg/m3 in the air. New research has shown that these particles are twice as dangerous to health as previously thought.
• Therefore, this rating is based on data from the HouseFresh portal. They take into account the updated WHO healthy air targets for 2021.
• Cities and towns were ranked by the average PM2,5 concentration in µg/m3. Countries that do not have at least five cities were excluded from the selection.
The dirtiest cities in the world in terms of PM2,5
• 49 of the 50 most polluted cities in the world are in Bangladesh, Pakistan, China and India. And this is not surprising.
- India and China are the world's two most populous and fastest growing industrial powers, and air pollution is inevitable there.
- Bangladesh is one of the fastest growing countries in the world, its industrial sector is growing at a rate of 13% per year.
- In Pakistan, air pollution is attributed to a number of factors: political instability, high population density, and the inertia of the authorities in dealing with environmental problems.
• Here is what the top three cities with the worst air look like:
- Breathing is worst in the Chinese city of Hotan, where PM2,5 levels were 110,2 µg/m3. This is due to local sandstorms – the city is located on the southwestern outskirts of the Takla Makan desert. This is one of the largest sandy deserts in the world.
- Ghaziabad (India) is the second most polluted city in the world with a PM2,5 of 106,6 µg/m3. This city is called the gateway to Uttar Pradesh and the large number of people moving in and out of Ghaziabad is the cause of the high levels of air pollution.
- In third place is Manikganj (Bangladesh) with a PM2,5 of 80,2 µg/m3. The main sources of air pollution are motor vehicles and industrial emissions.
• As for Russia, HouseFresh does not mention the dirtiest city. And according to the latest IQAir data, the top ten in the Russian Federation is headed by Krasnoyarsk (109 µg/m3).
• In Moscow, the concentration of PM2.5 in the air is about 1.8 times higher than the average annual air value recommended by WHO and is 18.3 µg/m3.
Cities with the cleanest air in the world
• The Japanese city of Obihiro has become the cleanest city in Asia, the content of PM2,5 in the air is 5,6 µg/m3. The list also includes Judbury (Australia, 2,4 µg/m3), Kailua-Kona (USA, 2,6 µg/m3), and Muonio (Finland, 2,8 µg/m3).
• Judbury is a rural region of Tasmania with a population of just 392. Likewise, only 2308 people live in Muonio. Hawaiian Kailua-Kona has a population of 11.
• Of the Russian cities, the easiest breathing is for the residents of Vladivostok (3,6 µg/m3).
For whom is polluted air most dangerous?
• 9 out of 10 city dwellers suffer from air pollution. Children are particularly at risk from air pollution. Even low levels of PM2,5 exposure are associated with structural changes in their developing brains.
• In addition, children whose mothers constantly breathed air with a high concentration of ultrafine particles during pregnancy are more at risk of autism, attention deficit hyperactivity disorder (ADHD).
How to deal with particulate matter in the air at home
• Cleaning indoor air reduces the concentration of hazardous particulate matter. The US Environmental Protection Agency (EPA) recommends the use of floor-mounted or portable air purifiers for the home.
• Two key features that a good air purifier should have:
- High Efficiency Particulate Filter (HEPA) available.
- The presence of an activated carbon filter to filter gases and odors.
• It is better to place such a unit in the center of the room, so it will suck in air well and blow out clean air. If you place the purifier in a corner, the circulation will be disturbed, and air from other corners will not enter the device.