Key points
- Delhi is subject to a high level of pollution throughout the year
- Dhaka is subject to some fairly bad pollution levels annually
- Lahore suffers from high levels of air pollution
- Copenhagen is the cleanest city in the world
ISLAMABAD: Here is a look at the top five most polluted and top five cleanest cities in the world.
New Dehli, India
Delhi is subject to a high level of pollution throughout the year. The levels of fine and coarse particulate matter, known respectively as PM2.5 and PM10 are often prevalent in the air, along with other forms of pollutants and toxic chemicals finding their way into the atmosphere, each with their dangerous impacts on human health.
There are around 30.2 million people registered living in Delhi as of 2025, all squeezed into a relatively small area of 1,484km², giving it an extremely high population density.
Dhaka, Bangladesh
Dhaka, formerly known as Dacca, is the capital city of Bangladesh. It holds the title of not only being the largest city in the country but being the 9th largest city worldwide. It also ranks in 2nd place out of the most populous cities in the world, with just under 9 million people living within the city’s limits.
Due to these reasons, as well as being the economic hub of the whole country, Dhaka is subject to some fairly bad pollution levels annually, with only brief periods of respite, that despite being lower still hold some relatively high numbers of pollution readings, making its air harmful to breathe year-round.
Kampala, Uganda
Kampala is a city located in Uganda, holding the title of both capital and largest city in the country, with some 6.7 million inhabitants.
Kampala is regarded to be one of the fastest-growing cities in the African continent, with a high yearly population growth rate.
Alongside this, it has made a widescale move towards heavy urbanization, industrialisation, and other economic developments in the last few decades and more prominently so in recent times, classed as one of the best-emerging cities in East Africa to live in.
Lahore, Pakistan
Lahore suffers from high levels of air pollution, with the city regularly ranking at the top of IQAir AirVisual’s live pollution rankings of major global cities. However, pollution only rose to the top of the public’s consciousness in early 2017, when actionable air quality data was published for the first time in Pakistan.
In the absence of publicly available government data, a network of citizen-operated sensors began to monitor fine particulate matter, also known as PM2.5, and report data in real time. The data laid bare Lahore’s high levels of air pollution, shocking the public and becoming a media talking point.
Chongqing, China
Chongqing is a megacity in southwest China. The population was estimated to be approximately 31 million in 2018.
It is one of the four municipalities which fall under the direct control of the central Chinese government. The other three are Beijing, Shanghai, and Tianjin.
5 CLEANEST CITIES
Copenhagen, Denmark
Copenhagen is the capital city of Denmark and is also the largest as well as the cleanest city in the world. It is located on the eastern coast of the island of Zealand. Its population is approximately 2,057,142.
Montreal, Canada
Montreal is a city located in the Canadian province of Quebec, being the most populous city of the province and the second most populous city in the whole of Canada.
It lies just above the United States border, and is home to a majority of French Canadians, with English being the second most commonly spoken language.
Melbourne, Australia
Melbourne generally experiences relatively healthy air in global comparison to other major cities. However, like many other Australian regions, the capital of Victoria state is also subject to occasional extreme air pollution events, which can pose significant health risks to its almost 5 million residents.
Detroit, United States
Detroit is an industrial city located on the Detroit River in the south-eastern area of Michigan. It is the state’s largest city. Like other areas of Michigan, Detroit’s climate is influenced by the Great Lakes, exhibiting a humid continental climate featuring cold winters and warm or hot summers.
Sydney, Australia
In general, air quality in Australia is relatively healthy by global standards – however, there is room for improvement, and particularly several areas in Australia are facing health risks from air pollution concerning increasing occurrences of bushfires.
Sydney air quality is no exception to this, as the city experiences year-round exposure to a range of air pollutants, in addition to more extreme, short-term air pollution events such as wildfires and dust storms.
