The 12 most polluted cities in the world: Causes, effects and solutions

When you’re out and about in the city, there might be a few things on your mind. What should I get for lunch? That pointy building is really ugly. Do pigeons make good pets? You’re probably not thinking about the air you’re breathing, even though the data says you really should.

Research by Swiss air technology firm IQAir has shown that 90 per cent of the air the world inhales exceeds that of the maximum limit set by the World Health Organisation (WHO) for pollution. This includes the UK – whose atmosphere is 1.8 times higher than the WHO’s recommended threshold.

Whether it’s caused by humans or the natural environment, pollution is a growing problem. And it’s an issue that several cities and countries face, by virtue of where they’re located, the habits of their people, or the inclination of their governments to curtail it.

We’re breaking down the 12 most polluted cities and countries in the world, unpacking pollution’s causes, effects, as well as the potential solutions – from both an individual and governmental perspective – to combat it.

So which are the planet’s most polluted places – and does your home make the list?

Among the different sources we used to rank the planet’s most polluted places include IQAir’s rankings of the most polluted cities in the world. IQAir is a Swiss company that – in addition to selling air purifiers, air monitors, and face masks – tracks the world’s levels of airborne contaminants.

IQAir’s rankings rate the world’s cities by their overall average emissions by month and year. Since the average annual data for 2023 isn’t yet available, we’ve relied on IQAir’s overall 2022 averages – though we’ve also taken into account data from IQAir’s live rankings, which are updated in close to real time.

We’ve also utilised pollution data from the World Bank and the WHO’s National Air Quality Standards for a fully-rounded, impartial analysis of the most polluted population centres on the planet. Our experts have also considered the levels and causes of greenhouse gas emissions by each city to develop a deeper understanding of the breadth and scale of each place’s pollution problem.

Topping the list of the planet’s most polluted places is Pakistan’s Lahore. With an average PM2.5 concentration of 97.4μg/m³ in 2022 – with November and December both registering particularly high levels of 190.5μg/m³ and 192.9μg/m³, respectively – the data paints a bleak picture of Lahore’s air pollution. One that’s not just already the worst in the world – but getting even worse.

Among the causes are industrial pollution and waste burning, as well as emissions from vehicles, industry, and fossil fuel-fired power plants. The burning of coal to power the city’s myriad brick kilns is adding to the problem, while Lahore’s transport-related emissions – amplified by fuel adulteration and a laissez-faire approach to vehicular inspections – are sky-high.

Recently, Lahore’s air pollution has also developed a visual manifestation, a sinister smog that settles upon the city and returns, with greater intensity, each winter. Pakistan’s Faisalabad, Gujranwala, Peshawar and Bahawalpur also don’t cover themselves in glory when it comes to clean air as they all rank highly on IQAir’s list.

Malaysia’s most populous city and capital of Sarawak state, Kuching – as of IQAir’s real-time rankings in September 2023 – is the most polluted city in the world.

It doesn’t quite do enough to take top spot (despite a recent pollution spike, its historical levels still pale in relation to Lahore’s) but Kuching’s PM2.5 concentration of 108.8μg/m³ is currently almost 22 times greater than the WHO’s recommended maximum levels. 

The coal-fuelled power plants driving the Sarawak capital’s status as a major centre of industry certainly contribute to the high pollution levels – as do emissions from the myriad vehicles gridlocking the Borneo-based city every day.

However, some of Kuching’s pollution woes aren’t, in geopolitical terms, its own fault, but owe more to the practices of its international neighbours. Some of Kuching’s recent record-high levels of pollution are a result of fires in nearby Indonesia (with which it shares the island of Borneo) – particularly the Sumatran region. Winds carry huge clouds of haze and smoke over to Kuching, where it fills the Malaysian air with particulate matter and contaminants that its population of around 570,000 people breathe in every day.

The devastating forest fires that tore through Indonesia in 2019 – destroying lives and livelihoods – demonstrated the region’s vulnerability to the unchecked flame. And in 2023, Indonesia is again bracing for further forest fires, with the El Nino weather phenomenon predicted to return. Alongside the crisis this could lead to for Indonesia, Kuching’s increasing levels of pollution mean it’s not just Indonesia set to be affected  – but Malaysia, too. 

The concrete jungle of Hotan is located in China’s far west, close to the border with Pakistan. In 2022, Hotan registered average PM2.5 concentration levels of 94.3μg/m³ – around 5.6 times the WHO’s recommended air quality threshold.

Like the rest of China, Hotan’s pollution comes from a rapid rise in industrial practices since the turn of the century, as well as from freight and private vehicle activity. Economic factors such as rampant poverty also take their toll, with companies moving into Hotan and setting up factories to take advantage of the cheap labour available.

What’s more, Hotan’s topography doesn’t do its air any favours. Hotan is located close to the Taklimakan, the largest shifting sand desert on Earth – exposing the city to an unceasing influx of atmosphere-irritating pollutants.

These sandstorms tend to be worse in the pre-summer period, which we see reflected in Hotan’s levels of 132.7μg/m³ (March 2022), 106.2μg/m³ (April 2022), and 120.5μg/m³ (May 2022) – three of the city’s five most polluted months.

In 2022, Bhiwadi registered a PM2.5 concentration of 92.7μg/m³, which – despite improving on its 2021 (106.2μg/m³) and 2020 (95.5μg/m³) totals, is still enough to earn Bhiwadi fourth place on our list.

Home to steel mills, furnaces, plus a range of electronic and automobile manufacturing plants, industry accounts for much of Bhiwadi’s robust greenhouse gas emission output. However, road dust is also a major factor; it’s thought to account for around half (48 to 50 per cent) of Bhiwadi’s pollution levels.

As of September 2023, Johannesburg’s live PM2.5 concentration levels (69.2μg/m³) place it third in IQAir’s real-time pollution rankings – behind only Kuching and Beijing.

Looking at South Africa’s historical levels of pollution – as analysed in an article from the Centre for Research on Energy and Clean Air – its current spike comes as little surprise. Air pollution in South Africa during its winter tends to be higher due to weather conditions that spur the creation of smog – but Johannesburg’s 2023 winter (May to August) levels, the article notes, are “alarmingly high”.

Some of the causes include waste burning – a common practice in South Africa – while industrial emissions from power plants and the transportation industry also feed into the problem. Use of the dumping grounds and decommissioned mining facilities at Johannesburg’s fringes have created unofficial, unregulated landfills.

Officially the National Capital Territory (NCT) of Delhi, India’s capital territory isn’t just leading its country – it’s leading the way for pollution levels on a global scale.

In 2022, Delhi’s PM2.5 concentration of 92.6μg/m³ was on par with Bhiwadi’s – although its most pollutant-ridden month, November 2022 (176.8μg/m³) was much higher than the 149.5μg/m³ seen in Bhiwadi’s worst month, April 2022.

Most of Delhi’s polluted air can hold vehicular emissions (which contribute just over half, 51 per cent, of its PM2.5 levels) to account. The next biggest source of Delhi’s air pollution is residential sources (13 per cent), industrial sources (11 per cent), construction (7 per cent), waste burning and the energy sector (5 per cent), with road dust – a huge issue for Bhiwadi’s less-maintained transport infrastructure – less of a problem for Delhi at just 4 per cent.

Pakistan’s sixth-largest city by population, Peshawar’s issues stem predominantly from transport-related emissions, which contribute well over half (58.45 per cent) of the city’s output. These are followed closely by dust, industry, the domestic sector, the (usually unregulated) incineration of waste, as well as the usual suspect – commercial and industrial activities.

In 2022, the average PM2.5 concentration of Peshawar’s air was 91.7μg/m³ – although its December 2022 average (212.1μg/m³) was easily double that. Peshawar’s 2022 total also represented a slight increase compared to 2021 (89.6μg/m³), and a more drastic one from its 2019 (63.9μg/m³) levels.

Placing eighth in our list of the world’s most polluted cities is India’s Darbhanga, with an average PM2.5 concentration level of 90.3μg/m³ in 2022.

As with the rest of the Indian cities in the top 12, agricultural processes, fuel-glugging freight vehicles, and waste burning account for a large chunk of its emissions, while Darbhanga nurtures an ongoing, unhealthy reliance on oil, coal, diesel and natural gas.

In 2022, Asopur’s average PM2.5 concentration was 90.2μg/m³ (only very marginally worse than Darbhanga’s). December 2022 was a bad one for Asopur’s air, with an average air quality of 201.2μg/m³ painting a damning picture of its practices. Among these, the city’s burning of domestic fuel stands out as the most destructive.

Due to this being the first year IQAir has collected data from Asopur, it’s difficult to get a sense of historical trends and understand the northeastern Indian city’s overall pollution trajectory.

N’Djamena’s overall PM2.5 concentration levels of 89.7μg/m³ spiked in March 2022, when it registered year-high levels of 245.6μg/m³ (IQAir) – the highest PM2.5 concentration levels recorded in a single month, across IQAir’s entire index.

Among the causes? N’Djamena’s textile, meatpacking, and oil industries, as well as vehicle emissions and waste-burning. Worse still, N’Djamena relies on fossil fuels for close to the entirety of its electricity needs.

Located in Delhi, New Delhi’s levels of pollution (89.1μg/m³ in 2022) suffer from many of the same antecedents as its territory: shabby vehicles, construction, waste burning, and road dust. The burning of organic matter – like wood – for cooking and domestic purposes also takes a toll, as do the power plants and factories littering the urban landscape.

These factors compound to make New Delhi’s air 7.5 times more polluted than the maximum level the WHO recommends.

Rounding out the top 12 most polluted cities on Earth is Patna, India’s 19th-most-populated city, which is located in the country’s northeast, close to its borders with Nepal and Bangladesh.

In 2022, Patna registered an average PM2.5 concentration of 88.9μg/m³, representing a steady historical increase from 78.2μg/m³ in 2021 and 68.4μg/m³ in 2020. Similarly to the several other Indian cities we’ve profiled here, December 2022 was a particularly egregious month for Patna’s air quality, with an average of 209.2μg/m³.

Like Asopur, Patna is also located in the Indian state of Bihar and, as such, shares many of the same pollution-contributing issues, including waste and straw stubble burning and non-compliant vehicles. Government-mandated construction also contributes, as do other domestic and industrial factors.

One reason has less human causes, though – and that’s the Ganges.

India’s largest river (upon whose banks Patna is situated) has changed its course over the last two decades: moving four kilometres away from the city, and leaving swathes of dry, arid sand in its wake. Picked up by the strong winds blowing off the nearby Himalayas, this sand is being scattered throughout the city – leading its residents to deal with the increased levels of air pollution it causes.

As we’ve seen, many causes – both natural and human-driven – contribute to the pollution of the world’s cities. Where pollution comes from depends on a variety of factors – including industrialisation, urbanisation, geographical population and population density – so let’s take a closer look at its chief causes.

Human-related causes of air pollution

• Vehicular and transport-related emissions: Exhaust emissions from cars, buses and trucks – especially if they’re older models – release pollutants, such as carbon monoxide, nitrogen oxides, volatile organic compounds (VOCs), and particulate matter into the atmosphere; the average car alone creates close to six tonnes of pollutants every year.
• Industrial activities: Manufacturing and energy production processes – particularly if they rely on burning fossil fuels, rather than on renewable sources like solar energy – emit a vast range of pollutants (including greenhouse gases, sulphur dioxide, particulate matter, heavy metals, and other toxic chemicals) into a city’s air and water.
• Urban development: When cities expand, room to build roads and homes has to be made – which often leads to the deforestation of local forests and land. This loss of green cover contributes to air and soil pollution, while stymying the Earth’s ability to naturally rid its atmosphere of carbon dioxide. Considering that the average tree absorbs 10 kilograms of CO2 every year, the loss of local greenery has devastating consequences not only for pollution levels – but for the future of our planet.
• Domestic activities: In many cities, such as those in Pakistan and India, traditional methods of heating and cooking involve the burning of low-quality or biomass fuels in brick kilns, which emit smoke and indoor air pollutants.
• Improper waste management and disposal: In some countries, the unregulated burning of waste (including plastic and rubber) is commonplace. Inadequate sanitation adds to the problem, as does a lack of recycling – which means recyclable materials like paper and plastic end up in landfills, creating emissions.
• Construction and agricultural practices: The dust and particulate matter generated by construction (especially demolition) contributes to the pollution of city air. Agricultural practices do, too – particularly when chemical-rich pesticides and fertilisers run off into water bodies or evaporate into a city’s air and water.

Natural causes of air pollution

The extent to which your city will be affected by air pollution’s causes depends on where it’s located, and on the unique features of its climate and topography.

Instances of pollution being caused by the natural environment include:

• Volcanic eruptions: These release huge amounts of ash, sulphur dioxide and other gases into the atmosphere.
• Forest fires: Naturally occurring wildfires emit particulate matter, carbon monoxide and VOCs into the atmosphere; playing a role in smog formation and polluting the air.
• Dust storms: A common contributor to the air pollution of arid African, Asian and Middle Eastern countries, dust storms (caused by wind eroding soil) release particulate matter into the air  – then transport it downwind to many other cities and regions.

There are other sources of natural pollutants – including sea spray aerosols, pollen allergens, geothermal activity, and the VOCs plants and trees naturally release into the atmosphere – but it’s the above three that tend to have the most tangible impact on city air quality.

We’ve explored the most polluted cities in the world at length, and examined the array of causes behind them.

But what harm does city pollution lead to – on our people, our economies, and our planet?

Let’s take a look.

City air pollution’s health risks for humans

Particulate matter and other air pollutants in cities have been linked to a litany of acute and chronic health issues in people, including:

• Respiratory issues, such as asthma and bronchitis, as well as exacerbating existing conditions
• Lung damage and reduced long-term lung damage
• Cardiovascular problems, including heart disease and strokes
• Neurological effects, including reduced cognitive function and an increased risk of developing neurodegenerative diseases, such as Parkinson’s disease

Worse still, some air pollutants – such as formaldehyde and benzene – are classified as carcinogens and breathing them in can increase a city-dweller’s cancer risk.

City air pollution’s environmental impact

Air and water pollution adds not only to human ailments, but those of our environment – and its non-human denizens, too. Pollution’s negative environmental effects include:

• The disruption of natural and aquatic ecosystems: harming plant, animal and marine ecosystems
• A loss of biodiversity, as pollutants kill off (and eventually render extinct) whole species of native plants and animals
• Soil contamination, which impacts its quality and fertility – and, therefore, its ability to nurture the plant growth so crucial to combating Earth’s ongoing climate crisis

City air pollution’s economic impact

Air pollution also has a wide-ranging set of impacts on a country’s economy – impacts which, sooner or later, end up getting passed down to its citizens. These include:

• Increased healthcare expenses (for both individuals and governments) due to higher incidences of illness and hospitalisations
• Reduced worker productivity and increased employee absenteeism due to health-related issues
• A decline in reputation as the tourism industries in countries with higher levels of pollution problems may suffer (it’s unlikely, for instance, that you’ll be rushing to book a holiday to Hotan or N’Djamena after reading this list)
• A decline in property values, which can affect homeowners and investors
• Damage to infrastructure: pollutants can corrode public buildings and monuments, leading to ballooning maintenance and repair costs
• A struggle to meet regulatory compliance demands as governments grapple with growing pollution issues and the resultant climate change initiatives they inspire
• A spike in energy costs as governments scramble to mitigate pollution by transitioning to cleaner energy sources, such as solar panels. Renewable energy will save individuals and countries money in the long run – but in the short-term, the transition can lead to a spike in energy costs (which is passed down to the consumer)

1. Chad

Laying claim to the unwanted accolade of being the most polluted country in the world is central African country, Chad. With a world-highest PM2.5 concentration of 89.7μg/m³, Chad’s air quality in 2022 was almost 18 times more than the WHO annual air quality guidelines value – an increase of 18 per cent from its 2021 levels.

Unsurprisingly, Chad also ranks rock bottom in our guide to the worst countries to live in as the climate crisis rages on. Among the factors fuelling the country’s meteoric pollution levels and poor climate-resilience are unregulated waste burning, dirty fuel, and a lack of adequate public transport exacerbating vehicle emissions.

The actions of Chad’s populace aren’t the sole reason for its pollution problems, though. Dust storms originating from the Bodele Depression (Chad’s lowest geographic point; and, perhaps, its figurative one, too) account for around half of the 40 million tonnes of dust swept across the Atlantic each year – and play their role in Chad’s world-worst quality of air.

To begin curtailing this, Chad has committed – with international aid – to scale back its total greenhouse gas emissions by 19.3 per cent by 2030.

2. Iraq

With an overall PM2.5 concentration of 80.1μg/m³ in 2022 – a steep increase from its 2021 level of 49.7μg/m³ – Iraq is the planet’s second-most polluted country. The Middle Eastern country’s emissions are a shocking 16 times beyond the WHO’s recommended levels.

Vehicular emissions, fires from oil and gas refiners and a heavy reliance on generator usage – borne from Iraq’s poor electrical infrastructure – all contribute to their pollution levels. The government’s increasing focus on oil production – without the accompanying safety protocols – has also being doing its bit to pump pollutants into Iraq’s atmosphere. In 2021, Iraq’s oil production (around four million barrels per day) was nearly double 2010 levels.

That said, it’s not just the oil production itself that accounts for the pollution – but how Iraq is going about it. “Flaring” – a controversial practice that involves burning off excess natural gas during oil extraction, and that’s been linked to asthma and cancer – is rife. And today, Iraq is the world’s second-worst culprit for flaring-associated greenhouse gas emissions.

Iraq’s plan to tackle pollution involves ambitious targets to lower its greenhouse gas emissions by 15 per cent below business-as-usual levels by 2035.

3. Pakistan

As the fifth-most populated country in the world, it’s no huge shock that Pakistan is among the worst countries when it comes to pollution.

With an air quality exceeding WHO-recommended levels 14-fold, Pakistan’s sprawling megacities – particularly the vehicles that traverse them and the steel mills fuelling their growth – account for most of its emissions. The practice of unregulated straw stubble and waste-burning is rife, particularly in the colder months – as are the brick kilns so integral to the daily lives of Pakistani people.

Fortunately for them, their government has plans to curtail emissions: with a cumulative, conditional target of a 50 per cent projected-emissions reduction by 2030.

4. India

Globally, there may be three countries that are more polluted than India – but when you break it down to city level, things don’t look good for Asia’s second-most-populated country.

A staggering 14 of the 20 most polluted cities of IQAir’s research belong to India: Bhiwadi (third), Delhi (fourth), Darbhanga (sixth), Asopur (seventh), New Delhi (ninth), Patna (10th), Ghaziabad (11th), Dharuhera (12th), Chapra (14th), Muzaffarnagar (15th), Greater Noida (17th), Bahadurgarh (18th), Faridabad (19th) and Muzaffarpur (20th).

Expand this focus out to the top 50 cities and 39 of them are Indian. That means 78 per cent of the 50 most polluted cities on the planet are located there – making it both a literal and metaphorical hot bed when it comes to the climate crisis.

So where is India’s shocking pollution problem coming from? Well, over half (51 per cent) of it comes from industrial pollution, including dust from construction. Fuelling this are exhaust fumes from vehicles (27 per cent), crop burning (17 per cent) as well as waste burning and domestic cooking.

The result? More than 140 million Indian people breathing air ten times – or more – than the safe limit the WHO sets.

But as we’ve seen, India’s pollution woes aren’t just an issue for the health of its own people – but for the planet at large. Fortunately, the country’s government has pledged to do something about it, with the target being to reduce India’s total projected carbon emissions by a billion metric tons from 2022 through to 2030. India has also promised to reduce its economy’s carbon intensity by at least 45 per cent by 2030 and hit net-zero emissions by 2070.

5. Bahrain

Despite having less than one-hundredth (0.63 per cent) of Pakistan’s population, Bahrain’s air pollution levels are at a similarly toxic level – with a PM2.5 concentration level of 66.6μg/m³ that’s more than 13 times higher than the WHO’s recommended benchmark.

Sandstorms, private vehicle emissions and the fertiliser manufacturing industry all contribute to Bahrain’s struggles for clean air, while – from a marine pollution standpoint – the country’s oil industry, population growth and increased marine litter have contributed to the decline of the local coral reefs, sea turtles and dugongs.

To combat this and pave the way for a more sustainable future, Bahrain committed, in 2021, to achieving net-zero greenhouse gas emissions by 2060.

6. Bangladesh

Sandwiched between India, Bhutan, and Myanmar, Bangladesh’s large population, low-lying terrain, and hot temperatures leave it uniquely vulnerable to climate change – as do its close to world-leading levels of pollution.

Bangladesh’s 2022 PM2.5 concentration levels of 65.8μg/m³ is less than previous years, but still high. Its capital, Dhaka, ranks 49th amongst the planet’s most polluted cities, with emissions from outdated buses, motorbikes, cars, and trucks among the top emission sources.

Like Pakistan, the Bangladeshi people rely on fossil fuel-burning brick kiln stoves for cooking, while – on an industrial level – the country’s clothing, food, and shipbuilding industries contribute to its greenhouse gas emitting endeavours. Bangladesh is hoping to reduce these, however, with plans to cut emissions 21.8 per cent by 2023.

7. Kuwait

After a sharp increase from the year prior, Kuwait’s 2022 PM2.5 concentration levels (55.8μg/m³, almost double that of 2021’s 29.7μg/m³) are better than only six other countries in the world.

Its most polluted city, the capital Kuwait City, registers PM2.5 concentrations of a staggering 152μg/m³ alone – while even its least polluted city, As Salimiyah, still posts a dangerously high level of 94μg/m³.

Despite having the strongest currency in the world – due to Kuwait’s rich glut of natural oil reserves – this wealth comes at a cost. And its high levels of air pollution are linked strongly to the extraction and exportation of this oil, as well as its processing and preparation for internal use. Vehicular emissions – particularly from heavy-duty transport carriers – play a role, too.

Kuwait’s environmental sustainability efforts aren’t quite as ambitious as some of the other pollution strugglers on this list, but they exist, and the goal is to reduce carbon emissions by 7.4 per cent by 2035.

8. Burkina Faso

West African country Burkina Faso’s 2022 PM2.5 concentration levels of 63μg/m³ place it eighth on the list of the world’s most polluted countries.

Among the culprits are old vehicles, biomass burning, and combustion processes, with citizens of the capital, Ouagadougou – the 55th most polluted city in the world – breathing some of the the planet’s most unsafe air. Wood burning and dusty dirty roads also play a role (as they do in the plight of all African countries grappling with severe air pollution).

In a country with limited access to healthcare and poor sanitation practices, pollution has even more serious consequences – and, in Burkina Faso, indoor air pollution accounts for 8.5 per cent of its population’s general morbidity.

Burkina Faso is, however, joining many of its international counterparts in committing to change. In 2021, the country set an emissions target – its first ever – of cutting emissions by just under 30 per cent by 2030.

9. Egypt

Placing ninth in our list of the most polluted countries in the world, with an average PM2.5 concentration level of 46.5μg/m³, is Egypt.

Like its fellow African countries Chad and Burkina Faso, Egypt’s topography impacts the country’s air pollution. Egypt’s dryness and the desert regions that surround it mean the country faces a steady influx of dust – without the natural cleansing effects of rainfall.

That said, industrial and vehicular emissions – as well as the open burning of waste material – also play their part. However, Egypt does have plans to do something about it. The “Egypt Vision 2030” project aims to reduce the country’s air pollution by 50 per cent by 2030.

10. China

With eight countries in the top 50 of IQAir’s live rankings (Beijing (second), Chengdu (ninth), Wuhan (14th), Shenyang (19th), Chongqing (26th), Guangzhou (28th), Shenzhen (30th), and Hangzhou (46th)), China’s cities are heavily overrepresented on the global stage when it comes to pollution.

Its cities Hotan and Kashgar were also two of the world’s most polluted, on average, in 2022 – placing second and 30th with PM2.5 concentration levels of 94.3μg/m³ and 73.4μg/m³, respectively.

Fuelling China’s air pollution are the emissions created by its rapid, and ongoing, economic and industrial growth – as well as the country’s power plants and coal-producing sectors. Also implicated are vehicular emissions, and the burning of fossil fuels in domestic settings for heating and cooking purposes.

It’s not just China’s air that’s suffering, either – but its water. The chemical fertilisers, raw sewage, and industrial waste that end up in China’s rivers and lakes accounts for around half of the $69 billion (£54.6 billion) its economy loses to pollution annually.

China’s pollution levels are, however, something the country is attempting to do something about. Plans are in place to decrease its carbon intensity by around two thirds (65 per cent) compared to its 2005 levels; to achieve more than 1,200GW of wind and solar power; and to observe a 25 per cent non-fossil fuel share in primary energy consumption by 2030.

11. United Arab Emirates

With a 2022 average PM2.5 concentration level of 45.9μg/m³, the UAE is one of the world’s most polluted countries. 

The most recent data supports this, too – with September 2023’s live IQAir rankings identifying the UAE’s largest city, Dubai, as the 10th-most polluted city in the world; its current PM2.5 concentration of 55μg/m³ constituting bad news for Dubai’s 3.3 million citizens.

Factors at play in the UAE’s pollution situation – as with most other countries that share the Middle Eastern country’s hot, dusty climate – include a mixture of both human and natural causations. The UAE’s high humidity levels and extreme heat trap pollutants in the atmosphere.

In the UAE, they’re from vehicular emissions (Dubai, in particular, is known as a place that demands private transport to get around), and from fuel combustion for water, energy, and other industrial activities, such as the country’s desalination plants.

What’s more, costly conservation efforts to turn around 130,000 square metres of land in Dubai into a giant tree nursery failed when the initiative interfered with plans to create the world’s largest shopping mall. The trees – which could’ve played a vital role in offsetting some of the UAE’s robust carbon dioxide emissions – perished, en masse.

The UAE’s climate goals, however, are transparent and ambitious. And, if the country achieves its target of net-zero emissions by 2050, it will be the first Middle East and North Africa (MENA) country to do so.

12. Tajikistan

Flanked by China to the East, Afghanistan to the South, and Uzbekistan to the West, Tajikistan rounds out this list of the top 12 most polluted countries in the world.

Though its current PM2.5 concentration levels have improved since the year prior (46μg/m³ in 2022, down from 59.4μg/m³ in 2021), Tajikistan still has a fair way to go to improve its air quality. A country that was under the rule of the Soviet Union before its collapse in 1991, Tajikistan’s current pollution woes are, unfortunately, ongoing effects from the unethical practices and policies the Soviet government imposed.

Among these? The widespread use of agricultural chemicals and mineral fertilisers – including herbicides, defoliants, and an insecticide called DDT (dichlorodiphenyltrichloroethane). Banned for agricultural uses worldwide by the 2001 Stockholm Convention on Persistent Organic Pollutants, DDT has continued to circulate illegally in Tajikistan for decades.

So much so that a WHO report stated that, in Tajikistan, the mean concentration of DDT in human breakfast milk is four times higher than the permissible level. Exposure to high doses can cause tremors, vomiting, shakiness, and seizures – and the chemical is considered a possible carcinogen for humans, too.

Other contributing factors to Tajikistan’s pollution include industry – namely, non ferrous metal production. The Talco aluminium plant at Tursunzoda (Tajikistan’s primary economic asset) generates huge amounts of toxic waste gases that’ve been linked to a spike in the number of birth defects among local people. 

To help combat its polluted air and protect its populace, Tajikistan has committed to a 40 to 50 percent emissions reduction by 2030 compared to 1990 levels (albeit conditional on international support; without that, the goal is a 30 to 40 per cent reduction).

Discussing the causes of city and country pollution, and its effects on our health and home can all be a bit demoralising, to say the least.

But, even if there isn’t a way out when it comes to air pollution’s role in the climate emergency, there is a way forward. So let’s unpack some of the potential solutions to tackling city pollution, and how governments – as well as how you, as an individual – can play a vital role.

Encouraging sustainable transportation alternatives

Transport is responsible for around one-fifth of all global carbon dioxide emissions – and, of this, cars account for 39 per cent of the transport-related CO2 in our atmosphere.

Is there a more energy-efficient way to get around, and to minimise a city’s transport-related pollutant output? There is – and it includes:

• Public transport: Cities with reliable bus, tram, subway, and train networks can help reduce individual reliance on private vehicles
• Cycling infrastructure: Dedicated cycling lanes and bike-sharing programs help to promote cycling as a sustainable alternative to driving (for context, cycling’s carbon footprint is just 33 grams per mile; 30 times less than that of a fossil-fuel-powered car.)
• Pedestrian-friendly spaces: Walkable urban areas with traffic-free paths and accessible crossings encourage city-dwellers to walk distances they’d otherwise drive
• Electric vehicles (EVs): Electric cars, scooters, and bikes don’t create the same pollutants as traditional cars. By incentivising EV uptake, providing comprehensive charging infrastructure, and promoting EV-friendly policies, city governments can help increase the number of EVs on the road (and decrease the ubiquity of their pollutant-producing counterparts)

Implementing urban planning strategies for greener cities

We’ve discussed above how investing in cycling and EV infrastructure, as well as designing pedestrian-friendly spaces, can cut down pollution. So what else can your city do?

• Increase the number of public parks, gardens, and green spaces in inner-city areas – planting trees and vegetation to provide shade, absorb pollutants, and enhance your city’s aesthetic appeal
• Plan for mixed-use developments that integrate residential, commercial, and recreation spaces – and reduce the need for long commutes
• Prioritise compact urban design – minimising the urban sprawl (and its associated transport emissions) by encouraging denser development
• Implement green building codes and standards that prioritise sustainable materials, green technology, and energy efficiency

Adopting stricter environmental regulations and policies

Green incentives and encouragement work well – particularly among a city’s more eco-conscious inhabitants. But at some point, anti-pollution principles need to become practice, which often means enshrining them in policy, first. This could include:

• Enforcing stringent emission standards for vehicles, industries, and power plants
• Implementing effective waste management systems to reduce litter, promote recycling and composting, and drive down landfill emissions
• Monitor and regulate industrial processes to minimise pollution and promote cleaner production practices
• Use zoning regulations to prevent heavy-polluting industries from setting up shop in your city’s most densely populated areas
• Demand thorough environmental impact assessments for new developments to understand their climate impact, and ensure they won’t exacerbate pollution

Ultimately, though, the best solution to reducing levels of air, water (and even noise) pollution in cities is by transitioning to renewable energy sources like solar, wind, and hydropower.

For more information about this – and what it looks like at an individual level – explore our guide to how to be more eco-friendly.

So – what have we discovered from this exploration of the world’s most polluted countries?

First, that there’s a clear link between pollution and poverty. Between Chad, Pakistan, India, Iraq, Bangladesh, Tajikistan, and Burkina Faso, deprived and developing countries comprise the bulk of the world’s most polluted countries, as do the cities that belong to them. Many of these countries are also the places least equipped to withstand climate change.

As predominantly hot countries close to the Equator, these countries’ geographical location and topography (often arid, desertised places) predisposes them to global boiling’s worst effects. What’s more, their struggling economies (with some notable exceptions, including Kuwait, India, and Bahrain) and poor socio-economic conditions mean they’re both unready for, and vulnerable to, the climate emergency’s most damaging impacts.

What does this all mean? That pollution and climate crisis isn’t the responsibility of its most egregious contributors alone. It’s a global effort; a matter of humanitarian aid.

Going forward, it’s the responsibility of wealthier countries to spearhead a united effort: to step forward, hand in hand, with countries like Chad, Burkina Faso, and Tajikistan, and walk with them as the world forges a pathway out of pollution – and towards a collective future defined by cleaner, greener, and more sustainable forms of energy.

A future that isn’t warmer – just brighter!