Nearly ALL of the world is breathing dirty air: Shocking map reveals how just 17% of cities have safe levels of air pollution - so, how toxic is your hometown? READ MORE: Charts reveal deadly air pollution levels in cities over 160 years By WILIAM HUNTER Published: 16:36 GMT, 11 March 2025 | Updated: 16:57 GMT, 11 March 2025 Nearly the entire world is breathing dirty air, a shocking new study has revealed. A report from the air quality monitoring database, IQAir, found that just 17 per cent of cities meet the World Health Organisation's (WHO's) air pollution guidelines. As this map reveals, 91 per cent of all countries had unsafe levels of air pollution in 2024. Chad, Congo, Bangladesh, Pakistan and India had the dirtiest air. Meanwhile, India was home to six of the nine most polluted cities. The town of Byrnihat in northeastern India came in as the world's most polluted area. Worryingly, experts say that the real levels of pollution could be even higher still, as many places around the world lack proper monitoring technology. Frank Hammes, Global CEO of IQAir, says: 'Air pollution remains a critical threat to both human health and environmental stability, yet vast populations remain unaware of their exposure levels.' A map shows how just 17 per cent of cities meet air pollution guidelines. On this map, only blue circles show areas with levels of air pollution considered safe by the WHO India was home to seven of the nine most polluted cities in the world, including New Delhi (pictured) which had 91.6 micrograms of PM2.5 particles per square metre of air - 18 times higher than guidelines recommend Pakistan (pictured) had levels of air pollution more than 14 times higher than the WHO guidelines The IQAir survey draws on data from 40,000 air quality monitoring stations in 138 countries. Together these create a comprehensive picture of the levels of pollution in most major cities around the world. To find out how dirty your hometown is, you can explore the IQAir interactive air pollution map at this link. To find a specific location, either zoom in or use the search bar in the top right-hand corner and click on the coloured circle above the city. According to the WHO, levels of pollution above 5µg/m3 of fine pollution particles, also known as PM2.5, are 'associated with important risks to public health.' Polluted air can cause respiratory illness, Alzheimer´s disease and cancer and the WHO estimates that seven million people die each year from exposure to air pollution concentrations above safe levels. However, as this map shows, the vast majority of the world's cities exceed the guideline levels. On the map, only the cities represented by blue circles have safe air pollution levels, green circles show those cities with PM2.5 levels up to double the WHO threshold, and darker colours represent more severe levels of pollution. Although some countries such as China and Korea have seen some improvements in air pollution levels, Asia remains one of the most polluted regions on Earth Lahore, Pakistan had pollution levels more than 20 times higher than the WHO considers safe. During November, Lahore's average pollution concentration was 57 times higher than the guideline amount The most polluted area in the US was Ontario, California with 14.3µg/m3 or air pollution. The most polluted major city was Los Angeles, California which has levels of air pollution twice the recommended average Oceania is the world's least polluted continent, home to 57 per cent of regional cities meeting the WHO guidelines. Australia is also one of seve countries to have average air pollution levels below the WHO guidelines The 10 most polluted cities in the world Byrnihat, India: 128.2µg/m3 Delhi, India: 108.3µg/m3 Karaganda, Kazakhstan: 104.8µg/m3 Mullanpur, India: 102.3µg/m3 Lahore, Pakistan: 102.1µg/m3 Faridabad, India: 101.2µg/m3 Dera Ismail Khan, Pakistan: 93µg/m3 N'Djamena Chad: 91.8µg/m3 Loni, India: 91.7µg/m3 New Delhi, India: 91.6µg/m3 Advertisement The most polluted cities, with particulate levels more than 10 times higher than the WHO threshold, are shown in purple. Most of these are clustered in Southern and Central Asia which is home to the world's seven most polluted cities. Byrnihat, an industrial town in northern India, was the most polluted metropolitan area of 2024, with an annual average PM2.5 concentration of 128.2 µg/m3 - more than 25 times higher than the WHO's recommended levels. This was followed by Delhi with pollution levels of 108.3 µg/m3 and Karaganda, Kazakhstan with a pollution level of 104.8µg/m3. In the UK, the most polluted area is Northwood in northwest London which had an annual average PM2.5 concentration of 11.3µg/m3 - more than twice the level recommended by the WHO. Liverpool followed closely as the second most polluted city, with 10.3µg/m3, while Greetham in the East Midlands came in third with 10µg/m3 on average. Only seven countries met the WHO's annual average pollution guidelines during 2024. Those countries were: Australia, the Bahamas, Barbados, Estonia, Grenada, Iceland, and New Zealand. The most polluted area in the UK was Northwood in northwest London, which had an annual average PM2.5 concentration of 11.3µg/m3 - more than twice the level recommended by the WHO Previous studies have shown how London's air pollution fell sharply after reaching a peak in the 1960s However, all areas of London (pictured) currently remain above the WHO's recommended air pollution levels Overall, Oceania was the world's cleanest region with 57 per cent of regional cities meeting the WHO guidelines. Additionally, some of the world's most polluted regions showed some signs of improvement year on year. The IQAir report notes that every city in Southeast Asia decreased its levels of pollution between 2023 and 2024. Several cities like Beijing, Seoul, South Korea, and Rybnik in Poland have successfully improved their air quality through stricter regulations on pollution from vehicles, power plants and industry. Common household products create plumes of indoor air pollution that you 'shouldn't be breathing in' Another notable efforts to curb severe air pollution was the Association of Southeast Asian Nations agreement on transboundary haze pollution. Even though it has had limited success so far, ten countries in the region pledged to work together to monitor and curb pollution from large forest fires, a common occurrence in the region during dry seasons. However, the vast majority of the world continues to face dirty air. Aidan Farrow, senior air quality scientist with Greenpeace International, says: 'The World Air Quality Report, which compiles measurements of air pollution from around the globe, should be a rallying call for urgent and concerted international efforts to cut pollutant emissions.' Revealed: MailOnline dissects the impact greenhouse gases have on the planet - and what is being done to stop air pollution Carbon dioxide Carbon dioxide (CO2) is one of the biggest contributors to global warming. After the gas is released into the atmosphere it stays there, making it difficult for heat to escape - and warming up the planet in the process. It is primarily released from burning fossil fuels such as coal, oil and gas, as well as cement production. The average monthly concentration of CO2 in the Earth's atmosphere, as of April 2019, is 413 parts per million (ppm). Before the Industrial Revolution, the concentration was just 280 ppm. CO2 concentration has fluctuated over the last 800,000 years between 180 to 280ppm, but has been vastly accelerated by pollution caused by humans. AirVisual Privacy Policy Nitrogen dioxide The gas nitrogen dioxide (NO2) comes from burning fossil fuels, car exhaust emissions and the use of nitrogen-based fertilisers used in agriculture. Although there is far less NO2 in the atmosphere than CO2, it is between 200 and 300 times more effective at trapping heat. Sulfur dioxide Sulfur dioxide (SO2) also primarily comes from fossil fuel burning, but can also be released from car exhausts. SO2 can react with water, oxygen and other chemicals in the atmosphere to cause acid rain. Carbon monoxide Carbon monoxide (CO) is an indirect greenhouse gas as it reacts with hydroxyl radicals, removing them. Hydroxyl radicals reduce the lifetime of carbon dioxide and other greenhouse gases. Particulates What is particulate matter? Particulate matter refers to tiny parts of solids or liquid materials in the air. Some are visible, such as dust, whereas others cannot be seen by the naked eye. Materials such as metals, microplastics, soil and chemicals can be in particulate matter. Particulate matter (or PM) is described in micrometres. The two main ones mentioned in reports and studies are PM10 (less than 10 micrometres) and PM2.5 (less than 2.5 micrometres). Air pollution comes from burning fossil fuels, cars, cement making and agriculture Scientists measure the rate of particulates in the air by cubic metre. Particulate matter is sent into the air by a number of processes including burning fossil fuels, driving cars and steel making. Why are particulates dangerous? Particulates are dangerous because those less than 10 micrometres in diameter can get deep into your lungs, or even pass into your bloodstream. Particulates are found in higher concentrations in urban areas, particularly along main roads. Health impact What sort of health problems can pollution cause? According to the World Health Organization, a third of deaths from stroke, lung cancer and heart disease can be linked to air pollution. Some of the effects of air pollution on the body are not understood, but pollution may increase inflammation which narrows the arteries leading to heart attacks or strokes. As well as this, almost one in 10 lung cancer cases in the UK are caused by air pollution. Particulates find their way into the lungs and get lodged there, causing inflammation and damage. As well as this, some chemicals in particulates that make their way into the body can cause cancer. Deaths from pollution Around seven million people die prematurely because of air pollution every year. Pollution can cause a number of issues including asthma attacks, strokes, various cancers and cardiovascular problems. Asthma triggers Air pollution can cause problems for asthma sufferers for a number of reasons. Pollutants in traffic fumes can irritate the airways, and particulates can get into your lungs and throat and make these areas inflamed. Problems in pregnancy Women exposed to air pollution before getting pregnant are nearly 20 per cent more likely to have babies with birth defects, research suggested in January 2018. Living within 3.1 miles (5km) of a highly-polluted area one month before conceiving makes women more likely to give birth to babies with defects such as cleft palates or lips, a study by University of Cincinnati found. For every 0.01mg/m3 increase in fine air particles, birth defects rise by 19 per cent, the research adds. Previous research suggests this causes birth defects as a result of women suffering inflammation and 'internal stress'. What is being done to tackle air pollution? Paris agreement on climate change The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. It hopes to hold the increase in the global average temperature to below 2°C (3.6ºF) 'and to pursue efforts to limit the temperature increase to 1.5°C (2.7°F)'. Carbon neutral by 2050 The UK government has announced plans to make the country carbon neutral by 2050. They plan to do this by planting more trees and by installing 'carbon capture' technology at the source of the pollution. Some critics are worried that this first option will be used by the government to export its carbon offsetting to other countries. International carbon credits let nations continue emitting carbon while paying for trees to be planted elsewhere, balancing out their emissions. No new petrol or diesel vehicles by 2040 In 2017, the UK government announced the sale of new petrol and diesel cars would be banned by 2040. However, MPs on the climate change committee have urged the government to bring the ban forward to 2030, as by then they will have an equivalent range and price. The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. Pictured: air pollution over Paris in 2019. Norway's electric car subsidies The speedy electrification of Norway's automotive fleet is attributed mainly to generous state subsidies. Electric cars are almost entirely exempt from the heavy taxes imposed on petrol and diesel cars, which makes them competitively priced. A VW Golf with a standard combustion engine costs nearly 334,000 kroner (34,500 euros, $38,600), while its electric cousin the e-Golf costs 326,000 kroner thanks to a lower tax quotient. Criticisms of inaction on climate change The Committee on Climate Change (CCC) has said there is a 'shocking' lack of Government preparation for the risks to the country from climate change. The committee assessed 33 areas where the risks of climate change had to be addressed – from flood resilience of properties to impacts on farmland and supply chains – and found no real progress in any of them. The UK is not prepared for 2°C of warming, the level at which countries have pledged to curb temperature rises, let alone a 4°C rise, which is possible if greenhouse gases are not cut globally, the committee said. It added that cities need more green spaces to stop the urban 'heat island' effect, and to prevent floods by soaking up heavy rainfall. PakistanIndia Share or comment on this article: Nearly ALL of the world is breathing dirty air: Shocking map reveals how just 17% of cities have safe levels of air pollution - so, how toxic is your hometown? Add comment