Map reveals most polluted cities in the world, as fumes are linked to surge in lung and colon cancer...how does your area fair?

Daily Mail​

07-05-2025

The global air pollution crisis was today laid bare in an interactive map revealing the catastrophic levels of toxic fumes in some regions—including parts of the UK.
The World Health Organisation (WHO) has long demanded countries take tougher action to combat the scourge of pollution, which is thought to kill 7million people every year globally.
In a fresh study tracking more than 13,000 urban areas worldwide, US researchers used satellite data and computer models to measure the amount of harmful carbon dioxide released into the atmosphere.
Average levels of three pollutants close to residential areas were also assessed over 14 years.
These included particles less than 2.5 micrometers in diameter (PM2.5), nitrogen dioxide (NO2) and ozone (O3).
Exposure to all four has been linked to increased risk of a host of deadly diseases, including lung and colon cancer, as well as heart disease and dementia.
The particles, emitted by car exhausts and wood-burning stoves, can be so small they are invisible to the naked eye, yet travel deep into the lungs and bloodstream.
Now the numbers — packaged into an interactive tool by MailOnline — allow you to see how many particles are released on average depending on where you live in the UK. The interactive global map can also be accessed here.
According to the latest 2019 figures collected by the scientists, in the UK the East of England fared worst for PM2.5—which can lodge in the heart, brain and other organs.
Ipswich in Suffolk took top spot with 15.88 parts per billion (ppb), followed only by Basildon and Southend, both in Essex, reporting rates of 15.81 and 15.79 respectively.
Cambridge and Chelmsford also recorded levels at 15.52 and 15.36.
By comparison, Londonderry in Northern Ireland and Greenock, in western Scotland, reported the lowest rates of 6.36 and 7.33 ppb.
Research has long indicated PM2.5 can promote the growth of cancer-causing cells in the lungs and colon.
On 2022 study by scientists at University College London revealed around 300,000 lung cancer deaths were attributed to PM2.5 exposure in 2019.
Another, published last year by Chinese researchers also found just a 5 μg/m3 or 2.83 ppb increase in PM2.5 exposure could increase the risk of colon cancer by 27 per cent.
But many other of its heath effects are still to be discovered.
O3, meanwhile, is created by reactions between nitrogen oxides and volatile organic compounds, both emitted by vehicles and industrial processes.
At ground level, ozone causes a smoggy haze typically seen in cities and can cause breathing problems, especially for vulnerable people who suffer from lung diseases such as asthma.
Hereford and Folkestone in Kent recorded the highest O3 levels in the country, at 37.96 and 37.94 ppb respectively.
York, in contrast, ranked lowest at 24.08.
Under WHO guidelines, O3 levels should not exceed roughly 47 ppb over an 8-hour period.
London was the highest CO2 emitter, the figures also suggested—exceeding recommended guidelines—and the only part of the UK to hit the CO2 red zone.
Newcastle and Chatham, meanwhile, ranked highest for NO2 levels, at 11.75 and 11.42ppb emitted.
London and Peterborough followed with 11.33 and 11.03ppb respectively.
NO2 has been found to trigger respiratory problems that can cause hospital and emergency department admissions, such as asthma and symptoms including coughing, wheezing and difficulty breathing.
UK laws currently state hourly levels of toxic NO2 must not exceed the threshold of roughly 21ppb, more than 18 times a year.
Globally, O3 levels increased 6 per cent between 2005 and 2019, the researchers found.
However, PM2.5 and NO2 showed 'little to no overall change'.
The highest levels of PM2.5 were found in India, with Indian cities double the global average ppb levels.
'Highly polluted PM2.5 clusters' were also observed in Bangladesh, Pakistan, Nigeria, Saudi Arabia and China, the researchers said.
Urban areas with the highest NO2 levels—exceeding 12.1 ppb—were also primarily in 'China and high-income countries'.
Similar to PM2.5, cities in India also recorded the highest levels of O3—averaging 66.7 ppb—almost a third (30 per cent) higher than the global average (51.2 ppb).
South Asia—largely due to India—and China had higher levels of PM2.5 and O3 concentrations compared to other regions, the scientists said.
Professor Susan Anenberg, an expert in environmental and occupational health at George Washington University and study co-author also added: 'This study provides a powerful snapshot of how urban environments are evolving across the globe.
'It also shows that progress is possible but uneven, with some cities seeing worsening pollution while others are experiencing cleaner air over time.'
Writing in the journal Communications Earth & Environment, however, the scientists noted the research had 'some limitations'.
While the study incorporated 'state-of-the-art methods to improve the accuracy of measurements', the data may 'still contain errors due to insufficient input data, incorrect model processes, and erroneous emission data', they said.