The Big Smoke — Is London Killing Us?

Air pollution is a serious issue in the Capital. But an unlikely success story can be found in one inner-London borough.

They don’t call it “The Big Smoke” for nothing. London is famous for more than just its red buses and overly-reserved residents. The Capital’s smog has loitered along the city’s skyline for centuries, a tangible indicator of a startling air pollution problem. But how bad exactly is the air in London, and what can we do about it?

An invisible killer

Ella Kissi-Debrah was only nine years old when she died from acute respiratory failure in 2013. Although the cause of the asthma attack was not determined, evidence this year has revealed that “without the unlawful levels of air pollution at the time, Ella would not have died”. Stephen Holgate — a professor of immunopharmacology at the University of Southampton — found a correlation between spikes in nitrogen dioxide levels in the air, and Ella’s hospital admissions. Ella’s mother is now fighting for a new inquest into her death, with the help of human rights lawyers. Jocelyn Cockburn, from Hodge Jones & Allen Solicitors has written to the Attorney General asking for a fresh probe into Ella’s untimely death. Cockburn believes that “lessons can be learned to prevent future deaths”.

Although Ella’s death was likely an immediate consequence of spikes in air pollution, it turns out that thousands of Londoners die each year due to long-term exposure to pollutants. One such category of pollutants is NOx (oxides of nitrogen), which is a mixture of all gases made up of nitrogen and oxygen. Oxides of nitrogen have been proven to instigate serious respiratory diseases; they cause inflammation of the airways, and can trigger asthma attacks. But where do these gases come from? A significant amount of oxides of nitrogen are released from car exhausts, making our roads hotbeds for harmful gases. Approximately 50% of all air pollution in London comes from road transport, with 40% coming from diesel.

In 2013 — the latest year an accurate air pollution model is available — it was found that most main roads in London were breaching EU air pollution limits. A visual representation of London is shown below, with the percentage of main roads in each borough that exceeded EU limits.

A cartographic representation of the percentage of roads in each district breaking EU pollution laws.

The top five worst local authorities were Camden, Hammersmith & Fulham, Kensington & Chelsea, Westminster, and the City of London. For each of these districts, 100% of all their main roads surpassed EU air pollution limits.

Pollution over time

When levels of oxides of nitrogen are visualised for these districts, the severity of the situation is exposed. Please note, recent data for Hammersmith & Fulham is not available due to data-collection at monitoring sites being discontinued.

Levels of oxides of nitrogen for four London boroughs over time.

The first thing you might notice is how ‘noisy’ the pollution levels are. Over time, you see sharp spikes in oxides of nitrogen — the same spikes that may have killed Ella Kissi-Debrah. The EU limit for oxides of nitrogen is approximately 20 parts per billion (ppb). If this limit is exceeded, then air pollution levels are deemed to be detrimental to human health. You don’t need to be an environmental expert to see that all the districts mentioned breach this limit by an extraordinary amount. In fact, the City of London went 3700% over this limit at one point in 2013! But what is the underlying trend for pollution in London? Let’s remove all the noise and find out.

The underlying trend for oxides of nitrogen of four London boroughs over time.

The average trend for each district can tell us a lot about how air pollution is managed in London. The good news is that pollution levels are falling. And the bad news? Pollution isn’t decreasing fast enough. Oxides of nitrogen in the City of London and Kensington & Chelsea have only decreased by 0.9% and 0.3% respectively over the last five years; this is not a significant change at all. Oxides of nitrogen have fallen by 4% since 2013 in Camden. The real success story however is Westminster: pollution has fallen by over 7% in the last five years. Westminster started off in 2013 with the highest levels of oxides of nitrogen out of the four investigated districts, but the most recent readings in 2018 show that Westminster — on average — has lower levels of air pollution than Camden and the City of London.

Westminster — a success story

A significant reason for Westminster’s rapidly improving air quality is the implementation of several environmental strategies. To name a few of their policies, Westminster City Council has pioneered low emission zones, introduced discounted parking and increased recharging points for electric vehicles, established ‘Coach and Heavy Goods Vehicles Ban Areas’, reduced Council fleet emissions, and engaged with the public to encourage sustainable driving practices.

Westminster City Council is at present considering putting in place parking surcharges for diesel vehicles. Over the last year, Westminster has trialled this strategy in a few areas, but it may now roll this out across the entire borough. In addition to this, there have been talks of potentially pedestrianising Oxford Street — a controversial yet progressive possibility.

Air pollution is not a distant danger; it has killed thousands upon thousands of Londoners over the years, and it is slowly killing us. But our story doesn’t need to have a tragic ending. If drastic policies are executed across the city — following Westminster’s example — we can prevent our lives from being needlessly shortened.

For more information, visit

To download pollution data, visit

If you are concerned about air pollution in your area, write to your local councillor or MP.

The data was visualised by the author, Ismail Jan.

Creating honest narratives through data.

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