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London's air pollution and what it means for your health

Written by Laura Devaney

, 7 min read

London's air pollution and what it means for your health

Air pollution. In London, it’s just one of those things that you take as part of the full package of being resident here – along with lack of eye contact and overpriced pints. You breathe in that saturated air, with its signature chemical tang and somehow you romanticize it; that almost grey smell is synonymous with the beating heart of the city, the grungy, restless spirit of such a diverse and multifaceted place. But that ‘character’ that you’re inhaling is beginning to seriously damage your health.

When we think of air pollution, we think of a dusky amber sun only just peeping out from swathes of grey-brown smog, probably looking out over a congested highway in an Asian city. London rarely features in this largely foreign picture - but air pollution in our city has been labelled the “invisible killer”. The highly noticeable “smog” in other parts of the world is mostly due to coal-based pollution from energy production, which is far more noticeable, as the emissions particles are bigger, according to a study by King’s College London. What’s so worrying about the emissions in London, is that they are smaller and therefore mainly invisible - emerging from diesel car exhausts on our busy streets, particularly in the more congested parts of the city. So when you’re traipsing by Piccadilly Circus, or hurrying over Waterloo bridge, you are immersed in what is known as particulate matter, specifically nitrogen dioxide (NO2) - among other, more obvious things such as CO2. Considering that we can still admire a clear view of the Thames and enjoy a bright spring day, despite these pollutants densely surrounding us, proves how their invisibility is a large factor in why we have managed to ignore it for so long.

These NO2 particles are smaller than other emissions, having been measured at 2.5 micrometres of particulate matter, or PM2.5, in areas of London. According to the aforementioned King’s College London study, particulate matter that is smaller than PM10 is able to travel through the alveoli in your lungs and thus into the cardiovascular system, which can result in health complications, such as exacerbated lung conditions like asthma and emphysema. It also has the potential to block arteries, increasing the risk of stroke and heart attacks (BBC News). According to The Guardian, scientists have published studies that are even beginning to make links between exposure to PM2.5 particles and dementia, teenage psychosis, and even premature births and defects. Pretty scary right? So how did it get this bad?

The World Health Organisation (WHO) has advised on certain boundaries concerning particulate matter emissions, however the EU and UK governments did not accept them, and instead set higher levels. According to the WHO website, the guidelines for PM2.5 matter as an annual average is 10 micrograms per cubic metre, or 10μg/m3 . In an air quality report, the UK Department of Environment Food & Rural Affairs states its 2020 target as an annual average of 25μg/m3, which exceeds the WHO guidelines by 15μg/m3 .This often means that we regularly fall under the upper limits enforced by the government, but consistently exceed those advised by the WHO - without ringing any legal alarm bells. As a result of these arguably lax controls on emissions, air pollution is linked to at least 40,000 premature deaths per year from lung and heart disease, as stated in The Guardian. Thankfully, other actions are being taken to ease such severe levels - particularly where it is at its highest in Central London.

As of the 8th April this year, the Mayor of London Sadiq Khan enforced an Ultra Low Emission Zone (ULEZ). Khan has set this in action within the same area as the Congestion Charge, after dubbing our poor air quality a “public health emergency”. This is in a move to improve the city’s air quality overall, but with particular focus on children, who are among the most vulnerable to heart and lung problems as a result of polluted air. A figure included on the TfL website states that there are 360 primary schools in areas with illegal levels of pollution. Being exposed to densely polluted air at such a young age can negatively impact a child’s development. A study included in a BBC News report has stated that children who grow up in heavily polluted areas have up to a 5% smaller lung capacity than those who live in cleaner areas. This means that something as uncontrollable as your childhood environment can have a hugely significant effect on an aspect as vital as lung health for the rest of your life.

Such issues have not gone unnoticed by everyone - there are a number of environmental groups who are trying to raise awareness on the topic. One of the most notable is Extinction Rebellion, who occupied busy areas of London over a week-long period in April, bringing them to a standstill. This resulted in the government declaring a Climate Emergency. If we can improve London’s pollution problem, it will be the first step in similar actions to be taken throughout the globe. And, that which is good for our planet is often good for our health too. They really do go hand in hand; from the way we get around, to the materials that we use and even down to the food that we eat.

With this in mind, until the effects of the above actions come into fruition, there are things that you can do to protect yourself from air pollution:

  • Use backstreets or less travelled roads if walking, cycling or running. Pollution levels are highest around areas with high traffic, so aim to avoid congested and busy areas when possible. Main roads and junctions are particularly traffic heavy. The government’s Clean Air Route Finder is a great resource. It will pick out your route to fit quieter, less busy roads so you can bypass polluted routes.
  • Avoid travelling at times of the day when pollution levels are at their highest. Pollution levels vary throughout the day. Midday and rush hour are especially bad times to be out and about. Of course it is not always possible or practical to avoid travelling at these times, but a suggestion from the British Lung Foundation is to consider leaving for (and from) work a little earlier so as to avoid rush hour.
  • Don’t exercise outdoors in areas where pollution levels are high. Exercise is incredibly important and fundamental to maintaining good health, but it also makes you breathe faster and deeper, therefore increasing the amount of pollution entering your lungs. Aim to either exercise indoors, or away from areas of high traffic and roadsides. If this is not possible, try to exercise at times of the day when pollution levels are at their lowest (very early mornings and late evenings).
  • Maintain a healthy diet, filled with fresh fruit and vegetables. Pollutants are known to deplete antioxidants. A study in Mexico found results suggesting that when asthmatic children take an antioxidant supplement, they are better protected against the effects of pollution on their airways.1 Fresh fruit and vegetables are packed with antioxidants, so could well offer you some protection.
  • Keep an eye on your breathing. If you have asthma or a lung condition, take your inhalers or medication regularly. Make sure you speak to a GP if your are concerned about your breathing.
  • Check the air pollution forecast. Visit and take note of any official announcements that advise of high air pollution levels.
  • Join the houseplant trend! Besides photosynthesis that removes carbon dioxide and returns oxygen to the air, plants can remove toxins from air, soil, and water2. Various studies (including one by the National Aeronautics and Space Administration, NASA) have suggested that plants might improve indoor air and make interior breathing spaces healthier. The findings aren’t always 100% conclusive nor entirely relatable to the average home or office environment, but there’s no harm in dotting a potted plant or two here and there.

If you really are worried about your health in view of London’s poor air quality, you can always have a look at Babylon’s Healthcheck, which will take into account the air pollution in urban, suburban or rural areas when asking various questions about your lung and respiratory health. Ensuring that you keep tabs on it and reporting anything unusual is key to spotting problems that may arise as a result of living in highly polluted areas. And remember: what’s good for the planet is usually what’s good for your health too.


  1. Romieu et al. Antioxidant supplementation and lung functions among children with asthma exposed to high levels of air pollutants. Am J Respir Crit Care Med. 2002 Sep 1;166(5):703-9.
  2. Luz Claudio. Planting Healthier Indoor Air. Environ Health Perspect. 2011 Oct; 119(10): a426–a427

Further information

LondonAir -

UK Air - Health Matters: Air pollution -

The information provided is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Seek the advice of a doctor with any questions you may have regarding a medical condition. Never delay seeking or disregard professional medical advice because of something you have read here.

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