Air pollution’s impact on health


Evidence is mounting of associations between air pollution and a number of conditions including heart and lung disease, respiratory conditions, dementia, miscarriage, stunted lung growth in children, teenage psychotic episodes and reduced cognitive ability.

The two pollutants of most concern are Nitrogen Dioxide (NO2) and Particulate Matter (PM2.5 or 10). Other dangerous pollutants include ozone and sulphur dioxide.


Road transport is estimated to be responsible for about 50% of nitrogen oxide emissions in London. Diesel engines, once promoted as more environmentally-friendly alternatives to petrol, have contributed to the high levels of nitrogen dioxide (NO2) in London.

King’s College amongst others has strong evidence that nitrogen dioxide is harmful to health, with the most common outcomes being a shortness of breath and a cough. It inflames the lining of the lungs and reduces immunity to lung infections. This is worse for people with asthma.

In London, NO2 levels regularly exceed legal limits set by the European Union. EU standards require that NO2 annual mean value may not exceed 40 micrograms per cubic metre (µg/m3). In Brixton in 2017 that figure was 95 µg/m3). In 2018/19 monitoring in Brixton has been interrupted because of problems with the main monitoring station on Brixton Road.


Particulate Matter is tiny particles of liquids or solids such as metals or rubber suspended in the air. They mostly originate from engines (carbon emissions), and from engine wear and braking, but can include wind-blown dust. The WHO estimates that 30% of PM emissions in European cities comes from road transport. King’s College estimates that between 25% and 31% of London’s particulate emissions come from domestic wood burning for secondary heating.

According to the World Health Organisation (WHO), air pollution-related deaths are most closely linked to PM emissions. The majority of particles that can penetrate the airway are too small to see but are present in air that seems clean. Particles smaller than about 10 micrometers, (PM10, about 1/10 of a hair wide), enter the body via the lungs and are too small to be filtered out. They can then settle anywhere in the body, including the brain.


Although EVs offer improvements on CO2 and NO2 emissions, they continue to emit damaging PM due to tyre wear.  

Road transport is estimated to be responsible for about 50% of nitrogen oxide emissions in London

How can we tackle air pollution?

London’s Ultra Low Emission Zone (ULEZ)


Mayor Sadiq Khan introduced the new London ULEZ in April 2019, initially covering the area of the central London Congestion Charge. The ULEZ involves charging drivers of the most polluting vehicles to enter central London. For diesel vehicles this would be those which do not meet the Euro 6 engine standard.

The charge is enforced using number-plate recognition and the DVLA database, which includes every vehicle’s emission standards. Mr Khan has said the scheme aims to reduce tailpipe emissions from road transport in London by 45%.


The mayor has plans to expand the ULEZ to cover all areas inside the North and South circular roads in October 2021. Mums for Lungs fully supports that vision and sees it as an important step to tackling London’s dirty air. However, we would like it to go further. We would like to see the introduction of a London-wide ULEZ as soon as possible.

© Shutterstock

© Shutterstock

Mr Khan has said he hopes the ULEZ will reduce tailpipe emissions from road transport in London by 45%.


Central government action


The UK government published its national Clean Air Strategy in January 2019. The strategy for reducing sources of pollution also aims to increase awareness of air pollution, and includes a target to halve the population exposed to particulate matter (PM) exceeding WHO guidelines. However dealing with emissions from road transport, essential in dealing with particle emissions, is a glaring omission from this plan. While the strategy states that legislation to prohibit the sale of the most polluting fuels will be forthcoming, the government’s separate plans for phasing out diesel and petrol by 2040, Road To Zero and Air Quality Plan on Nitrogen Dioxide, are too little too late.

Today’s children will continue to breathe dirty air for years to come, and will be in their late 20s before diesel is phased out. We want to see the end of sales of new combustion engines by 2030 at the latest.

There have also been calls for a new Clean Air Act fit for the modern day. However the Prime Minister has said that new legislation covering clean air will be part of a new Environment Bill which is being drawn up for when the UK exits the European Union. The Department for Food and Rural Affairs (DEFRA) is currently drafting this legislation. Mums for Lungs would like to see WHO targets, particularly on Particulate Matter, enshrined in this law as binding levels.

Mums for Lungs Clean Air street party in Herne Hill, June 2019

Mums for Lungs Clean Air street party in Herne Hill, June 2019