Air quality

Toxic air is one of the biggest threats to our health. Air pollution damages healthy lungs and makes problems worse for people living with a lung condition.

Air pollution is linked to up to 36,000 deaths in England every year and costs society more than £20 billion. Two of the most dangerous pollutants are nitrogen dioxide (NO2) from vehicles and particulate matter (PM2.5) from vehicles, wood burning, industry and farming. 

About Air Pollution

Here we answer some of the most asked questions around air pollution…

What is air pollution?

An air pollutant is anything in the air that could harm people’s health. There are many pollutants in the air, but the two most dangerous to health are nitrogen dioxide (NO2) and fine particulate matter (PM2.5).

Nitrogen Dioxide (NO2) is a gas formed by Nitrogen Oxides mixing with other gases in the atmosphere.

Fine Particulate Matter (PM2.5) is the name given to tiny particles of solids and liquids in the air, such as dust or dirt. The number refers to the size of the particles, so PM2.5 pollution has a diameter smaller than 2.5μm: 30 times smaller than the average human hair.

Where does air pollution come from?

Different emitters of NO2: Vehicles, industry, power generation and domestic heating


The main source of NO2 pollution is road traffic. At the roadside, 80% of NO2 comes from transport. Other sources include the energy industries, manufacturing and construction and non-road transport.


The main source of PM2.5 pollution is the manufacturing and construction sector, contributing 27% of PM2.5 emissions in 2020. However, domestic combustion – the burning of wood, coal and biomass at home – is the second largest source of emissions. It contributes 25% of all emissions, 70% of these are made up purely from burning wood. Road transport contributes 13% of PM2.5 emissions.

There is some level of PM2.5 that stems from natural sources such as sea spray and pollen, and some that travels to the UK from mainland Europe. It may therefore be impossible to completely remove PM2.5 from the air.

Where is air pollution worst?

Air pollution is worst near main roads during peak rush-hour periods. Short-term exposure to high quantities of air pollution on these roads can cause inflammation of the airways and increase susceptibility to respiratory infections. NO2 can exacerbate the symptoms of those already suffering from lung or heart conditions, causing symptom flare ups or asthma attacks which could lead to hospitalisation.

Similarly, pollution levels from wood burning are likely to be highest in the evenings during winter, or on bonfire night.

Find the levels of NO2 and PM2.5 air pollution across England and in your local areas using our lung health data tracker.

Can air pollution give you lung disease?

Air pollution is bad for everyone and breathing it in throughout our lives poses a threat to us all. It increases our risk of lung cancer and cardiovascular disease, and has been linked to up to 36,000 people dying early each year in the UK.  

It can worsen lung conditions, causing symptoms flare ups and asthma attacks, and even lead to hospitalisations or death. In 2020 air pollution was formally declared the cause of death of 9-year-old Ella Adoo-Kissi-Debrah. 

Short term exposure to air pollution can lead to: 

  • inflammation and irritation of the lining of the airways, which can cause symptoms such as coughing and difficulty breathing.  ​
  • asthma attacks, heart attacks or COPD flare-ups for people with lung conditions, including potential hospitalisation.  

Long-term exposure to air pollution can lead to: 

  • increased chance of early death, lung cancer and cardiovascular disease  
  • damage to developing lungs and brains during pregnancy.  
  • increased chance of low birth weight and premature birth.  
  • likely to cause new cases of asthma.  
  • stunted and smaller lungs in children, increased lung infections and likelihood of future lung problems.  
  • ​potentially increased risk of type 2 diabetes and dementia. 

Help and more info

Visit our website for more information on air pollution.