‘Air quality’ describes the cleanliness of the air we breathe, and ‘poor air quality’ means that the air is polluted with gases and particles which are harmful to our health.
Nitrogen dioxide (NO2 or NOx)
NO2 is an invisible gas produced when fossil fuels are burned, for example, petrol and diesel in vehicle engines, and gas in boilers and gas stoves. NO2 is sometimes expressed as ‘NOx’, which includes NO2 and nitrogen oxide (NO), another gas produced at the same time as NO2.
NO2 is a respiratory irritant and can cause inflammation of the airways. This can lead to coughing, wheezing, and shortness of breath. Exposure to NO2 can reduce lung development in babies and children, which can affect lung health throughout life.
Particulate matter (PM)
Particulate matter refers to solid or liquid particles suspended in the air. PM is often written as ‘PM10’ or ‘PM2.5’; the number indicates the size of the particles in micrometres (a micrometre is one-thousandth of a millimetre). For comparison, human hair is about 50 micrometres in diameter. PM2.5 is referred to as ‘fine particulate matter’ because it is so small and can reach deep into the lungs and even the bloodstream.
The majority of PM is from human activities such as burning fossil fuels in vehicle engines, in kitchens and in open fireplaces and wood-burning stoves. Outdoor fires (such as garden bonfires) are also a source of PM. PM is also produced when building materials are crushed or broken on construction sites, and by friction between surfaces such as vehicle tyres on roads.
Long-term exposure to PM increases the risk of heart and lung disease, while short-term exposure can trigger or exacerbate health conditions such as asthma. The World Health Organization does not believe there to be any safe level of exposure to PM2.5.
Air pollution and health
Long-term exposure to air pollution is estimated to cause as many as 36,000 deaths each year. Air pollution can affect everyone’s health at any stage in our lives, but children and young people, older people, and people with existing lung or heart conditions are more vulnerable to the health effects of air pollution.
Some communities are disproportionately affected by air pollution, meaning they are exposed to more air pollution and experience worse health impacts as a result. Typically in the United Kingdom deprived neighbourhoods and Black, Asian and minority ethnic populations are exposed to higher levels of air pollution. This is an environmental health inequity and Camden is committed to tackling this.
For further information about air quality and health, visit Public Health England’s information page ‘Health matters: air pollution’.
We were the first local authority to commit to achieving the World Health Organization air quality standards by 2030, and our mission is to realise Camden’s citizens’ vision for a borough in which nobody suffers ill-health as a result of the air they breathe.