What is air pollution

Air pollution is the contamination of air, both indoor and outdoor, from the presence of harmful substances in the atmosphere1.

Currently, the pollutants causing the most significant health impacts in the UK are emissions of nitrogen dioxide and particulate matter.

Particulate matter is made up of tiny pieces of solids or liquids that we breathe daily. Once inhaled, particulate matter circulates around the human body and embeds itself into organs, causing health risks. Particulate matter may contain soot, smoke, dust, and dirt2 and is normally referred to as PM2.5 when smaller than 2.5 micrometres in diameter or PM10 when smaller than ten micrometres in diameter.

Primary particulate matter comes from human made sources such as smoke from fires, soot from vehicle exhausts, dust from tyres and brakes, as well as emissions from industry and natural sources such as pollen and desert dust. Secondary particulate matter is the combination of other chemicals, such as sulphur dioxide, nitrogen oxides and ammonia.

Nitrogen dioxide (NO2) is a gas that is mainly produced during the combustion of fossil fuels, along with nitric oxide (NO). The Air Quality Standards Regulations 2010 require that the annual mean concentration of NO2 must not exceed 40 µg/m3 and that there should be no more than 18 exceedances of the hourly mean limit value (concentrations above 200 µg/m3) in a single year. Most concentrations of nitrogen dioxide measured at the roadside come from local transport sources4.

Air pollution and health

Air pollution is cited by the World Health Organisation as the one of the greatest environmental risks to our health3, with poor air quality contributing to 4.2 million premature deaths in 2016 alone – in the UK that figure is between 28,000 – 36,000 annually5.

The negative health impact of air pollution is significant, and, in some cases, severe. Those in particularly pollutant areas may experience the onset or worsening of asthma, respiratory problems, lung cancer, reduced lung growth, strokes, and cardiac disease6.

Those who are particularly vulnerable to air pollution are7:

  • Children
  • Elderly
  • Those with respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD) and emphysema
  • Those with heart disease or other heart conditions

As cited in the Air Quality Summary Report 2020, in Portsmouth there are around:

  • 52,200 children aged 19 and under
  • 13,800 people aged 65 and over
  • 3400 people living with a limiting long-term illness

Air pollution can damage our health even before birth. A 2022 study8 found that foetuses absorbed air pollution particles and were born with nanoparticles – known as black carbon – in their developing lungs and other vital organs. Heavily pregnant women spend 57%9 more time in a car, where they are exposed to higher volumes of particulate matter than pedestrians or cyclists, and low birth weights are a known result of air pollution exposure10.

Adapt everyday habits for big impact

If we can lower the volume that we smoke around others to address secondhand smoking health effects, why are we not doing the same for our air pollution use? Research in 2019 by British Heart Foundation discovered that air pollution health damage in the most polluted UK areas equate to the equivalent of smoking over 150 cigarettes a year11.

We can’t erase air pollution. But we can act to lower it.

So, Portsmouth, what are we going to do about it?