The World Health Organisation states that air pollution is a “public health emergency”.
The World Health Organisation states that air pollution is a “public health emergency”.
illustration of three clouds getting larger and flowing of of each other

Nine out of ten people breath polluted air which exceeds the safe guideline limits outlined by the World Health Organisation.

Air pollution is the 5th highest health risk factor for death in the world, 7 million people die every year. Air pollution causes one third of deaths from stroke, lung cancer and heart disease.

Particles of soot can pass from the lungs into the placenta of pregnant women living in areas with poor air quality.


How air pollution affects our health

All people are at risk from breathing in polluted air but those with greater exposure or susceptibility are most at risk – children and unborn babies, people living in cities with poor air quality, and office workers in poorly ventilated buildings.


Air is polluted by particles of harmful chemicals emitted during vehicle combustion, energy generation, and manufacturing processes.


These particles make their way into the human body where they can inflame and constrict the movement of blood in fine blood vessels which increases blood pressure. This can happen within the lungs, heart, and throughout the whole body, raising the risk of stroke or heart attack and heart disease.


The particles we breath in from polluted air are known as Particulate Matter or PM. The term is used to describe the mixture of solid particles and liquid droplets in the air.


Particulate matter varies in size; particles with a diameter of less than 10 micrometres are referred to as PM. Smaller particles are known as fine particulate matter or PM2.5 and have a diameter of less than 2.5 micrometres or one 400th of a millimetre wide. PM2.5 typically makes up two thirds of all particulate matter. It is considered to be the most harmful to human health.

Long term exposure to particulate air pollution can result in creating a health body burden.



Particulate matter can cause headaches and anxiety, strokes, and dementia. Fine particulate matter (PM2) can make its way into the central nervous system.


Air polluted by particulate matter causes breathing problems and inflammation in the lining of the lungs, reducing key functions and immunity. It can lead to infections, especially for people with asthma; children are most at risk. It increases the risk of COPD. Exposure to air pollution can also age the lungs, shortening life expectancy.


Particulate matter can harden the arteries and constrict blood vessels, leading to coronary disease, heart attacks, and damage to other key body organs.


Particulate matter and nitrogen oxides can make their way into the bloodstream reducing the body’s natural ability to detoxify. Possible wider effects of a compromised detoxification system aren't yet understood, but epidemiological studies have linked trace toxicity to a wide range of conditions, including cancers.

Reproduction and babies

Airborne soot can pass from mothers to unborn children via the placenta. This can result in premature births and low birth weights. Air pollution can also result in lower fertility levels in women who are trying to conceive.

A diagram of a man with his head rotated to the right Brain Lungs Heart Liver Reproduction
A blue circle with a diagram of the human brain outlined within the circle a smaller red dot indicates a part of it
Blue circle with the diagram of lungs in the centre and a small red circle indicating part of the lung
A blue circle with a diagram of a human heart in the centre with a little red dot indicating part of it
Blue circle with diagram of the liver outlined with little red circle indicating part of the liver
Blue circle with image of Reproductive glands (Ovaries) outlined in the centre
of air pollution

Cars and transportation

  • Nitrogen released during vehicle engine combustion combines with oxygen in the atmosphere to create nitric oxide, or NO. Nitric oxide combines with oxygen to form nitrogen dioxide, or NO2. NO and NO2 are collectively known as NOx, or nitrogen oxides. Vehicles are their primary source.
  • Nitrogen oxides react with other chemicals in the air to form both particulate matter and ozone.
  • Benzene is emitted by transport, which is its primary source. Domestic and industrial combustion also emits benzene.
  • 1,3 butadiene is emitted by petrol engines and during the production of synthetic products such as vehicle tyres.
  • Carbon monoxide is formed when fossil fuels are combusted, especially in transport.

Burning, combustion and industry

  • Polycyclic aromatic hydrocarbons or PAH’s arise from a range of sources including domestic burning of wood and coals and fires generally.
  • Sulphur dioxide, SO2 is emitted when fuel containing sulphur is combusted. This includes coal and oils used at power stations and for domestic heating.
  • Ammonia is common bi product of agricultural production, especially livestock that emit gases and slurry containing ammonia.


  • Ozone arises when other airborne pollutants react and combine to form new compounds. The primary source of ozone arises when NOx and volatile organic compounds (VOC’s) combine, triggered by string sunlight. Ozone can still be formed even when emissions originate up to thousands of miles away.


The Health Risks
of Air Pollutants
A mother with a pushchair crossing the road on a sunny day
Reduce exposure
to air pollution
People planting and watering trees on a sunny day
Scientific evidence
on air pollution
Several power stations releasing fumes and smoke into the sky from cooling towers