What is Air Pollution?

An air pollutant is any substance in the air that could harm people.

There are many pollutants in the air. Some are more harmful than others. Particulate matter, nitrogen dioxide and ozone are particularly damaging types of air pollution.

Different areas of the UK have different levels of air pollution. High concentrations can be found in most UK towns and cities. This is where sources of pollution, such as road traffic, are more concentrated.

The amount of air pollution can also change depending on the weather and the season. For example, it’s harder for pollution to disperse during still, sunny weather in summer and still, foggy weather in winter. This means the pollution becomes more concentrated causing a high pollution episode. These episodes often affect towns and cities, but they can also affect areas of the countryside as wind blows pollution across the country.

A variety of air pollutants have known or suspected harmful effects on human health and the environment. In most areas of Europe, these pollutants are principally the products of combustion from space heating, power generation or from motor vehicle traffic. Pollutants from these sources may not only prove a problem in the immediate vicinity of these sources but can travel long distances.

car exhaust pollution

The table below shows the types of health effects experienced by the most common pollutants at elevated levels:

Pollutant Health effects at very high levels
Nitrogen Dioxide, Sulphur Dioxide, Ozone These gases irritate the airways of the lungs, increasing the symptoms of those suffering from lung diseases
Particles Fine particles can be carried deep into the lungs where they can cause inflammation and a worsening of heart and lung diseases
Carbon Monoxide This gas prevents the uptake of oxygen by the blood. This can lead to a significant reduction in the supply of oxygen to the heart, particularly in people suffering from heart disease


source: British Lung Foundation & DEFRA