Air pollution is closely related to other forms of pollution. Sulphur dioxide and nitrogen oxides can react with water droplets in the air to produce acid rain. Acid rain pollutes lakes and streams and, in high concentrations, can harm soil fertility.
How might air pollution affect you?
If your health is good, the levels of air pollution we usually experience in the UK are unlikely to have any serious short-term effects. But on the rare occasions when air pollution levels are high, some people may feel eye irritation, others may start to cough, and some may find that breathing deeply hurts.
People with lung diseases or heart conditions are at greater risk, especially if they are elderly. Daily changes in air pollution trigger increased admissions to hospital and contribute to the premature death of those who are seriously ill.
The table below describes how the health of people who are sensitive to air pollutants might be affected by pollution at the different levels or bands.
People with heart conditions or severe lung diseases (for example, chronic bronchitis or emphysema) might be more sensitive to changes in air pollution than the descriptions suggest.
The changes from band to band are not sudden steps. The effects of air pollutants on health increase gradually as air pollution levels rise.
It is important to look at the levels and bands in the light of personal experience. Some people - especially those who are sensitive to pollution - will learn from experience how air pollution affects them. Some may still notice the effects for several days after pollution levels have fallen to low or moderate levels.
Air pollution is also likely to affect health over the longer term. Understanding of the long-term health effects of exposure to air pollution is currently rather limited, but experts suggest that cutting long term exposure to fine particles by half could increase life expectancy by between 1 and 11 months on average. This is not as great as the effect of smoking on life expectancy (on average, non-smokers live 7 years longer than smokers).
Asthma
There is little evidence that air pollution itself causes asthma. Research is continuing on this subject. However, if you already have asthma, you may find that air pollution triggers an attack, although infections and allergens are more likely to do so.
In winter
- If traffic fumes make breathing harder, avoid busy streets as much as you can.
- If you are elderly, stay indoors as much as possible and keep warm.
In summer
- If you find it harder to breathe on hot sunny days, avoid energetic outdoor activities, especially in the afternoons when pollution levels tend to be higher.
- If your child has asthma, they should still be able to take part in games as normal, but they may need to use their reliever inhaler more before they start. They do not need to stay away from school.
The table below describes the health effects that sensitive individuals might experience at very high levels of these pollutants.
With the exception of carbon monoxide, very high levels of all these pollutants can irritate the lungs and cause inflammation. People with lung diseases, especially the elderly, may feel less well than usual. In some cases their symptoms may increase to such an extent that they need a change in treatment, or admission to hospital.
Summer Smog
Caused by mixture of pollutants from:
- road vehicles
- fuels used to provide electricity and heating in offices, factories and homes
- vapours from petrol and certain industrial premises
Formed by:
- Action of sunlight on these pollutants forms low-level ozone close to the ground
Winter Smog
Caused by mixture of pollutants from:
- road vehicles
- fuels used to provide electricity and heating in offices, factories and homes
Formed by:
- Pollutants building up at ground level in urban areas. The \'lid\' of cold air above the warm air traps the pollutants
This may occur on cold, calm days, often after a clear, cloudless night and an early-morning frost or mist close to the ground.
Like photochemical pollutants, sulphur oxides contribute to the incidence of respiratory diseases. , a form of precipitation that contains high levels of sulphuric or nitric acids, can contaminate drinking water and vegetation, damage aquatic life, and erode buildings. When a weather condition known as a prevents dispersal of smog, inhabitants of the area, especially children and the elderly and chronically ill, are warned to stay indoors and avoid physical stress. The dramatic and debilitating effects of severe air pollution episodes in cities throughout the world—such as the London smog of 1952 that resulted in 4,000 deaths—have alerted governments to the necessity for crisis procedures. Even everyday levels of air pollution may insidiously affect health and behaviour. Indoor air pollution is a problem in developed countries, where efficient insulation keeps pollutants inside the structure. In less developed nations, the lack of running water and indoor sanitation can encourage respiratory infections. Carbon monoxide, for example, by driving oxygen out of the bloodstream, causes apathy, fatigue, headache, disorientation, and decreased muscular coordination and visual acuity.
Air pollution may possibly harm populations in ways so subtle or slow that they have not yet been detected. For that reason research is now under way to assess the long-term effects of chronic exposure to low levels of air pollution—what most people experience—as well as to determine how air pollutants interact with one another in the body and with physical factors such as , stress, alcohol, cigarette , and common medicines. Another subject of investigation is the relation of air pollution to , , and genetic .
Many people spend large portion of time indoors - as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted. For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than outdoor pollution.
There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapours from building materials, paints, furniture, etc. cause pollution inside buildings.
Air pollution is made up of many kinds of gases, droplets and particles that reduce the quality of the air. Air can be polluted in both the city and the country. In the city, air pollution may be caused by cars, buses and airplanes, as well as industry and construction.
Air pollution in the country may be caused by dust from tractors ploughing fields, trucks and cars driving on dirt or gravel roads, rock quarries and smoke from wood and crop fires.
Ground-level ozone is the major part of air pollution in most cities. Ground-level ozone is created when engine and fuel gases already released into the air interact when sunlight hits them. Ozone levels increase in cities when the air is still and the sun is bright and the temperature is warm. Ground-level ozone should not be confused with the "good" ozone that is miles up in the atmosphere and that protects us from the sun's harmful radiation.
A recently discovered result of air pollution is an increasing “hole” in the ozone layer in the atmosphere above Antarctica, coupled with growing evidence of global ozone depletion. This can increase the amount of ultraviolet radiation reaching the earth, where it damages crops and plants and can lead to and . This depletion has been caused largely by the emission of chlorofluorocarbons (CFCs) from refrigerators, air conditioners, and aerosols.
