Air Pollution Factsheet

Air pollution consists of substances present in the atmosphere in high enough levels to harm humans, other animals, plants, or materials. Air pollution can result from human activities such as driving cars. It can also come from natural sources, such as smoke from forest fires caused by lightning or from volcano eruptions.

The story so far: Pollution caused by humans is now disturbing the delicate balance of nature on earth. Far from being a new problem, pollution has been around for centuries. However, as the population increases, pollution problems also increase. A combination of a rapidly multiplying population, and the growth of industries and car use are the main causes of air pollution today.
Much of the worlds' population lives in areas where air pollution levels exceed World Health Organisation (WHO) guidelines. In Asia, rapid urbanisation, with the associated growth in industry and vehicle use, has increased emissions of sulphur dioxide and nitrogen oxides. Further large increases of air pollutants are expected if current development patterns persist.

• Suspended Particulate Matter

This is a mixture of solid and liquid particles suspended in the air. Suspended particulates are seen as dust, smoke, and haze which can make breathing difficult, especially for people with chronic respiratory problems.

• Volatile OrganicCompounds (VOCs)

VOCs include gasoline, paint solvents, and organic cleaning solutions. They evaporate and enter the air as vapour, and as molecules resulting from the incomplete burning of fuels and wastes.

• Carbon Monoxide (CO)

One source of carbon monoxide is vehicle emissions. This is an invisible, odourless gas that is highly toxic to air-breathing animals because it interferes with the blood's ability to transport oxygen. Even low levels can start or increase damage to the heart in individuals with artery or heart problems. At medium concentrations, carbon monoxide causes headaches and fatigue. As the concentration increases, reflexes slow down and drowsiness occurs. At high levels carbon monoxide causes death. People at greatest risk from carbon monoxide include pregnant women, infants, and those with heart or respiratory diseases.

• Nitrogen Oxides (NOX)

Nitrogen Oxides are lung irritants that can lead to acute respiratory diseases in children. They may also cause over-sensitivity to pollen and dust in people suffering from asthma.

•Sulphur Oxides (SOX)

Sulphur Dioxide is converted to sulphuric acid in the atmosphere. It can be poisonous to both plants and animals. Like particulates, sulphur dioxide irritates the respiratory tract, causing airways to close, and interfering with the lungs. Children and the elderly are especially sensitive to sulphur dioxide, as are people suffering from asthma and emphysema.

• Lead & other heavy metals

Lead is dangerous, even at low concentrations and can lead to reduced intelligence in children, brain damage and death. It accumulates in the body and damages body tissue.

• Ground Level Ozone

Ozone in the upper atmosphere shields us from ultraviolet radiation. However on ground level, it is highly toxic to both plants and animals as it can damage lungs. It can bring on coughing, asthma attacks and lower the immune system.

• Fuel wood

Indoor air pollution is caused by the burning of fuel-wood and dung for cooking, and can cause suffocation.

• Motor vehicles

The two main sources of air pollution are motor vehicles & industries. When they burn petrol, cars and trucks release significant quantities of sulphur dioxide, oxides of nitrogen, carbon monoxide, lead, and suspended particulate matter. Lead used in petrol to protect engines is also dangerous. Diesel powered cars produce large quantities of particulates in the form of black soot. Reduced use of private cars, proper legislation and enforcement of laws can curb this menace.

• Industry

Electrical power plants and industries emit particulate matter, sulphur oxides, nitrogen oxides, hydrocarbons and carbon dioxides.
The top three industrial sources of toxic air pollutants are the chemical, metal, and paper industries.

• Municipal Solid Waste

When solid waste is burnt, heavy metals like lead, gases and soot are spread over residential areas. Rubbish, dust and gases found during the decomposition of waste, all contribute to air pollution.

• Smog

When air pollution in urban areas reduces visibility it is often called smog. There are different types of smog. Smoke pollution from industries is sometimes called industrial smog. The pollutants it contains are sulphur oxides and particulates. Photochemical smog is a brownish orange haze formed by chemical reactions involving sunlight.

• Medical waste

Burning medical waste is a serious source of air pollution, particularly in cities. Most incinerators are rudimentary by today's standards. They burn waste incompletely, releasing acidic gases, heavy metals, and dioxins into the air.

• Developing countries

As developing countries become more industrialised, they also produce more air pollution. The leaders of most developing countries believe they must become industrialised rapidly in order to be economically competitive. Environmental quality is usually a low priority in the race to develop. Thus, while air quality is slowly improving in developed countries, it is rapidly deteriorating in developing countries.
Improving the well being of developing nations does not have to result in increased pollution. The key to future development lies in providing the products and services which people want by using the most efficient technologies, and consuming the lowest possible level of resources.

Exposure to low levels of pollutants such as ozone, sulphur oxides, nitrogen oxides, and particulates, irritates eyes and causes inflammation of the respiratory tract. Evidence exists that many air pollutants also suppress the immune system, increasing susceptibility to infection. In addition, evidence continues to accumulate indicating that exposure to air pollution during respiratory illnesses may result in people developing chronic respiratory diseases, such as emphysema and bronchitis as they get older. Other health problems that can result from long-term exposure to toxic air-pollutants are cancer, chronic obstructive pulmonary disease, asthma, respiratory infections, and cardiovascular disease.
Air pollution can also cause acidification of lakes and soils and impacts on crop productivity, forest growth, and biodiversity. Some research indicates that the ozone and sulphur dioxide is reducing crop yields. The potential for crop losses in Asia has been indicated by a study in Pakistan where a 40 per cent reduction in rice yields was linked to the presence of pollutants in the air.

Encourage people to leave their car at home and walk or ride a bicycle to travel short distances.
Develop efficient public transport systems to help reduce dependence on private cars.
Provide Government subsidies to encourage the introduction of petrol with low sulphur and no lead.
Focus on regional inter-Governmental cooperation. Pollutants can be carried from one country to another, so individual countries cannot solve the associated problems alone. Currently, regional/sub-regional agreements on air pollution either do not exist or are at initial stages.
Promote energy efficiency and conservation. Energy efficiency means using technology to accomplish tasks with less energy. Energy conservation focuses on cutting down on wasteful energy consuming activities. These approaches are not only cost effective ways of reducing harmful emissions from industries and vehicles, but they also give us time to search for safer and cheaper alternative energy sources.
Use smaller, more efficient cars as they consume less fuel and so produce fewer emissions.
Design cars so that combustion temperatures are lower and less nitrogen oxide is formed.
Use lighter materials and better designed cars. Currently available technology already makes it possible for cars to have fuel efficiencies of 60-65 miles per gallon.
Find better alternative fuels, as petroleum reserves will not last for ever. Alcohol, solar power, electricity and liquid hydrogen are some of the options that car manufacturers have investigated in the search for alternative fuels. Although cars that can use these fuels have already been designed or are currently being worked on, the cost and accessibility of fuel remains a problem. All alternative fuels will not necessary be environmentally friendly. For instance, if the electricity for electricity-powered cars is produced by coal-fired power plants, the eventual volume of emissions will be higher than for conventionally fuelled cars.
Fit smoke-stacks with electrostatic precipitators, fabric filters, scrubbers, or other technologies to remove particulate matter.
Use careful land-excavating methods to control particulates. For example, water can be sprinkled on dry soil that is being moved during road construction.
Remove sulphur dioxide from fuel by switching to a low-sulphur fuel such as natural gas or even to a non-fossil source such as solar energy.
Modify furnaces and engines to provide more complete combustion. This helps control the production of both carbon monoxide and hydrocarbons.

According to the PEPA, 1997, no person shall operate a motor vehicle, from which air or noise pollutants are being emitted in an excessive amount.

According to the same Act, the function of the Federal Agency shall be to take all necessary measures for the protection, conservation, rehabilitation and improvement of the environment, prevention and control of pollution, and promotion of sustainable development.

WWF-Pakistan is a Non Government Organisation which aims to raise awareness and take practical, positive action on a range of environmental issues, as well as working to save nature. The Environmental Pollution Unit (EPU) has been involved in various projects to control pollution problems. For example, a low cost Air Pollution Monitoring (APM) kit was developed to provide students and environmentalists with an economical, and quick way to analyse air pollution.

For more information on Air Pollution, please visit the following sites:

Compiled and edited by Environmental Pollution Unit, WWF- Pakistan.