Air Pollutants
An air pollutant is any unwanted substance or chemical that contaminate the air that we breathe resulting in a decline in air quality. Air pollutants occur both outdoors and indoors.
Outdoor pollutants include smoke, carbon monoxide, nitrogen oxides, sulphur dioxide, particulates and ozone. Smoke is a type of pollution that can be seen because it is made up of solid particles. You can often see it coming out of chimneys. Carbon monoxide is a pollutant that is mainly produced by cars. It has no colour or smell but can be very poisonous. Nitrogen oxides are emitted from cars and power stations. Very high amounts can be recorded in cities during rush-hour traffic. Sulphur dioxide is a colourless gas that is mainly given off from power stations. It combines with water in the air to produce acid rain. Particulates are small bits of solid or liquid matter, for example soot, dust, fumes and aerosols carried in the air. They are produced by factories, cars and coal burning in some homes. Ozone, a form of oxygen, is more commonly associated with the ozone layer, which protects life on Earth from the Sun's harmful rays. Near the ground however, it is a harmful pollutant made in the air when other pollutants mix together in sunlight. It is the main gas found in modern urban smogs.
Lead, a harmful pollutant, is also found in the environment. It is given off by old cars which cannot use unleaded petrol. Lead can be particularly harmful to children.
Carbon monoxide and nitrogen oxides are also found indoors, given off by faulty gas heaters and cookers. Carbon monoxide is also given off when people smoke cigarettes. There are also some biological pollutants such as dust mites and mould. Since most of us spend 80 to 90% of the time indoors, indoor air quality can have a major influence on our health.
Print Topic
Websites
Other topics
Technical Page
• Infoplease.Com
• Hong Kong Education
• Introduction
• Cars
• Doing Our Bit
• Human Health
• Impacts
• Indoors
• Industry & Power
• London Smog
• Outdoors
• Pollutants
• Smog
• Wildlife