First 404 words of the document:
Air pollution is the introduction of chemicals, particulate matter, or biological
materials that cause harm or discomfort to humans or other living organisms, or
cause damage to the natural environment or built environment, into the
atmosphere. Air is 99.9% nitrogen, oxygen, water vapour and inert gases.
There are lots of different types of air pollution and the main air pollution is
carbon monoxide (SO2), nitrogen oxide (CO), sulphur dioxide (NO2) and
particulate (microscopic particles of carbon). A lot of the air pollution comes
from burning fossil fuels. The main ones are gas, coal and oil.
Particulates are tiny bits of solid suspended in the air and they are measured
part per million and per billion. Particulates are caused by humans activity e.g.
burning fossil fuels and it cause making things dirty and it can be breathed into
your lungs. Particulates can make asthma worse and it can make lung infection
Humans can reduce the amount of pollution that they produce in lot of different
ways e.g. add catalytic converters to your car exhaust and clean the gases that
comes out of the factories be for they come out.
Car catalytic converters
Catalytic converters are added to the exhaust system of modern cars. They
remove carbon monoxide and nitrogen monoxide from the exhaust gases. Inside
the catalytic converter is a metal honeycomb. It is coated with a thin layer of
platinum; this metal acts as a catalyst. It makes chemical reaction happen more
quickly in the exhaust gases. These reactions convert the air pollutants CO and
NO to less harmful gases.
Cleaning wasted gases in factories
Burning fossil fuels in power station can produce the air pollutant SO2. This can
be removed from the wasted gases before they leave the chimney.
Waste gases pass through a spray of powered lime (calcium oxide) water and air.
The SO2 in the gases combines with the mixture to form a new chemical called
calcium sulphate. This is a solid so the SO2 is captured before it can escape from
Cleaner fuels make less pollutants sulphur compounds can be removed from
natural gas. This reduces the SO2 produced when it is burned. Also low-sulphur
petrol is now available.