AIR POLLUTION

Air Pollution

Air pollution refers to the discharge of harmful gases and dust into the atmosphere. When these harmful substances enter the air around us, they may cause irreversible damage to humans and to our environment.

Some of the main air pollutants are:

• Sulphur dioxide (SO₂)
• Carbon monoxide (CO)
• Ozone (O₃)
• Nitrogen dioxide (NO₂)

So, what about those gases?

SULPHUR DIOXIDE

Responsible for acid rain.

CARBON MONOXIDE

Enters the blood stream and reduces the delivery of oxygen to the body's organs and tissues.
Elevated levels of CO may result in impairment of visual perception, work capacity, manual dexterity, learning ability and performance of complex tasks.

OZONE

Damage to lung tissues and reduces lung functioning.
Reduces agricultural crop yield; causes foliar damage in many crops and trees.

NITROGEN DIOXIDE

Contributes to acid rain.
Irritates lungs and lowers resistance to respiratory infections e.g. influenza

Scientists also have found that some of these air pollutants are responsible for the following phenomena:

• Acid Rain
• Ozone Depletion
• Global Warming

What causes air pollution?

Air pollution can be caused by two main components, natural and human factors.

Natural factors such as volcano eruptions and natural forest fires often cause tons of ash and tiny air pollutants to be released to our earth's atmosphere.

Did You Know? According to the World's Health Organization, each year about tens of thousands of people die in the world's major cities due to the breathing in of poor quality air. As many as one billion people around the world are regularly exposed to pollution levels up to 100 times more than WHO guidelines.

However, the human factors are much more devastating.

IN INDUSTRIES

The most serious cause of air pollution is heavy industrial activity. Many heavy industries produce a large amount of air pollutants. This often causes air pollution.

IN POWER PLANTS

When fossil fuels such as coal and oil are burnt to produce electricity, large quantities of sulphur dioxide and nitrogen dioxide ( gases that are responsible for acid rain) are released into the air. These substances are damaging to the environment and all things.

IN VEHICLES

Vehicles use either diesel or petrol to generate power and, as a result, produce fumes that contain lead and carbon monoxide which pollute the environment and harm living things.

IN DEVELOPING COUNTRIES

In these countries, the burning of wood and animal waste for cooking and heating also adds pollutants into the air.